Publications by authors named "Shingo Baba"

101 Publications

Compared to conventional PET/CT scanners, silicon-photomultiplier-based PET/CT scanners show higher arterial 18F-FDG uptake in whole-body 18F-FDG-PET/CT.

Nucl Med Commun 2021 Aug 3. Epub 2021 Aug 3.

Department of Radiology, Fukuoka Memorial PET Imaging and Medical Checkup Center Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University Department of Radiology, Fukuoka Memorial Hospital, Fukuoka, Japan.

Objectives: To clarify differences in arterial 18F-FDG (fluorodeoxyglucose) uptake between silicon photomultiplier (SiPM)-based and conventional PET/CT scanners, and to compare clinical and phantom results.

Patients And Methods: Twenty-six patients with lung tumours underwent serial SiPM-based and conventional PET/CT scans on the same day. We compared the target-to-background ratios [TBRsi (SiPM), TBRc (conventional)] and the percentage difference between TBRsi and TBRc (ΔTBR) in the carotid artery, aorta and peripheral arteries. The correlation between ΔTBR and vessel size was also investigated. In the carotid artery, active segment analyses were performed with the threshold (TBR ≥1.6), and we compared each scanner's ratio of active segments and TBR values. We compared the clinical results with the recovery coefficients (RCs).

Results: The TBRsi was significantly higher than the TBRc in the carotid artery, aorta and peripheral arteries (1.63 ± 0.22 vs. 1.43 ± 0.22, 1.65 ± 0.19 vs. 1.53 ± 0.15 and 1.37 ± 0.31 vs. 1.11 ± 0.27, mean ± SD, P ≤ 0.0001 for all), and the peripheral arteries showed the highest ΔTBR (24.4 ± 16.8%). The small (10-15 mm) vessels (26.9 ± 15.9%) showed significantly higher ΔTBRs than the larger vessels (7.3 ± 8.5% for 15-20 mm, 8.0 ± 12.8% for ≥20 mm, P < 0.0001 for both). The carotid artery showed significantly higher ratios of active segment (54.5 vs. 20.5%, P < 0.0001) and TBR values (1.85 ± 0.25 vs. 1.76 ± 0.15, P = 0.0006) for TBRsi vs. TBRc. The differences in RCs were similar to those of ΔTBR for each vessel size.

Conclusions: SiPM-based PET/CT scanners showed higher arterial 18F-FDG uptake (especially in vessels <15 mm) than conventional scanners, and the threshold TBR ≥1.6 is not applicable for the carotid artery for SiPM-based PET/CT systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MNM.0000000000001468DOI Listing
August 2021

Impact of Metabolic Activity in Hepatocellular Carcinoma: Association With Immune Status and Vascular Formation.

Hepatol Commun 2021 Jul 26;5(7):1278-1289. Epub 2021 Mar 26.

Department of Surgery and Science Graduate School of Medical Sciences Kyushu University Fukuoka Japan.

We evaluated the prognostic value of fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) in hepatocellular carcinoma (HCC). Their association with programmed death ligand 1 (PD-L1) expression and vascular formation was further investigated. In this retrospective study, using a database of 418 patients who had undergone F-FDG PET/CT before hepatic resection for HCC, immunohistochemical staining of PD-L1, clusters of differentiation (CD) 8, CD68, and CD34 was performed. Patients with a high maximum standardized uptake value (SUVmax) on F-FDG PET/CT showed a significantly worse recurrence-free survival (RFS) (hazard ratio [HR]: 1.500; 95% confidence interval [CI]: 1.088-2.069;  = 0.0133) and overall survival (OS) (HR: 2.259; 95% CI: 1.276-4.000;  = 0.0052) than patients with a low SUVmax. Logistic regression analysis showed that a high SUVmax in HCC was significantly associated with PD-L1-positive expression (odds ratio: 4.407; 95% CI: 2.265-8.575;  < 0.0001). SUVmax values of HCC were associated with intratumoral CD8-positive T-cell counts ( = 0.0044) and CD68-positive macrophage counts ( = 0.0061). Stratification based on SUVmax, PD-L1 expression, and the vessels that encapsulate tumor clusters (VETC) status was also significantly associated with RFS and OS. SUVmax, VETC, and PDL1 expression were independently predictive of survival on multivariable analysis. Our large cohort study showed that a high SUVmax on F-FDG PET/CT is associated with a poor clinical outcome and PD-L1 expression in patients with HCC. Additionally, stratification of patients based on the combination of SUVmax, PD-L1 expression, and the VETC status predicts poor clinical outcome.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hep4.1715DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279470PMC
July 2021

Estimation of the lower limits for feasible Ra-223 SPECT imaging: a Monte Carlo simulation study.

Asia Ocean J Nucl Med Biol 2021 ;9(2):131-139

Division of Medical Quantum Science, Department of Health Sciences, Kyushu University, Fukuoka, Japan.

Objectives: Ra-223 is a promising radionuclide for the treatment of skeletal metastases in castration-resistant prostate cancer patients. This study aims to estimate the lower limits for feasible Ra-223 single-photon emission computerized tomography (SPECT) imaging using a Monte Carlo simulation study.

Methods: The SPECT images were produced on a homemade code: the Monte Carlo simulation of electrons and photons for SPECT (MCEP-SPECT). The National Electrical Manufacturers Association (NEMA) phantom with six hot spheres of diameters of 37, 28, 22, 17, 13, and 10 mm installed inside, was used. The background activity concentration was 0.6 kBq/mL, and the ratios of hot concentrations to the background ( ) were 25, 20, 15, 10, and 5. When was 15, the background concentrations of 1.5, 0.9, 0.3, and 0.15 kBq/mL were also tested. The energy window was 84 keV±10%. The number of projections was 60/360°, and the acquisition time was 60 s per projection. Two kinds of collimators: middle-energy general-purpose (MEGP) and high-energy general-purpose (HEGP), were examined. The SPECT images were evaluated based on two quantitative indexes: contrast-to-noise ratio (CNR) for detectability and contrast recovery coefficient (CRC) for quantitative accuracy.

Results: The CRC for the HEGP collimator was 35-40%, while the CRC for the MEGP collimator was 25-30%. The CNRs for the MEGP collimator were larger than those for the HEGP collimator. The CNRs of the hot spheres with diameters less than 22 mm were lower than 5.0 for both collimators, when and the background concentration were 15 and 0.6 kBq/mL, respectively. Based on the obtained results, it was estimated that the lower limit of for the detection of the hot sphere with a diameter of 37 mm would be approximately 20 if the background concentration is 0.05 kBq/mL.

Conclusions: The MEGP collimator is superior in terms of detectability, while the HEGP collimator is superior in terms of quantitative accuracy. When the lesion size is small, the MEGP collimator may be favorable. Based on these results, the estimated lower limit of the activity concentration would be approximately 1 kBq/mL if the background concentration is 0.05 kBq/mL for a large lesion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22038/AOJNMB.2021.54386.1372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8255527PMC
January 2021

Monte Carlo simulation of the acquisition conditions for Lu molecular imaging of hepatic tumors.

