Publications by authors named "Anna Kuisma"

9 Publications

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Kinetic analysis and optimisation of F-rhPSMA-7.3 PET imaging of prostate cancer.

Eur J Nucl Med Mol Imaging 2021 Apr 12. Epub 2021 Apr 12.

Clinical Research Services Turku - CRST Ltd, Turku, Finland.

Purpose: This phase 1 open-label study evaluated the uptake kinetics of a novel theranostic PET radiopharmaceutical, F-rhPSMA-7.3, to optimise its use for imaging of prostate cancer.

Methods: Nine men, three with high-risk localised prostate cancer, three with treatment-naïve hormone-sensitive metastatic disease and three with castration-resistant metastatic disease, underwent dynamic 45-min PET scanning of a target area immediately post-injection of 300 MBq F-rhPSMA-7.3, followed by two whole-body PET/CT scans acquired from 60 and 90 min post-injection. Volumes of interest (VoIs) corresponding to prostate cancer lesions and reference tissues were recorded. Standardised uptake values (SUV) and lesion-to-reference ratios were calculated for 3 time frames: 35-45, 60-88 and 90-118 min. Net influx rates (K) were calculated using Patlak plots.

Results: Altogether, 44 lesions from the target area were identified. Optimal visual lesion detection started 60 min post-injection. The F-rhPSMA-7.3 signal from prostate cancer lesions increased over time, while reference tissue signals remained stable or decreased. The mean (SD) SUV (g/mL) at the 3 time frames were 8.4 (5.6), 10.1 (7) and 10.6 (7.5), respectively, for prostate lesions, 11.2 (4.3), 13 (4.8) and 14 (5.2) for lymph node metastases, and 4.6 (2.6), 5.7 (3.1) and 6.4 (3.5) for bone metastases. The mean (SD) lesion-to-reference ratio increases from the earliest to the 2 later time frames were 40% (10) and 59% (9), respectively, for the prostate, 65% (27) and 125% (47) for metastatic lymph nodes and 25% (19) and 32% (30) for bone lesions. Patlak plots from lesion VoIs signified almost irreversible uptake kinetics. K, SUV and lesion-to-reference ratio estimates showed good agreement.

Conclusion: F-rhPSMA-7.3 uptake in prostate cancer lesions was high. Lesion-to-background ratios increased over time, with optimal visual detection starting from 60 min post-injection. Thus, F-rhPSMA-7.3 emerges as a very promising PET radiopharmaceutical for diagnostic imaging of prostate cancer.

Trial Registration: NCT03995888 (24 June 2019).
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April 2021

Validation of automated magnetic resonance image segmentation for radiation therapy planning in prostate cancer.

Phys Imaging Radiat Oncol 2020 Jan 13;13:14-20. Epub 2020 Mar 13.

Turku University Hospital, Department of Oncology and Radiotherapy, Hämeentie 11, FI-20521 Turku, Finland.

Background And Purpose: Magnetic resonance imaging (MRI) is increasingly used in radiation therapy planning of prostate cancer (PC) to reduce target volume delineation uncertainty. This study aimed to assess and validate the performance of a fully automated segmentation tool (AST) in MRI based radiation therapy planning of PC.

Material And Methods: Pelvic structures of 65 PC patients delineated in an MRI-only workflow according to established guidelines were included in the analysis. Automatic vs manual segmentation by an experienced oncologist was compared with geometrical parameters, such as the dice similarity coefficient (DSC). Fifteen patients had a second MRI within 15 days to assess repeatability of the AST for prostate and seminal vesicles. Furthermore, we investigated whether hormonal therapy or body mass index (BMI) affected the AST results.

Results: The AST showed high agreement with manual segmentation expressed as DSC (mean, SD) for delineating prostate (0.84, 0.04), bladder (0.92, 0.04) and rectum (0.86, 0.04). For seminal vesicles (0.56, 0.17) and penile bulb (0.69, 0.12) the respective agreement was moderate. Performance of AST was not influenced by neoadjuvant hormonal therapy, although those on treatment had significantly smaller prostates than the hormone-naïve patients (p < 0.0001). In repeat assessment, consistency of prostate delineation resulted in mean DSC of 0.89, (SD 0.03) between the paired MRI scans for AST, while mean DSC of manual delineation was 0.82, (SD 0.05).

