A pancreatic cancer risk prediction model (Prism) developed and validated on large-scale US clinical data

BACKGROUND

Pancreatic Duct Adenocarcinoma (PDAC) screening can enable early-stage disease detection and long-term survival. Current guidelines use inherited predisposition, with about 10% of PDAC cases eligible for screening. Using Electronic Health Record (EHR) data from a multi-institutional federated network, we developed and validated a PDAC RISk Model (Prism) for the general US population to extend early PDAC detection.

METHODS

Neural Network (PrismNN) and Logistic Regression (PrismLR) were developed using EHR data from 55 US Health Care Organisations (HCOs) to predict PDAC risk 6-18 months before diagnosis for patients 40 years or older. Model performance was assessed using Area Under the Curve (AUC) and calibration plots. Models were internal-externally validated by geographic location, race, and time. Simulated model deployment evaluated Standardised Incidence Ratio (SIR) and other metrics.

FINDINGS

With 35,387 PDAC cases, 1,500,081 controls, and 87 features per patient, PrismNN obtained a test AUC of 0.826 (95% CI: 0.824-0.828) (PrismLR: 0.800 (95% CI: 0.798-0.802)). PrismNN's average internal-external validation AUCs were 0.740 for locations, 0.828 for races, and 0.789 (95% CI: 0.762-0.816) for time. At SIR = 5.10 (exceeding the current screening inclusion threshold) in simulated model deployment, PrismNN sensitivity was 35.9% (specificity 95.3%).

INTERPRETATION

Prism models demonstrated good accuracy and generalizability across diverse populations. PrismNN could find 3.5 times more cases at comparable risk than current screening guidelines. The small number of features provided a basis for model interpretation. Integration with the federated network provided data from a large, heterogeneous patient population and a pathway to future clinical deployment.

FUNDING

Prevent Cancer Foundation, TriNetX, Boeing, DARPA, NSF, and Aarno Labs.

Risk Factors Predicting Relapse 10 Years Following Extreme Dose-Escalated SBRT for Intermediate-Risk Prostate Cancer: Is De-Intensification Feasible in Unfavorable Subgroups?

PURPOSE/OBJECTIVE(S)

Adding short-term androgen-deprivation therapy (ADT) to radiotherapy is recommended in unfavorable intermediate-risk (UIR) prostate cancer (PCa). Data supporting the addition of ADT to stereotactic body radiotherapy (SBRT) in intermediate-risk (IR) patients are limited. Given ADT has well-documented toxicities, we sought to identify the UIR prognostic factors that predict for relapse following SBRT without ADT. We combined results from two mature multicenter trials to determine if extreme dose-escalated SBRT yielded UIR subgroups in which the omission of ADT may be considered.

MATERIALS/METHODS

Between 2008 and 2011, two prospective national trials enlisted 39 centers to enroll 285 patients with IR PCa: 182 had Memorial Sloan Kettering (MSK) favorable intermediate-risk (FIR) and 103 had MSK UIF PCa. All were treated with a non-coplanar robotic SBRT platform using real-time tracking of implanted fiducials. Two dose regimens were used: 40Gy in 5 fractions of 8Gy, and 38Gy in 4 fractions of 9.5Gy. ADT was not allowed. Univariate and multivariate analyses using a Cox proportional hazards model was performed for relapse free survival (RFS): relapse included pathologic or radiographic failure, initiation of salvage or systemic therapy, or biochemical relapse by the nadir + 2 definition. Insufficient events prevented similar analyses for local control, metastasis-free and PCa-specific survival. Examined risk factors included dose regimen, clinical T-stage, Gleason score, pre-treatment PSA, % positive biopsy cores, and number of unfavorable risk factors (URFs). All reported rates are actuarial, using Kaplan-Meier method.

RESULTS

Median follow-up was 8.1 years. 71 patients were followed 10 years. There were no statistically significant differences in rates of toxicity, local failure, RFS, overall nor metastasis-free survival between the two dose regimens. For the entire group, 10-year overall survival was 82.9%, RFS was 83.2%, and the local failure rate was 3.6%. On univariate analysis, primary Gleason pattern 4 (PGP4) and >2 URFs predicted for RFS. On multivariate analysis, only PGP4 (hazard ratio: 3.71, p = 0.0053) was statistically significant. Examining the UIR subgroup, the only predictor for RFS was PGP4 (HR: 3.64, p = 0.0253). 10-year RFS was 88.4% for FIR and 89.1% for UIR without PGP4; this fell to 58.5% in patients with a PGP4.

CONCLUSION

Following dose-escalated SBRT monotherapy, 10-year RFS rates were favorable in UIR patients without PGP4. Extreme dose escalation appeared to effectively address UIR factors correlating with tumor bulk (i.e., CS T2b, >50% cores+, PSA 10-20), but was less effective with biologically aggressive pathology (PGP4). A randomized trial, ideally including genomic classification, would be necessary to determine if dose-escalated SBRT allows de-intensification (omission of ADT) in such biologically less aggressive UIR subgroups. The high relapse rate observed in UIR patients with PGP4 affirms the need for adjuvant ADT in this subgroup.

Transient Radiographic Pseudoprogression Following Fractionated SBRT for Primary Renal Cell Carcinoma

PURPOSE/OBJECTIVE(S)

SBRT is an emerging treatment for patients with RCC who are not surgical candidates. Pooled analysis of an international consortium suggests promising short term local control. In the event of local failure, other ablative methods may be used to salvage these patients. Trends in radiographic surveillance are not well characterized post SBRT. In this study we observe a common transient increase in the tumor size followed by stability or decline in patients treated with fractionated SBRT on a phase II clinical protocol.

MATERIALS/METHODS

Radiographic studies of patients enrolled in a phase II clinical trial were reviewed for this report. Primary RCC tumors were treated using SBRT with two fractionation schema (48 Gy in 3 or 4 fractions) based on a 5 cm size threshold. Patients were followed with routine imaging per protocol at 3, 6, 12, 18, and 24 months post-treatment. Percent change in greatest dimension is analyzed over time and subsequently stratified by dose, baseline tumor diameter, and PTV. An increase in tumor size by 10% or greater followed by tumor shrinkage or stability was considered a transient increase.

RESULTS

From August of 2013 to December of 2022, 40 patients were enrolled in this trial with a median age of 77.5 and follow up of 18 months. 32 patients with at least two follow up images (minimum of 6 months post-SBRT) were included in the analysis. 26 of these patients were treated with 48 Gy in 3 fractions and 6 were treated with 48 Gy in 3 fractions. Median tumor size was 38.4 cc with a median diameter of 3.5 cm. 46.9% of patients experienced a transient increase with a median increase of 19.7% (range = 63.1, IQR = 13.9%-38.6%) of the pretreatment largest dimension. 66.7% of patients with tumors ≥ 5 cm experienced a transient increase vs. 42.3% of patients with tumors < 5cm. 56.3% of patients with PTV ≥ 38.4 cc experienced a transient increase vs. 40% of patients with a PTV < 38.4cc. Patients with PTV < 38.4 cc experienced a median 19% increase compared with the PTV ≥ 38.4 cc median increase of 37.5%. Most common transient increase was observed at 3 months post treatment. Of patients evaluated with CT scans, 50% experienced a transient increase, compared with 37.5% of those evaluated with MRI scans.

CONCLUSION

SBRT is a promising treatment for primary RCC, however radiographic surveillance of the disease post-treatment is not well characterized. In this study of patients enrolled in a Phase II protocol, there appears to be a transient radiographic increase in the size of primary tumors followed by stability and decline. Further investigations will guide the timing and need for salvage treatment for post- SBRT RCC.

5-Year Renal Function Outcomes after SABR for Primary Renal Cell Carcinoma: A Report from the International Radiosurgery Oncology Consortium of the Kidney (IROCK)

PURPOSE/OBJECTIVE(S)

Renal cell carcinoma (RCC) presents uncommonly in patients with a congenital solitary kidney or prior contralateral nephrectomy. The objective of this study was to compare renal function outcomes of stereotactic ablative body radiotherapy (SABR) in patients with solitary vs. bilateral kidneys.

MATERIALS/METHODS

Patients with primary RCC with ≥2 years of follow-up at 12 participating International Radiosurgery Consortium for Kidney (IROCK) institutions were included. Patients with upper tract urothelial carcinoma or metastatic disease were excluded. Renal function was measured by estimated glomerular filtration rate (eGFR). For patients where eGFR was not recorded, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to estimate eGFR based on known creatinine. Baseline characteristics and renal function outcomes were compared between solitary vs. bilateral kidneys. Multivariable logistic regression was used to identify factors predictive of eGFR decline ≥ 15 mL/min and any eGFR increase evaluated at 1-year post-SABR.

RESULTS

One hundred and ninety patients with solitary (n = 56) or bilateral kidneys (n = 134) underwent SABR and were followed for a median of 5.0 years (IQR: 3.4-6.8). Pre-SABR eGFR (mean ± SD) was similar in patients with solitary (61.1 ± 23.2 mL/min) vs. bilateral kidneys (58.0 ± 22.3 mL/min, p = 0.324). Mean tumor size was 3.70 ± 1.40 cm in solitary and 4.35 ± 2.50 cm in bilateral kidneys (p = 0.026). After SABR, an initial compensatory increase in eGFR was observed in both cohorts (22.7% solitary and 17.7% bilateral at 1 year). This compensatory increase persisted in patients with bilateral but not a solitary kidney (10.3% vs. 0% at 3-years and 21.1% vs. 0% at 5-years, respectively). At 5-years post-SABR, eGFR decreased by -14.5 ± 7.6 in solitary and -13.3 ± 15.9 mL/min in bilateral kidneys (p = 0.665). At all timepoints assessed, there were no significant differences in eGFR decline between solitary vs. bilateral cohorts (all p > 0.05). There were also no significant differences in post-SABR end-stage renal disease (7.1% vs. 6.7%) or dialysis (3.6% vs. 3.7%) in solitary vs. bilateral, respectively. Multivariable analysis demonstrated that increasing tumor size (OR per 1 cm: 1.57; 95% CI: 1.14-2.16, p = 0.006) and baseline eGFR (OR per 10 mL/min: 1.30; 95% CI: 1.02-1.66, p = 0.034) was more likely to be associated with eGFR decline ≥ 15 mL/min. There was no significant association between solitary vs. bilateral kidney and eGFR decline (OR: 1.22; 95% CI: 0.45-3.34, p = 0.693).

CONCLUSION

There was no observed difference between renal function outcomes in patients with a solitary vs. bilateral kidneys. While larger tumor size may increase the risk of eGFR decline post-SABR, treatment of a solitary kidney does not appear to increase the risk of renal dysfunction long-term.

Five-Year Patient-Reported Outcomes in NRG Oncology RTOG 0938, Evaluating Two Ultrahypofractionated Regimens for Prostate Cancer

PURPOSE

There is considerable interest in very short (ultrahypofractionated) radiation therapy regimens to treat prostate cancer based on potential radiobiological advantages, patient convenience, and resource allocation benefits. Our objective is to demonstrate that detectable changes in health-related quality of life measured by the bowel and urinary domains of the Expanded Prostate Cancer Index Composite (EPIC-50) were not substantially worse than baseline scores.

