Publications by authors named "Michael Dohopolski"

14 Publications

  • Page 1 of 1

Radiation Therapy in Non-Small-Cell Lung Cancer.

Cold Spring Harb Perspect Med 2021 Jun 14. Epub 2021 Jun 14.

Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas, USA.

The management of non-small-cell lung cancer (NSCLC) varies according to stage. Surgical resection is reserved for operable patients with early-stage NSCLC, while high-dose target radiation-stereotactic body radiation therapy (SBRT)-is reserved for patients whose comorbidities prohibit them from a major surgical procedure. The treatment of locally advanced NSCLC (LA-NSCLC) is stratified according to resectability. Those with resectable disease may require additional treatments such as chemotherapy and radiation, while patients with unresectable disease will require definitive chemoradiation therapy with adjuvant durvalumab. Patients with limited metastatic disease benefit from the combination of SBRT and systemic therapy.
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http://dx.doi.org/10.1101/cshperspect.a037713DOI Listing
June 2021

A deep learning-based framework for segmenting invisible clinical target volumes with estimated uncertainties for post-operative prostate cancer radiotherapy.

Med Image Anal 2021 Aug 17;72:102101. Epub 2021 May 17.

Medical Artificial Intelligence and Automation Laboratory and Department of Radiation Oncology,University of Texas Southwestern Medical Center, Dallas, Texas, United States. Electronic address:

In post-operative radiotherapy for prostate cancer, precisely contouring the clinical target volume (CTV) to be irradiated is challenging, because the cancerous prostate gland has been surgically removed, so the CTV encompasses the microscopic spread of tumor cells, which cannot be visualized in clinical images like computed tomography or magnetic resonance imaging. In current clinical practice, physicians' segment CTVs manually based on their relationship with nearby organs and other clinical information, but this allows large inter-physician variability. Automating post-operative prostate CTV segmentation with traditional image segmentation methods has yielded suboptimal results. We propose using deep learning to accurately segment post-operative prostate CTVs. The model proposed is trained using labels that were clinically approved and used for patient treatment. To segment the CTV, we segment nearby organs first, then use their relationship with the CTV to assist CTV segmentation. To ease the encoding of distance-based features, which are important for learning both the CTV contours' overlap with the surrounding OARs and the distance from their borders, we add distance prediction as an auxiliary task to the CTV network. To make the DL model practical for clinical use, we use Monte Carlo dropout (MCDO) to estimate model uncertainty. Using MCDO, we estimate and visualize the 95% upper and lower confidence bounds for each prediction which informs the physicians of areas that might require correction. The model proposed achieves an average Dice similarity coefficient (DSC) of 0.87 on a holdout test dataset, much better than established methods, such as atlas-based methods (DSC<0.7). The predicted contours agree with physician contours better than medical resident contours do. A reader study showed that the clinical acceptability of the automatically segmented CTV contours is equal to that of approved clinical contours manually drawn by physicians. Our deep learning model can accurately segment CTVs with the help of surrounding organ masks. Because the DL framework can outperform residents, it can be implemented practically in a clinical workflow to generate initial CTV contours or to guide residents in generating these contours for physicians to review and revise. Providing physicians with the 95% confidence bounds could streamline the review process for an efficient clinical workflow as this would enable physicians to concentrate their inspecting and editing efforts on the large uncertain areas.
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http://dx.doi.org/10.1016/j.media.2021.102101DOI Listing
August 2021

Future Directions in the Use of SAbR for the Treatment of Oligometastatic Cancers.

