Use of Decipher Prostate Biopsy Test in Patients with Favorable-risk Disease Undergoing Conservative Management or Radical Prostatectomy in the Surveillance, Epidemiology, and End Results Registry.

BACKGROUND AND OBJECTIVE: The extent of prostate cancer found on biopsy, as well as prostate cancer grade and genomic tests, can affect clinical decision-making. The impact of these factors on the initial management approach and subsequent patient outcomes for men with favorable-grade prostate cancer has not yet been determined on a population level. Our objective was to explore the association of Decipher 22-gene genomic classifier (GC) biopsy testing on the initial use of conservative management versus radical prostatectomy (RP) and to determine the independent effect of GC scores on RP pathologic outcomes. METHODS: A total of 87 140 patients diagnosed with grade group 1 and 2 prostate cancer between 2016 and 2018 from the Surveillance, Epidemiology, and End Results registry data were linked to GC testing results (2576 tested and 84 564 untested with a GC). The primary endpoints of interest were receipt of conservative management or RP, pathologic upgrading (pathologic grade group 3-5), upstaging (pathologic ≥T3b), and adverse pathologic features (pathologic upgrading, upstaging, or lymph node invasion). Multivariable logistic regressions quantified the association of variables with outcomes of interest. KEY FINDINGS AND LIMITATIONS: GC tested patients were more likely to have grade group 2 on biopsy (51% vs 46%, p < 0.001) and lower prostate-specific antigen (6.1 vs 6.3, p = 0.016). Conservative management increased from 37% to 39% and from 22% to 24% during 2016-2018 for the GC tested and untested populations, respectively. GC testing was significantly associated with increased odds of conservative management (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.9-2.4, p < 0.001). The distribution of biopsy GC risk was as follows: 45% low risk, 30% intermediate risk, and 25% high risk. In adjusted analyses, higher GC (per 0.1 increment) scores (OR 1.24, 95% CI 1.17-1.31, p < 0.001) and percent positive cores (1.07, 95% CI 1.02-1.12, p = 0.009) were significantly associated with the receipt of RP. A higher GC score was significantly associated with all adverse outcomes (pathologic upgrading [OR 1.29, 95% CI 1.12-1.49, p < 0.001], upstaging [OR 1.31, 95% CI 1.05-1.62, p = 0.020], and adverse pathology [OR 1.27, 95% CI 1.12-1.45, p < 0.001]). Limitations include observational biases associated with the retrospective study design. CONCLUSIONS AND CLINICAL IMPLICATIONS: Men who underwent GC testing were more likely to undergo conservative management. GC testing at biopsy is prognostic of adverse pathologic outcomes in a large population-based registry. PATIENT SUMMARY: In this population analysis of men with favorable-risk prostate cancer, those who underwent genomic testing at biopsy were more likely to undergo conservative management. Of men who initially underwent radical prostatectomy, higher genomic risk but not tumor volume was associated with adverse pathologic outcomes. The use of genomic testing at prostate biopsy improves risk stratification and may better inform treatment decisions than the use of tumor volume alone.

Assessing the Clinical Utility of Published Prostate Cancer Polygenic Risk Scores in a Large Biobank Data Set.