METHODS AND MATERIALS

NRG Oncology's RTOG 0938 is a nonblinded randomized phase 2 study of National Comprehensive Cancer Network low-risk prostate cancer in which each arm is compared with a historical control. Patients were randomized to 5 fractions (7.25 Gy in 2 week and a day [twice a week]) or 12 fractions (4.3Gy in 2.5 weeks [5 times a week]). Secondary objectives assessed patient-reported toxicity at 5 years using the EPIC. Chi-square tests were used to assess the proportion of patients with a deterioration from baseline of >5 points for bowel, >2 points for urinary, and >11 points for sexual score.

RESULTS

The study enrolled 127 patients to 5 fractions (121 eligible) and 128 patients to 12 fractions (125 eligible). The median follow-up for all patients at the time of analysis was 5.38 years. The 5-year frequency for >5 point change in bowel score were 38.4% (P = .27) and 23.4% (P = 0.98) for 5 and 12 fractions, respectively. The 5-year frequencies for >2 point change in urinary score were 46.6% (P = .15) and 36.4% (P = .70) for 5 and 12 fractions, respectively. For 5 fractions, 49.3% (P = .007) of patients had a drop in 5-year EPIC-50 sexual score of ≥11 points; for 12 fractions, 54% (P < .001) of patients had a drop in 5-year EPIC-50 sexual score of ≥11 points. Disease-free survival at 5 years is 89.6% (95% CI: 84.0-95.2) in the 5-fraction arm and 92.3% (95% CI: 87.4-97.1) in the 12-fraction arm. There was no late grade 4 or 5 treatment-related urinary or bowel toxicity.

CONCLUSIONS

This study confirms that, based on long-term changes in bowel and urinary domains and toxicity, the 5- and 12-fraction regimens are well tolerated. These ultrahypofractionated approaches need to be compared with current standard radiation therapy regimens.

5-year outcomes after stereotactic ablative body radiotherapy for primary renal cell carcinoma: an individual patient data meta-analysis from IROCK (the International Radiosurgery Consortium of the Kidney)

BACKGROUND

Stereotactic ablative body radiotherapy (SABR) is a non-invasive treatment option for primary renal cell carcinoma, for which long-term data are awaited. The primary aim of this study was to report on long-term efficacy and safety of SABR for localised renal cell carcinoma.

METHODS

This study was an individual patient data meta-analysis, for which patients undergoing SABR for primary renal cell carcinoma across 12 institutions in five countries (Australia, Canada, Germany, Japan, and the USA) were eligible. Eligible patients had at least 2 years of follow-up, were aged 18 years or older, had any performance status, and had no previous local therapy. Patients with metastatic renal cell carcinoma or upper-tract urothelial carcinoma were excluded. SABR was delivered as a single or multiple fractions of greater than 5 Gy. The primary endpoint was investigator-assessed local failure per the Response Evaluation Criteria in Solid Tumours version 1.1, and was evaluated using cumulative incidence functions.

FINDINGS

190 patients received SABR between March 23, 2007, and Sept 20, 2018. Single-fraction SABR was delivered in 81 (43%) patients and multifraction SABR was delivered in 109 (57%) patients. Median follow-up was 5·0 years (IQR 3·4-6·8). 139 (73%) patients were men, and 51 (27%) were women. Median age was 73·6 years (IQR 66·2-82·0). Median tumour diameter was 4·0 cm (IQR 2·8-4·9). 96 (75%) of 128 patients with available operability details were deemed inoperable by the referring urologist. 56 (29%) of 190 patients had a solitary kidney. Median baseline estimated glomerular filtration rate (eGFR) was 60·0 mL/min per 1·73 m2 (IQR 42·0-76·0) and decreased by 14·2 mL/min per 1·73 m2 (IQR 5·4-22·5) by 5 years post-SABR. Seven (4%) patients required dialysis post-SABR. The cumulative incidence of local failure at 5 years was 5·5% (95% CI 2·8-9·5) overall, with single-fraction SABR yielding fewer local failures than multifraction (Gray's p=0·020). There were no grade 3 toxic effects or treatment-related deaths. One (1%) patient developed an acute grade 4 duodenal ulcer and late grade 4 gastritis.

INTERPRETATION

SABR is effective and safe in the long term for patients with primary renal cell carcinoma. Single-fraction SABR might yield less local failure than multifraction, but further evidence from randomised trials is needed to elucidate optimal treatment schedules. These mature data lend further support for renal SABR as a treatment option for patients unwilling or unfit to undergo surgery.

FUNDING

None.

Grading our quality: An academic and community cancer center dashboard

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Background: Quality scorecards provide a high-level view of key performance metrics and guide data-driven decision making. Dashboards specific to cancer care have not been widely published. Our goal was to implement a quality dashboard to guide and monitor local improvement efforts at an academic and community cancer center. Methods: With the leadership of a Project Manager and Nursing and Physician Quality Directors of the Cancer Center, and input of key Cancer Center stakeholders, quality metrics across national organizations were evaluated. Metrics were chosen based on their ease of collection and their mapping to institutional priorities of clinical quality, patient safety, access, and financial stability. Additional internal measures and benchmarks were created to capture local improvement efforts. Numerous internal and third-party databases were accessed to extract, analyze and display our data. Additionally, a data dictionary was developed for the measure set. Results: Six months of data from fiscal year 2022 was collected, analyzed, and displayed on 10 core and 3 disease-specific measures for breast (B) and lung (L) cancers. (Breast and lung). As of 5/2022, the measures presented on the dashboard include new patient access, non-template chemotherapy orders, medication harm events, likelihood of recommending practice, preventable admissions and emergency department visits, inpatient mortality, and length of stay, readmission, survivorship care plan (B), return to operating room (L), and adequate lymph node sampling (L). These measures pertain to several of the Institute of Medicine’s domains of healthcare quality: effective, efficient, patient-centered, safe, and timely. Conclusions: Compiling data from multiple sources into a single dashboard may guide Cancer Center leadership in strategic planning and monitoring improvement for ongoing initiatives. The data will be updated quarterly. Future iterations will include more disease specific measures and attempts to build automatic data extraction.

Preloaded 22-gauge fine-needle system facilitates placement of a higher number of fiducials for image-guided radiation therapy compared with traditional backloaded 19-gauge approach

BACKGROUND AND AIMS

Image-guided radiation therapy (IGRT) often relies on EUS-guided fiducial markers. Previously used manually backloaded fiducial needles have multiple potential limitations including safety and efficiency concerns. Our aim was to evaluate the efficacy, feasibility, and safety of EUS-guided placement of gold fiducials using a novel preloaded 22-gauge needle compared with a traditional, backloaded 19-gauge needle.

METHODS

This was a single-center comparative cohort study. Patients with pancreatic and hepatobiliary malignancy who underwent EUS-guided fiducial placement (EUS-FP) between October 2014 and February 2018 were included. The main outcome was the technical success of fiducial placement. Secondary outcomes were mean procedure time, fiducial visibility during IGRT, technical success of IGRT delivery, and adverse events.

RESULTS

One hundred fourteen patients underwent EUS-FP during the study period. Of these, 111 patients had successful placement of a minimum of 2 fiducials. Fifty-six patients underwent placement using a backloaded 19-gauge needle and 58 patients underwent placement using a 22-gauge preloaded needle. The mean number of fiducials placed successfully at the target site was significantly higher in the 22-gauge group compared with the 19-gauge group (3.53 ± .96 vs 3.11 ± .61, respectively; P = .006). In the 22-gauge group, the clinical goal of placing 4 fiducials was achieved in 78%, compared with 23% in the 19-gauge group (P < .001). In univariate analyses, gender, age, procedure time, tumor size, and location did not influence the number of successfully placed fiducials. Technical success of IGRT with fiducial tracking was high in both the 19-gauge (51/56, 91%) and the 22-gauge group (47/58, 81%; P = .12).

CONCLUSIONS

EUS-FP using a preloaded 22-gauge needle is feasible, effective, and safe and allows for a higher number of fiducials placed when compared with the traditional backloaded 19-gauge needle.

Toxicity After Stereotactic Body Radiation Therapy for Prostate Cancer in Patients With Inflammatory Bowel Disease: A Multi-institutional Matched Case-Control Series

Purpose

To evaluate the safety of stereotactic body radiation therapy (SBRT) for prostate cancer in men with inflammatory bowel disease (IBD).

Methods and Materials

We queried a consortium database for patients with IBD receiving SBRT for prostate cancer between 2006 and 2012. Identified patients were matched with patients without a history of IBD in a 3:1 fashion based on dose, fractionation, use of androgen deprivation therapy, and age distribution. Logistic regression was used to evaluate the association between having IBD and experiencing acute and late gastrointestinal (GI) and genitourinary (GU) toxicities as scored on the Common Terminology Criteria for Adverse Events scale. Time to late toxicity was evaluated using proportional hazard Cox models. Our study was limited by absence of data on prostate size, baseline International Prostate Symptom Score, and rectal dose-volume histogram parameters.

Results

Thirty-nine patients with flare-free IBD at time of treatment (median follow-up 83.9 months) and 117 matched controls (median follow-up 88.7 months) were identified. A diagnosis of IBD was associated with increased odds of developing any late grade GI toxicity (odds ratio [OR] 6.11, P <.001) and GU toxicity (odds ratio 6.14, P < .001), but not odds of developing late grade ≥2 GI (P = .08) or GU toxicity (P = .069). Acute GI and GU toxicity, both overall and for grade ≥2 toxicities, were more frequent in men with IBD (P < .05). Time to late GI and GU toxicity of any grade was significantly shorter in patients with IBD (P < .001). Time to late grade ≥2 GU, but not grade ≥2 GI toxicity, was also shorter in patients with IBD (P = .044 for GU and P = .144 for GI).

Conclusions

Patients with IBD who received SBRT for PCa had a higher likelihood of developing acute GI and GU toxicity, in addition to experiencing lower grade late toxicities that occurred earlier. However, patients with IBD did not have a higher likelihood for late grade ≥2 GI or GU toxicity after SBRT compared with the control cohort. Interpretation of this data are limited by the small sample size. Thus, men with IBD in remission should be properly counseled about these risks when considering SBRT.