Ann Nucl Med 2021 Jul 31;35(7):823-833. Epub 2021 May 31.

Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.

Objective: To examine the impact of acquisition time on Lutetium-177 (Lu) single-photon emission computed tomography (SPECT) images using Monte Carlo simulation.

Methods: A gamma camera simulation based on the Monte Carlo method was performed to produce SPECT images. The phantom was modeled on a NEMA IEC BODY phantom including six spheres as tumors. After the administration of 7.4 GBq of Lu, radioactivity concentrations of the tumor/liver at 6, 24, and 72 h after administration were set to 1.85/0.201, 2.12/0.156, and 1.95/0.117 MBq/mL, respectively. In addition, the radioactivity concentrations of the tumor at 72 h after administration varied by 1/2, 1/4, and 1/8 when comparison was made. Acquisition times examined were 1.2, 1.5, 2, 3, 6, and 12 min. To assess the impact of collimators, SPECT data acquired at 72 h after the administration using six collimators of low-energy high-resolution (LEHR), extended low-energy general-purpose (ELEGP), medium-energy, and general-purpose (MEGP-1, MEGP-2, and MEGP-3) and high-energy general-purpose (HEGP) were examined. After prefiltering using a Butterworth filter, projection images were reconstructed using ordered subset expectation maximization. The detected photons were classified into direct rays, scattered rays, penetrating rays, and characteristic X-rays from lead. The image quality was evaluated through visual assessment, and physical assessment of contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR). In this study, the CNR threshold for detectability was assumed to be 5.0.

Results: To compare collimators, the highest sensitivity was observed with ELEGP, followed by LEHR and MEGP-1. The highest ratio of direct ray was also observed in ELEGP followed by MEGP-1. In comparison of the radioactivity concentration ratios of tumor/liver, CRC and CNR were significantly decreased with smaller radioactivity concentration ratios. This effect was greater with larger spheres. According to the visual assessment, the acquisition time of 6, 6, and 3 min or longer was required using ELEGP collimator at 6, 24, and 72 h after administration, respectively. Physical assessment based on CNR and CRC also suggested that 6, 6, and 3 min or longer acquisition time was necessary at 6, 24, and 72 h after administration.

Conclusion: Lu-SPECT images generated via the Monte Carlo simulation suggested that the recommended acquisition time was 6 min or longer at 6 and 24 h and 3 min or longer at 72 h after administration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-021-01620-9DOI Listing
July 2021

Obesity is a risk factor for intrahepatic cholangiocarcinoma progression associated with alterations of metabolic activity and immune status.

Sci Rep 2021 Mar 12;11(1):5845. Epub 2021 Mar 12.

Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.

Body mass index (BMI) is well known to be associated with poor prognosis in several cancers. The relationship between BMI and the long-term outcomes of patients with intrahepatic cholangiocarcinoma (ICC) is incompletely understood. This study investigated the relationships of BMI with clinicopathological characteristics and patient outcomes, focusing on metabolic activity and immune status. The relationship between BMI and the maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) was analyzed. In addition, immunohistochemistry was performed for programmed cell death-ligand 1 (PD-L1), cluster of differentiation 8 (CD8), and forkhead box protein P3 (Foxp3). Seventy-four patients with ICC were classified into normal weight (BMI < 25.0 kg/m, n = 48) and obesity groups (BMI ≥ 25.0 kg/m, n = 26), respectively. Serum carbohydrate antigen 19-9 levels were higher in the obesity group than in the normal weight group. Tumor size and the intrahepatic metastasis rate were significantly larger in the obesity group. Patients in the obesity group had significantly worse prognoses than those in the normal weight group. Moreover, BMI displayed a positive correlation with SUVmax on F-FDG PET/CT (n = 46, r = 0.5152). Patients with high F-FDG uptake had a significantly higher rate of PD-L1 expression, lower CD8 + tumor-infiltrating lymphocyte (TIL) counts, and higher Foxp3 + TIL counts. The elevated BMI might predict the outcomes of patients with ICC. Obesity might be associated with ICC progression, possibly through alterations in metabolic activity and the immune status.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-85186-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7955092PMC
March 2021

I metaiodobenzylguanidine (MIBG) uptake predicts early relapse of neuroblastoma using semi-quantitative SPECT/CT analysis.

Ann Nucl Med 2021 May 14;35(5):549-556. Epub 2021 Feb 14.

Department of Clinical Radiology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka, 812-8582, Japan.

Objective: I metaiodobenzylguanidine (MIBG) scintigraphy is a useful tool for the diagnosis of neuroblastoma (NB). MIBG uptake is correlated with norepinephrine transporter expression; hence, it is expected that high-MIBG tumors would be more highly differentiated and have a better prognosis than those with lower expression. We have introduced a method of assessing MIBG accumulation semi-quantitatively using SPECT/CT fusion images. The purpose of this study was to evaluate the relationship of I MIBG uptake measured by semi-quantitative values of SPECT/CT and early relapse of NB.

Methods: We studied the cases of 11 patients (5 males and 6 females, age 5-65 months, median age 20 months) with histopathologically proven NB between April 2010 and March 2015. The early-relapse group was defined as patients who had relapsed within 3 years after the first I MIBG SPECT/CT exam. Other patients were classified as the delay-relapse group. Uptake of MIBG was evaluated using the count ratio of tumor and muscles. T/Mmax and T/Mmean were defined as follows: T/Mmax = max count of tumor/max count of muscle, T/Mmean = mean count of tumor/mean count of muscle.

Results: The average T/Mmean values of the early-relapse group and delay-relapse group were 2.65 ± 0.58 and 7.66 ± 2.68, respectively. The T/Mmean values of the early-relapse group were significantly lower than those of delay-relapse group (p < 0.05). The average T/Mmax of the early-relapse group and delay-relapse group were 8.86 ± 3.22 and 16.20 ± 1.97, respectively. There was no significant difference in T/Mmax values between the two groups.

Conclusions: Low I MIBG uptake using semi-quantitative SPECT/CT analysis was correlated with early relapse of NB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-021-01595-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8079305PMC
May 2021

Diagnostic accuracy for the epileptogenic zone detection in focal epilepsy could be higher in FDG-PET/MRI than in FDG-PET/CT.

Eur Radiol 2021 May 15;31(5):2915-2922. Epub 2020 Oct 15.

Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.

Objectives: To examine the utility of FDG-PET/MRI in patients with epilepsy by comparing the diagnostic accuracy of PET/MRI and PET/CT in epileptogenic zone (EZ) detection.

Methods: This prospective study included 31 patients (17 males, 14 females) who underwent surgical resection for EZ. All patients were first scanned using FDG-PET/CT followed immediately with FDG-PET/MRI. Two series of PET plus standalone MR images were interpreted independently by five board-certified radiologists. A 4-point visual score was used to assess image quality. Sensitivities and visual scores from both PETs and standalone MRI were compared using the McNemar test with Bonferroni correction and Dunn's multiple comparisons test.