Semin Radiat Oncol 2021 Jul;31(3):253-262

Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX; Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, WI. Electronic address:

The role of local therapy as a sole therapy or part of a combined approach in treating metastatic cancer continues to evolve. The most obvious requirements for prudent implementation of local therapies like stereotactic ablative radiotherapy (SAbR) to become mainstream in treating oligometastases are (1) Clear guidance as to what particular patients might benefit, and (2) Confirmation of improvements in outcome after such treatments via clinical trials. These future directional requirements are non-negotiable. However, innovation and research offer many more opportunities to understand and improve therapy. Identifying candidates and personalizing their therapy can be afforded via proteomic, genomic and epigenomic characterization techniques. Such molecular profiling along with liquid biopsy opportunities will both help select best therapies and facilitate ongoing monitoring of response. Technologies both to find targets and help deliver less-toxic therapy continue to improve and will be available in the marketplace. These technologies include molecular-based imaging (eg, PET-PSMA), FLASH ultra-high dose rate platforms, Grid therapy, PULSAR adaptive dosing, and MRI/PET guided linear accelerators. Importantly, a treatment approach beyond oligometastastic could evolve including a rationale for using SAbR in the oligoprogressive, oligononresponsive, oligobulky and oligolethal settings as well as expansion beyond oligo- toward even plurimetastastic disease. In any case, lessons learned and experiences required by the implementation of using SAbR in oligometastatic cancer will be revisited.
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http://dx.doi.org/10.1016/j.semradonc.2021.03.004DOI Listing
July 2021

Oligometastatic non-small cell lung cancer: a narrative review of stereotactic ablative radiotherapy.

Ann Palliat Med 2021 May 23;10(5):5944-5953. Epub 2021 Feb 23.

Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA.

Non-small cell lung cancer (NSCLC) is the most common and deadly malignancy in the United States. A significant portion of these individuals can present with or later develop metastatic NSCLC (mNSCLC). These patients typically do not survive more than two to three years after diagnosis despite the use of systemic therapies; however, there are individuals with low burden mNSCLC (oligometastatic disease) who can potentially be cured with the use of aggressive local therapies-such as stereotactic ablative radiotherapy (SAbR)-in conjunction with or without systemic therapy. Oligometastatic disease represents an intermediate state prior to the development of widespread metastases. SAbR has been shown to be an effective modality for treating patients with oligometastatic NSCLC. The combination of immunotherapy and SAbR likely represents one of the most effective while still tolerable therapies in this patient population. There are other subtypes of oligometastatic disease, including oligoprogressive disease which are amenable to SAbR. The current literature supports the use of SAbR in this population to increase the time of a patient's current systemic therapy; however, there are prospective studies evaluating the efficacy of treatment on progression free survival (PFS).
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http://dx.doi.org/10.21037/apm-20-1409DOI Listing
May 2021

Attention Guided Lymph Node Malignancy Prediction in Head and Neck Cancer.

Int J Radiat Oncol Biol Phys 2021 Jul 6;110(4):1171-1179. Epub 2021 Feb 6.

Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas. Electronic address:

Purpose: Accurate lymph node (LN) malignancy classification is essential for treatment target identification in head and neck cancer (HNC) radiation therapy. Given the constraints imposed by relatively small sample sizes in real-world medical applications, to classify LN malignancy status accurately, we proposed an attention-guided classification (AGC) scheme that (1) incorporates human knowledge (ie, LN contours) into model training to guide model's "learning" direction, alleviating the critical requirement of large training samples by deep learning approaches; and (2) does not require accurate delineation of LNs in the inference stage but can highlight the discriminative region nearby the LN, which is important for malignancy determination.

Methods And Materials: In the proposed AGC scheme, there is an attention-guided convolutional neural network (agCNN) module, followed by a classification convolutional neural network (cCNN) module. The input of the proposed AGC scheme is a region of interest (ROI) containing the LN and its surrounding tissues. The agCNN is designed to find the discriminative region in the ROI, which outputs an activation map whose voxel values indicate the importance of the voxels in malignancy prediction. Through multiplying the activation map with the ROI, we obtain the input for the cCNN, which finally outputs the LN malignancy probability. To demonstrate the effectiveness of the proposed scheme, we performed experimental studies using positron emission tomography and contrast-enhanced computed tomography from 129 surgical HNC patients, including 791 LNs, with pathologic ground truth of malignancy status. To evaluate the performance, 5-folder cross validation was used.