Development of a pancreatic cancer prediction model using a multinational medical records database

394

Background: Previous work by our group has demonstrated that leveraging Machine Learning on diagnostic codes from Electronic Health Records (EHRs), can identify individuals at high-risk for Pancreatic Duct Adenocarcinoma (PDAC), as early as 1 year before current cancer diagnosis. We aim to improve the performance of our existing PDAC risk stratification model, by using an independent, multi-center dataset, and adding lab test features. Methods: EHR data from TriNetX, a federated global health research network, was utilized to develop Logistic Regression (LR) models. Diagnoses and lab test data from 32 different Health Care Organizations in the United States from 2015-2020 was used. PDAC patients ages 60-80 years, were identified using ICD codes, and cross-checked with tumor registry and pathology data to decrease false positives. Only patients with one or more clinical encounter/s, at least 6 months prior to cancer diagnosis, were included. Prediction time cutoffs of 180, 270, and 360 days before PDAC diagnosis were used. Preliminary basic data analysis was initially performed to explore potential lab test features that could be used to improve model performance. The discriminatory capabilities of the LR models were compared using Area Under the Receiver Operating Characteristic Curve (AUC) and 95% Confidence Interval using empirical bootstrap over test data were computed. We used L2-regularized LR, and performed evaluation using cross-validation. We report cross-validation performance. In contrast to prior published work that used predefined feature sets for model development, we incorporated a wide range of indicators, and relied on regularization to address potential overfitting risk. Results: The LR models were trained and evaluated on diagnoses and labs for 25,644 patients (cases= 1352; age-sex paired controls). Lab test administration per patient (i.e., for a given patient, what lab tests were administered and how frequently), was found to be the most valuable feature for improving discrimination. For almost every type of lab test, the average number of administrations per patient was higher for PDAC patients than controls. The top lab tests with highest discriminatory coefficients included glucose, potassium, hematocrit, hemoglobin, sodium, chloride and creatinine. With a 365-day lead time, the diagnoses-based LR obtained a test AUC of 0.58, the lab-test based LR obtained a test AUC of 0.72. The combined diagnoses and lab-test model (“concatenated LR model”) outperformed both of these models, obtaining a test AUC of 0.73. Conclusions: Our findings demonstrate that LR models based on concatenated lab test and diagnoses feature sets (“concatenated LR models”), can outperform both diagnoses-based LR models and lab-test-based LR models, and can be utilized in early prediction of PDAC development.

Development and validation of a pancreatic cancer risk model for the general population using electronic health records: An observational study

AIM

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at a late, incurable stage. We sought to determine whether individuals at high risk of developing PDAC could be identified early using routinely collected data.

METHODS

Electronic health record (EHR) databases from two independent hospitals in Boston, Massachusetts, providing inpatient, outpatient, and emergency care, from 1979 through 2017, were used with case-control matching. PDAC cases were selected using International Classification of Diseases 9/10 codes and validated with tumour registries. A data-driven feature selection approach was used to develop neural networks and L2-regularised logistic regression (LR) models on training data (594 cases, 100,787 controls) and compared with a published model based on hand-selected diagnoses ('baseline'). Model performance was validated on an external database (408 cases, 160,185 controls). Three prediction lead times (180, 270 and 365 days) were considered.

RESULTS

The LR model had the best performance, with an area under the curve (AUC) of 0.71 (confidence interval [CI]: 0.67-0.76) for the training set, and AUC 0.68 (CI: 0.65-0.71) for the validation set, 365 days before diagnosis. Data-driven feature selection improved results over 'baseline' (AUC = 0.55; CI: 0.52-0.58). The LR model flags 2692 (CI 2592-2791) of 156,485 as high risk, 365 days in advance, identifying 25 (CI: 16-36) cancer patients. Risk stratification showed that the high-risk group presented a cancer rate 3 to 5 times the prevalence in our data set.

CONCLUSION

A simple EHR model, based on diagnoses, can identify high-risk individuals for PDAC up to one year in advance. This inexpensive, systematic approach may serve as the first sieve for selection of individuals for PDAC screening programs.

Stereotactic Ablative Radiotherapy for ≥T1b Primary Renal Cell Carcinoma: A Report From the International Radiosurgery Oncology Consortium for Kidney (IROCK)

PURPOSE

Patients with larger (T1b, >4 cm) renal cell carcinoma (RCC) not suitable for surgery have few treatment options because thermal ablation is less effective in this setting. We hypothesize that SABR represents an effective, safe, and nephron-sparing alternative for large RCC.

METHODS AND MATERIALS

Individual patient data from 9 institutions in Germany, Australia, USA, Canada, and Japan were pooled. Patients with T1a tumors, M1 disease, and/or upper tract urothelial carcinoma were excluded. Demographics, treatment, oncologic, and renal function outcomes were assessed using descriptive statistics. Kaplan-Meier estimates and univariable and multivariable Cox proportional hazards regression were generated for oncologic outcomes.

RESULTS

Ninety-five patients were included. Median follow-up was 2.7 years. Median age was 76 years, median tumor diameter was 4.9 cm, and 81.1% had Eastern Cooperative Oncology Group performance status of 0 to 1 (or Karnofsky performance status ≥70%). In patients for whom operability details were reported, 77.6% were defined as inoperable as determined by the referring urologist. Mean baseline estimated glomerular filtration rate (eGFR) was 57.2 mL/min (mild-to-moderate dysfunction), with 30% of the cohort having moderate-to-severe dysfunction (eGFR <45mL/min). After SABR, eGFR decreased by 7.9 mL/min. Three patients (3.2%) required dialysis. Thirty-eight patients (40%) had a grade 1 to 2 toxicity. No grade 3 to 5 toxicities were reported. Cancer-specific survival, overall survival, and progression-free survival were 96.1%, 83.7%, and 81.0% at 2 years and 91.4%, 69.2%, 64.9% at 4 years, respectively. Local, distant, and any failure at 4 years were 2.9%, 11.1%, and 12.1% (cumulative incidence function with death as competing event). On multivariable analysis, increasing tumor size was associated with inferior cancer-specific survival (hazard ratio per 1 cm increase: 1.30; P < .001).

CONCLUSIONS

SABR for larger RCC in this older, largely medically inoperable cohort, demonstrated efficacy and tolerability and had modest impact on renal function. SABR appears to be a viable treatment option in this patient population.

Stereotactic body radiotherapy boost toxicity for high and intermediate-risk prostate cancer: Report of a multi-institutional study

365

Background: External beam radiation therapy (EBRT) with androgen suppression (AS) and low dose rate (LDR)brachytherapy boost has been shown to improve biochemical progression free survival in unfavorable intermediate risk and high-risk prostate cancer (PC) compared to EBRT and AS. Excellent rates of local control in locally advanced prostate cancer with EBRT with high dose rate brachytherapy (HDR) boost. Prostate Stereotactic Radiosurgery (SBRT) may be an alternative to brachytherapy in patients with unfavorable intermediate and high-risk PC. Here we report the toxicity of pelvic lymph node/prostate EBRT and SBRT as the radiation boost in a large retrospective cohort. Methods: 473 patients with intermediate or high-risk PC, from the Radiosurgery Society Registry, Beth Israel Deaconess Medical Center, Georgetown University, and 5 Australian centers, were included. Patients received treatment from 3/2004- 9/2018 were the basis of this IRB approved retrospective study. The prostate and pelvis nodes were treated with between 36-50.4 Gy in 1.8/2.0 Gy fractions of radiation therapy EBRT. Patients received a SBRT boost to the prostate. Boost dose was 19-19.5 Gy (range 19-36.25 Gy). 274 and 199 patients presented with unfavorable or high-risk disease. The median follow-up was 33 months (IQR:18-63). Results: 33 deaths of 473 patients occurred in this cohort, 8 of which were caused by PC. There were 13.9% (n=66) acute Grade 1 or 2 GI toxicities (11.8% grade 1, 2.1% grade 2). There were 27.7% (n=131) acute Grade 1 or 2 GU toxicities (19.2% grade 1, 8.5% grade 2). No severe acute GU or GI toxicities were reported. There were 32 (6.8%) Grade 1 and 3 (0.6%) Grade 2 late GI toxicities. There were 9 (1.9%) Grade 3 and 1 (0.2%) Grade 4 late GI toxicities. There were 60 (12.7%) Grade 1 and 23 (4.9%) Grade 2 late GU toxicities. 15 (3.2%) Grade 3, but no Grade 4 late GU toxicity were reported. Conclusions: In this large multi-institutional retrospective cohort SBRT boost to pelvic/prostate EBRT had acceptable acute and late toxicities. The high dose per fraction of SBRT is similar to the dose delivered with HDR. This data raises the hypothesis that SBRT boost should be evaluated in additional clinical trials.

Development and validation of a pancreatic cancer prediction model from electronic health records using machine learning

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Background: Pancreatic Adenocarcinoma (PDAC) is often diagnosed at an advanced stage. We sought to develop a model for early PDAC prediction in the general population, using electronic health records (EHRs) and machine learning. Methods: We used three EHR datasets from Beth-Israel Deaconess Medical Center (BIDMC) and Partners Healthcare (PHC): 1. “BIDMC-Development-Data” (BIDMC-DD) for model development, using a feed-forward neural network (NN) and L2-regularized logistic regression,randomly split (80:20) into training and test groups. We tuned hyperparameters using cross-validation in training, and report performance on the test split. 2. “BIDMC-Large-Data” (BIDMC-LD) to re-fit and calibrate models. 3. “PHC-Data” for external validation. We evaluate using Area Under the Receiver Operating Characteristic Curve (AUC) and compute 95% CI using empirical bootstrap over test data. PDAC patients were selected using ICD9/-10 codes and validated with tumor registries. In contrast to prior work, we did not predefine feature sets based on known clinical correlates and instead employed data-driven feature selection, specifically importance-based feature pruning, regularization, and manual validation, to identify diagnostic-based features. Results: BIDMC-DD included demographics, diagnoses, labs and medications for 1018 patients (cases = 509; age-sex paired controls). BIDMC-LD included diagnoses for 547,917 patients (cases = 509), and PHC included diagnoses for 160,593 patients (cases = 408). We compared our approach to adapted and re-fitted published baselines. With a 365-day lead-time, NN obtained a BIDMC-DD test AUC of 0.84 (CI 0.79 - 0.90) versus the previous best baseline AUC of 0.70 (CI 0.62 - 0.78). We also validated using BIDMC-DD’s test cancer patients and BIDMC LD controls. The AUC was 0.71 (CI 0.67 - 0.76) at the 365-day cutoff. NN’s external validation AUC on PHC-Data was 0.71 (CI 0.63 - 0.79), outperforming an existing model’s AUC of 0.61 (CI 0.52 - 0.70) (Baecker et al, 2019). Conclusions: Models based on data-driven feature selection outperform models that use predefined sets of known clinical correlates and can help in early prediction of PDAC development.