Results: The EZs were confirmed histopathologically via resection as hippocampal sclerosis (n = 11, 35.5%), gliosis (n = 8, 25.8%), focal cortical dysplasia (n = 6, 19.4%), and brain tumours (n = 6, 19.4%) including cavernous haemangioma (n = 3), dysembryoplastic neuroepithelial tumour (n = 1), ganglioglioma (n = 1), and polymorphous low-grade neuroepithelial tumour of the young (n = 1). The sensitivity of FDG-PET/MRI was significantly higher than that of FDG-PET/CT and standalone MRI (FDG-PET/MRI vs. FDG-PET/CT vs. standalone MRI; 77.4-90.3% vs. 58.1-64.5% vs. 45.2-80.6%, p < 0.0001, respectively). The visual scores derived from FDG-PET/MRI were significantly higher than those of FDG-PET/CT, as well as standalone MRI (2.8 ± 1.2 vs. 2.0 ± 1.1 vs. 2.1 ± 1.2, p < 0.0001, respectively). Compared to FDG-PET/CT, FDG-PET/MRI increased the visual score (51.9%, increased visual scores of 2 and 3).

Conclusions: The diagnostic accuracy for the EZ detection in focal epilepsy could be higher in FDG-PET/MRI than in FDG-PET/CT.

Key Points: • Sensitivity of FDG-PET/MRI was significantly higher than that of FDG-PET/CT and standalone MRI (FDG-PET/MRI vs. FDG-PET/CT vs. standalone MRI; 77.4-90.3% vs. 58.1-64.5% vs. 45.2-80.6%, p < 0.0001, respectively). • Visual scores derived from FDG-PET/MRI were significantly higher than those of FDG-PET/CT and standalone MRI (2.8 ± 1.2 vs. 2.0 ± 1.1 vs. 2.1 ± 1.2, p < 0.0001, respectively). • Compared to FDG-PET/CT, FDG-PET/MRI increased the visual score (51.9%, increased visual scores of 2 and 3).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00330-020-07389-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8043950PMC
May 2021

Comparison of F-FDG PET/CT and Ga-SPECT for the diagnosis of fever of unknown origin: a multicenter prospective study in Japan.

Ann Nucl Med 2021 Jan 9;35(1):31-46. Epub 2020 Oct 9.

Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan.

Objective: The aim of this multicenter prospective study was to compare the sensitivity of F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) with that of Ga single photon emission computed tomography (SPECT) for the identification of the site of greatest importance for the final diagnosis of the cause of fever of unknown origin (FUO).

Methods: The study participants consisted of patients with an axillary temperature ≥ 38.0 °C on ≥ 2 occasions within 1 week, with repeated episodes for ≥ 2 weeks prior to providing consent, and whose final diagnosis after undergoing specific examinations, including a chest-to-abdomen CT scan, was uncertain. All the patients underwent FDG-PET/CT imaging first, followed by Ga-SPECT imaging within 3 days. The results of the FDG-PET/CT and Ga-SPECT examinations were reviewed by the central image interpretation committee (CIIC), which was blinded to all other clinical information. The sensitivities of FDG-PET/CT and Ga-SPECT were then evaluated with regard to identifying the site of greatest importance for a final diagnosis of the cause of the fever as decided by the patient's attending physician. The clinical impacts (four grades) of FDG-PET/CT and Ga-SPECT on the final diagnosis were evaluated.

Results: A total of 149 subjects were enrolled in this study between October 2014 and September 2017. No adverse events were identified among the enrolled subjects. Twenty-one subjects were excluded from the study because of deviations from the study protocol. Among the 128 remaining subjects, a final diagnosis of the disease leading to the appearance of FUO was made for 92 (71.9%) subjects. The final diagnoses in these 92 cases were classified into four groups: noninfectious inflammatory disease (52 cases); infectious disease (31 cases), malignancy (six cases); and other (three cases). These 92 subjects were eligible for inclusion in the study's analysis, but one case did not meet the PET/CT image acquisition criteria; thus, PET/CT results were analyzed for 91 cases. According to the patient-based assessments, the sensitivity of FDG-PET/CT (45%, 95% CI 33.1-58.2%) was significantly higher than that for Ga-SPECT (25%, 95% CI 15.5-37.5%) (P = 0.0029). The clinical impact of FDG-PET/CT (91%) was also significantly higher than that for Ga-SPECT (57%, P < 0.001).

Conclusions: FDG-PET/CT showed a superior sensitivity to Ga-SPECT for the identification of the site of greatest importance for the final diagnosis of the cause of FUO.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-020-01533-zDOI Listing
January 2021

Evaluating and comparing the image quality and quantification accuracy of SiPM-PET/CT and PMT-PET/CT.

Ann Nucl Med 2020 Oct 3;34(10):725-735. Epub 2020 Jul 3.

Department of Health Science, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.

Objective: The aim of this study was to evaluate the image quality and the quantification accuracy of Biograph Vision PET/CT scanner as a SiPM-PET in comparison to the conventional PMT-PET, Biograph mCT PET/CT scanner.

Methods: This study consisted of a phantom study and a retrospective clinical analysis where patients underwent F-FDG PET/CT in both PET systems. The body phantom of the NEMA IEC with 10-37 mm diameter spheres were filled with an F-FDG solution. The root mean square error (RMSE) of SUV, the detectability of 10-mm sphere, NEC, the background variability (N) and the contrast-noise-ratio (Q/N) were calculated based on the phantom analysis. We also examined the quality of the acquired clinical images using the NEC, NEC, SNR, SUV and SUV.

Results: In the phantom study on Vision scanner, RMSE was relatively lower when the iteration number was 2, 3 or 4. To satisfy a visual score of 1.5 and the reference range of Q/N, a 60-s or longer acquisition was required. Our clinical findings show that NEC averaged 17.4 ± 1.72 Mcounts/m in mCT and 29.1 ± 2.83 Mcounts/m in Vision. Furthermore, NEC averaged 0.29 ± 0.05 kcounts/cm in mCT and 0.53 ± 0.09 kcounts/cm in Vision, respectively, whereas SNR averaged 14.6 ± 3.77% in mCT and 21.3 ± 1.69% in Vision (P = 0.0156), respectively. Finally, SUV averaged 2.82 ± 0.28 and 2.55 ± 0.30, SUV ranged 1.6-17.6 and 1.9-22.9 in mCT and Vision, respectively.

Conclusion: SiPM-PET/CT provides superior image quality and quantification accuracy compared to PMT-PET/CT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-020-01496-1DOI Listing
October 2020

Uptake of 18F-FDG in Adrenal Adenomas Is Associated With Unenhanced CT Value and Constituent Cells.

Clin Nucl Med 2019 Dec;44(12):943-948

From the Departments of Clinical Radiology.

Purpose: The purposes of this study were to investigate the correlation between unenhanced CT attenuation values and F-FDG uptake in adrenal adenomas, and to clarify the mechanism of FDG uptake in adrenal adenomas based on immunohistochemical findings.