Results: The sensitivity, specificity, accuracy, and area under the receiver operating characteristic (ROC) curve values obtained by the proposed AGC scheme were 0.91, 0.93, 0.92, and 0.98, respectively, significantly outperforming conventional convolutional neural network and radiomics approaches at a significance level of .05 under a paired ROC comparison statistical test.

Conclusions: We developed an AGC scheme that can highlight the discriminative region in an image for LN malignancy prediction, outperforming a conventional radiomics method that requires accurate segmentation and a standard convolutional neural network model without involving segmentation.
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http://dx.doi.org/10.1016/j.ijrobp.2021.02.004DOI Listing
July 2021

Predicting lymph node metastasis in patients with oropharyngeal cancer by using a convolutional neural network with associated epistemic and aleatoric uncertainty.

Phys Med Biol 2020 11 12;65(22):225002. Epub 2020 Nov 12.

Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, United States of America.

There can be significant uncertainty when identifying cervical lymph node (LN) metastases in patients with oropharyngeal squamous cell carcinoma (OPSCC) despite the use of modern imaging modalities such as positron emission tomography (PET) and computed tomography (CT) scans. Grossly involved LNs are readily identifiable during routine imaging, but smaller and less PET-avid LNs are harder to classify. We trained a convolutional neural network (CNN) to detect malignant LNs in patients with OPSCC and used quantitative measures of uncertainty to identify the most reliable predictions. Our dataset consisted of images of 791 LNs from 129 patients with OPSCC who had preoperative PET/CT imaging and detailed pathological reports after neck dissections. These LNs were segmented on PET/CT imaging and then labeled according to the pathology reports. An AlexNet-like CNN was trained to classify LNs as malignant or benign. We estimated epistemic and aleatoric uncertainty by using dropout variational inference and test-time augmentation, respectively. CNN performance was stratified according to the median epistemic and aleatoric uncertainty values calculated using the validation cohort. Our model achieved an area under the receiver operating characteristic (ROC) curve (AUC) of 0.99 on the testing dataset. Sensitivity and specificity were 0.94 and 0.90, respectively. Epistemic and aleatoric uncertainty values were statistically larger for false negative and false positive predictions than for true negative and true positive predictions (p < 0.001). Model sensitivity and specificity were 1.0 and 0.98, respectively, for cases with epistemic uncertainty lower than the median value of the incorrect predictions in the validation dataset. For cases with higher epistemic uncertainty, sensitivity and specificity were 0.67 and 0.41, respectively. Model sensitivity and specificity were 1.0 and 0.98, respectively, for cases with aleatoric uncertainty lower than the median value of the incorrect predictions in the validation dataset. For cases with higher aleatoric uncertainty, sensitivity and specificity were 0.67 and 0.37, respectively. We used a CNN to predict the malignant status of LNs in patients with OPSCC with high accuracy, and we showed that uncertainty can be used to quantify a prediction's reliability. Assigning measures of uncertainty to predictions could improve the accuracy of LN classification by efficiently identifying instances where expert evaluation is needed to corroborate a model's prediction.
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http://dx.doi.org/10.1088/1361-6560/abb71cDOI Listing
November 2020

The Reintroduction of Radiotherapy Into the Integrated Management of Kidney Cancer.

Cancer J 2020 Sep/Oct;26(5):448-459

From the Departments of Radiation Oncology.

The incidence of renal cell carcinoma (RCC) has been increasing, with a moderate subgroup of individuals who later develop metastatic disease. Historically, metastatic RCC has been managed with systemic therapy because RCC was believed to be radioresistant. Local therapies, such as stereotactic body radiation therapy, also known as stereotactic ablative radiotherapy, which utilize focused high-dose-rate radiation delivered over a limited number of treatments, have been successful in controlling local disease and, in some cases, extending survival in patients with intracranial and extracranial metastatic RCC. Stereotactic ablative radiotherapy is highly effective in treating intact disease when patients are not surgical candidates. Stereotactic ablative radiotherapy is well tolerated when used in conjunction with systemic therapy such as tyrosine kinase inhibitors and immune checkpoint inhibitors. These successes have prompted investigators to evaluate the efficacy of stereotactic body radiation therapy in novel settings such as neoadjuvant treatment of advanced RCC with tumor thrombus and oligometastatic/oligoprogressive disease states.
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http://dx.doi.org/10.1097/PPO.0000000000000475DOI Listing
September 2020

The Prognostic Significance of p16 Status in Patients With Vulvar Cancer Treated With Vulvectomy and Adjuvant Radiation.