Improving the survivorship care plan process across an academic and community cancer center

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Background: The goal of a survivorship care plan (SCP) is to improve provider coordination and engage patients in their care. Despite requirements from professional societies, implementation of SCPs is challenging. From April to July 2018, 36% of eligible patients received an SCP at our institution. We aimed to identify barriers to SCP completion and implement interventions to increase their delivery for all cancer types at our academic and community cancer sites. Methods: We created a survey to assess physician, nursing and trainee perceptions and identify barriers to SCP completion. The survey was sent to providers within our medical, surgical, and radiation oncology departments. Providers were asked to rate their satisfaction with our current SCP process and identify obstacles and solutions to achieve SCP completion. In response, we held meetings between oncology attendings, trainees, tumor registry staff, and health information management personnel to design an improvement plan. Results: Of 178 providers, 74 (41.6%) responded. Four percent were satisfied with our current process. The most frequently cited barriers were time (62.1%), lack of clarity regarding who completes the SCP (52%), and insufficient personnel (47.3%). The most frequently cited solutions were dedicated personnel (84.9%), disease-specific templates (61.6%), and education regarding SCPs (48.1%). Based on these results, we: (1) Streamlined our SCP process by entering a partially-templated SCP into an eligible patient’s electronic medical record by our tumor registrar; (2) Asked for disease-specific recommendations that can be included in the template; (3) Asked providers to identify additional team members who assist with SCP completion so that SCPs can be appropriately queued; and (4) Designed an online educational module. Conclusions: We identified multiple barriers to SCP completion at our institution. In response, we implemented a multifaceted improvement plan across our academic and community cancer sites. An analysis of its effects are forthcoming.

Multi-institutional analysis of high-risk prostate cancer patients treated with stereotactic body radiotherapy

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Background: Stereotactic Body Radiotherapy (SBRT) delivers ablative doses of radiation (RT) over a course of five treatments and has been increasingly used as a definitive RT option for low- and intermediate-risk prostate cancer (PCa). Ongoing prospective trials are evaluating the efficacy of SBRT for high-risk PCa, but clinical outcomes reports are limited. Methods: Patients treated for high-risk PCa between 2006-2017 at any of five institutions were included. SBRT doses ranged from 35-40 Gy in 5 fractions per institutional standards, with one institution using an integrated boost approach. The Phoenix definition was used to define biochemical failure (BCR). Physician-reported genitourinary (GU) and gastrointestinal (GI) toxicity outcomes were scored using the Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events systems. Results: In total, 182 patients were included in this study with a median follow-up time of 38.4 months (mos). The median age was 72. Most patients (72%) had Gleason 8-10 disease. Sixty-eight percent of patients received androgen deprivation therapy (ADT) for a median of 9 mos (interquartile range 6-9 mos). The rate of distant metastases was 3.8%. There were no acute Grade 3 (G3) or higher GU or GI toxicities. Three patients (1.6%) experienced a late G3 GU toxicity and one patient (0.5%) experienced a late G3 GI toxicity. The incidence of BCR was significantly higher in patients who did not receive ADT (30% vs. 15%, p = 0.02 by Chi-square). Conclusions: In this multi-institutional study, SBRT demonstrated an acceptable safety profile for the treatment of high-risk PCa. Longer term follow-up is necessary to evaluate the oncologic efficacy of this approach, but given the potentially higher incidence of BCR without ADT, ADT likely has an important oncologic role even with SBRT regimens.

Long-term Outcomes of Stereotactic Body Radiotherapy for Low-Risk and Intermediate-Risk Prostate Cancer

Importance

Stereotactic body radiotherapy harnesses improvements in technology to allow the completion of a course of external beam radiotherapy treatment for prostate cancer in the span of 4 to 5 treatment sessions. Although mounting short-term data support this approach, long-term outcomes have been sparsely reported.

Objective

To assess long-term outcomes after stereotactic body radiotherapy for low-risk and intermediate-risk prostate cancer.

Design, Setting, and Participants

This cohort study analyzed individual patient data from 2142 men enrolled in 10 single-institution phase 2 trials and 2 multi-institutional phase 2 trials of stereotactic body radiotherapy for low-risk and intermediate-risk prostate cancer between January 1, 2000, and December 31, 2012. Statistical analysis was performed based on follow-up from January 1, 2013, to May 1, 2018.

Main Outcomes and Measures

The cumulative incidence of biochemical recurrence was estimated using a competing risk framework. Physician-scored genitourinary and gastrointestinal toxic event outcomes were defined per each individual study, generally by Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events scoring systems. After central review, cumulative incidences of late grade 3 or higher toxic events were estimated using a Kaplan-Meier method.

Results

A total of 2142 men (mean [SD] age, 67.9 [9.5] years) were eligible for analysis, of whom 1185 (55.3%) had low-risk disease, 692 (32.3%) had favorable intermediate-risk disease, and 265 (12.4%) had unfavorable intermediate-risk disease. The median follow-up period was 6.9 years (interquartile range, 4.9-8.1 years). Seven-year cumulative rates of biochemical recurrence were 4.5% (95% CI, 3.2%-5.8%) for low-risk disease, 8.6% (95% CI, 6.2%-11.0%) for favorable intermediate-risk disease, 14.9% (95% CI, 9.5%-20.2%) for unfavorable intermediate-risk disease, and 10.2% (95% CI, 8.0%-12.5%) for all intermediate-risk disease. The crude incidence of acute grade 3 or higher genitourinary toxic events was 0.60% (n = 13) and of gastrointestinal toxic events was 0.09% (n = 2), and the 7-year cumulative incidence of late grade 3 or higher genitourinary toxic events was 2.4% (95% CI, 1.8%-3.2%) and of late grade 3 or higher gastrointestinal toxic events was 0.4% (95% CI, 0.2%-0.8%).

Conclusions and Relevance

In this study, stereotactic body radiotherapy for low-risk and intermediate-risk disease was associated with low rates of severe toxic events and high rates of biochemical control. These data suggest that stereotactic body radiotherapy is an appropriate definitive treatment modality for low-risk and intermediate-risk prostate cancer.

Patient Reported Outcomes in NRG Oncology RTOG 0938, Evaluating Two Ultrahypofractionated Regimens for Prostate Cancer

PURPOSE

There is considerable interest in very short (ultrahypofractionated) radiation therapy regimens to treat prostate cancer based on potential radiobiological advantages, patient convenience, and resource allocation benefits. Our objective is to demonstrate that detectable changes in health-related quality of life measured by the bowel and urinary domains of the Expanded Prostate Cancer Index Composite (EPIC-50) were not substantially worse than baseline scores.

METHODS AND MATERIALS

NRG Oncology's RTOG 0938 is a nonblinded randomized phase 2 study of National Comprehensive Cancer Network low-risk prostate cancer in which each arm is compared with a historical control. Patients were randomized to 5 fractions (7.25 Gy in 2 weeks) or 12 fractions (4.3 Gy in 2.5 weeks). The co-primary endpoints were the proportion of patients with a change in EPIC-50 bowel score at 1 year (baseline to 1 year) >5 points and in EPIC-50 urinary score >2 points tested with a 1-sample binomial test.

RESULTS

The study enrolled 127 patients to 5 fractions (121 analyzed) and 128 patients to 12 fractions (125 analyzed). Median follow-up for all patients at the time of analysis was 3.8 years. The 1-year frequency for >5 point change in bowel score were 29.8% (P < .001) and 28.4% (P < .001) for 5 and 12 fractions, respectively. The 1-year frequencies for >2 point change in urinary score were 45.7% (P < .001) and 42.2% (P < .001) for 5 and 12 fractions, respectively. For 5 fractions, 32.9% of patients had a drop in 1-year EPIC-50 sexual score of ≥11 points (P = .34); for 12 fractions, 30.9% of patients had a drop in 1-year EPIC-50 sexual score of ≥ 11 points (P = .20). Disease-free survival at 2 years is 99.2% (95% confidence interval: 97.5-100) in the 5-fraction arm and 97.5% (95% confidence interval: 94.6-100) in the 12-fraction arm. There was no late grade 4 or 5 treatment-related urinary or bowel toxicity.

CONCLUSIONS

This study confirms that, based on changes in bowel and urinary domains and toxicity (acute and late), the 5- and 12-fraction regimens are well tolerated. These ultrahypofractionated approaches need to be compared with current standard radiation therapy regimens.

Multicenter Trial of Stereotactic Body Radiation Therapy for Low- and Intermediate-Risk Prostate Cancer: Survival and Toxicity Endpoints

PURPOSE

The radiobiology of prostate cancer may favor the extreme hypofractionation inherent in stereotactic body radiation therapy (SBRT); however, data from a large multicenter study are lacking. We therefore examined the hypothesis that dose-escalated SBRT can be safely administered across multiple institutions, with favorable 5-year disease-free survival (DFS) rates compared with historical controls.

METHODS AND MATERIALS

Twenty-one centers enrolled 309 patients with prostate adenocarcinoma: 172 with low-risk (LR) and 137 with intermediate-risk (IR) disease. All were treated with a non-coplanar robotic SBRT platform using real-time tracking of implanted fiducials. The prostate was prescribed 40 Gy in 5 fractions of 8 Gy. We assessed toxicities using Common Terminology Criteria for Adverse Events (CTCAE) version 3 and biochemical failure using the "nadir + 2" definition. The study population yielded 90% power to identify excessive (>10%) rates of grade ≥3 genitourinary (GU) or gastrointestinal toxicities and, in the LR group, 80% power to show superiority in DFS over a 93% historical comparison rate.

RESULTS

At a median follow-up of 61 months, 2 LR patients (1.2%) and 2 IR patients (1.5%) experienced grade 3 GU toxicities, far below the 10% toxicity rate deemed excessive (upper limits of 95% confidence interval, 3.5% and 4.3%, respectively). No grade 4 or 5 toxicities occurred. All grade 3 toxicities were GU, occurring 11 to 51 months after treatment. For the entire group, the actuarial 5-year overall survival rate was 95.6% and the DFS rate was 97.1%. The 5-year DFS rate was 97.3% for LR patients (superior to the 93% DFS rate for historical controls; P = .0008; lower limit of 95% confidence interval, 94.6%) and 97.1% for IR patients.

CONCLUSIONS

Dose-escalated prostate SBRT was administered with minimal toxicity in this multi-institutional study. Relapse rates compared favorably with historical controls. SBRT is a suitable option for LR and IR prostate cancer.

Survivorship care plans: Implementation in an academic medical center

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Background: There are more than 14 million cancer survivors in the US. The Commission on Cancer requires survivorship care plans (SCPs) for patients with Stages I-III cancer. We developed a centralized process to create and monitor SCPs at an academic medical center. Methods: Tumor registry (TR) and clinical decision support teams built an SCP report to identify patients with stage I-III malignancies diagnosed within the past year (18 months for breast cancer patients on hormonal therapy) with a future appointment with medical, radiation or surgical oncology. The TR runs this report to identify patients nine-months post-diagnosis and then e-mails providers a draft SCP two days prior to the appointment. The provider edits this SCP and creates a note linked to the problem list item “Cancer Survivorship,” which is captured as a field in the SCP report. The SCP is mailed to the PCP and handed to the patient. If the SCP is not completed, the TR will send a reminder to the clinician. Results: From September to October 2017, 77 potential cases were reviewed by the TR and 25 (32%) were excluded because of active treatment (9), treatment with palliative intent (5), recurrence (8), and treatment by an outside provider (1). Of the 53 SCP’s e-mailed to providers, 12 were completed and 11 were excluded for active treatment (3), treatment with palliative intent (1), recurrence (3), missed/cancelled appointment (2), SCP sent to provider not providing treatment (1) and inability to discuss SCP with patient (1). An additional five had SCPs completed but were not in the electronic medical record. The overall completion rate of SCPs on eligible patients was 17/42 (40%). SCPs were completed in melanoma, breast, stomach, colon, and prostate cancers by medical, surgical, and radiation oncologists. Conclusions: At an academic medical center, we centrally implemented SCPs across a variety of disease types by a variety of providers. SCPs were completed without the need for additional visits, providers or workspace. Screening patients for eligibility before sending SCPs was vital as many were ineligible. Resources including 20% of a tumor registrar’s time, disease-group level buy-in and leadership support were vital.

