Radiation therapy and IRreversible electroporation for intermediate risk prostate cancer (RTIRE).

INTRODUCTION: Radiation Therapy and IRreversible Electroporation for Intermediate Risk Prostate Cancer (RTIRE) is a phase II clinical trial testing combination of radiation therapy and irreversible electroporation for intermediate risk prostate cancer BACKGROUND: PCa is the most common non-cutaneous cancer in men and the second leading cause of cancer death in men. PCa treatment is associated with long term side effects including urinary, sexual, and bowel dysfunction. Management of PCa is based on risk stratification to prevent its overtreatment and associated treatment-related toxicity. There is increasing interest in novel treatment strategies, such as focal therapy, to minimize treatment associated morbidity. Focal therapy alone has yet to be included in mainstream guidelines, given ongoing concerns with potentially higher risk of recurrence. We hypothesize combining focal therapy with whole gland, reduced dose radiotherapy will provide acceptable oncologic efficacy with minimal treatment associated morbidity. RTIRE is a phase II single institution, investigator-initiated study combining a local ablative technique though local irreversible electroporation (IRE) with MR guided RT (MRgRT) to treat the entire prostate. The goal is to provide excellent oncologic outcomes and minimize treatment related side effects through leveraging benefits of locally ablative therapy with established radiation treatment techniques. METHODS: A total of 42 men with intermediate risk PCa per NCCN guidelines and focal grade group (GG) 2 or 3, Gleason Score (GS) 3 + 4 or GS 4 + 3, cancer in an MRI target will be enrolled. Patients with MRI visible foci of GG2/GG3 will undergo focal therapy with IRE of this lesion. Following successful focal therapy, patients will then undergo a course of reduced dose, whole gland MRgRT with either 32.5 Gy in 5 Fractions or 22 Gy in 2 fractions. The primary objective of the study is to determine safety. Secondary outcomes include evaluation of oncologic efficacy (as measured by the proportion of patients free of clinically significant cancer as defined as > Grade Group 1 at 1-year follow-up biopsy), imaging characteristics of patients pre and post RTIRE, impact on quality of life (QoL), and PSA kinetics. DISCUSSION: Combining IRE with a reduced dose radiotherapy may offer a new treatment paradigm for PCa by both reducing treatment effects of full dose radiotherapy and minimizing the risk of recurrence observed with focal therapy. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT05345444. Date of registration: April 25, 2022. PROTOCOL VERSION: 6.0, July 7, 2023.

A randomized phase II trial of MR-guided prostate stereotactic body radiotherapy administered in 5 or 2 fractions for localized prostate cancer (FORT).

BACKGROUND: Ultra-hypofractionated regimens for definitive prostate cancer (PCa) radiotherapy are increasingly utilized due in part to promising safety and efficacy data complemented by greater patient convenience from a treatment course requiring fewer sessions. As such, stereotactic body radiation therapy (SBRT) is rapidly emerging as a standard definitive treatment option for patients with localized PCa. The commercially available magnetic resonance linear accelerator (MR-LINAC) integrates MR imaging with radiation delivery, providing several theoretical advantages compared to computed tomography (CT)-guided radiotherapy. MR-LINAC technology facilitates improved visualization of the prostate, real-time intrafraction tracking of prostate and organs-at-risk (OAR), and online adaptive planning to account for target movement and anatomical changes. These features enable reduced treatment volume margins and improved sparing of surrounding OAR. The theoretical advantages of MR-guided radiotherapy (MRgRT) have recently been shown to significantly reduce rates of acute grade ≥ 2 GU toxicities as reported in the prospective randomized phase III MIRAGE trial, which compared MR-LINAC vs CT-based 5 fraction SBRT in patients with localized PCa (Kishan et al. JAMA Oncol 9:365-373, 2023). Thus, MR-LINAC SBRT-utilizing potentially fewer treatments-is warranted and clinically relevant for men with low or intermediate risk PCa electing for radiotherapy as definitive treatment. METHODS/DESIGN: A total of 136 men with treatment naïve low or intermediate risk PCa will be randomized in a 1:1 ratio to 5 or 2 fractions of MR-guided SBRT using permuted block randomization. Randomization is stratified by baseline Expanded PCa Index Composite (EPIC) bowel and urinary domain scores. Patients undergoing 5 fractions will receive 37.5 Gy to the prostate over 10-14 days and patients undergoing 2 fractions will receive 25 Gy to the prostate over 7-10 days. The co-primary endpoints are GI and GU toxicities as measured by change scores in the bowel and urinary EPIC domains, respectively. The change scores will be calculated as pre-treatment (baseline) score subtracted from the 2-year score. DISCUSSION: FORT is an international, multi-institutional prospective randomized phase II trial evaluating whether MR-guided SBRT delivered in 2 fractions versus 5 fractions is non-inferior from a gastrointestinal (GI) and genitourinary (GU) toxicity standpoint at 2 years post-treatment in men with low or intermediate risk PCa. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04984343 . Date of registration: July 30, 2021. PROTOCOL VERSION: 4.0, Nov 8, 2022.