Int J Radiat Oncol Biol Phys 2019 01 16;103(1):152-160. Epub 2018 Aug 16.

Department of Radiation Oncology, University of Pittsburgh Hillman Cancer Center, Pittsburgh, Pennsylvania. Electronic address:

Purpose: Vulvar squamous cell carcinoma (VSCC) is a relatively rare malignancy. Human papillomavirus has been implicated as a causative factor for a subset of these patients. The purpose of this study was to evaluate whether p16-positivity (a human papillomavirus surrogate) predicts for better response rates in women who undergo surgery followed by adjuvant radiation therapy (RT).

Methods And Materials: We retrospectively analyzed data from women with VSCC who were treated with adjuvant RT. p16-Positivity was defined as diffuse strong immunoreactivity within the tumor. Time to event outcomes was performed with Kaplan-Meier and cumulative incidence methodologies.

Results: Thirty-nine women were identified. Ten had positive results for p16 (p16+), and 29 had negative results (p16-). The median follow-up was 25.7 months. The median age at diagnosis was 59 years for women with p16+ tumors and 74 years for women with p16- tumors (P = .022). The distribution of stage did not differ by p16 status. The indications for adjuvant RT were close/positive margins in 19 women, positive nodes in 9 women, and both in 11 women. There were 21 recurrences: 15 vulvar, 3 isolated nodal, 2 synchronous vulvar/nodal, and 1 distant metastasis. In-field relapse rates at 3 years were lower in p16+ patients (32.5%) than in p16- patients (59.1%, P = .072). This trend was also observed in progression-free survival (P = .062). A p16+ status and a lower International Federation of Gynecology and Obstetrics stage were associated with fewer in-field relapses and improved progression-free survival in multivariable analyses. The p16 status was not a predictor of overall survival.

Conclusions: p16-Positivity appears to be a prognostic factor for in-field relapse rates in patients with VSCC appropriately treated with adjuvant RT.
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http://dx.doi.org/10.1016/j.ijrobp.2018.08.014DOI Listing
January 2019

Thoracic reirradiation with SBRT for residual/recurrent and new primary NSCLC within or immediately adjacent to a prior high-dose radiation field.

Pract Radiat Oncol 2018 May - Jun;8(3):e117-e123. Epub 2017 Dec 8.

Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania. Electronic address:

Purpose: Local failure following concurrent chemoradiation and in-lobe failures following stereotactic body radiation therapy (SBRT) are common. We evaluated our institutional experience using SBRT as salvage in this setting.

Methods And Materials: Seventy-two patients were reirradiated with SBRT for residual, locally recurrent, or new primary non-small cell lung cancer within or adjacent to a high-dose external beam radiation therapy or SBRT field. Kaplan-Meier analysis with log-rank test were used to estimate endpoints and differentiate cohorts.

Results: Median follow-up was 17.9 months. Patients had residual or recurrent disease (54.2%); 45.8% had new lung primaries. Median reirradiated T size was 2.5 cm (range, 0.8-7.8 cm). Median pre-retreatment maximum standardized uptake value (SUV) was 7.15 (range, 1.2-37.6). The most common SBRT reirradiation regimen was 48 Gy in 4 fractions (range, 17-60 Gy in 1-5 fractions). Median progression-free survival was 15.2 months, and median overall survival was 20.8 months. Two-year local failure was 21.6%. Patients with SUV at reirradiation <7.0 had a 2-year local control of 93.1% versus 61.1% above the median (P < .001). The 2-year rate of distant metastases was 10.4% versus 54.1% in patients treated for a new primary versus residual or recurrent disease (P < .001). Median progression-free survival was 31.9 months versus 8.4 months, respectively (P = .037). Median survival of patients treated for new primary was 25.2 months versus 16.2 months with residual or recurrent disease (P = .049), and median survival for patients with reirradiation SUV below the median was 42.0 months versus 9.8 months above the median (P < .001). Acute any-grade toxicity was seen in 29.2% of patients, acute grade 3 toxicity in 11.1%, and late grade 3 toxicity in 1.4% with no treatment-related deaths.