Materials And Methods: In 57 adrenal adenomas, the correlation between SUVmax on F-FDG PET and unenhanced CT attenuation was retrospectively investigated. In the 11 surgically resected nodules, the clear cell ratio (CCR) and expression levels of glucose transporters (GLUTs) 1 to 4 were pathologically evaluated. The GLUT expression levels were scored at 0 to 3 points for each transporter, and the sum of these expression levels was defined as the GLUT score. The relationships between CCR and either the CT attenuation number or SUVmax, and between the GLUT score and each of the CT attenutation value, SUVmax, or CCR were evaluated.

Results: There was a significant positive correlation between SUVmax and the CT attenuation value for the group of 57 adenomas (R = 0.44, P = 0.0007). For the 11 surgically resected cases, there was a nonsignificant trend of negative correlation between SUVmax and CCR (R = 0.57, P = 0.06). There was a significant positive correlation between GLUT score and CT attenuation value (R = 0.68, P = 0.02), and a significant negative correlation between GLUT score and CCR (R = 0.60, P = 0.003).

Conclusions: Adrenal adenomas composed of many compact cells or having high attenuation on unenhanced CT showed high FDG uptake. FDG uptake of adrenal adenomas may depend on the constituent cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLU.0000000000002759DOI Listing
December 2019

Differences in edge artifacts between 68Ga- and 18F-PET images reconstructed using point spread function correction.

Nucl Med Commun 2019 Nov;40(11):1166-1173

Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.

Objective: Edge artifacts have been reported on in relation to F-PET using point spread function correction algorithms. The positron range of Ga is longer than F, and this difference is thought to result in different edge artifacts. The purpose of this study is to clarify the difference in edge artifacts in PET images using point spread function correction in Ga- and F-PET.

Methods: We used a National Electrical Manufacturers Association International Electrotechnical Commission body phantom. The phantom was filled severally with Ga and F solution. The PET data were obtained over a 90 minutes period using a True Point Biograph 16 scanner. The images were then reconstructed with the ordered subset expectation maximization with point spread function correction. The phantom image analyses were performed by a visual assessment of the PET images and profiles, and an absolute recovery coefficient, which was the ratio of the maximum radioactivity of any given hot sphere to its true radioactivity.

Results: The ring-like edge artifacts of Ga-PET were less prominent than those in F-PET. The relative radioactivity profiles of Ga-PET showed low overshoots of the maximum radioactivity although high overshoots did appear in F-PET. The absolute recovery coefficients of Ga-PET were smaller than those of F-PET.

Conclusion: The edge artifacts of Ga-PET were less prominent than those of F-PET, and their overshoots were smaller. The difference in the positron range between Ga and F may possibly result in the difference in edge artifacts of images reconstructed using the point spread function correction algorithm.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MNM.0000000000001079DOI Listing
November 2019

Clinical results of carbon-ion radiotherapy with separation surgery for primary spine/paraspinal sarcomas.

Int J Clin Oncol 2019 Nov 6;24(11):1490-1497. Epub 2019 Jul 6.

Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.

Purpose: To evaluate the clinical outcome of combination of carbon-ion radiotherapy with separation surgery (CIRT-SS) in patients with primary spinal/paraspinal sarcoma (PSPS) and epidural spinal cord compression (ESCC).

Methods: CIRT-SS was performed in 11 consecutive patients. Patients treated in the primary and salvage settings were categorized into Group A (n = 8) and Group B (n  = 3), respectively. Clinical results and imaging findings were collected, with a particular focus on ESCC grade, treatment-associated adverse events (AEs), and the locoregional control (LRC) rate and overall survival (OS).

Results: The median follow-up period from the start of CIRT-SS was 25 months (7-57 months). ESCC was improved by SS in all cases. No patients exhibited radiation-induced myelopathy (RIM), but three developed Grade 3 vertebral compression fracture (VCF) during follow-up. Locoregional recurrences were observed in four patients [Group A: 1 (12.5%), Group B: 3 (100%)]. Over the entire follow-up period, three patients developed distant metastases and two patients died. The 2-year LRC rate and OS were 70% and 80%, respectively.

Conclusion: CIRT-SS in the primary setting achieved acceptable LRC and OS without RIM in patients with PSPS and with ESCC. VCF was the most frequent AE associated with CIRT-SS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10147-019-01505-yDOI Listing
November 2019

Nuclear medicine practice in Japan: a report of the eighth nationwide survey in 2017.

Ann Nucl Med 2019 Oct 24;33(10):725-732. Epub 2019 Jun 24.

Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan.

Objective: Subcommittee on Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to survey contemporary nuclear medicine practice and its changes over the years.

Methods: The subcommittee sent questionnaires, including the number and category of examinations as well as the kind and dose of the radiopharmaceuticals during the 30 days of June 2017, to all nuclear medicine institutes. The total numbers for the year 2017 were then estimated.

Results: A total of 1132 institutes responded to the survey, including 351 PET centers. The recovery rate was 90.6%. The number of gamma cameras installed was 1332 in total, with 7.0% decrease in 5 years. Dual-head cameras and hybrid SPECT/CT scanners accounted for 88.2 and 23.6%, respectively. The number of single-photon tracer studies in 2017 was 1.08 million which means a decrease in 5.7% in 5 years and 23.6% in 10 years. All but neurotransmitter system, sentinel lymph node, and liver scintigraphy decreased. Bone scintigraphy was a leading examination (32.3%), followed by myocardial scintigraphy (24.1%) and cerebral perfusion study (18.0%) in order. SPECT studies showed an increase from 47.2% to 63.5%. PET centers have also increased from 295 to 389, as compared to the last survey. The 112 PET centers have installed one or two in-house cyclotrons. PET studies showed 24.5% increase in 5 years, with oncology accounting for 88.9%. F-FDG accounted for 98.2% (630,570 examinations). PET examinations using C-methionine have decreased, with 2440 examinations in 2017. PET examinations using N-NH have been increasing, with 2363 examinations in 2017. The number of PET studies using C-PIB was 904. I-radioiodine targeted therapies showed an increase in 5 years (23.1%), including 4487 patients for thyroid cancer. Out-patient thyroid bed ablation therapy with 1,110 MBq of I accounted for 36.6% of cancer patients. The number of admission rooms increased from 135 to 157 in 5 years. The number of Ra targeted therapies for castration-resistant metastatic prostate cancer was 1194 patients.

Conclusions: Single-photon examinations showed a continuous tendency toward a decline in the survey. In contrast, the number of hybrid SPECT/CT scanner examinations has increased. PET/CT study and radionuclide targeted therapy have steadily increased.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-019-01382-5DOI Listing
October 2019

The severity of obstructive sleep apnea syndrome cannot predict the accumulation of brain amyloid by imaging with [11C]-Pittsburgh compound B PET computed tomography in patients with a normal cognitive function.

Ann Nucl Med 2019 Jul 18;33(7):541-544. Epub 2019 Mar 18.

Sleep Apnea Center, Kyushu University Hospital, Fukuoka, Japan.

Objective: Disturbed sleep due to obstructive sleep apnea syndrome (OSAS) might accelerate amyloidβ (Aβ) deposition, which can be a crucial factor in Alzheimer's disease. We studied Aβ deposition in untreated OSAS patients with normal cognition.