Randomized phase II trial of MRI-guided salvage radiotherapy for prostate cancer in 4 weeks versus 2 weeks (SHORTER).

BACKGROUND: Ultra-hypofractionated image-guided stereotactic body radiotherapy (SBRT) is increasingly used for definitive treatment of localized prostate cancer. Magnetic resonance imaging-guided radiotherapy (MRgRT) facilitates improved visualization, real-time tracking of targets and/or organs-at-risk (OAR), and capacity for adaptive planning which may translate to improved targeting and reduced toxicity to surrounding tissues. Given promising results from NRG-GU003 comparing conventional and moderate hypofractionation in the post-operative setting, there is growing interest in exploring ultra-hypofractionated post-operative regimens. It remains unclear whether this can be done safely and whether MRgRT may help mitigate potential toxicity. SHORTER (NCT04422132) is a phase II randomized trial prospectively evaluating whether salvage MRgRT delivered in 5 fractions versus 20 fractions is non-inferior with respect to gastrointestinal (GI) and genitourinary (GU) toxicities at 2-years post-treatment. METHODS: A total of 136 patients will be randomized in a 1:1 ratio to salvage MRgRT in 5 fractions or 20 fractions using permuted block randomization. Patients will be stratified according to baseline Expanded Prostate Cancer Index Composite (EPIC) bowel and urinary domain scores as well as nodal treatment and androgen deprivation therapy (ADT). Patients undergoing 5 fractions will receive a total of 32.5 Gy over 2 weeks and patients undergoing 20 fractions will receive a total of 55 Gy over 4 weeks, with or without nodal coverage (25.5 Gy over 2 weeks and 42 Gy over 4 weeks) and ADT as per the investigator's discretion. The co-primary endpoints are change scores in the bowel and the urinary domains of the EPIC. The change scores will reflect the 2-year score minus the pre-treatment (baseline) score. The secondary endpoints include safety endpoints, including change in GI and GU symptoms at 3, 6, 12 and 60 months from completion of treatment, and efficacy endpoints, including time to progression, prostate cancer specific survival and overall survival. DISCUSSION: The SHORTER trial is the first randomized phase II trial comparing toxicity of ultra-hypofractionated and hypofractionated MRgRT in the salvage setting. The primary hypothesis is that salvage MRgRT delivered in 5 fractions will not significantly increase GI and GU toxicities when compared to salvage MRgRT delivered in 20 fractions. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04422132. Date of registration: June 9, 2020.

Natural history of lower urinary tract symptoms among men undergoing stereotactic body radiation therapy for prostate cancer with and without a Rectal Hydrogel Spacer.

PURPOSE: Stereotactic body radiation therapy (SBRT) is increasingly used for prostate cancer, but has morbidity as both the bladder and rectum are radiated during treatment. Our goal was to document and compare lower urinary tract symptoms (LUTS) among men who underwent SBRT with and without SpaceOAR hydrogel (Augmenix, Inc., Bedford, MA). METHODS: We performed a retrospective analysis of 87 men (50 SpaceOAR and 37 non-SpaceOAR) who underwent SBRT. Primary outcomes were patient reported symptoms during radiation therapy, pharmacotherapy usage, and urologic and bowel survey scores up to 6-months post-SBRT. RESULTS: 78% of men were on α-inhibitors at the end of SBRT, an increase from 27.6% baseline usage (p < 0.001). Post-SBRT urinary frequency was more common in the non-SpaceOAR group versus the SpaceOAR group (68% versus 38%, p = 0.006), as was nocturia (35% vs. 8%, p = 0.002). Acute gastrointestinal symptoms did not differ. 58.8% of men were on α-inhibitors at 6-months of follow-up post-SBRT, an increase from 27.6% baseline usage (p < 0.001). Importantly, there was a difference of α-inhibitor use between non-SpaceOAR and SpaceOAR groups at the end of SBRT and at 1.5-, 3-, and 6-months follow up (86% vs. 53% [p = 0.002], 83% vs. 53% [p = 0.005], 72% vs. 49% [p = 0.038], respectively). CONCLUSION: LUTS after SBRT remains a significant problem for men undergoing treatment for prostate cancer. LUTS affects men during and up to 6-months following SBRT. Owing to these increased LUTS, preemptive minimally invasive solutions and their mechanisms of protection, including the SpaceOAR, should be further investigated.