Conclusion: Fully automated MRI segmentation tool showed good agreement and repeatability compared with manual segmentation and was found clinically robust in patients with PC. However, manual review and adjustment of some structures in individual cases remain important in clinical use.
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January 2020

Safety, Biodistribution, and Radiation Dosimetry of F-rhPSMA-7.3 in Healthy Adult Volunteers.

J Nucl Med 2021 May 16;62(5):679-684. Epub 2020 Oct 16.

Clinical Research Services Turku-CRST Ltd., Turku, Finland.

This first-in-humans study investigated the safety, biodistribution, and radiation dosimetry of a novel F-labeled radiohybrid prostate-specific membrane antigen (rhPSMA) PET imaging agent, F-rhPSMA-7.3. Six healthy volunteers (3 men, 3 women) underwent multiple whole-body PET acquisitions at scheduled time points up to 248 min after the administration of F-rhPSMA-7.3 (mean activity, 220; range, 210-228 MBq). PET scans were conducted in 3 separate sessions, and subjects were encouraged to void between sessions. Blood and urine samples were collected for up to 4 h after injection to assess metabolite-corrected radioactivity in whole blood, plasma, and urine. Quantitative measurements of F radioactivity in volumes of interest over target organs were determined directly from the PET images at 8 time points, and normalized time-activity concentration curves were generated. These normalized cumulated activities were then inputted into the OLINDA/EXM package to calculate the internal radiation dosimetry and the subjects' effective dose. F-rhPSMA-7.3 was well tolerated. One adverse event (mild headache, not requiring medication) was considered possibly related to F-rhPSMA-7.3. The calculated effective dose was 0.0141 mSv/MBq when using a 3.5-h voiding interval. The organs with the highest mean absorbed dose per unit of administered radioactivity were the adrenals (0.1835 mSv/MBq), the kidneys (0.1722 mSv/MBq), the submandibular glands (0.1479 mSv), and the parotid glands (0.1137 mSv/MBq). At the end of the first scanning session (mean time, 111 min after injection), an average of 7.2% (range, 4.4%-9.0%) of the injected radioactivity of F-rhPSMA-7.3 was excreted into urine. The safety, biodistribution, and internal radiation dosimetry of F-rhPSMA-7.3 are considered favorable for PET imaging.
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May 2021

Prediction of prostate cancer aggressiveness using F-Fluciclovine (FACBC) PET and multisequence multiparametric MRI.

Sci Rep 2020 06 10;10(1):9407. Epub 2020 Jun 10.

Department of Diagnostic Radiology, University of Turku, Turku, Finland.

The aim of this prospective single-institution clinical trial (NCT02002455) was to evaluate the potential of advanced post-processing methods for F-Fluciclovine PET and multisequence multiparametric MRI in the prediction of prostate cancer (PCa) aggressiveness, defined by Gleason Grade Group (GGG). 21 patients with PCa underwent PET/CT, PET/MRI and MRI before prostatectomy. DWI was post-processed using kurtosis (ADC, K), mono- (ADC), and biexponential functions (f, D, D) while Logan plots were used to calculate volume of distribution (V). In total, 16 unique PET (V, SUV) and MRI derived quantitative parameters were evaluated. Univariate and multivariate analysis were carried out to estimate the potential of the quantitative parameters and their combinations to predict GGG 1 vs >1, using logistic regression with a nested leave-pair out cross validation (LPOCV) scheme and recursive feature elimination technique applied for feature selection. The second order rotating frame imaging (RAFF), monoexponential and kurtosis derived parameters had LPOCV AUC in the range of 0.72 to 0.92 while the corresponding value for V was 0.85. he best performance for GGG prediction was achieved by K parameter of kurtosis function followed by quantitative parameters based on DWI, RAFF and F-FACBC PET. No major improvement was achieved using parameter combinations with or without feature selection. Addition of F-FACBC PET derived parameters (V, SUV) to DWI and RAFF derived parameters did not improve LPOCV AUC.
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June 2020

Correlation between F-1-amino-3-fluorocyclobutane-1-carboxylic acid (F-fluciclovine) uptake and expression of alanine-serine-cysteine-transporter 2 (ASCT2) and L-type amino acid transporter 1 (LAT1) in primary prostate cancer.