Phase II study of enzalutamide monotherapy with radiation therapy for intermediate risk prostate cancer

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Background: Castrating androgen deprivation therapy (ADT) is standardly prescribed in combination with radiation therapy (RT) for intermediate or high-risk prostate cancer (PCa). ADT is associated with multiple side effects including weight gain, loss of libido, hot flashes and muscle atrophy. In contrast, enzalutamide monotherapy is associated with much fewer side effects. Methods: At Dana-Farber/ Harvard Cancer Center we performed an open label phase II study of enzalutamide for 6 months as neo- and adjuvant treatment for intermediate risk PCa patients (NCCN criteria) receiving RT. The primary endpoint was the proportion of patients achieving a PSA response of ≤0.2 . This endpoint is predictive of long term PSA response in a similar risk-group of patients treated with RT and ADT. PSA values were obtained at baseline and monthly on 6 cycles of enzalutamide (160mg/day). 79.2 Gy in 44 fractions of IMRT was started between 6 and 10 weeks after the initiation of enzalutamide. Quality of life questionnaires, hormone levels and anthropomorphic measurements were obtained. Results: 45 of 60 evaluable patients had a PSA ≤0.2 at the end of 6 months of enzalutamide. With a sample size of 64 evaluable patients, if the number achieving a PSA level is ≤0.2 is 44 or more, the null hypothesis is rejected with a target error rate of alpha = 0.10. Also 54 of 60 evaluable patients had a PSA of ≤0.5ng/ml. Importantly, less than half of the participants experienced erectile dysfunction or decreased libido and these were predominantly grade I. Less than a quarter of patients reported hot flashes (all grade I). Waist circumference did not change with therapy. The most frequent grade 2 or greater events were hypertension and gynecomastia. Testosterone and free testosterone levels rose significantly on enzalutamide therapy. Conclusions: Enzalutamide monotherapy with RT may be as effective as castrating ADT, and associated with fewer side effects. Larger, randomized trials are needed to further evaluate enzalutamide monotherapy, instead of ADT, to be used in combination with RT. Clinical trial information: NCT0208988.

Long-term outcomes of stereotactic body radiotherapy for low- and intermediate-risk prostate adenocarcinoma: A multi-institutional consortium study

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Background: While a growing body of evidence supports the use of stereotactic body radiotherapy (SBRT) for the treatment of low- and intermediate-risk prostate adenocarcinoma (PCa), some trepidation exists regarding its long-term efficacy and safety. Methods: Men with low- and intermediate-risk PCa, as defined per the National Comprehensive Cancer Network guidelines, who were enrolled on various institutional phase II trials of SBRT between 2000-2012 were included in a multi-institutional consortium. Biochemical relapse (BCR) was defined as PSA > “nadir +2” or initiation of androgen deprivation therapy (ADT). Toxicity data were scored according to the CTCAE v 3.0 or Radiation Therapy Oncology Group scoring systems. Results: A total of 1644 men were eligible for analysis, with a median followup of 7.2 years. 297 patients (18.1%) had at least 9 years of followup. Fractionation schemes ranged from 33.50-40 Gy in 4-5 fractions. 892 patients had low-risk disease and 752 had intermediate-risk disease. 59 patients (3.6%) received short-term ADT. 100 patients (6.0%) experienced BCR, and 7 (0.4%) experienced distant metastases. No patients died of PCa. By Kaplan-Meier analysis, 5- and 10-year BCR-free survival rates were 98% and 94% in the low-risk group and 96% and 90% in the intermediate-risk group (p < 0.05 by log-rank test). 5- and 10-year overall survival rates were 93% and 86% in the low-risk group and 95% and 91% in the intermediate-risk group (p > 0.05 by log-rank test). Five patients (0.3%) experienced grade 3 acute genitourinary (GU) toxicities, including urinary retention, hematuria, and frequency. 30 (2%) experienced grade 3 late GU toxicity, including urinary strictures, hematuria, and retention. One late grade 4 GU toxicity (hemorrhagic urethritis) and one late grade 4 gastrointestinal toxicity (fistula-in-ano) were seen. Conclusions: To the best of our knowledge, this is the largest analysis of long-term outcomes following SBRT for PCa. The results indicate that SBRT has an efficacy and toxicity profile that compares favorably to more widespread forms of treatment, such as conventionally-fractionated external beam radiotherapy and brachytherapy.

A secondary analysis of PSA response in NRG Oncology/RTOG 9902: A phase III trial of adjuvant chemotherapy with androgen suppression and radiation for high-risk prostate cancer (CaP)

5078

Background: RTOG 9902 was a randomized controlled trial of the addition of adjuvant chemotherapy (CT; paclitaxel, oral etoposide, and estramustine x4 cycles) to 24 mo of androgen suppression (AS) and radiation (RT) for patients (pts) with high-risk CaP., beginning with an initial 4 mo of AS; RT began after 2 mo. 9902 accrued 397 pts and closed early due to excess toxicity. At a median follow-up of 9.2 years, there was no benefit to CT, but it is hypothesized that a subset analysis by post-RT PSA identifies pts that benefit from treatment intensification with CT. Methods: Post-RT PSA status was dichotomized at > 0.2 ng/mL within 1 mo of RT. Landmark analysis redefined starting times for disease-free survival (DFS), time to distant metastasis (TDM) and overall survival (OS) at 16 weeks post-RT (36 weeks post-randomization) when CT was planned to complete. Pts were excluded if they did not get RT or assigned CT, or experienced DFS events/lost to follow-up < 36 wks post-randomization. Hazard ratios (HR), 95% confidence intervals (CI), and PSA-by-treatment interaction were estimated by Cox or competing-risks regression. Results: 333 pts were analyzed: 190 without and 143 with CT. 37% of pts had a post-RT PSA ≤0.2, 34% > 0.2, and 29% no recorded PSA in the defined interval. CT was associated with improved DFS for pts with PSA > 0.2 (HR 0.59, 0.38-0.91), but not for those with PSA ≤0.2 (HR 0.94, 0.60-1.46; interaction p = 0.13). This association, for those with PSA > 0.2, persisted in those pts who received the full course of CT and trended in the same direction for pts receiving 1-3 cycles. CT was associated with a trend toward improved TDM in the PSA > 0.2 group (HR 0.56, 0.23-1.35) and not in the PSA≤0.2 group (HR 1.31, 0.36-4.70), based on 32 pts with metastases. OS did not show the same pattern (PSA > 0.2: HR 0.98, 0.55-1.77; PSA≤0.2: HR 0.57, 0.29-1.13). Conclusions: This analysis suggests that men with high-risk CaP and suboptimal response to AS+RT, as identified by post-RT PSA > 0.2, may benefit from adjuvant CT. Prospective trials using contemporary CT (e.g. docetaxel) will help optimize treatment for these men. NRG-GU002, recently activated, is addressing this issue.

Predicting return of erectile function following external beam radiotherapy or brachytherapy for prostate cancer using EPIC-CP

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Background: EPIC-CP (Expanded Prostate Cancer Index Composite for Clinical Practice) is a one page, 16-item questionnaire designed and validated to measure patient-reported health related quality of life in prostate cancer (PC) patients at the point of care in the clinical setting. We previously developed and externally validated models predictive of intact sexual function (i.e. achieving an erection firm enough for intercourse) at two years following external beam radiation (EBRT) or brachytherapy (BT) using EPIC-26, the parent tool from which EPIC-CP was derived. We aimed to enable the use of these models in clinical practice by recalibrating them for use with EPIC-CP. Methods: Using a previously described multicenter longitudinal cohort (PROST-QA), we identified 217 men treated with EBRT and 230 with BT with complete sexual domain and model covariate information. We used the established covariates predictive of functional erections in the EPIC-26-based models (baseline sexual score, neoadjuvant hormonal therapy, and baseline PSA for EBRT, and baseline sexual score, age, race, and BMI for BT) to recalibrate the multivariable logistic regression models for use with EPIC-CP. We examined Pearson residuals to determine goodness of fit and compared the individual predictions based on the revised models with those generated by the EPIC-26-based models. Results: The recalibrated EPIC-CP-based models demonstrated excellent discrimination (AUC 0.81 for EBRT, AUC 0.87 for BT). Odds ratio estimates for the EPIC-CP models changed by no more than 0.2 from their EPIC-26 counterparts, and remained statistically significant. EPIC-CP and EPIC-26-based predictions had good concordance: the mean ± SD difference in predicted probability between EPIC-26 and EPIC-CP models was 0.0 ± 0.08 in each treatment group. Predicted probabilities were within 15.4% and 15.8% for 95% of the subjects treated with EBRT and BT, respectively. Conclusions: EPIC-CP-based nomograms predicting erectile function two years after EBRT or BT are in good agreement with established EPIC-26-based tools and offer an easily applied and accurate prediction regarding a common and impactful side effect of PC treatment.

Patient reported outcomes in NRG Oncology/RTOG 0938, evaluating two ultrahypofractionated regimens (UHR) for prostate cancer (CaP)

27

Background: The considerable interest in short UHR 5-12 fractions(fr) in management of CaP is based on potential radiobiological advantages, patient convenience & resource allocation benefits. Prior to comparison with standard RT regimens (SRTR), a study was undertaken whose primary objective was to demonstrate that 1-year health-related quality of life (HRQOL) for at least one UHR arm was not significantly lower than baseline as measured by the Bowel & Urinary domains EPIC instrument(EPIC B&U). Secondary objectives included acute & late GI & GU toxicity. Methods: RTOG 0938 is a randomized phase II study of CaP patients(pts), (Gleason score 2-6, stage T1-2a & PSA < 10 ng/mL) receiving 36.25 Gy (5 fr of 7.25 Gy in 2 wks), or 51.6 Gy (12 fr of 4.3 Gy in 2.5 wks). Pts were stratified according to RT technique – Cyberknife vs IMRT/VMAT or protons. A change in EPIC bowel domain score (baseline to 1-year) > 5 points & in EPIC urinary domain score > 2 points were felt to be clinically significant. The frequency for > 5 point change in bowel score (FREQE-B) in ≤ 35% of pts was considered acceptable, with the frequency ≥ 55% unacceptable. Similarly, the frequency for > 2 point change in urinary score (FREQE-U) in ≤ 40% was considered acceptable, with the frequency ≥ 60% unacceptable. A sample size of 156 pts was needed for 95% power with one-sided significance level of 0.025 to preserve an overall level of 0.05. Results: 240 pts were enrolled to ensure adequacy of data for analysis. The compliance for HRQOL completion was good ( > 80%). The 1 year FREQE-B for 5 fr was 23.5% (p < 0.001) & 12 fr was 23.1% (p < 0.001). The 1 year FREQE-U for 5 fr was 35.3% (p < 0.001) & 12 fr was 34.7% (p < 0.001). Conclusions: This study confirms that based on changes in EPIC B&U (baseline to 1-year), acute & late toxicity, both the 5 & 12 fr regimens are well tolerated. These UHR need to be compared to current SRTR in the context of a RCT with efficacy & toxicity endpoints. Supported by grants U10CA21661, U10CA180868, U10CA180822, U10CA37422, UG1CA189867 from the National Cancer Institute (NCI). Clinical trial information: NCT01434290. [Table: see text]

Ipilmumab and cranial radiation in metastatic melanoma patients: a case series and review

Background

Ipilimumab improves survival in metastatic melanoma patients. This population frequently develops brain metastases, which have been associated with poor survival and are often treated with radiation. Therefore, outcomes following ipilimumab and radiation are of interest, especially given case reports and animal studies suggest combined treatment may generate abscopal responses outside the radiation field.