Active Surveillance for Men with Intermediate Risk Prostate Cancer.

PURPOSE: Optimal treatment of intermediate risk prostate cancer remains unclear. National Comprehensive Cancer Network® guidelines recommend active surveillance, prostatectomy or radiotherapy. Recent trials demonstrated no difference in prostate cancer specific mortality for men undergoing active surveillance for low risk prostate cancer compared to prostatectomy or radiotherapy. The use of active surveillance for intermediate risk prostate cancer is less clear. In this study we characterize U.S. national trends for demographic, clinical and socioeconomic factors associated with active surveillance for men with intermediate risk prostate cancer. MATERIALS AND METHODS: This retrospective cohort study examined 176,122 men diagnosed with intermediate risk prostate cancer from 2010 to 2016 in the National Cancer Database. Temporal trends in demographic, clinical and socioeconomic factors among men with intermediate risk prostate cancer and association with the use of active surveillance were characterized. The analysis was performed in April 2020. RESULTS: In total, 176,122 men were identified with intermediate risk prostate cancer from 2010 to 2016. Of these men 57.3% underwent prostatectomy, 36.4% underwent radiotherapy and 3.2% underwent active surveillance. Active surveillance nearly tripled from 1.6% in 2010 to 4.6% in 2016 (p <0.001). On multivariate analysis use of active surveillance was associated with older age, diagnosis in recent years, lower Gleason score and tumor stage, type of insurance, treatment at an academic center and proximity to facility, and attaining higher education (p <0.05). Race and comorbidities were not associated with active surveillance. CONCLUSIONS: Our findings highlight increasing active surveillance use for men with intermediate risk prostate cancer demonstrating clinical and socioeconomic disparities. Prospective data and improved risk stratification are needed to guide optimal treatment for men with intermediate risk prostate cancer.

Ductal Carcinoma in Situ in Young Women: Increasing Rates of Mastectomy and Variability in Endocrine Therapy Use.

BACKGROUND: Young women with ductal carcinoma in situ (DCIS) represent a unique cohort given considerations for future risk reduction and treatment effects on fertility and quality of life. We evaluated national patterns of care in the treatment of young women and the impact of those treatments on overall survival (OS). METHODS: Women younger than 50 years of age diagnosed with pure DCIS from 2004 to 2016 in the National Cancer Database (NCDB) were identified. Clinical, demographic, and choice of local therapy are summarized and trended over time. OS was analyzed using Cox proportional hazard models. RESULTS: A total of 52,150 women were identified, and the most common surgical treatment was breast-conservation surgery (BCS; 59%). Bilateral mastectomy (BM) increased in frequency from 2004 to 2016 (11-27%; p < 0.001). In women < 40 years of age, BM (39%) surpassed BCS (35%) in 2010 with a continued upward trend. On multivariable analysis, no OS benefit of BM (hazard ratio [HR] 0.99, p = 0.90) or unilateral mastectomy (UM; HR 0.98, p = 0.80) was observed when compared with BCS + radiation therapy (RT). Inferior OS was seen with BCS, Black race, estrogen receptor (ER)-negative, and tumor ≥ 2.5 cm (p ≤ 0.006). In ER+ patients, there was a significant difference in endocrine therapy (ET) use between BM (11%), UM (33%), and BCS (28%) compared with BCS + RT (64%, p < 0.001). CONCLUSION: The use of BM for DCIS is increasing in younger patients and now exceeds breast-conservation approaches in women < 40 years of age with no evidence of improved OS. Among ER+ patients, the rates of ET are lower in the BM, UM, and BCS-alone groups compared with BCS + RT.

Deep learning-based synthetic CT generation for MR-only radiotherapy of prostate cancer patients with 0.35T MRI linear accelerator.