Method: We performed polysomnography (PSG) and Aβ imaging with [C]-Pittsburgh compound B PET computed tomography (C-PiB PET CT) in 14 untreated OSAS patients (apnea-hypopnea index: 43.8 ± 26.3/h).

Results: The abnormal accumulation of enhanced C-PiB PET was observed only one patient with severe, but not the most severe.

Conclusions: The OSAS severity alone may not predict Aβ deposition in OSAS patients with normal cognition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-019-01349-6DOI Listing
July 2019

The Influence of Minimal Misalignment on the Repeatability of PET Images Examined by the Repositioning of Point Sources.

J Nucl Med Technol 2019 Mar 9;47(1):55-59. Epub 2018 Nov 9.

Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan

We aimed to evaluate the influence of minimal misalignment of a hot spot on the repeatability of PET images using repositioning of point sources. Point sources with an inner diameter of 1 mm were made with 1 μL of F solution. Seven point sources were placed on the -axis in the field of view. For fixed-position imaging, PET data were acquired for 10 min 5 times serially. For variable-position imaging, PET data were acquired for 10 min each with the point sources placed at 0, ±0.5, and ±1.0 mm in the -axis direction. The data were reconstructed using ordered-subsets expectation maximization (OSEM) and OSEM plus point-spread function (PSF). The image matrix was 128 × 128, 200 × 200, 256 × 256, 400 × 400, and 512 × 512 pixels. The normalized maximum count (rMax), the coefficient of variance (CV), and the full width at half maximum were analyzed. The hot spots on OSEM images far from the center became faint and broad, whereas those on OSEM+PSF images became small and dense. Although rMax was overestimated at the 5-cm position on OSEM images, rMax at other positions was overestimated on OSEM+PSF images with a matrix of at least 256 × 256. rMax showed a similar pattern in fixed- and variable-position images. CV in fixed-position OSEM images was less than 2%, irrespective of matrix size. In contrast, CV in variable-position images was higher than in fixed-position images. CV was higher for OSEM+PSF images than for OSEM images. The full width at half maximum increased at positions far from the center on OSEM images but was stable at all positions on OSEM+PSF images. The repeatability of the small hot spot was affected by the minimal misalignment, especially on OSEM+PSF images. Precise positioning is necessary if PET is to be used as a biomarker. Professionals should recognize that PSF correction worsens the repeatability of the small hot spot although improving the spatial resolution of PET images.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2967/jnmt.118.208835DOI Listing
March 2019

The Effect of Interim FDG-PET-guided Response-Adapted Therapy in Pediatric Patients with Hodgkin's Lymphoma (HL-14) : Protocol for a Phase II Study.

Acta Med Okayama 2018 Aug;72(4):437-440

Department of Pediatrics, Graduate School of Medical Sciences Kyushu University, Fukuoka 812-8582,

This trial enrolls patients with untreated Hodgkin's lymphoma aged<20 years at diagnosis and examines the effects of omitting radiation therapy if the FDG-positron emission tomography (PET) findings after two completed cycles of combination chemotherapy are negative. It thereby aims to determine whether patients who truly require radiation therapy can be identified by FDG-PET. If so, this modality could be used to omit radiation therapy for all other patients, decreasing the risk of serious long-term complications without affecting survival rates. The outcomes of patients for whom FDG-PET is used to assess early treatment response will also be determined.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18926/AMO/56185DOI Listing
August 2018

Prognostic outcome and complications of sentinel lymph node navigation surgery for early-stage cervical cancer.

Int J Clin Oncol 2018 Dec 9;23(6):1167-1172. Epub 2018 Aug 9.

Department of Obstetrics and Gynecology, Faculty of Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.

Background: To evaluate the prognostic outcome and surgical complications in patients with early-stage cervical cancer who underwent sentinel node navigation surgery (SNNS) for hysterectomy or trachelectomy.

Methods: A total of 139 patients who underwent SNNS using Tc phytate between 2009 and 2015 were evaluated. No further lymph node dissection was performed when intraoperative analysis of the sentinel lymph nodes (SLNs) was negative for metastasis. We compared the surgical complications between the SNNS group and 67 matched patients who underwent pelvic lymph node dissection (PLND) after SLN mapping between 2003 and 2008. We also examined the clinical outcomes in the SNNS group.

Results: The mean number of detected SLNs was 2.5 per patient. Fourteen of the 139 patients in the SNNS group underwent PLND based on the intraoperative SLN results. The amount of blood loss, the operative time, and the number of perioperative complications were significantly less in the SNNS group than in the matched PLND group. There was no recurrence during a follow-up period ranging from 2 to 88 months (median 40 months) in the SNNS group.

Conclusions: Using SNNS for early-stage cervical cancer is safe and effective and does not increase the recurrence rate. A future multicenter trial is warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10147-018-1327-yDOI Listing
December 2018

Assessment of collimators in radium-223 imaging with channelized Hotelling observer: a simulation study.

Ann Nucl Med 2018 Dec 2;32(10):649-657. Epub 2018 Aug 2.

Division of Medical Quantum Science, Department of Health Sciences, Kyushu University, Fukuoka, Japan.

Objective: Radium-223 (Ra) is used in unsealed radionuclide therapy for metastatic bone tumors. The aim of this study is to apply a computational model observer to Ra planar images, and to assess the performance of collimators in Ra imaging.

Methods: The Ra planar images were created via an in-house Monte Carlo simulation code using HEXAGON and NAI modules. The phantom was a National Electrical Manufacturers Association body phantom with a hot sphere. The concentration of the background was 55 Bq/mL, and the sphere was approximately 1.5-20 times that of the background concentration. The acquisition time was 10 min. The photopeaks (and the energy window) were 84 (full width of energy window: 20%), 154 (15%), and 270 keV (10%). Each 40 images, with and without hot concentration, were applied to a three-channel difference-of-Gaussian channelized Hotelling observer (CHO), and the signal-to-noise ratio (SNR) of the hot region was calculated. The images were examined using five different collimators: two low-energy general-purpose (LEGP), two medium-energy general-purpose (MEGP), and one high-energy general-purpose (HEGP) collimators.

Results: The SNR value was linearly proportional to the contrast of the hot region for all collimators and energy windows. The images of the 84-keV energy window with the MEGP collimator that have thicker septa and larger holes produced the highest SNR value. The SNR values of two LEGP collimators were approximately half of the MEGP collimators. The HEGP collimator was halfway between the MEGP and LEGP. Similar characteristics were observed for other energy windows (154, 270 keV). The SNR value of images captured via the 270-keV energy window was larger than 154-keV, although the sensitivity of the 270-keV energy window is lower than 154-keV. The results suggested a positive correlation between the SNR value and the fraction of unscattered photons.