BACKGROUND AND OBJECTIVE: Polygenic risk scores (PRSs) have been developed to identify men with the highest risk of prostate cancer. Our aim was to compare the performance of 16 PRSs in identifying men at risk of developing prostate cancer and then to evaluate the performance of the top-performing PRSs in differentiating individuals at risk of aggressive prostate cancer. METHODS: For this case-control study we downloaded 16 published PRSs from the Polygenic Score Catalog on May 28, 2021 and applied them to Michigan Genomics Initiative (MGI) patients. Cases were matched to the Michigan Urological Surgery Improvement Collaborative (MUSIC) registry to obtain granular clinical and pathological data. MGI prospectively enrolls patients undergoing surgery at the University of Michigan, and MUSIC is a multi-institutional registry that prospectively tracks demographic, treatment, and clinical variables. The predictive performance of each PRS was evaluated using the area under the covariate-adjusted receiver operating characteristic curve (aAUC), and the association between PRS and disease aggressiveness according to prostate biopsy data was measured using logistic regression. KEY FINDINGS AND LIMITATIONS: We included 18 050 patients in the analysis, of whom 15 310 were control subjects and 2740 were prostate cancer cases. The median age was 66.1 yr (interquartile range 59.9-71.6) for cases and 56.6 yr (interquartile range 42.6-66.7) for control subjects. The PRS performance in predicting the risk of developing prostate cancer according to aAUC ranged from 0.51 (95% confidence interval 0.51-0.53) to 0.67 (95% confidence interval 0.66-0.68). By contrast, there was no association between PRS and disease aggressiveness. CONCLUSIONS AND CLINICAL IMPLICATIONS: Prostate cancer PRSs have modest real-world performance in identifying patients at higher risk of developing prostate cancer; however, they are limited in distinguishing patients with indolent versus aggressive disease. PATIENT SUMMARY: Risk scores using data for multiple genes (called polygenic risk scores) can identify men at higher risk of developing prostate cancer. However, these scores need to be refined to be able to identify men with the highest risk for clinically significant prostate cancer.

Major Complications and Adverse Events Related to Use of SpaceOAR Hydrogel for Prostate Cancer Radiotherapy.

OBJECTIVE: To determine the prevalence and severity of SpaceOAR-related adverse events using the Manufacturer and User Facility Device Experience (MAUDE) database. METHODS: We analyzed SpaceOAR-related adverse event reports in the Manufacturer and User Facility Device Experience (MAUDE) database from January 2015 to May 2023. For each report, the event type, associated device and patient problems, event description, event timing, and event severity stratified by the Common Terminology Criteria for Adverse Events version 5.0 (CTCAE) grading system were recorded. RESULTS: From 2015 to 2022, 206,619 SpaceOAR devices were sold. From January 2015 to May 2023, we identified 981 reports describing 990 SpaceOAR-related adverse events. Malfunctions were the most common event type (N = 626), followed by patient injuries (N = 350) with few reported deaths (N = 5). Device positioning problems were the most frequent device issue (N = 686). Pain was the most reported patient problem (N = 216). Abscesses and fistulas related to the device were each reported in 91 events. A noteworthy portion of relevant adverse events occurred before the initiation of radiation (N = 35, 22.4%), suggesting the device, rather than the radiation, was responsible. In total, 470 (50.2%) and 344 (36.7%) of the adverse events were CTCAE grade 1 and 2, respectively. There were 123 (13.1%) events that were CTCAE grade ≥3. CONCLUSION: We identified multiple reports of SpaceOAR-related adverse events, many of which are more serious than have been reported in clinical trials. While SpaceOAR use is common, suggesting these events are rare, these data highlight the need for continued postmarket surveillance.

Artificial intelligence applications in prostate cancer.

Artificial intelligence (AI) applications have enabled remarkable advancements in healthcare delivery. These AI tools are often aimed to improve accuracy and efficiency of histopathology assessment and diagnostic imaging interpretation, risk stratification (i.e., prognostication), and prediction of therapeutic benefit for personalized treatment recommendations. To date, multiple AI algorithms have been explored for prostate cancer to address automation of clinical workflow, integration of data from multiple domains in the decision-making process, and the generation of diagnostic, prognostic, and predictive biomarkers. While many studies remain within the pre-clinical space or lack validation, the last few years have witnessed the emergence of robust AI-based biomarkers validated on thousands of patients, and the prospective deployment of clinically-integrated workflows for automated radiation therapy design. To advance the field forward, multi-institutional and multi-disciplinary collaborations are needed in order to prospectively implement interoperable and accountable AI technology routinely in clinic.

Radiotheranostics in advanced prostate cancer: Current and future directions.