PURPOSE: To develop a deep learning model to generate synthetic CT for MR-only radiotherapy of prostate cancer patients treated with 0.35 T MRI linear accelerator. MATERIALS AND METHODS: A U-NET convolutional neural network was developed to translate 0.35 T TRUFI MRI into electron density map using a novel cost function equalizing the contribution of various tissue types including fat, muscle, bone, and background air in training. The impact of training time, dataset size, image standardization, and data augmentation approaches was also quantified. Mean absolute error (MAE) between synthetic and planning CTs was calculated to measure the goodness of the model. RESULTS: With 20 patients in training, our U-NET model has the potential to generate synthetic CT with a MAE of about 29.68 ± 4.41, 16.34 ± 2.67, 23.36 ± 2.85, and 105.90 ± 22.80 HU over the entire body, fat, muscle, and bone tissues, respectively. As expected, we found that the number of patients used for training and MAE are nonlinearly correlated. Data augmentation and our proposed loss function were effective to improve MAE by ~9% and ~18% in bony voxels, respectively. Increasing the training time and image standardization did not improve the accuracy of the model. CONCLUSION: A U-NET model has been developed and tested numerically to generate synthetic CT from 0.35T TRUFI MRI for MR-only radiotherapy of prostate cancer patients. Dosimetric evaluation using a large and independent dataset warrants the validity of the proposed model and the actual number of patients needed for the safe usage of the model in routine clinical workflow.

Quantifying the impact of SpaceOAR hydrogel on inter-fractional rectal and bladder dose during 0.35 T MR-guided prostate adaptive radiotherapy.

PURPOSE: To investigate the impact of rectal spacing on inter-fractional rectal and bladder dose and the need for adaptive planning in prostate cancer patients undergoing SBRT with a 0.35 T MRI-Linac. MATERIALS AND METHODS: We evaluated and compared SBRT plans from prostate cancer patients with and without rectal spacer who underwent treatment on a 0.35 T MRI-Linac. Each group consisted of 10 randomly selected patients that received prostate SBRT to a total dose of 36.25 Gy in five fractions. Dosimetric differences in planned and delivered rectal and bladder dose and the number of fractions violating OAR constraints were quantified. We also assessed whether adaptive planning was needed to meet constraints for each fraction. RESULTS: On average, rectal spacing reduced the maximum dose delivered to the rectum by more than 8 Gy (p < 0.001). We also found that D3cc received by the rectum could be 12 Gy higher in patients who did not have rectal spacer (p < 9E-7). In addition, the results show that a rectal spacer can reduce the maximum dose and D15cc to the bladder wall by more than 1 (p < 0.004) and 8 (p < 0.009) Gy, respectively. Our study also shows that using a rectal spacer could reduce the necessity for adaptive planning. The incidence of dose constraint violation was observed in almost 91% of the fractions in patients without the rectal spacer and 52% in patients with implanted spacer. CONCLUSION: Inter-fractional changes in rectal and bladder dose were quantified in patients who underwent SBRT with/without rectal SpaceOAR hydrogel. Rectal spacer does not eliminate the need for adaptive planning but reduces its necessity.

Practice patterns and outcomes for patients with node-negative hormone receptor-positive breast cancer and intermediate 21-gene Recurrence Scores.

BACKGROUND: The recommendation for chemotherapy in early-stage breast cancer patients has been refined by the 21-gene Recurrence Score. However, uncertainty remains whether patients in the Intermediate Risk category benefit from chemotherapy. METHODS: We analyzed female patients from the National Cancer Database from 2006 to 2012 who had pT1c-T2N0M0 breast cancer, were ER/PR-positive and HER2-negative, received endocrine therapy, and had a 21-gene Recurrence Score from 11 to 25. We performed univariate and multivariate logistic regression analyses to see what impacted chemotherapy receipt. We compared overall survival using Kaplan-Meier curves and the log-rank test. A multivariable Cox proportional hazards regression model was used to assess what variables impacted overall survival. RESULTS: Of 21,991 patients who met all inclusion and exclusion criteria, 4646 (21.1%) received chemotherapy and 17,345 (78.9%) did not. Chemotherapy was more often received by patients who were younger (adjusted odds ratios (aORs) compared to age < 40 years, 0.48 for 40s, 0.34 for 50s, 0.20 for 60s, 0.10 for 70s, and 0.07 for 80+), had private insurance vs Medicare (aOR = 1.37), were from metro vs urban counties (aOR = 1.15), and were treated in community cancer centers vs academic programs (aOR = 1.26), and those with tumors of higher grade (grade 2 vs 1, aOR = 1.72; grade 3 vs 1, aOR = 3.76), higher tumor stage (pT2 vs pT1c, aOR = 1.62), or presence of lymphovascular invasion (LVI) (aOR = 1.41). At a median follow-up of 46.4 months, there was no significant difference in overall survival between patients who received chemotherapy vs those who did not (5-year estimated overall survival, 97.4% vs 97.8%, p = 0.89). On multivariable analysis, worse overall survival was associated with Black race, treatment at a community program, Medicaid, high-grade tumors, pT2 vs pT1c, higher Charlson-Deyo score, and no radiotherapy. Utilization trends showed that chemotherapy receipt in these patients has been decreasing from 25.8% in 2010 to 18.4% in 2013 (p < 0.001). CONCLUSIONS: In these patients where the benefit of chemotherapy remains uncertain, current practices see chemotherapy more likely to be used in patients with younger age, higher pathologic T stage, higher grade tumors, and LVI. No apparent difference was seen in overall survival between those who received chemotherapy and those who did not.