Conclusions: The SNR value of CHO reflected the performance of collimators and was available to assess and quantitatively evaluate the collimator performance in Ra imaging. The SNR value depends on the magnitudes of unscattered photon count and the fraction of unscattered photon count. Consequently, in this study, MEGP collimators performed better than LEGP and HEGP collimators for Ra imaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12149-018-1286-4DOI Listing
December 2018

Evaluation of the Reconstruction Parameters of Brain Dopamine Transporter SPECT images Obtained by a Fan Beam Collimator: A Comparison with Parallel-hole Collimators.

Asia Ocean J Nucl Med Biol 2018 ;6(2):120-128

Division of Medical Quantum Science, Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Objectives: The purpose of this study was to examine the optimal reconstruction parameters for brain dopamine transporter SPECT images obtained with a fan beam collimator and compare the results with those obtained by using parallel-hole collimators.

Methods: Data acquisition was performed using two SPECT/CT devices, namely a Symbia T6 and an Infinia Hawkeye 4 (device A and B) equipped with fan-beam (camera A-1 and B-1), low- and medium-energy general-purpose (camera A-2 and B-2), and low-energy high-resolution (camera A-3 and B-3) collimators. The SPECT images were reconstructed using filtered back projection (FBP) with Chang's attenuation correction. However, the scatter correction was not performed. A pool phantom and a three-dimensional (3D) brain phantom were filled with I solution to examine the reconstruction parameters. The optimal attenuation coefficient was based on the visual assessment of the profile curve, coefficient of variation (CV) [%], and summed difference from the reference activity of the pool phantom. The optimal Butterworth filter for the 3D-brain phantom was also determined based on a visual assessment. The anthropomorphic striatal phantom was filled with I solution at striatum-to-background radioactivity ratios of 8, 6, 4, and 3. The specific binding ratio (SBR) of the striatum (calculated by the CT method) was used to compare the results with those of the parallel-hole collimators.

Results: The optimal attenuation coefficients were 0.09, 0.11, 0.05, 0.05, 0.11, and, 0.10 cm for cameras A-1, A-2, A-3, B-1, B-2, and B-3, respectively. The cutoff frequencies of the Butterworth filter were 0.32, 0.40, and 0.36 cycles/cm for camera A, and 0.46, 0.44, and 0.44 cycles/cm for camera B, respectively. The recovery rates of the SBR with camera A were 51.2%, 49.4%, and 45.6%, respectively. The difference was not statistically significant. The recovery rates of the SBR with camera B were 59.2%, 50.7%, and 50.8%, respectively. Camera B-1 showed significantly high SBR values.

Conclusion: As the findings indicated, the optimal reconstruction parameters differed according to the devices and collimators. The fan beam collimator was found to provide promising results with each device.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22038/aojnmb.2018.10330DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6038970PMC
January 2018

Time-of-Flight Information Improved the Detectability of Subcentimeter Spheres Using a Clinical PET/CT Scanner.

J Nucl Med Technol 2018 Sep 29;46(3):268-273. Epub 2018 Mar 29.

Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; and

Recent advancements in clinical PET/CT scanners have improved the detectability of small lesions. However, the ideal reconstruction parameters for detecting small lesions have not yet been sufficiently clarified. The purpose of this study was to investigate the detectability of subcentimeter spheres using a clinical PET/CT scanner. We used a clinical PET/CT scanner to obtain the data of a National Electrical Manufacturers Association body phantom consisting of 6 small spheres (inner diameters, 4.0, 5.0, 6.2, 7.9, 10, and 37 mm) containing F solution. The background activity was 2.65 kBq/mL, and the sphere-to-background ratio was 8. The PET data obtained for 2 and 120 min were reconstructed using ordered-subsets expectation maximization (OSEM), OSEM + point-spread function (PSF), and OSEM + time-of-flight (TOF) with voxel sizes of 2.04 × 2.04 × 2.00 mm (2-mm voxels) and 4.07 × 4.07 × 3.99 mm (4-mm voxels). A gaussian filter was not used. The image quality was evaluated by visual assessment, as well as by physical assessment of the detectability index and recovery coefficients. According to the visual assessment, the detectability of the spheres improved using TOF and a longer acquisition. Using the OSEM+TOF model, the smallest visually detected spheres were 5 mm in diameter with a 120-min acquisition and 6 mm in diameter with a 2-min acquisition. According to physical assessment, the detectability of spheres 10 mm or smaller using the OSEM+TOF image was superior to that using the OSEM image. In addition, the detectability of each hot sphere and recovery coefficient with 2-mm voxels was superior to that with 4-mm voxels. Although OSEM+PSF images showed less background noise, detectability and the recovery coefficient were not improved for spheres 8 mm or smaller. The TOF model with 2-mm voxels improved the detectability of subcentimeter hot spheres on a clinical PET/CT scanner.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2967/jnmt.117.204735DOI Listing
September 2018

Comparison of TOF-PET and Bremsstrahlung SPECT Images of Yttrium-90: A Monte Carlo Simulation Study.

Asia Ocean J Nucl Med Biol 2018 ;6(1):24-31

Division of Medical Quantum Science, Department of Health Sciences, Kyushu University, Fukuoka, Japan.

Objectives: Yttrium-90 (Y) is a beta particle nuclide used in targeted radionuclide therapy which is available to both single-photon emission computed tomography (SPECT) and time-of-flight (TOF) positron emission tomography (PET) imaging. The purpose of this study was to assess the image quality of PET and Bremsstrahlung SPECT by simulating PET and SPECT images of Y using Monte Carlo simulation codes under the same conditions and to compare them.

Methods: In-house Monte Carlo codes, MCEP-PET and MCEP-SPECT, were employed to simulate images. The phantom was a torso-shaped phantom containing six hot spheres of various sizes. The background concentrations of Y were set to 50, 100, 150, and 200 kBq/mL, and the concentrations of the hot spheres were 10, 20, and 40 times of those of the background concentrations. The acquisition time was set to 30 min, and the simulated sinogram data were reconstructed using the ordered subset expectation maximization method. The contrast recovery coefficient (CRC) and contrast-to-noise ratio (CNR) were employed to evaluate the image qualities.

Results: The CRC values of SPECT images were less than 40%, while those of PET images were more than 40% when the hot sphere was larger than 20 mm in diameter. The CNR values of PET images of hot spheres of diameter smaller than 20 mm were larger than those of SPECT images. The CNR values mostly exceeded 4, which is a criterion to evaluate the discernibility of hot areas. In the case of SPECT, hot spheres of diameter smaller than 20 mm were not discernable. On the contrary, the CNR values of PET images decreased to the level of SPECT, in the case of low concentration.

Conclusion: In almost all the cases examined in this investigation, the quantitative indexes of TOF-PET Y images were better than those of Bremsstrahlung SPECT images. However, the superiority of PET image became critical in the case of low activity concentrations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22038/aojnmb.2017.9673DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5765330PMC
January 2018

Characteristics of Smoothing Filters to Achieve the Guideline Recommended Positron Emission Tomography Image without Harmonization.

Asia Ocean J Nucl Med Biol 2018 ;6(1):15-23

Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.

Objectives: The aim of this study is to examine the effect of different smoothing filters on the image quality and SUV to achieve the guideline recommended positron emission tomography (PET) image without harmonization.