The discovery of small molecules that target the extracellular domain of prostate-specific membrane antigen (PSMA) has led to advancements in diagnostic imaging and the development of precision radiopharmaceutical therapies. In this review, we present the available existing data and highlight the key ongoing clinical evaluations of PSMA-based imaging in the management of primary, biochemically recurrent, and metastatic prostate cancer. We also discuss clinical studies that explore the use of PSMA-based radiopharmaceutical therapy (RPT) in metastatic prostate cancer and forthcoming trials that investigate PSMA RPT in earlier disease states. Multidisciplinary collaboration in clinical trial design and therapeutic administration is critical to the continued progress of this evolving radiotheranostics field.

Novel therapies for metastatic prostate cancer.

INTRODUCTION: Patients with metastatic prostate cancer, especially in the castrate-resistant setting, have a poor prognosis. Many agents have been approved for metastatic prostate cancer, such as androgen receptor pathway inhibitors, taxane-based chemotherapy, radiopharmaceuticals, and immunotherapy. However, prostate cancer remains the leading cause of cancer deaths in nonsmoking men. Fortunately, many more novel agents are under investigation. AREAS COVERED: We provide an overview of the broad group of novel therapies for metastatic prostate cancer, with an emphasis on active and recruiting clinical trials that have been recently published and/or presented at national or international meetings. EXPERT OPINION: The future for patients with metastatic prostate cancer is promising, with further development of novel therapies such as radiopharmaceuticals. Based on a growing understanding of prostate cancer biology, novel agents are being designed to overcome resistance to approved therapies. There are many trials using novel agents either as monotherapy or in combination with already approved agents with potential to further improve outcomes for men with advanced prostate cancer.

Increasing Use of Shorter-Course Radiotherapy for Prostate Cancer.

Importance: Randomized clinical trials have demonstrated the noninferiority of shorter radiotherapy (RT) courses (termed hypofractionation) compared with longer RT courses in patients with localized prostate cancer. Although shorter courses are associated with cost-effectiveness, convenience, and expanded RT access, their adoption remains variable. Objective: To identify the current practice patterns of external beam RT for prostate cancer in the US. Design, Setting, and Participants: This cohort study obtained data from the National Cancer Database, which collects hospital registry data from more than 1500 accredited US facilities on approximately 72% of US patients with cancer. Patients were included in the sample if they had localized prostate adenocarcinoma that was diagnosed between 2004 and 2020 and underwent external beam RT with curative intent. Analyses were conducted between February and March 2023. Exposures: Radiotherapy schedules, which were categorized as ultrahypofractionation (≤7 fractions), moderate hypofractionation (20-30 fractions), and conventional fractionation (31-50 fractions). Main Outcomes and Measures: Longitudinal pattern in RT fractionation schedule was the primary outcome. Multivariable logistic regression was performed to evaluate the variables associated with shorter RT courses. Covariables included age, National Comprehensive Cancer Network risk group, rurality, race, facility location, facility type, median income, insurance type or status, and Charlson-Deyo Comorbidity Index. Results: A total of 313 062 patients with localized prostate cancer (mean [SD] age, 68.8 [7.7] years) were included in the analysis. There was a temporal pattern of decline in the proportion of patients who received conventional fractionation, from 76.0% in 2004 to 36.6% in 2020 (P for trend <.001). From 2004 to 2020, use of moderate hypofractionation increased from 22.0% to 45.0% (P for trend <.001), and use of ultrahypofractionation increased from 2.0% to 18.3% (P for trend <.001). By 2020, the most common RT schedule was ultrahypofractionation for patients in the low-risk group and moderate hypofractionation for patients in the intermediate-risk group. On multivariable analysis, treatment at a community cancer program (compared with academic or research program; odds ratio [OR], 0.54 [95% CI, 0.52-0.56]; P < .001), Medicaid insurance (compared with Medicare; OR, 1.49 [95% CI, 1.41-1.57]; P < .001), Black race (compared with White race; OR, 0.90 [95% CI, 0.87-0.92]; P < .001), and higher median income (compared with lower median income; OR, 1.28 [95% CI, 1.25-1.31]; P < .001) were associated with receipt of shorter courses of RT. Conclusions and Relevance: Results of this cohort study showed an increase in the use of shorter courses of RT for prostate cancer from 2004 to 2020; a number of social determinants of health appeared to be associated with reduced adoption of shorter treatment courses. Realignment of reimbursement models may be necessary to enable broader adoption of ultrahypofractionation to support technology acquisition costs.