Trends in Active Surveillance for Men With Intermediate-Risk Prostate Cancer.

Importance: Initial management of intermediate-risk prostate cancer is evolving, with no clear recommendation for treatment. Data on utilization of active surveillance for patients with newly diagnosed intermediate-risk prostate cancer may help clarify emerging trends. Objective: To further characterize US national trends of initial management of intermediate-risk prostate cancer. Design, Setting, and Participants: This cohort study included patients with intermediate-risk prostate cancer diagnosed from January 1, 2010, to December 31, 2020. Eligible patients were diagnosed in US hospitals included in the National Cancer Database; National Comprehensive Cancer Network risk stratification guidelines were used to characterize as favorable vs unfavorable intermediate risk. Analysis was performed in September 2023. Exposure: Active surveillance vs intervention with surgery and/or radiation or no treatment. Main Outcomes and Measures: Temporal trends in demographic, clinical, and socioeconomic factors among men with intermediate-risk prostate cancer and their association with the use of active surveillance; further subgroup analysis was conducted for those with favorable vs unfavorable intermediate risk classification. Results: In total, 289 584 men diagnosed with intermediate-risk prostate cancer were identified from 2010 to 2020 (46 147 Black [15.9%], 230 071 White [79.5%]). Among patients, 153 726 (53.1%) underwent prostatectomy, 107 152 (37.0%) underwent radiotherapy, and 15 847 (5.5%) underwent active surveillance as initial treatment strategy. Overall, active surveillance quadrupled from 418 of 21 457 patients (2.0%) in 2010 to 2428 of 28 192 patients (8.6%) in 2020 for the entire cohort (P < .001). Active surveillance increased from 317 of 12 858 patients (2.4%) in 2010 to 2020 of 12 902 patients (13.5%) in 2020 in men with favorable intermediate-risk prostate cancer (P < .001). In the unfavorable intermediate-risk cohort, active surveillance increased from 101 of 8181 patients (1.2%) in 2010 to 408 of 12 861 patients (3.1%) in 2020 (P < .001). On multivariable analysis, use of active surveillance was associated with increased age (age 70-80 years vs <50 years: odds ratio [OR], 3.09; 95% CI, 2.66-3.59), lower Gleason score (3 + 3 vs 3 + 4: OR, 3.45; 95% CI, 3.25-3.66), early T stage (T2c vs T1a through T2a: OR, 0.35; 95% CI, 0.32-0.38), treatment at an academic center (community vs academic center: OR, 0.72; 95% CI, 0.67-0.78), higher level of education (communities with 21% or higher population without high school vs less than 7%: OR, 0.73; 95% CI, 0.67-0.79), insurance type (Medicare or other governmental service vs private: OR, 1.11; 95% CI, 1.07-1.16), proximity to treatment facility (greater than 120 miles vs less than 60 miles: OR, 0.75; 95% CI, 0.68-0.84), facility location (South Atlantic vs New England: OR, 0.54; 95% CI, 0.46-0.53), and lower income (less than $38 000 vs $63 000 or greater: OR, 1.22; 95% CI, 1.14-1.31). Conclusions and Relevance: These findings highlight increasing implementation of active surveillance in the initial management of intermediate risk prostate cancer. Prospective data with improved risk stratification incorporating genomics and digital pathology artificial intelligence as well as novel surveillance strategies may continue to better delineate optimal treatment recommendations in this patient population.