EJNMMI Res 2019 May 31;9(1):50. Epub 2019 May 31.

Turku PET Centre, Turku, Finland.

Purpose: To evaluate the expression of alanine-serine-cysteine-transporter 2 (ASCT2) and L-type amino acid transporter1 (LAT1) in prostate cancer (PCa) and their impact on uptake of F-1-amino-3-fluorocyclobutane-1-carboxylic acid (F-fluciclovine) which is approved for the detection of recurrent PCa.

Methods: Twenty-five hormone-naïve patients with histologically confirmed PCa underwent PET/CT before prostatectomy. Dynamic imaging was performed immediately after injection of 368 ± 10 MBq of F-fluciclovine and the uptake in PCa was expressed as SUV at six sequential 4-min time frames and as tracer distribution volume (V) using Logan plots over 0-24 min. The expression of ASCT2 and LAT1 was studied with immunohistochemistry (IHC) on a tissue microarray (TMA) containing three cores per carcinoma lesion. The TMA slides were scored independently by two trained readers based on visual intensity of ASCT2/LAT1 expression on a four-tiered scale. The correlations between ASCT2/LAT1 staining intensity, SUVmax/V, and Gleason grade group (GGG) were assessed using Spearman's rank correlation coefficient (ρ).

Results: Forty tumor foci (> 0.5 mm in diameter, max. 3 per patient) were available for TMA. In visual scoring, low, moderate, and high staining intensity of ASCT2 was observed in 4 (10%), 24 (60%), and 12 (30%) tumors, respectively. No tumors showed high LAT1 staining intensity while moderate intensity was found in 10 (25%), 25 (63%) showed low, and the remaining 5 (12%) were negative for staining with LAT1. Tumors with GGG > 2 showed significantly higher uptake of F-fluciclovine and higher LAT1 staining intensity (p < 0.05). The uptake of F-fluciclovine correlated significantly with LAT1 expression (ρ = 0.39, p = 0.01, for SUV at 2 min and ρ = 0.39, p = 0.01 for V). No correlation between ASCT2 expression and F-fluciclovine uptake or GGG was found.

Conclusions: Our findings suggest that LAT1 is moderately associated with the transport of F-fluciclovine in local PCa not exposed to hormonal therapy. Both high and low Gleason grade tumors express ASCT2 while LAT1 expression is less conspicuous and may be absent in some low-grade tumors. Our observations may be of importance when using F-fluciclovine imaging in the planning of focal therapies for PCa.
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May 2019

Comparison of standardized uptake values between Tc-HDP SPECT/CT and F-NaF PET/CT in bone metastases of breast and prostate cancer.

EJNMMI Res 2019 Jan 24;9(1). Epub 2019 Jan 24.

Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Kiinamyllynkatu 4-8, 20521, Turku, Finland.

Background: Despite recent technological advances allowing for quantitative single-photon emission computed tomography (SPECT), quantitative SPECT has not been widely used in the clinical practice. The aim of this study is to evaluate the feasibility of quantitative SPECT for measuring metastatic bone uptake in breast and prostate cancer by comparing standard uptake values (SUVs) measured with Tc-HDP SPECT/CT and F-NaF PET/CT.