Conclusions: SBRT appears to be a safe and effective means of salvaging recurrent, residual, or new primary NSCLC in or adjacent to a previous high-dose radiation field.
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http://dx.doi.org/10.1016/j.prro.2017.11.011DOI Listing
September 2018

Stereotactic Body Radiation Therapy for Pulmonary Oligometastases Arising from Non-lung Primaries in Patients Without Extrapulmonary Disease.

Cureus 2018 Feb 7;10(2):e2167. Epub 2018 Feb 7.

Department of Radiation Oncology, University of Pittsburgh Cancer Institute, UPMC.

Purpose Stereotactic body radiation therapy (SBRT) is increasingly used in the management of patients with oligometastatic cancers and is under prospective evaluation by the Radiation Therapy Oncology Group (RTOG). Here we report outcomes from a high-volume institution of patients treated with SBRT for pulmonary oligometastases. Materials and methods We conducted a retrospective review of 105 patients who had one to five pulmonary oligometastases (185 lesions) without extrapulmonary disease treated with SBRT from 2002-2014. Target failure-free survival (TFFS), progression-free survival (PFS), and overall survival (OS) were calculated. Univariate and multivariate Cox regression analyses were performed on factors predictive of outcomes. Results The median age at first SBRT was 68 years and the median follow-up was 29.5 months. The median time from initial diagnosis of primary to SBRT was 42.7 months; 14.3% had synchronous oligometastases and 76.7% had one to two pulmonary lesions at first SBRT. The distribution of primaries was as follows: 36.2% colorectal, 16.2% head/neck, 9.5% genitourinary, 9.5% sarcoma, 7.6% gynecologic, 6.7% other, 5.7% breast, 5% melanoma, and 4% esophageal. The median lesion size was 1.6 cm and the most common regimen was 60 Gy in three fractions (range: 12-60 Gy in one to five fractions). TFFS was 94.4% and 90.8% at two and three years, respectively. Two and three year OS were 87.9% and 60.2%, respectively. Median PFS and OS were 16.2 and 45.3 months, respectively. In multivariate analysis, age at primary cancer diagnosis and biologically effective dose with an alpha-beta ratio of 10 (BED10) were identified as factors significantly affecting OS (p<0.05). Conclusions Comprehensive treatment of pulmonary oligometastases with SBRT in the absence of extrapulmonary disease results in excellent target control and modest survival outcomes.
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http://dx.doi.org/10.7759/cureus.2167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5889151PMC
February 2018

Single-institutional outcomes of adjuvant brachytherapy for Stage I endometrial cancer-Are outcomes consistent with randomized studies?

Brachytherapy 2018 May - Jun;17(3):564-570. Epub 2018 Feb 14.

Department of Radiation Oncology, University of Pittsburgh Hillman Cancer Center, Pittsburgh, PA. Electronic address:

Purpose: Vaginal brachytherapy (VBT) alone has been shown to be a viable adjuvant treatment strategy for most patients with Stage I endometrioid endometrial cancer. We sought to examine our institutional data following practice pattern changes resulting from the publications of GOG-99 and PORTEC-2.

Methods And Materials: We retrospectively analyzed women who underwent adjuvant VBT after surgical staging for Stage 1 endometrioid endometrial cancer at our institution from 2007 to 2014.