MR-LINAC, a New Partner in Radiation Oncology: Current Landscape.

Technological advances in radiation oncology are oriented towards improving treatment precision and tumor control. Among these advances, magnetic-resonance-image-guided radiation therapy (MRgRT) stands out, with technological advances to deliver targeted treatments adapted to a tumor's anatomy on the day while minimizing incidental exposure to organs at risk, offering an unprecedented therapeutic advantage compared to X-ray-based IGRT delivery systems. This new technology changes the traditional workflow in radiation oncology and requires an evolution in team coordination to administer more precise treatments. Once implemented, it paves the way for newer indication for radiation therapy to safely deliver higher doses than ever before, with better preservation of healthy tissues to optimize patient outcomes. In this narrative review, we assess the technical aspects of the novel linear accelerators that can deliver MRgRT and summarize the available published experience to date, focusing on oncological results and future challenges.

Reasons for Discordance between 68Ga-PSMA-PET and Magnetic Resonance Imaging in Men with Metastatic Prostate Cancer.

BACKGROUND: PSMA PET has emerged as a "gold standard" imaging modality for assessing prostate cancer metastases. However, it is not universally available, and this limits its impact. In contrast, whole-body MRI is much more widely available but misses more lesions. This study aims to improve the interpretation of whole-body MRI by comparing false negative scans retrospectively to PSMA PET. METHODS: This study was a retrospective sub-analysis of a prospectively collected database of patients who participated in a clinical trial of PSMA PET/MRI comparing PSMA PET and whole-body MRI from 2018-2021. Subjects whose separately read PSMA PET and MRI diagnostic reports showed discrepancies ("false negative" MRI cases) were selected for sub-analysis. The cases were reviewed by the same attending radiologist who originally read the scans. The radiologist noted specific features on MRI indicating metastatic disease that were initially missed. RESULTS: Of 263 cases, 38 (14%) met the inclusion criteria and were reviewed. Six classes of mpMRI false negatives were identified: anatomically normal (18, 47%), atypical MRI appearance (6, 16%), mischaracterization (1, 3%), undercall (6, 16%), obscured (4, 11%), and no abnormality on MRI (3, 8%). Considering that the atypical and undercalled cases could have been adjusted in retrospect, and that 4 additional cases had positive lesions to the same extent and 11 further cases had disease confined to the pelvis, only 11 (4%) of the original 263 would have had disease outside of a conventional radiation treatment plan. CONCLUSION: Notably, almost 50% of the cases, including most lymph node metastases, were anatomically normal using standard criteria. This suggests that current anatomic criteria for evaluating prostate cancer lymph node metastases are not ideal, and there is a need for improved criteria. In addition, 32% of cases involved some element of human interpretive error, and, therefore, improving reader training may lead to more accurate results.

Intensifying Salvage Therapy in Prostate-specific Antigen Recurrent Prostate Cancer After Radical Prostatectomy with Apalutamide, Salvage Radiation, and Docetaxel: The Phase 2 STARTAR Trial.

BACKGROUND AND OBJECTIVE: Androgen deprivation therapy (ADT) with salvage radiation therapy (RT) improves survival for patients with prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP) for prostate cancer (PC), but many patients suffer further relapse. This study aims to determine the benefit of the combination of ADT, apalutamide, salvage RT, and docetaxel for high-risk PSA recurrent PC. METHODS: STARTAR is a multicenter, investigator-initiated phase 2 trial of men with PSA recurrent PC after RP. The key inclusion criteria included M0 by computed tomography/bone scan, Gleason 7 with either T3/positive margin/N1 disease or Gleason 8-10 prostate adenocarcinoma, PSA relapse (0.2-4 ng/ml) <4 yr after RP, and fewer than four positive resected lymph nodes. Patients received ADT with apalutamide for 9 mo, RT starting week 8, and then six cycles of docetaxel. The primary endpoint was 36-mo progression-free survival (PFS) with testosterone recovery and compared against the prior STREAM trial. KEY FINDINGS AND LIMITATIONS: We enrolled 39 men, including those with Gleason 8-10 (46%), pN1 (23%); the median PSA was 0.58 ng/ml. The median follow-up was 37 mo. All patients achieved undetectable PSA nadir. At 24 and 36 mo, PFS rates were 84% and 71%, respectively, which improved significantly over 3-yr 47% historic PFS and 54% enzalutamide/ADT/RT (STREAM) PFS rates (p = 0.004 and p = 0.039, respectively). Common any-grade adverse events included 98% hot flashes, 88% fatigue, 77% alopecia, 53% rash (10% G3), and 5% febrile neutropenia. CONCLUSIONS AND CLINICAL IMPLICATIONS: In this phase 2 trial of ADT, apalutamide, salvage RT, and six cycles of docetaxel for high-risk PSA recurrence, the 3-yr PFS rate improved to 71%, indicating feasible and efficacious treatment intensification, with durable remissions beyond historic data. PATIENT SUMMARY: Prostate cancer recurrence after surgical removal of the tumor occurs often, and current treatment options to limit recurrence after surgery are only partially effective. In this study, we found that the addition of an androgen receptor inhibitor and docetaxel chemotherapy to standard postsurgery radiation therapy and androgen deprivation therapy significantly improved progression-free survival at 3 yr after treatment. These results suggest that intensification of treatment after surgery can provide long-term benefit to a subset of patients with high-risk prostate cancer.