Methods: Twenty-six breast and 27 prostate cancer patients at high risk of bone metastases underwent both Tc-HDP SPECT/CT and F-NaF PET/CT within 14 days of each other. The SPECT and PET data were reconstructed using ordered-subset expectation-maximization algorithms achieving quantitative images. Metastatic and benign skeletal lesions visible in both data sets were identified, and their maximum, peak, and mean SUVs (SUV, SUV, and SUV) were determined. SUV ratios (SUVRs) between the lesions and adjacent normal appearing bone were also calculated. Linear regression was used to evaluate the correlations between the SUVs of SPECT and PET and Bland-Altman plots to evaluate the differences between the SUVs and SUVRs of SPECT and PET.

Results: A total of 231 skeletal lesions, 129 metastatic and 102 benign, were analyzed. All three SUV measures correlated very strongly between SPECT and PET (R ≥ 0.80, p < 0.001) when all lesions were included, and the PET SUVs were significantly higher than SPECT SUVs (p < 0.001). The median differences were 21%, 12%, and 19% for SUV, SUV, and SUV, respectively. On the other hand, the SUVRs were similar between SPECT and PET with median differences of 2%, - 9%, and 2% for SUVR, SUVR, and SUVR, respectively.

Conclusion: The strong correlation between SUVs and similar SUVRs of Tc-HDP SPECT/CT and F-NaF PET/CT demonstrate that SPECT is an applicable tool for clinical quantification of bone metabolism in osseous metastases in breast and prostate cancer patients.
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January 2019

Prospective evaluation of F-FACBC PET/CT and PET/MRI versus multiparametric MRI in intermediate- to high-risk prostate cancer patients (FLUCIPRO trial).

Eur J Nucl Med Mol Imaging 2018 03 16;45(3):355-364. Epub 2017 Nov 16.

Turku PET Centre, Turku, Finland.

Purpose: The purpose of this study was to evaluate F-FACBC PET/CT, PET/MRI, and multiparametric MRI (mpMRI) in detection of primary prostate cancer (PCa).

Methods: Twenty-six men with histologically confirmed PCa underwent PET/CT immediately after injection of 369 ± 10 MBq F-FACBC (fluciclovine) followed by PET/MRI started 55 ± 7 min from injection. Maximum standardized uptake values (SUV) were measured for both hybrid PET acquisitions. A separate mpMRI was acquired within a week of the PET scans. Logan plots were used to calculate volume of distribution (V). The presence of PCa was estimated in 12 regions with radical prostatectomy findings as ground truth. For each imaging modality, area under the curve (AUC) for detection of PCa was determined to predict diagnostic performance. The clinical trial registration number is NCT02002455.

Results: In the visual analysis, 164/312 (53%) regions contained PCa, and 41 tumor foci were identified. PET/CT demonstrated the highest sensitivity at 87% while its specificity was low at 56%. The AUC of both PET/MRI and mpMRI significantly (p < 0.01) outperformed that of PET/CT while no differences were detected between PET/MRI and mpMRI. SUV and V of Gleason score (GS) >3 + 4 tumors were significantly (p < 0.05) higher than those for GS 3 + 3 and benign hyperplasia. A total of 442 lymph nodes were evaluable for staging, and PET/CT and PET/MRI demonstrated true-positive findings in only 1/7 patients with metastatic lymph nodes.

Conclusions: Quantitative F-FACBC imaging significantly correlated with GS but failed to outperform MRI in lesion detection. F-FACBC may assist in targeted biopsies in the setting of hybrid imaging with MRI.
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March 2018

Prospective evaluation of planar bone scintigraphy, SPECT, SPECT/CT, 18F-NaF PET/CT and whole body 1.5T MRI, including DWI, for the detection of bone metastases in high risk breast and prostate cancer patients: SKELETA clinical trial.

Acta Oncol 2016 2;55(1):59-67. Epub 2015 Apr 2.

d Turku PET Centre , Turku , Finland.

Purpose: Detection of bone metastases in breast and prostate cancer patients remains a major clinical challenge. The aim of the current trial was to compare the diagnostic accuracy of (99m)Tc-hydroxymethane diphosphonate ((99m)Tc-HDP) planar bone scintigraphy (BS), (99m)Tc-HDP SPECT, (99m)Tc-HDP SPECT/CT, (18)F-NaF PET/CT and whole body 1.5 Tesla magnetic resonance imaging (MRI), including diffusion weighted imaging, (wbMRI+DWI) for the detection of bone metastases in high risk breast and prostate cancer patients.