Results: We identified 297 women. Median time to last followup or death was 52.3 months (interquartile range: 32.3-72.3 months). By International Federation of Gynecology and Obstetrics 2009 staging, 162 patients (54.5%) had Stage IA and 128 (43.1%) had Stage IB disease. Ninety-nine (33.3%) patients had Grade 1, 153 (51.5%) had Grade 2, and 45 (15.2%) had Grade 3 disease. According to GOG-249 and PORTEC-2 criteria, 167 (56.2%) and 127 (42.7%) patients were with high-intermediate-risk disease. Two women had Stage IB Grade 3 disease. The most common high-dose-rate-VBT regimen was 2100 cGy/three fractions to a depth of 5 mm. Four (two acute and two late) (1.3%) Grade 3 genitourinary toxicities were reported: three episodes of vaginal dehiscence (after second course of VBT, 2 months after completion of VBT, and 1 year after completion of VBT) and one episode of radiation necrosis. Twenty-one (7%) women recurred: three recurred in the vagina, two recurred in the pelvic lymph nodes, and 16 recurred distantly.

Conclusions: Outcomes appear consistent with published randomized data in women with high-intermediate-risk endometrial cancer who are treated with brachytherapy alone. Recurrence and complication rates were minimal.
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http://dx.doi.org/10.1016/j.brachy.2018.01.004DOI Listing
February 2019

Stereotactic body radiation therapy for isolated hilar and mediastinal non-small cell lung cancers.

Lung Cancer 2018 01 10;115:1-4. Epub 2017 Nov 10.

Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, United States.

Objectives: The seminal phase II trial for pulmonary stereotactic body radiation therapy (SBRT) suggested that SBRT to central lesions resulted in unacceptable toxicity. Alternative dose-fractionation schemes have been proposed which may improve safety without compromise of efficacy. We report our institutional outcomes of SBRT for hilar/mediastinal non-small cell lung cancer (NSCLC).

Materials And Methods: A retrospective review was conducted of patients with NSCLC in a hilar or mediastinal nodal station which was treated with SBRT. Patients presented with a lesion involving the hilum or mediastinum from primary or oligorecurrent NSCLC. Kaplan-Meier with log-rank testing and Cox analysis were utilized for outcomes analysis.

Results: From 2008-2015, 40 patients with median age of 70 were treated with SBRT for primary/oligorecurrent hilar/mediastinal NSCLC with median follow-up of 16.4 months. 85% presented with oligorecurrent disease at a median of 22.4 months following definitive therapy. The aortico-pulmonary window was the target in 40%, the hilum in 25%, lower paratracheal in 20%, subcarinal in 10%, and prevascular in 5%. The median dose was 48Gy in 4 fractions (range: 35-48Gy in 4-5 fractions). Median overall (OS) and progression-free (PFS) survivals were 22.7 and 13.1 months, respectively. Two-year local control was 87.7% and not significantly different between hilar and mediastinal targets. Median PFS was significantly improved in patients with hilar vs mediastinal nodal targets: 33.3 vs 8.4 months, respectively (p=0.031). OS was not statistically different between hilar and mediastinal targets (p=0.359). On multivariable analysis, hilar vs mediastinal target predicted for PFS (HR 3.045 95%CI [1.044-8.833], p=0.042), as did shorter time to presentation in patients with oligorecurrence (HR 0.983 [95%CI 0.967-1.000], p=0.049). Acute grade 3+ morbidity was seen in 3 patients (hemoptysis, pericardial/pleural effusion, heart failure) and late grade 3+ morbidity (hemoptysis) in 1 patient.

Conclusion: Hilar/mediastinal SBRT appears to be a safe technique for the local control of isolated nodal disease with limited toxicity from the fractionation schemes utilized.
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http://dx.doi.org/10.1016/j.lungcan.2017.10.014DOI Listing
January 2018

Stereotactic body radiotherapy for locally-advanced unresectable pancreatic cancer-patterns of care and overall survival.

J Gastrointest Oncol 2017 Oct;8(5):766-777

Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.