Biochemical Recurrence Surrogacy for Clinical Outcomes After Radiotherapy for Adenocarcinoma of the Prostate.

PURPOSE: The surrogacy of biochemical recurrence (BCR) for overall survival (OS) in localized prostate cancer remains controversial. Herein, we evaluate the surrogacy of BCR using different surrogacy analytic methods. MATERIALS AND METHODS: Individual patient data from 11 trials evaluating radiotherapy dose escalation, androgen deprivation therapy (ADT) use, and ADT prolongation were obtained. Surrogate candidacy was assessed using the Prentice criteria (including landmark analyses) and the two-stage meta-analytic approach (estimating Kendall's tau and the R2). Biochemical recurrence-free survival (BCRFS, time from random assignment to BCR or any death) and time to BCR (TTBCR, time from random assignment to BCR or cancer-specific deaths censoring for noncancer-related deaths) were assessed. RESULTS: Overall, 10,741 patients were included. Dose escalation, addition of short-term ADT, and prolongation of ADT duration significantly improved BCR (hazard ratio [HR], 0.71 [95% CI, 0.63 to 0.79]; HR, 0.53 [95% CI, 0.48 to 0.59]; and HR, 0.54 [95% CI, 0.48 to 0.61], respectively). Adding short-term ADT (HR, 0.91 [95% CI, 0.84 to 0.99]) and prolonging ADT (HR, 0.86 [95% CI, 0.78 to 0.94]) significantly improved OS, whereas dose escalation did not (HR, 0.98 [95% CI, 0.87 to 1.11]). BCR at 48 months was associated with inferior OS in all three groups (HR, 2.46 [95% CI, 2.08 to 2.92]; HR, 1.51 [95% CI, 1.35 to 1.70]; and HR, 2.31 [95% CI, 2.04 to 2.61], respectively). However, after adjusting for BCR at 48 months, there was no significant treatment effect on OS (HR, 1.10 [95% CI, 0.96 to 1.27]; HR, 0.96 [95% CI, 0.87 to 1.06] and 1.00 [95% CI, 0.90 to 1.12], respectively). The patient-level correlation (Kendall's tau) for BCRFS and OS ranged between 0.59 and 0.69, and that for TTBCR and OS ranged between 0.23 and 0.41. The R2 values for trial-level correlation of the treatment effect on BCRFS and TTBCR with that on OS were 0.563 and 0.160, respectively. CONCLUSION: BCRFS and TTBCR are prognostic but failed to satisfy all surrogacy criteria. Strength of correlation was greater when noncancer-related deaths were considered events.

Use of the Decipher genomic classifier among men with prostate cancer in the United States.