Findings

We reviewed sixteen consecutive melanoma patients who received 1 to 8 courses of radiation, with a sum total of 51, systematically evaluating abscopal responses by following the largest extra-cranial lesion. We also reviewed other series of patients treated with cranial radiation and ipilimumab.

Our patients received between 1 and 8 courses of cranial radiation. Four patients received radiation concurrently with ipilimumab. Median survival was 14 months, and 17 months in patients initially treated with SRS. Interestingly, after radiotherapy, there was a 2.8-fold increased likelihood that the rate of extra-cranial index lesion response improved that didn’t reach statistical significance (p = 0.07); this was more pronounced when ipilimumab was administered within three months of radiation (p < 0.01).

Conclusion

Our experience and review of recently published series suggest ipilimumab and cranial radiation is well tolerated and can result in prolonged survival. Timing of ipilimumab administration in relation to radiation may impact outcomes. Additionally, our results demonstrate a trend for favorable systemic response following radiotherapy worthy of further evaluation in studies powered to detect potential synergies between radiation and immunotherapy.

Models of care and NCCN guideline adherence in very-low-risk prostate cancer

NCCN Guidelines recommend active surveillance as the primary management option for patients with very-low-risk prostate cancer and an expected survival of less than 20 years, reflecting the favorable prognosis of these men and the lack of perceived benefit of immediate, definitive treatment. The authors hypothesized that care at a multidisciplinary clinic, where multiple physicians have an opportunity to simultaneously review and discuss each case, is associated with increased rates of active surveillance in men with very-low-risk prostate cancer, including those with limited life expectancy. Of 630 patients with low-risk prostate cancer managed at 1 of 3 tertiary care centers in Boston, Massachusetts in 2009, 274 (43.5%) had very-low-risk classification. Patients were either seen by 1 or more individual practitioners in sequential settings or at a multidisciplinary clinic, in which concurrent consultation with 2 or more of the following specialties was obtained: urology, radiation oncology, and medical oncology. Patients seen at a multidisciplinary prostate cancer clinic were more likely to select active surveillance than those seen by individual practitioners (64% vs 30%; P<.001), an association that remained significant on multivariable logistic regression (odds ratio [OR], 4.16; P<.001). When the analysis was limited to patients with an expected survival of less than 20 years, this association remained highly significant (72% vs 34%, P<.001; OR, 5.19; P<.001, respectively). Multidisciplinary care is strongly associated with selection of active surveillance, adherence to NCCN Guidelines and minimization of overtreatment in patients with very-low-risk prostate cancer.

Sterotactic body radiosurgery for primary small renal tumors: A retrospective analysis

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Background: Small renal tumors are being diagnosed with increased frequency with the increasing use of axial imaging. Partial or total nephrectomy is the "gold standard" for management. Often patients are not candidates or refuse surgery. Stereotactic Radiotherapy (SBRT) is used to treat brain metastases from RCC. This study is aimed to evaluate the efficacy and toxicity of SBRT in the treatment of renal tumor. Methods: From June 2009 to December 2012, 21 patients with 22 lesions treated with 48Gy in 3 fractions were retrospectively evaluated. 21 patients had RCC and 1 had lymphoma. All patients had tracking during respiration. The Cyberknife system was used. All patients were with ondansetron and /or prochlorperazine to prevent nausea. Follow-up abdominal CT scans or MRI’s were used to evaluate efficacy. Blood Creatinine and urea values were used to track renal function. Clinical records were also evaluated for hypertension. Results: The median Follow up was 21 months (3-48 months). The median age was 82 (56-95). 4 patients had baseline chronic renal failure and 13 patients had baseline hypertension. 12 lesions (54.5%) were left sided and 10 lesions (45.5%) were right sided. 9 lesions (42.9%) were located at upper pole, 6 (28.5%) at lower pole, 5 (23.8%) at middle pole and 1 (4.8%) at renal pelvis. Median maximal tumor size was 3.8cm (1.9-7.7) and median treatment volume was 46cc (7.7-237cc). Five patients developed acute grade 1 fatigue and one patient developed pain which was attributed to inflammation and resolved. One patient developed worsening renal function and 1 patient developed hypertension. There were two local failures at 13 and 21 months. Two patients underwent surgery because one had progressive disease and one as a result of patient choice. 1y and 2y overall survival were both 95%. 1 y and 2 y local control rates were 92 and 84% respectively. Conclusions: This is the largest experience to report on the use of SBRT to treat small renal tumors. SBRT with a dose of 48Gy in 3 fractions of 16 Gy for small renal tumors seems to be an effective and a safe treatment with minimal acute toxicities. In addition tumors in locations not amenable to ablation (renal pelvis) can be safely treated with SBRT.

The effect of prostate brachytherapy technique on quality of life outcomes: 5-year outcomes of a prospective cohort study

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Background: Brachytherapy (BT) is widely used to treat clinically localized prostate cancer, but techniques vary and may affect patient outcomes. Methods: We prospectively studied three Boston-area patient cohorts who received different BT techniques: MRI guided, target volume avoids transition zone (MRBT) and two cohorts using standard imaging and planning techniques (USBT1 and USBT2). We surveyed patients pretreatment and at intervals after, using the validated PCSI scales for urinary incontinence (incont), obstruction/irritation (obstir) bowel problems, sexual dysfunction and the effect of incont on their lives (incontQOL). Based on early results showing increased acute urinary toxicity, USBT2 providers adopted an element of USBT1 technique. We report final 5-year follow-up. Results: Of 286 eligible patients, 73 MRBT patients and 190 USBT patients (99 USBT1 and 91 USBT2 patients) completed at least 3-month surveys. Patient differed by age (median: MRBT 65.3 years vs. USBT 68.3 p=0.005, USBT2 65.3 vs. USBT1 68.3 p=0.004) and education (MRBT 8%≤high school vs. USBT 23%, p<0.001) but other demographic and clinical variables were similar. MRBT patients had more pretreatment obstir symptoms and better sexual function pretreatment. USBT2 patients had greater increases in acute (3-month) obstir (28.8 vs. 20.0, p=0.01) and incont (12.2 vs. 7.1, p=0.01) than USBT1 but not bowel or sexual dysfunction, and all outcomes were similar at 5 years. Changing USBT2 technique eliminated the acute urinary differences. Compared to MRBT, USBT patients had greater increases in acute urinary morbidity (obstir 28.8 vs. 20.0, p=0.01; incont 9.6 vs. 2.2, p=0.002; incontQOL 10.2 vs. 2.4, p=0.0002) and long-term incontinence (incont 7.5 vs. 3.3, p=0.05; incontQOL 5.6 vs. 1.2, p=0.01). Other outcomes did not differ. Conclusions: QOL outcomes vary by BT technique. Measuring QOL may provide useful information for patients choosing treatment and providers assessing their technique. Clinical trial information: NCT00681694.

Response of blood flow to hyperthermia in human prostate tumors: Opportunities for enhanced radiation effect and drug delivery

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Background: Tissue perfusion may be a significant factor affecting outcome of prostate cancer treatment. Hyperthermia has been shown to have beneficial anti-cancer effects when combined with other anti-neoplastic modalities including radiation, chemotherapy, and immunotherapy. For instance, hyperthermia may increase prostate perfusion resulting in radiosensitization through increased oxygenation and chemotherapy through enhanced drug delivery. We previously reported significant benefit to the addition of hyperthermia to radiation on a phase II trial for men with locally advanced prostate cancer. To better understand tissue perfusion in patients with prostate cancer and response to hyperthermia, we measured perfusion levels in patients on this trial before and after hyperthermia. Methods: Prostate perfusion was measured before and immediately after heating in a total of 21 hyperthermia treatments in 14 patients with prostate cancer. A trans-rectal ultrasound device with a water cooled jacket was used to heat the prostate. Prostate tissue temperatures were measured using three multisensory thermocouple probes. Perfusion was measured with the TDP-200 Thermal Diffusion Probe, a thermistor-based device which quantifies perfusion with a modified wash-out technique. Results: In 19 treatments in which perfusion was measured before heating, average and standard deviation was 18.3 ± 10.6 ml/100g-min and in 17 treatments in which perfusion was measured after heating, it was 30.7 ± 20.8 ml/100g-min. This represents a statistically significant increase of 68% (p = 0.018). Perfusion increased 12 of 15 treatments in which measurements were obtained before and after hyperthermia. Notably, prostate tissue that was most ischemic prior to heating experienced the largest heat-induced perfusion increase. Conclusions: Prostate perfusion increased significantly with a majority of hyperthermia treatments. Enhanced prostate oxygenation may have been a contributing factor to the benefit noted with hyperthermia in this phase II trial. The use of hyperthermia to augment prostate perfusion to enhance radiation, chemotherapy, and immunotherapy warrants further investigation.

Medical oncology consultation and minimization of overtreatment in men with low-risk prostate cancer

PURPOSE

Specialist bias, in which specialists recommend the therapy that they are capable of delivering, is thought to influence the treatment of patients with localized prostate cancer and to contribute to overtreatment of men with limited life expectancy. Consequently, rates of active surveillance, the preferred management modality per the National Comprehensive Cancer Network (NCCN) for patients with low- and very low-risk disease and a life expectancy of less than 10 and less than 20 years, respectively, are low. We sought to determine whether consultation with a medical oncologist is associated with increased rates of active surveillance in men with low-risk prostate cancer.

METHODS

We identified 188 patients with low-risk prostate cancer undergoing active surveillance at one of three referral centers in Boston, MA in 2009. Multivariable logistic regression was used to determine whether consultation with a medical oncologist was associated with selection of active surveillance. The data were reanalyzed for patients with low- and very low-risk disease and a life expectancy of less than 10 and less than 20 years, respectively.