Methods: We used a Biograph mCT PET scanner. A National Electrical Manufacturers Association (NEMA) the International Electrotechnical Commission (IEC) body phantom was filled with F solution with a background activity of 2.65 kBq/mL and a sphere-to-background ratio of 4. PET images obtained with the Biograph mCT PET scanner were reconstructed using the ordered subsets-expectation maximization (OSEM) algorithm with time-of-flight (TOF) models (iteration, 2; subset, 21); smoothing filters including the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters with various full width at half maximum (FWHM) values (1-15 mm) were applied. The image quality was physically assessed according to the percent contrast (Q), background variability (N), standardized uptake value (SUV), and recovery coefficient (RC). The results were compared with the guideline recommended range proposed by the Japanese Society of Nuclear Medicine and the Japanese Society of Nuclear Medicine Technology. The PET digital phantom was developed from the digital reference object (DRO) of the NEMA IEC body phantom smoothed using a Gaussian filter with a 10-mm FWHM and defined as the reference image. The difference in the SUV between the PET image and the reference image was evaluated according to the root mean squared error (RMSE).

Results: The FWHMs of the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters that satisfied the image quality of the FDG-PET/CT standardization guideline criteria were 8-12 mm, 9-11 mm, 9-13 mm, 10-13 mm, 9-11 mm, and 12-15 mm, respectively. The FWHMs of the Gaussian, Butterworth, Hamming, Hann, Parzen, and Shepp-Logan filters that provided the smallest RMSE between the PET images and the 3D digital phantom were 7 mm, 8 mm, 8 mm, 8 mm, 7 mm, and 11 mm, respectively.

Conclusion: The suitable FWHM for image quality or SUV depends on the type of smoothing filter that is applied.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22038/aojnmb.2017.26684.1186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5765329PMC
January 2018

Progression to bone-marrow carcinomatosis and extraosseous legion during treatment with radium-223 for multiple bone metastases.

Int Cancer Conf J 2018 Apr 30;7(2):48-51. Epub 2017 Dec 30.

1Department of Urology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 Japan.

A 67-year-old man with metastatic prostate cancer presented with progression to castration-resistant prostate cancer. After sequential therapies with flutamide, estramustine phosphate, docetaxel, enzalutamide, and cabazitaxel for castration-resistant prostate cancer, radium-223 was initiated and continued up to 4 cycles. However, concurrently with radiological and clinical progressions, pancytopenia was observed due to bone-marrow carcinomatosis by prostatic adenocarcinoma. This case suggested that radium-223 should be employed at appropriated timing before appearances of extraosseous and bone-marrow lesions in addition to visceral metastasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s13691-017-0316-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6498389PMC
April 2018

Value of Intraoperative Cytological and Pathological Sentinel Lymph Node Diagnosis in Fertility-Sparing Trachelectomy for Early-Stage Cervical Cancer.

Oncology 2018 15;94(2):92-98. Epub 2017 Nov 15.

Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Background And Objectives: Trachelectomy, a fertility-sparing surgery for early-stage cervical cancer, can be performed only when there is no extrauterine extension present. Therefore, identifying the sentinel lymph nodes (SLNs) and using them to obtain an intraoperative pathologic diagnosis can provide information on the feasibility and safety of trachelectomy. Our aim was to assess the value of an intraoperative SLN diagnosis.

Methods: We retrospectively analyzed the accuracy of intraoperative imprint cytology and frozen-section examination in 201 patients at our institution in whom trachelectomy was planned.

Results: All patients could be evaluated for SLNs; a total of 610 SLNs were analyzed. Although the specificity of both imprint cytology and frozen-section examination was 100.0%, the sensitivity was only 58.6 and 65.5%, respectively. The diagnostic sensitivity was higher in 2-mm slices along the short axis than on bisection along the longitudinal axis. Imprint cytology correctly diagnosed 2 patients who had false-negative results on frozen section. The nature of the metastatic foci that caused an intraoperative false-negative diagnosis was either micrometastasis or isolated tumor cells.

Conclusions: The accuracy of intraoperative SLN diagnosis requires improvement, especially when small metastatic foci are present.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000484049DOI Listing
March 2018

Metabolic characteristics of programmed cell death-ligand 1-expressing lung cancer on F-fluorodeoxyglucose positron emission tomography/computed tomography.

Cancer Med 2017 Nov 4;6(11):2552-2561. Epub 2017 Oct 4.

Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) have been identified as novel targets of immunotherapy of lung cancer. In present study, we evaluated the metabolic characteristics of lung cancer by using F-fluorodeoxyglucose positron emission tomography/computed tomography ( F-FDG PET/CT) with regard to PD-L1 protein expression. PD-L1 protein expression was evaluated by immunohistochemistry with the antibody clone SP142 in 579 surgically resected primary lung cancer patients. Cases with less than 5% tumor membrane staining were considered negative. We examined the association between the frequency of PD-L1 protein expression and the maximum standardized uptake value (SUVmax) in preoperative F-FDG PET/CT. The cut-off values for SUVmax were determined by receiver operating characteristic curve analyses. The SUVmax was significantly higher in nonsmall cell lung cancer (NSCLC) patients with PD-L1 protein expression compared with those without PD-L1 protein expression (P < 0.0001). However, there was no correlation between SUVmax and PD-L1 protein expression in patients with neuroendocrine tumors (P = 0.6545). Multivariate analysis revealed that smoking, the presence of pleural invasion, and high SUVmax were independent predictors of PD-L1 positivity. PD-L1-expressing NSCLC had a high glucose metabolism. The SUVmax in preoperative F-FDG PET/CT was a predictor of PD-L1 protein expression in patients with NSCLC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cam4.1215DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5673920PMC
November 2017

A Functional Scoring System Based on Salivary Gland Scintigraphy for Evaluating Salivary Gland Dysfunction Secondary to I therapy in Patients with Differentiated Thyroid Carcinoma.

J Clin Diagn Res 2017 Aug 1;11(8):TC23-TC28. Epub 2017 Aug 1.

Professor, Department of Clinical Radiology, Kyushu University Fukuoka, Fukuoka, Japan.

Introduction: Radioiodine therapy with I (I therapy) after total or near-total thyroidectomy has been established as an effective treatment for Differentiated Thyroid Carcinoma (DTC), but can induce dry mouth symptoms by salivary gland damage and impair the patients' quality of life.

Aim: To propose a functional scoring system based on Salivary Gland Scintigraphy (SGS) findings that evaluates development of salivary gland dysfunction secondary to I therapy in patients with DTC.

Materials And Methods: This retrospective study evaluated the records of 279 DTC patients who underwent SGS after one or more round(s) of I therapy, using 370 MBqof Tc-pertechnetate. The SGS results were assessed using a novel functional scoring system in the Parotid Glands (PGs) and Submandibular Glands (SMGs) according to visual evaluations based on a three-point uptake score, Washout Rate (%WR) score after lemon-juice stimulation, and functional score. The scores were compared among pre treatment, low-dose (<10 GBq), and high-dose (>10 GBq) groups and among pre treatment, symptom-positive, and symptom-negative groups. Risk factors for dry mouth were analyzed by univariate and multivariate logistic regression analyses.