BACKGROUND: Management of localized or recurrent prostate cancer since the 1990s has been based on risk stratification using clinicopathological variables, including Gleason score, T stage (based on digital rectal exam), and prostate-specific antigen (PSA). In this study a novel prognostic test, the Decipher Prostate Genomic Classifier (GC), was used to stratify risk of prostate cancer progression in a US national database of men with prostate cancer. METHODS: Records of prostate cancer cases from participating SEER (Surveillance, Epidemiology, and End Results) program registries, diagnosed during the period from 2010 through 2018, were linked to records of testing with the GC prognostic test. Multivariable analysis was used to quantify the association between GC scores or risk groups and use of definitive local therapy after diagnosis in the GC biopsy-tested cohort and postoperative radiotherapy in the GC-tested cohort as well as adverse pathological findings after prostatectomy. RESULTS: A total of 572 545 patients were included in the analysis, of whom 8927 patients underwent GC testing. GC biopsy-tested patients were more likely to undergo active active surveillance or watchful waiting than untested patients (odds ratio [OR] =2.21, 95% confidence interval [CI] = 2.04 to 2.38, P < .001). The highest use of active surveillance or watchful waiting was for patients with a low-risk GC classification (41%) compared with those with an intermediate- (27%) or high-risk (11%) GC classification (P < .001). Among National Comprehensive Cancer Network patients with low and favorable-intermediate risk, higher GC risk class was associated with greater use of local therapy (OR = 4.79, 95% CI = 3.51 to 6.55, P < .001). Within this subset of patients who were subsequently treated with prostatectomy, high GC risk was associated with harboring adverse pathological findings (OR = 2.94, 95% CI = 1.38 to 6.27, P = .005). Use of radiation after prostatectomy was statistically significantly associated with higher GC risk groups (OR = 2.69, 95% CI = 1.89 to 3.84). CONCLUSIONS: There is a strong association between use of the biopsy GC test and likelihood of conservative management. Higher genomic classifier scores are associated with higher rates of adverse pathology at time of surgery and greater use of postoperative radiotherapy.In this study the Decipher Prostate Genomic Classifier (GC) was used to analyze a US national database of men with prostate cancer. Use of the GC was associated with conservative management (ie, active surveillance). Among men who had high-risk GC scores and then had surgery, there was a 3-fold higher chance of having worrisome findings in surgical specimens.

Lutetium-177 PSMA for the treatment of metastatic castrate resistant prostate cancer: a systematic review.

INTRODUCTION: Metastatic castrate resistant prostate cancer (mCPRC) remains an aggressive form of prostate cancer that no longer responds to traditional hormonal treatment alone. Despite the advent of novel anti-androgen medications, many patients continue to progress, and as a result, there is a growing need for additional treatment options. AREAS COVERED: Lutetium-177 (177Lu) - PSMA-617 has become one of the new frontline treatment options for refractory metastatic castrate resistant prostate cancer after the failure of novel anti-androgen therapy and chemotherapy. Lu-177 has been used in real-world prospective trials and is now becoming utilized in newer phase III clinical trials. Here, we present a comprehensive overview of the current literature, covering retrospective studies, prospective studies, and clinical trials that established Lutetium-177-PSMA-617 (177Lu-PSMA-617) for the treatment of mCRPC. EXPERT OPINION: 177Lu - PSMA-617 has been approved for treatment of mCRPC based on positive phase III studies. While this treatment is tolerable and effective, biomarkers are necessary to determine which patients will benefit. In the future, radioligand treatments will likely be utilized in earlier lines of therapy and potentially in combination with other prostate cancer treatments.

Evaluation of Social Determinants of Health and Prostate Cancer Outcomes Among Black and White Patients: A Systematic Review and Meta-analysis.