RESULTS

Consultation with a medical oncologist was associated with increased rates of active surveillance (37% v 21%, P = .01), an association that remained significant on multivariable logistic regression (odds ratio [OR] = 2.70; 95% CI, 1.27 to 5.75; P = .01). When applied to patients with limited life expectancy, this finding remained significant (OR = 4.74; 95% CI, 1.17 to 19.25; P = .03).

CONCLUSION

Consultation with a medical oncologist is associated with increased rates of active surveillance, adherence to NCCN guidelines, and minimization of overtreatment in men with early prostate cancer and limited life expectancy.

Long-term efficacy of stereotactic body radiotherapy for localized prostate cancer: A multi-institutional pooled analysis

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Background: The purpose of this study is to report biochemical relapse-free survival (bRFS) rates for a group of localized prostate cancer patients from a pooled multi-institutional dataset with at least 5 years follow-up after stereotactic body radiotherapy (SBRT). Methods: The outcome data from 1101 patients treated with SBRT between 2003 and 2011 were pooled from 8 institutions. A subset of 135 cases had a minimum 5 years follow-up. All 135 cases had clinical stage T1 or T2A disease. The distribution by Gleason score (GS) was <6 in 80% and 7 in 20%. The median pretreatment PSA (iPSA) level was 5.1 ng/ml (range: 0.1-27.8). The distribution by risk was 77% low, 21% intermediate, and 2% high risk. The median dose was 36.25 Gy (35-40 Gy range) delivered either with 4 or 5 fractions. The prescribed dose groups were as follows: 35 Gy in 42%, 36.25 Gy in 47%, and >38 Gy in 11%. Androgen deprivation therapy was given to 21% of patients. Biochemical relapse, defined as a rise > 2 ng/ml above nadir, was determined in a total of 4 failures. Results: The median follow-up for all 135 cases was 60 months (range 60 to 72). For all patients, the bRFS rate at 5 years was 97%. The 5-year actuarial bRFS rates for GS < 6, and Gleason score 7 were 98%, and 92%, respectively (p=0.15). The 5-year actuarial bRFS rates for low versus intermediate/high-risk patients were 99% and 93%, respectively (p=0.11). The 5-year actuarial bRFS rates for patients receiving 35 Gy versus >36.25 Gy were 93% and 100%. No difference in bRFS was observed with the use of androgen deprivation (p=0.78). Multivariate analysis showed only GS to be an independent predictor of relapse (p=0.03); iPSA (p=0.10) and radiation dose (0.97) were not. Conclusions: In a relatively large cohort of localized prostate cancer patients treated with SBRT, long follow-up period (>5 years), excellent efficacy was demonstrated with 97% of patients being free from relapse. For low and intermediate risk cases, these results compare favorably with other modalities with similar follow-up periods. Although a trend for worse outcome was seen with total radiation doses of 35 Gy, this was not confirmed on multivariate analysis.

Multidisciplinary care and management of very low-risk prostate cancer

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Background: The National Comprehensive Cancer Network (NCCN) recommends active surveillance (AS) as the primary management option for patients with very low-risk prostate cancer (VLRPC) and an expected survival of <20 years. Factors associated with selection of AS are therefore of clinical importance. We hypothesized that care at a multidisciplinary clinic (MC), where multiple physicians simultaneously review each case, will be associated with increased rates of AS in men with VLRPC, including those with limited life expectancy. Methods: Of 630 patients with low-risk prostate cancer managed at one of three tertiary care centers in Boston, MA in 2009, 274 (43.5%) had VLRPC. Patients were either seen by one or more individual providers in sequential visits (N=178) or at an MC (N=96), in which concurrent consultation with two or more of the following specialties was obtained: urology, medical oncology, and radiation oncology. Results: Patients seen at an MC were more likely to select AS than those seen by individual providers (64% vs 30%, p<.001), an association which remained significant on multivariable logistic regression (OR=4.16, p<.001), see Table. When the analysis was limited to patients with an expected survival of <20 years based on the 2007 Social Security Life Table, this association remained highly significant (OR=5.19, p<.001). Conclusions: Multidisciplinary care is strongly associated with selection of AS, adherence to NCCN guidelines, and minimization of over-treatment in patients with VLRPC. [Table: see text]

Multidisciplinary care and pursuit of active surveillance in low-risk prostate cancer

PURPOSE

Multidisciplinary clinics offer a unique approach to the management of patients with cancer. Yet, limited data exist to show that such clinics affect management. The purpose of this study was to determine whether consultation at a multidisciplinary clinic is associated with selection of active surveillance in patients with low-risk prostate cancer.

PATIENTS AND METHODS

The study comprised 701 men with low-risk prostate cancer managed at three tertiary care centers in Boston, MA in 2009. Patients either obtained consultation at a multidisciplinary prostate cancer clinic, at which they were seen by a combination of urologic, radiation, and medical oncologists in a concurrent setting, or they were seen by individual practitioners in sequential settings. The primary outcome was selection of active surveillance.

RESULTS

Crude rates of selection of active surveillance in patients seen at a multidisciplinary clinic were double that of patients seen by individual practitioners (43% v 22%), whereas the proportion of men treated with prostatectomy or radiation decreased by approximately 30% (P < .001). On multivariate logistic regression, older age (odds ratio [OR], 1.09; 95% CI, 1.05 to 1.12; P < .001), unmarried status (OR, 1.66; 95% CI, 1.01 to 2.72; P = .04), increased Charlson comorbidity index (OR, 1.37; 95% CI, 1.06 to 1.77; P = .02), fewer positive cores (OR, 0.92; 95% CI, 0.90 to 0.94; P < .001), and consultation at a multidisciplinary clinic (OR, 2.15; 95% CI, 1.13 to 4.10; P = .02) were significantly associated with pursuit of active surveillance.

CONCLUSION

Multidisciplinary care is associated with increased selection of active surveillance in men with low-risk prostate cancer. This finding may have an important clinical, social, and economic impact.

Multidisciplinary care and pursuit of active surveillance in low-risk prostate cancer

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Background: Factors associated with pursuit of active surveillance in men with low-risk prostate cancer are not well-delineated.

Methods: 701 patients with low-risk prostate cancer (clinical stage < T2b, Gleason score < 7, and PSA < 10 ng/mL), treated in 2009 at three tertiary care centers affiliated with the same medical school and within the same health care system were identified. All patients were evaluated by one or more urological, radiation, and/or medical oncologists specializing in genitourinary malignancies, either sequentially at independent appointments with differing dates/locations, or concurrently at a multidisciplinary genitourinary oncology clinic in which all three specialists evaluated the patient jointly during a single visit. Pre-treatment and treatment-related variables were recorded. Logistic regression was performed to identify demographic and clinical factors associated with the employment of active surveillance.

Results: Forty three percent of patients referred to a multidisciplinary clinic underwent active surveillance, as opposed to 22% of patients seen by individual practitioners (p<.001). On multivariate logistic regression, older age (OR 1.09 (per year), p <.001), increased comorbidities (OR 1.41 (per unit increase in Charlson score), p=.01), unmarried social status (OR 1.76, p=.04), a smaller percentage of positive cores (OR 0.92 (per percent core increase), p<.001), and referral to a multidisciplinary clinic (OR 2.22, p<.01) were all significantly associated with pursuit of active surveillance. The number of physicians or specialities seen in consultation was not significantly associated with pursuit of active surveillance.

Conclusions: Older age, increased comorbidities, unmarried social status, and a smaller percentage of positive cores are associated with pursuit of active surveillance. Notably, referral to a multidisciplinary genitourinary oncology clinic significantly increases rates of active surveillance in men with low-risk prostate cancer, implying that the multidisciplinary clinic itself, and not merely the number or type of physicians seen, is important to the shared decision making process for a patient to elect active surveillance.

Hypofractionated stereotactic body radiotherapy in low-risk prostate adenocarcinoma: preliminary results of a multi-institutional phase 1 feasibility trial

BACKGROUND

Recent reports using extreme hypofractionated regimens in the treatment of low-risk prostate adenocarcinoma have been encouraging. Here, the authors report on their own multi-institutional experience with extreme hypofractionated stereotactic radiotherapy for early stage disease.

METHODS

In total, at 4 centers, 45 patients with National Comprehensive Cancer Network-defined, low-risk prostate adenocarcinoma were enrolled in a phase 1, multi-institutional trial of hypofractionated radiosurgery with a proprietary radiosurgical device (CyberKnife). Thirty-four patients received 7.5 grays (Gy) delivered in 5 fractions, 9 patients received 7.25 Gy delivered in 5 fractions, and 2 patients received other regimens. The variables evaluated were biochemical progression-free survival (bPFS), prostate-specific antigen (PSA) bounce, and toxicities. Health-related quality of life was evaluated using the Sexual Health Inventory for Men (SHIM), American Urological Association (AUA), and Expanded Prostate Cancer Index Composite (EPIC) questionnaires.

RESULTS

The median follow-up for surviving patients was 44.5 months (range, 0-62 months). The bPFS rate at 3 years was 97.7%. The median PSA declined from 4.9 ng/mL at diagnosis to 0.2 ng/mL at last follow-up, and the median percentage PSA decline at 12 months was 80%. Nine patients experienced at least 1 PSA bounce ≥0.4 ng/mL, and 4 patients experienced 2 PSA bounces. The median time to first PSA bounce was 11.6 months (range, 7.2-18.2 months), and the mean percentage PSA bounce was 1.07 ng/mL. There was 1 episode of late grade 3 urinary obstruction, and there were 2 episodes of late grade 3 proctitis. There was a significant late decline in SHIM and EPIC sexual scores and a small, late decline in the EPIC Bowel domain score.

CONCLUSIONS

In a select population, extreme hypofractionation with stereotactic radiosurgery was safe and effective for the treatment of low-risk prostate adenocarcinoma.

Prediction of erectile function following treatment for prostate cancer

CONTEXT

Sexual function is the health-related quality of life (HRQOL) domain most commonly impaired after prostate cancer treatment; however, validated tools to enable personalized prediction of erectile dysfunction after prostate cancer treatment are lacking.

OBJECTIVE

To predict long-term erectile function following prostate cancer treatment based on individual patient and treatment characteristics.

DESIGN

Pretreatment patient characteristics, sexual HRQOL, and treatment details measured in a longitudinal academic multicenter cohort (Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment; enrolled from 2003 through 2006), were used to develop models predicting erectile function 2 years after treatment. A community-based cohort (community-based Cancer of the Prostate Strategic Urologic Research Endeavor [CaPSURE]; enrolled 1995 through 2007) externally validated model performance. Patients in US academic and community-based practices whose HRQOL was measured pretreatment (N = 1201) underwent follow-up after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer. Sexual outcomes among men completing 2 years' follow-up (n = 1027) were used to develop models predicting erectile function that were externally validated among 1913 patients in a community-based cohort.

MAIN OUTCOME MEASURES

Patient-reported functional erections suitable for intercourse 2 years following prostate cancer treatment.