Transcriptomic Profiling of Primary Prostate Cancers and Nonlocalized Disease on Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography: A Multicenter Retrospective Study.

PURPOSE: To characterize the relationship between Decipher genomic classifier scores and prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-based metastatic spread. MATERIALS AND METHODS: We identified patients from four institutions who underwent PSMA PET/CT scans pretreatment for primary staging or postradical prostatectomy (RP) for suspected recurrence and had Decipher transcriptomic data available from biopsy or RP specimens. PSMA PET/CT-based patterns of spread were classified as localized (miT + N0M0) or nonlocalized (miN1M0 or miM1a-c). We calculated the association between Decipher scores and the risk of nonlocalized disease on PSMA PET/CT using multivariable logistic regression for pretreatment patients and multivariable Cox regression for post-RP patients. We also compared select transcriptomic signatures between patients with localized and nonlocalized diseases. RESULTS: Five hundred eighty-six patients were included (pretreatment: n = 329; post-RP: n = 257). Higher Decipher scores were associated with nonlocalized disease on PSMA PET/CT both pretreatment (odds ratio, 1.18 [95% CI, 1.03 to 1.36] per 0.1 increase in Decipher score, P = .02) and post-RP (hazard ratio, 1.15 [95% CI, 1.05 to 1.27] per 0.1 increase in Decipher score, P = .003). In the pretreatment setting, nonlocalized disease was associated with higher rates of TP53 mutations and lower rates of PAM50 luminal A subtype compared with localized disease. In the post-RP setting, overexpression of signatures related to metabolism, DNA repair, and androgen receptor signaling were associated with higher rates of nonlocalized disease. CONCLUSION: Higher Decipher scores were associated with nonlocalized disease identified on PSMA PET/CT both pretreatment and post-RP. There were several transcriptomic differences between localized and nonlocalized diseases in both settings.

Pulse Sequence Dependence of a Simple and Interpretable Deep Learning Method for Detection of Clinically Significant Prostate Cancer Using Multiparametric MRI.

RATIONALE AND OBJECTIVES: Multiparametric magnetic resonance imaging (mpMRI) is increasingly used for risk stratification and localization of prostate cancer (PCa). Thanks to the great success of deep learning models in computer vision, the potential application for early detection of PCa using mpMRI is imminent. MATERIALS AND METHODS: Deep learning analysis of the PROSTATEx dataset. RESULTS: In this study, we show a simple convolutional neural network (CNN) with mpMRI can achieve high performance for detection of clinically significant PCa (csPCa), depending on the pulse sequences used. The mpMRI model with T2-ADC-DWI achieved 0.90 AUC score in the held-out test set, not significantly better than the model using Ktrans instead of DWI (AUC 0.89). Interestingly, the model incorporating T2-ADC- Ktrans better estimates grade. We also describe a saliency "heat" map. Our results show that csPCa detection models with mpMRI may be leveraged to guide clinical management strategies. CONCLUSION: Convolutional neural networks incorporating multiple pulse sequences show high performance for detection of clinically-significant prostate cancer, and the model including dynamic contrast-enhanced information correlates best with grade.

Prostate cancer grade migration and facility-level treatment trends for grade group 1 disease.