Importance: As the field of medicine strives for equity in care, research showing the association of social determinants of health (SDOH) with poorer health care outcomes is needed to better inform quality improvement strategies. Objective: To evaluate the association of SDOH with prostate cancer-specific mortality (PCSM) and overall survival (OS) among Black and White patients with prostate cancer. Data Sources: A MEDLINE search was performed of prostate cancer comparative effectiveness research from January 1, 1960, to June 5, 2020. Study Selection: Two authors independently selected studies conducted among patients within the United States and performed comparative outcome analysis between Black and White patients. Studies were required to report time-to-event outcomes. A total of 251 studies were identified for review. Data Extraction and Synthesis: Three authors independently screened and extracted data. End point meta-analyses were performed using both fixed-effects and random-effects models. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was followed, and 2 authors independently reviewed all steps. All conflicts were resolved by consensus. Main Outcomes and Measures: The primary outcome was PCSM, and the secondary outcome was OS. With the US Department of Health and Human Services Healthy People 2030 initiative, an SDOH scoring system was incorporated to evaluate the association of SDOH with the predefined end points. The covariables included in the scoring system were age, comorbidities, insurance status, income status, extent of disease, geography, standardized treatment, and equitable and harmonized insurance benefits. The scoring system was discretized into 3 categories: high (≥10 points), intermediate (5-9 points), and low (<5 points). Results: The 47 studies identified comprised 1 019 908 patients (176 028 Black men and 843 880 White men; median age, 66.4 years [IQR, 64.8-69.0 years]). The median follow-up was 66.0 months (IQR, 41.5-91.4 months). Pooled estimates found no statistically significant difference in PCSM for Black patients compared with White patients (hazard ratio [HR], 1.08 [95% CI, 0.99-1.19]; P = .08); results were similar for OS (HR, 1.01 [95% CI, 0.95-1.07]; P = .68). There was a significant race-SDOH interaction for both PCSM (regression coefficient, -0.041 [95% CI, -0.059 to 0.023]; P < .001) and OS (meta-regression coefficient, -0.017 [95% CI, -0.033 to -0.002]; P = .03). In studies with minimal accounting for SDOH (<5-point score), Black patients had significantly higher PCSM compared with White patients (HR, 1.29; 95% CI, 1.17-1.41; P < .001). In studies with greater accounting for SDOH variables (≥10-point score), PCSM was significantly lower among Black patients compared with White patients (HR, 0.86; 95% CI, 0.77-0.96; P = .02). Conclusions and Relevance: The findings of this meta-analysis suggest that there is a significant interaction between race and SDOH with respect to PCSM and OS among men with prostate cancer. Incorporating SDOH variables into data collection and analyses are vital to developing strategies for achieving equity.

Sequencing of Androgen-Deprivation Therapy of Short Duration With Radiotherapy for Nonmetastatic Prostate Cancer (SANDSTORM): A Pooled Analysis of 12 Randomized Trials.

PURPOSE: The sequencing of androgen-deprivation therapy (ADT) with radiotherapy (RT) may affect outcomes for prostate cancer in an RT-field size-dependent manner. Herein, we investigate the impact of ADT sequencing for men receiving ADT with prostate-only RT (PORT) or whole-pelvis RT (WPRT). MATERIALS AND METHODS: Individual patient data from 12 randomized trials that included patients receiving neoadjuvant/concurrent or concurrent/adjuvant short-term ADT (4-6 months) with RT for localized disease were obtained from the Meta-Analysis of Randomized trials in Cancer of the Prostate consortium. Inverse probability of treatment weighting (IPTW) was performed with propensity scores derived from age, initial prostate-specific antigen, Gleason score, T stage, RT dose, and mid-trial enrollment year. Metastasis-free survival (primary end point) and overall survival (OS) were assessed by IPTW-adjusted Cox regression models, analyzed independently for men receiving PORT versus WPRT. IPTW-adjusted Fine and Gray competing risk models were built to evaluate distant metastasis (DM) and prostate cancer-specific mortality. RESULTS: Overall, 7,409 patients were included (6,325 neoadjuvant/concurrent and 1,084 concurrent/adjuvant) with a median follow-up of 10.2 years (interquartile range, 7.2-14.9 years). A significant interaction between ADT sequencing and RT field size was observed for all end points (P interaction < .02 for all) except OS. With PORT (n = 4,355), compared with neoadjuvant/concurrent ADT, concurrent/adjuvant ADT was associated with improved metastasis-free survival (10-year benefit 8.0%, hazard ratio [HR], 0.65; 95% CI, 0.54 to 0.79; P < .0001), DM (subdistribution HR, 0.52; 95% CI, 0.33 to 0.82; P = .0046), prostate cancer-specific mortality (subdistribution HR, 0.30; 95% CI, 0.16 to 0.54; P < .0001), and OS (HR, 0.69; 95% CI, 0.57 to 0.83; P = .0001). However, in patients receiving WPRT (n = 3,049), no significant difference in any end point was observed in regard to ADT sequencing except for worse DM (HR, 1.57; 95% CI, 1.20 to 2.05; P = .0009) with concurrent/adjuvant ADT. CONCLUSION: ADT sequencing exhibits a significant impact on clinical outcomes with a significant interaction with field size. Concurrent/adjuvant ADT should be the standard of care where short-term ADT is indicated in combination with PORT.