RESULTS

Two years after prostate cancer treatment, 368 (37% [95% CI, 34%-40%]) of all patients and 335 (48% [95% CI, 45%-52%]) of those with functional erections prior to treatment reported functional erections; 531 (53% [95% CI, 50%-56%]) of patients without penile prostheses reported use of medications or other devices for erectile dysfunction. Pretreatment sexual HRQOL score, age, serum prostate-specific antigen level, race/ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. Multivariable logistic regression models predicting erectile function estimated 2-year function probabilities from as low as 10% or less to as high as 70% or greater depending on the individual's pretreatment patient characteristics and treatment details. The models performed well in predicting erections in external validation among CaPSURE cohort patients (areas under the receiver operating characteristic curve, 0.77 [95% CI, 0.74-0.80] for prostatectomy; 0.87 [95% CI, 0.80-0.94] for external radiotherapy; and 0.90 [95% CI, 0.85-0.95] for brachytherapy).

CONCLUSION

Stratification by pretreatment patient characteristics and treatment details enables prediction of erectile function 2 years after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer.

Hyperthermia combined with radiation for the treatment of locally advanced prostate cancer: long-term results from Dana-Farber Cancer Institute study 94-153

BACKGROUND

The authors present long-term results from a phase 2 study that assessed the efficacy of transrectal ultrasound hyperthermia plus radiation with or without androgen suppression for the treatment of locally advanced prostate cancer.

METHODS

Patients with clinical T2b-T3bN0M0 disease (according to 1992 American Joint Committee on Cancer [AJCC] criteria) received radiation plus 2 transrectal ultrasound hyperthermia treatments. After the first 4 patients, 6 months of androgen suppression were allowed. The study was designed to assess absolute improvement in the 2-year disease-free survival rate compared with the short-term androgen suppression arm in Radiation Therapy Oncology Group (RTOG) study 92-02.

RESULTS

Thirty-seven patients received a total of 72 hyperthermia treatments. The mean cumulative equivalent minutes (CEM) T₉₀ 43°C was 8.4 minutes. According to the 1992 AJCC classification, there were 19 patients with T2b tumors, 8 patients with T2c tumors, 5 patients with T3a tumors, and 5 patients with T3b tumors. The median Gleason score was 7 (range, 6-9), and the median prostate-specific antigen (PSA) level was 13.3 ng/mL (range, 2-65 ng/mL). Thirty-three patients received androgen suppression. At a median follow-up of 70 months (range, 18-110 months), the 7-year overall survival rate was 94%, and 61% of patients remained failure free (according to the American Society for Therapeutic Radiology and Oncology definition for failure free survival). The absolute rate of disease-free survival at 2 years, which was the primary study endpoint, improved significantly (84%) compared with a rate of 64% for similar patients on the 4-month androgen suppression arm of RTOG 92-02. When Phoenix criteria (PSA nadir + 2 ng/mL) were used to define biochemical failure, 89% of patients were failure free at 2 years.

CONCLUSIONS

Hyperthermia combined with radiation for the treatment of locally advanced prostate cancer appeared to be promising. The current results indicated that further study of hyperthermia for the treatment of prostate cancer with optimal radiation and systemic therapy is warranted.

A 64-year-old man with low-risk prostate cancer: review of prostate cancer treatment

Earlier detection of prostate cancer in the past decade has been accompanied by greater reduction in US prostate cancer mortality than that seen with any other cancer. Prostate cancer is usually diagnosed at early stages and is most commonly treated by prostatectomy, radiotherapy, or brachytherapy. For intermediate- and high-risk prostate cancers, randomized clinical trials have shown survival benefit subsequent to prostatectomy or to combined radiation with androgen-suppressive therapy. However, prostatectomy, radiotherapy, and brachytherapy each can lead to distinct adverse effects. Moreover, for the lowest-risk categories of early stage prostate cancer, evidence supporting an intervention is only indirect. New approaches to surveillance of prostate cancer have consequently emerged that do not eschew treatment altogether. Instead "active" surveillance aims to implement definitive intervention effectively for those low-risk cancers that show a propensity for progression as evidenced by histopathological or serological change during the surveillance interval.

Prostate Postbrachytherapy Seed Distribution: Comparison of High-Resolution, Contrast-Enhanced, T1- and T2-Weighted Endorectal Magnetic Resonance Imaging Versus Computed Tomography: Initial Experience

PURPOSE

To compare contrast-enhanced, T1-weighted, three-dimensional magnetic resonance imaging (CEMR) and T2-weighted magnetic resonance imaging (T2MR) with computed tomography (CT) for prostate brachytherapy seed location for dosimetric calculations.

METHODS AND MATERIALS

Postbrachytherapy prostate MRI was performed on a 1.5 Tesla unit with combined surface and endorectal coils in 13 patients. Both CEMR and T2MR used a section thickness of 3 mm. Spiral CT used a section thickness of 5 mm with a pitch factor of 1.5. All images were obtained in the transverse plane. Two readers using CT and MR imaging assessed brachytherapy seed distribution independently. The dependency of data read by both readers for a specific subject was assessed with a linear mixed effects model.

RESULTS

The mean percentage (+/- standard deviation) values of the readers for seed detection and location are presented. Of 1205 implanted seeds, CEMR, T2MR, and CT detected 91.5% +/- 4.8%, 78.5% +/- 8.5%, and 96.1% +/- 2.3%, respectively, with 11.8% +/- 4.5%, 8.5% +/- 3.5%, 1.9% +/- 1.0% extracapsular, respectively. Assignment to periprostatic structures was not possible with CT. Periprostatic seed assignments for CEMR and T2MR, respectively, were as follows: neurovascular bundle, 3.5% +/- 1.6% and 2.1% +/- 0.9%; seminal vesicles, 0.9% +/- 1.8% and 0.3% +/- 0.7%; periurethral, 7.1% +/- 3.3% and 5.8% +/- 2.9%; penile bulb, 0.6% +/- 0.8% and 0.3% +/- 0.6%; Denonvillier's Fascia/rectal wall, 0.5% +/- 0.6% and 0%; and urinary bladder, 0.1% +/- 0.3% and 0%. Data dependency analysis showed statistical significance for the type of imaging but not for reader identification.

CONCLUSION

Both enumeration and localization of implanted seeds are readily accomplished with CEMR. Calculations with MRI dosimetry do not require CT data. Dose determinations to specific extracapsular sites can be obtained with MRI but not with CT.

Real-time computed tomography dosimetry during ultrasound-guided brachytherapy for prostate cancer

PURPOSE

Ultrasound-guided implantation of permanent radioactive seeds is a treatment option for localized prostate cancer. Several techniques have been described for the optimal placement of the seeds in the prostate during this procedure. Postimplantation dosimetric calculations are performed after the implant. Areas of underdosing can only be corrected with either an external beam boost or by performing a second implant. We demonstrate the feasibility of performing computed tomography (CT)-based postplanning during the ultrasound-guided implant and subsequently correcting for underdosed areas.

METHODS AND MATERIALS

Ultrasound-guided brachytherapy is performed on a modified CT table with general anesthesia. The postplanning CT scan is performed after the implant, while the patient is still under anesthesia. Additional seeds are implanted into "cold spots," and the resultant dosimetry confirmed with CT.

RESULTS

Intraoperative postplanning was successfully performed. Dose-volume histograms demonstrated adequate dose coverage during the initial implant, but on detailed analysis, for some patients, areas of underdosing were observed either at the apex or the peripheral zone. Additional seeds were implanted to bring these areas to prescription dose.

CONCLUSION

Intraoperative postplanning is feasible during ultrasound-guided brachytherapy for prostate cancer. Although the postimplant dose-volume histograms for all patients, before the implantation of additional seeds, were adequate according to the American Brachytherapy Society criteria, specific critical areas can be underdosed. Additional seeds can then be implanted to optimize the dosimetry and reduce the risk of underdosing areas of cancer.

Effect of random seed placement error in permanent transperineal prostate seed implant

BACKGROUND AND PURPOSE

Random seed placement error may adversely effect dose distribution in transperineal prostate seed implants. In this study, we investigated the extent to which individual seed activity influences dose-distribution degradation due to random seed placement error.

PATIENTS AND METHODS

Separate initial treatment plans were prepared for three prostate sizes, 27.3, 43.2 and 48.9 cc, using 0.35, 0.55 and 0.75 mCi iodine-125 seeds. All stated activities are understood to be apparent activities. The combinations produced a total of nine treatment plans. Each initial treatment plan was subjected to 1000 stochastic three-dimensional Gaussian perturbations of seed location, with a standard deviation of 4mm for a total of 9000 treatment plans. The resulting plans were evaluated for target coverage and urethra involvement.

RESULTS

Satisfactory initial treatment plans were prepared for all prostate sizes and seed activities. All 9000 perturbed treatment plans showed acceptable target coverage under the D90/90 criterion. Some of the perturbed plans for the 27.3 and 43.2 cc prostates with 0.55 and 0.75 mCi seeds failed the V100/90 criterion. Some of the randomly perturbed seed distributions showed significantly increased doses to the urethra relative to the unperturbed treatment plan. This effect was more pronounced with greater seed activity.

CONCLUSIONS

There may be a higher probability of unfavorable target coverage due to random seed placement error when performing transperineal iodine-125 prostate seed implants using seeds with activity greater than 0.35 mCi. There may also be a higher probability of unfavorable urethra involvement when using higher activity seeds.

Hyperthermia combined with radiation in treatment of locally advanced prostate cancer is associated with a favourable toxicity profile

PURPOSE

Hyperthermia is used to treat several pelvic tumours. An important step in establishing a broader role for hyperthermia in treatment of prostate cancer is verification of an acceptable toxicity profile. In this report, short- and long-term toxicity profiles of a completed phase II trial of transrectal ultrasound hyperthermia combined with radiation in treatment of locally advanced prostate cancer are presented.

METHODS AND MATERIALS

Thirty-seven patients enrolled on a phase II study of external beam radiation +/- androgen suppression with two transrectal ultrasound hyperthermia treatments were assessed for short- and long-term toxicity. Prostatic and anterior rectal wall temperatures were monitored. Rectal wall temperatures were limited to 40 degrees C (19 patients), 41 degrees C (three patients) and 42 degrees C (15 patients). Univariate logistic regression was used to estimate the log hazard of developing NCI CTC Grade 2 toxicity based on temperature parameters. Hazard ratios, 95% confidence intervals, p-values for statistical significance of each parameter and proportion of variability explained for each of the parameters were calculated.

RESULTS

Median follow-up was 42 months. Both short- and long-term GI toxicity were limited to grade 2 or less. Acute grade 2 proctitis was greater for patients with allowable rectal wall temperature of >40 degrees C. Eleven of 18 patients in this group had acute grade 2 proctitis vs three of 19 patients with rectal wall temperatures limited to 40 degrees C (p = 0.004). Long-term grade 2 GI and GU toxicity occurred in 5% and 19% of patients. No late grade 3 or greater toxicity occurred. Late GI and GU toxicity were not associated with the allowable rectal wall temperature.

CONCLUSION

Transrectal ultrasound hyperthermia combined with radiation for treatment of advanced clinically localized prostate cancer is safe and well tolerated.