Results: Dry mouth symptoms developed in 15.4% of the DTC patients after I therapy. The three-point uptake, %WR, and functional scores in both the PG and SMG were statistically significant between low-dose and high-dose groups, and between symptom-positive and symptom-negative groups. The PG/SMG functional scores were independent risk factors for dry mouth (odds ratio, 0.03 and 0.0007 respectively).

Conclusion: SGS-based PG and SMG functional scores were effective biomarkers to objectively evaluate salivary gland dysfunction, with the high strength of association with dry mouth symptoms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.7860/JCDR/2017/27340.10431DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5620881PMC
August 2017

Metabolic Tumor Volume by F-FDG PET/CT Can Predict the Clinical Outcome of Primary Malignant Spine/Spinal Tumors.

Biomed Res Int 2017 9;2017:8132676. Epub 2017 Aug 9.

Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.

Background And Purpose: Primary malignant spine/spinal tumors (PMSTs) are rare and life-threatening diseases. In this study, we demonstrated the advantage of volume-based F-FDG PET/CT metabolic parameter, metabolic tumor volume (MTV), for assessing the aggressiveness of PMSTs.

Materials And Methods: We retrospectively reviewed 27 patients with PMSTs and calculated SUV, MTV, and total lesion glycolysis (TLG) to compare their accuracy in predicting progression-free survival (PFS) and overall survival (OS) by receiver operating characteristic (ROC) curve analysis. Univariate and multivariate analyses were used to compare the reliability of the metabolic parameters and various clinical factors.

Results: MTV exhibited greater accuracy than SUV or TLG. The cut-off values for PFS and OS derived from the AUC data were MTV 45 ml and 83 ml and TLG 250 SUV⁎ml and 257 SUV⁎ml, respectively. MTV above cut-off value, but not TLG, was identified as significant prognostic factor for PFS by log-lank test ( = 0.04). In addition, MTV was the only significant predictive factors for PFS and OS in the multivariate analysis.

Conclusions: MTV was a more accurate predictor of PFS and OS in PMSTs compared to TLG or SUV and helped decision-making for guiding rational treatment options.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2017/8132676DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5568596PMC
May 2018

Influence of the Different Primary Cancers and Different Types of Bone Metastasis on the Lesion-based Artificial Neural Network Value Calculated by a Computer-aided Diagnostic System, BONENAVI, on Bone Scintigraphy Images.

Asia Ocean J Nucl Med Biol 2017 ;5(1):49-55

Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Objectives: BONENAVI, a computer-aided diagnostic system, is used in bone scintigraphy. This system provides the artificial neural network (ANN) and bone scan index (BSI) values. ANN is associated with the possibility of bone metastasis, while BSI is related to the amount of bone metastasis. The degree of uptake on bone scintigraphy can be affected by the type of bone metastasis. Therefore, the ANN value provided by BONENAVI may be influenced by the characteristics of bone metastasis. In this study, we aimed to assess the relationship between ANN value and characteristics of bone metastasis.

Methods: We analyzed 50 patients (36 males,14 females; age range: 87-42 yrs median age:72.5 yrs) with prostate, breast, or lung cancer who had undergone bone scintigraphy and were diagnosed with bone metastasis (32 cases of prostate cancer, nine cases of breast cancer, and nine cases of lung cancer). Those who had received systematic therapy over the past years were excluded. Bone metastases were diagnosed clinically, and the type of bone metastasis (osteoblastic, mildly osteoblastic, osteolytic, and mixed components) was decided visually by the agreement of two radiologists. We compared the ANN values (case-based and lesion-based) among the three primary cancers and four types of bone metastasis.

Results: There was no significant difference in case-based ANN values among prostate, breast, and lung cancers. However, the lesion-based ANN values were the highest in cases with prostate cancer and the lowest in cases of lung cancer (median values: prostate cancer, 0.980; breast cancer 0.909; and lung cancer, 0.864). Mildly osteoblastic lesions showed significantly lower ANN values than the other three types of bone metastasis (median values: osteoblastic,; 0.939 mildly osteoblastic; 0.788, mixed type; 0.991, and osteolytic. 0.969) The possibility of a lesion-based ANN value below 0.5 was %10.9 for bone metastasis in prostate cancer, %12.9 for breast cancer, and %37.2 for lung cancer. The corresponding possibility were %14.7 for osteoblastic metastases, %23.9 for mildly osteoblastic metastases, %7.14 for mixed-type metastases, and %16.0 for osteolytic metastases.

Conclusion: The lesion-based ANN values calculated by BONENAVI can be influenced by the type of primary cancer and bone metastasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22038/aojnmb.2016.7606DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5221686PMC
January 2017

The Efficiency of Respiratory-gated F-FDG PET/CT in Lung Adenocarcinoma: Amplitude-gating Versus Phase-gating Methods.

Asia Ocean J Nucl Med Biol 2017 ;5(1):30-36

Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.

Objectives: In positron emission tomography (PET) studies, thoracic movement under free-breathing conditions is a cause of image degradation. Respiratory gating (RG) is commonly used to solve this problem. Two different methods, i.e., phase-gating (PG) and amplitude-gating (AG) PET, are available for respiratory gating. It is important to know the strengths and weaknesses of both methods when selecting an RG method for a given patient. We conducted this study to clarify whether AG or PG is preferable for measuring fluorodeoxyglucose (FDG) accumulation in lung adenocarcinoma and to investigate patient conditions which are most suitable for AG and PG methods.

Methods: A total of 31 patients (11 males, 20 females; average age: 70.1±11.6 yrs) with 44 lung lesions, diagnosed as lung adenocarcinoma between April 2012 and March 2013, were investigated. Whole-body FDG-PET/CT scan was performed with both PG and AG methods in all patients. The maximum standardized uptake value (SUV) of PG, AG, and the control data of these two methods were measured, and the increase ratio (IR), calculated as IR(%)= (Post - Pre)/Pre × 100, was calculated. The diameter and position of lung lesions were also analyzed. We defined an 'effective lesion' of PG (or AG) as a lesion which showed a higher IR compared to AG (or PG). 8 (25.8%).

Results: The average SUV and average IR were 8.99±7.94 and %21.4±25.6 in PG and 7.60±6.70 and %4.0±14.4 in AG, respectively. Although there was no significant difference between the average SUV of PG and AG (P=0.09), the average IR of PG was significantly higher than that of AG (P<0.01). The number of PG- and AG-effective lesions was 32 (72.7%) and 12 (28.3%), respectively. There was no significant difference in the average diameter or position of the lesions between the PG- and AG-effective lesions. There were 23 (74.2%) PG-effective and 8 (25.8%) AG-effective patients. No significant difference was observed in sex or age between PG- and AG-effective patients.

Conclusion: The PG method was more effective for measuring FDG accumulation of lung lesions under free-breathing conditions in comparison with the AG method.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.22038/aojnmb.2016.7747DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5221683PMC
January 2017
-->