Nonoperative Management Following Complete Response in Rectal Cancer After Short-course Radiation Therapy and Consolidation Chemotherapy: Clinical Outcomes and Quality of Life Measures.

PURPOSE: The purpose of his study was to report on a cohort of patients managed with nonoperative management (NOM) with a watch-and-wait strategy after achieving complete response (CR) to sequential short-course radiation therapy (SCRT) and consolidation chemotherapy. METHODS: This was a retrospective study of patients treated SCRT and chemotherapy who achieved a CR and were managed with NOM. Bowel function was assessed with European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30, EORTC Quality of Life Questionnaire-Colorectal Cancer 29, and the low anterior resection syndrome (LARS) questionnaires. Endpoints included overall survival (OS), freedom from local failure (FFLF), freedom from distant metastasis, and disease-free survival (DFS). RESULTS: Twenty-six patients met inclusion criteria. Seven (26.9%) patients developed local failure at a median of 6.8 months following CR, of which 5 were successfully salvaged. Median FFLF was not reached, with 6-month, 1-, and 2-year FFLF rates of 100.0%, 82.3%, and 71.3%. Median OS was not reached, with 6-month, 1-, and 2-year OS rates of 100%. Median DFS was not reached, with 6-month, 1-, and 2-year DFS rates of 100%, 95.0%, and 89.4%. Questionnaire response rate was 83.3%. Median LARS score was 27. Major, minor, and no LARS occurred in 3 (20%), 6 (40%), and 6 (40%) patients, respectively. There were no differences in questionnaire scores between patients who had the majority of their anal sphincter complex irradiated and those who did not. CONCLUSION: NOM with a watch-and-wait strategy is safe and feasible in patients with locally advanced rectal cancer who achieve CR after sequential SCRT and chemotherapy, with evidence for good anorectal function.

Lutetium-177 Prostate-Specific Membrane Antigen Therapy: A Practical Review.

Prostate-specific membrane antigen is a transmembrane protein found predominately on prostate epithelium and is expressed at high levels in prostate cancer. In this review, we discuss the background, clinical data, patient selection, side effects, and necessary resources to deliver lutetium-177 prostate-specific membrane antigen in the research setting, or as standard of care if approved by the United States Food and Drug Administration. Targeted radionuclide therapeutics require understanding of fundamental principles of radiobiology and physics, and radiation oncologists and medical physicists are well-suited to play an integral role in their delivery and treatment response monitoring as key components of a multidisciplinary care team.

Lutetium-177 DOTATATE: A Practical Review.

Neuroendocrine tumors (NETs) are a heterogeneous group of tumors that originate in endocrine tissues throughout the body. Though most are indolent, clinical outcomes vary greatly based on histologic differentiation and grade. Peptide receptor radionuclide therapy has emerged as a promising treatment for patients with locally advanced and/or metastatic disease refractory to standard of care treatment. The phase III NETTER-1 trial found that [177Lu] Lu-DOTA-[Tyr3]-octreotate improved disease-free survival versus octreotide alone for somatostatin receptor-positive gastroenteropancreatic NETs and had a favorable toxicity profile, leading to Food and Drug Administration approval. [177Lu] Lu-DOTA-[Tyr3]-octreotate is an important new treatment that expands the role of radiation in the treatment of NETs. Several important trials are ongoing to better elucidate the role of this treatment.