Background: Unresectable pancreatic cancer remains a challenging disease to treat. Stereotactic body radiotherapy (SBRT) allows for a higher biologically equivalent dose in an abbreviated course more convenient for patients and the integration of systemic therapy. We sought to investigate utilization trends and survival outcomes for patients treated with pancreatic SBRT versus conventionally fractionated radiotherapy (CFRT).

Methods: We engaged the National Cancer Database (NCDB) from 1998-2012 and identified locally-advanced unresectable patients with histologically confirmed, non-metastatic, pancreatic adenocarcinoma who received radiotherapy. Patients who received CFRT (1.5-4.0 Gy per fraction to a dose of ≥45 Gy, n=11,879) were compared to those who received SBRT (6-15 Gy per fraction to a dose of ≥20 Gy, n=474).

Results: Median follow-up was 11.0 months (18.4 months for survivors). SBRT utilization increased from 0.2% to 7.4% from 1998 to 2012 (P<0.05). On multivariable analysis, factors predictive for preferential utilization of SBRT over CFRT were later year of diagnosis, age ≥75 years, increased facility volume, and no chemotherapy in the initial treatment plan. Unadjusted median survival was 11.2 months for CFRT . 12.6 months for SBRT (P=0.002). Results were consistent in the propensity matched model. Variables predictive for improved survival on multivariable analysis were diagnosis after 2010, younger age, lower comorbidity score, tumor size <3 cm, nodal stage zero, and receipt of chemotherapy (P<0.05).

Conclusions: SBRT utilization has increased significantly and is associated with a small absolute improvement in overall survival (OS) compared to CFRT. The decreased treatment time, without apparent compromise in survival, makes SBRT an attractive option for patients with unresectable pancreatic cancer warranting further research.
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http://dx.doi.org/10.21037/jgo.2017.08.04DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5674248PMC
October 2017

Glioblastoma multiforme (GBM) in the elderly: initial treatment strategy and overall survival.

J Neurooncol 2017 Aug 19;134(1):107-118. Epub 2017 May 19.

Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.

The EORTC trial which solidified the role of external beam radiotherapy (EBRT) plus temozolomide (TMZ) in the management of GBM excluded patients over age 70. Randomized studies of elderly patients showed that hypofractionated EBRT (HFRT) alone or TMZ alone was at least equivalent to conventionally fractionated EBRT (CFRT) alone. We sought to investigate the practice patterns and survival in elderly patients with GBM. We identified patients age 65-90 in the National Cancer Data Base (NCDB) with histologically confirmed GBM from 1998 to 2012 and known chemotherapy and radiotherapy status. We analyzed factors predicting treatment with EBRT alone vs. EBRT plus concurrent single-agent chemotherapy (CRT) using multivariable logistic regression. Similarly, within the EBRT alone cohort we compared CFRT (54-65 Gy at 1.7-2.1 Gy/fraction) to HFRT (34-60 Gy at 2.5-5 Gy/fraction). Multivariable Cox proportional hazards model (MVA) with propensity score adjustment was used to compare survival. A total of 38,862 patients were included. Initial treatments for 1998 versus 2012 were: EBRT alone = 50 versus 10%; CRT = 6 versus 50%; chemo alone = 1.6% (70% single-agent) versus 3.2% (94% single-agent). Among EBRT alone patients, use of HFRT (compared to CFRT) increased from 13 to 41%. Numerous factors predictive for utilization of CRT over EBRT alone and for HFRT over CFRT were identified. Median survival and 1-year overall survival were higher in the CRT versus EBRT alone group at 8.6 months vs. 5.1 months and 36.0 versus 15.7% (p < 0.0005 by log-rank, multivariable HR 0.65 [95% CI = 0.61-0.68, p < 0.0005], multivariable HR with propensity adjustment 0.66 [95% CI = 0.63-0.70, p < 0.0005]). For elderly GBM patients in the United States, CRT is the most common initial treatment and appears to offer a survival advantage over EBRT alone. Adoption of hypofractionation has increased over time but continues to be low.
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http://dx.doi.org/10.1007/s11060-017-2493-xDOI Listing
August 2017
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