Material And Methods: Twenty-six breast and 27 prostate cancer patients at high risk of bone metastases underwent (99m)Tc-HDP BS, (99m)Tc-HDP SPECT, (99m)Tc-HDP SPECT/CT, (18)F-NaF PET/CT and wbMRI+DWI. Five independent reviewers interpreted each individual modality without the knowledge of other imaging findings. The final metastatic status was based on the consensus reading, clinical and imaging follow-up (minimal and maximal follow-up time was 6, and 32 months, respectively). The bone findings were compared on patient-, region-, and lesion-level.

Results: (99m)Tc-HDP BS was false negative in four patients. In the region-based analysis, sensitivity values for (99m)Tc-HDP BS, (99m)Tc-HDP SPECT, (99m)Tc-HDP SPECT/CT, (18)F-NaF PET/CT, and wbMRI+DWI were 62%, 74%, 85%, 93%, and 91%, respectively. The number of equivocal findings for (99m)Tc-HDP BS, (99m)Tc-HDP SPECT, (99m)Tc-HDP SPECT/CT, (18)F-NaF PET/CT and wbMRI+DWI was 50, 44, 5, 6, and 4, respectively.

Conclusion: wbMRI+DWI showed similar diagnostic accuracy to (18)F-NaF PET/CT and outperformed (99m)Tc-HDP SPECT/CT, and (99m)Tc-HDP BS.
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December 2016

In vivo imaging of prostate cancer using [68Ga]-labeled bombesin analog BAY86-7548.

Clin Cancer Res 2013 Oct 9;19(19):5434-43. Epub 2013 Aug 9.

Authors' Affiliations: Department of Surgery, Division of Urology, Departments of Clinical Physiology and Nuclear Medicine, Oncology and Radiotherapy, and Pathology, Turku University Hospital; Turku PET Centre; Department of Diagnostic Radiology, University of Turku, Turku, Finland; Departments of Medical Oncology and Nuclear Medicine, University Hospital of Zurich; Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland; Bayer Pharma AG, Berlin, Germany.

Purpose: A novel [(68)Ga]-labeled DOTA-4-amino-1-carboxymethyl-piperidine-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 peptide (BAY86-7548) having high affinity to bombesin receptor subtype II to detect primary and metastatic prostate carcinoma using positron emission tomography/computed tomography (PET/CT) was synthesized and evaluated for prostate cancer.

Experimental Design: In this first human study with BAY86-7548, 14 men scheduled for radical prostatectomy (n = 11) or with biochemical recurrence after surgery or hormonal therapy (n = 3) were enrolled. The patients received an intravenous injection of BAY86-7548 followed by over 60-minute dynamic imaging of prostate gland (n = 10) and/or subsequent whole-body imaging (n = 14). The visual assessment of PET/CT images included evaluation of intraprostatic (12 subsextants) and pelvic nodal uptake of BAY86-7548 in 11 surgical patients and detection of potential metastatic foci in all patients. In patients with biochemical recurrence, results were compared with those of either [(11)C]-acetate (n = 2) or [(18)F]-fluoromethylcholine (n = 1) PET/CT.

Results: We found a sensitivity, specificity, and accuracy of 88%, 81% and 83%, respectively, for detection of primary PCa and sensitivity of 70% for metastatic lymph nodes using histology as gold standard. BAY86-7548 correctly detected local recurrence in prostate bed and showed nodal relapse in accordance with [(11)C]-acetate PET/CT in 2 patients with biochemical relapse. In the third hormone refractory patient, BAY86-7548 failed to show multiple bone metastases evident on [(18)F]-fluoromethylcholine PET/CT.

Conclusion: BAY86-7548 PET/CT is a promising molecular imaging technique for detecting intraprostatic prostate cancer.
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October 2013