Overdiagnosis and overtreatment of low-grade prostate cancer (PCa) reflect poor quality of care and prompted changes to guidelines over the past decade. We used the National Cancer Database to characterize Gleason Grade Group (GG)1 PCa diagnosis trends and assess facility-level treatment variability. Between 2010 and 2019, GG1 PCa incidence had a clinically and statistically significant decline, from 45% to 25% at biopsy and from 33% to 9.8% at radical prostatectomy (RP) pathology. Similarly, active surveillance (AS) uptake significantly increased to 49% and 62% among nonacademic and academic sites, respectively. Decreasing rates of definitive therapies were identified: among academic sites, RP decreased from 61.1% to 25.3% and radiation therapy (RT) from 25.2% to 12%, whereas among nonacademic sites, RP decreased from 53.6% to 28% and RT from 37.8% to 21.9% (Ptrend < .001). Declines in the diagnosis and treatment of low-grade disease demonstrate an encouraging shift in PCa epidemiology. However, heterogeneity in AS utilization remains and reflects opportunities for improvement.

The role of AI in prostate MRI quality and interpretation: Opportunities and challenges.

Prostate MRI plays an important role in imaging the prostate gland and surrounding tissues, particularly in the diagnosis and management of prostate cancer. With the widespread adoption of multiparametric magnetic resonance imaging in recent years, the concerns surrounding the variability of imaging quality have garnered increased attention. Several factors contribute to the inconsistency of image quality, such as acquisition parameters, scanner differences and interobserver variabilities. While efforts have been made to standardize image acquisition and interpretation via the development of systems, such as PI-RADS and PI-QUAL, the scoring systems still depend on the subjective experience and acumen of humans. Artificial intelligence (AI) has been increasingly used in many applications, including medical imaging, due to its ability to automate tasks and lower human error rates. These advantages have the potential to standardize the tasks of image interpretation and quality control of prostate MRI. Despite its potential, thorough validation is required before the implementation of AI in clinical practice. In this article, we explore the opportunities and challenges of AI, with a focus on the interpretation and quality of prostate MRI.

MRI-LINAC: A transformative technology in radiation oncology.

Advances in radiotherapy technologies have enabled more precise target guidance, improved treatment verification, and greater control and versatility in radiation delivery. Amongst the recent novel technologies, Magnetic Resonance Imaging (MRI) guided radiotherapy (MRgRT) may hold the greatest potential to improve the therapeutic gains of image-guided delivery of radiation dose. The ability of the MRI linear accelerator (LINAC) to image tumors and organs with on-table MRI, to manage organ motion and dose delivery in real-time, and to adapt the radiotherapy plan on the day of treatment while the patient is on the table are major advances relative to current conventional radiation treatments. These advanced techniques demand efficient coordination and communication between members of the treatment team. MRgRT could fundamentally transform the radiotherapy delivery process within radiation oncology centers through the reorganization of the patient and treatment team workflow process. However, the MRgRT technology currently is limited by accessibility due to the cost of capital investment and the time and personnel allocation needed for each fractional treatment and the unclear clinical benefit compared to conventional radiotherapy platforms. As the technology evolves and becomes more widely available, we present the case that MRgRT has the potential to become a widely utilized treatment platform and transform the radiation oncology treatment process just as earlier disruptive radiation therapy technologies have done.

Complex implementation factors demonstrated when evaluating cost-effectiveness and monitoring racial disparities associated with [18F]DCFPyL PET/CT in prostate cancer men.

Prostate cancer (PC) staging with conventional imaging often includes multiparametric magnetic resonance (MR) of the prostate, computed tomography (CT) of the chest, abdomen, and pelvis, and whole-body bone scintigraphy. The recent development of highly sensitive and specific prostate specific membrane antigen (PSMA) positron emission tomography (PET) has suggested that prior imaging techniques may be insufficiently sensitive or specific, particularly when evaluating small pathologic lesions. As PSMA PET/CT is considered to be superior for multiple clinical indications, it is being deployed as the new multidisciplinary standard-of-care. Given this, we performed a cost-effectiveness analysis of [18F]DCFPyL PSMA PET/CT imaging in the evaluation of PC relative to conventional imaging and anti-3-[18F]FACBC (18F-Fluciclovine) PET/CT. We also conducted a single institution review of PSMA PET/CT scans performed primarily for research indications from January 2018 to October 2021. Our snapshot of this period of time in our catchment demonstrated that PSMA PET/CT imaging was disproportionately accessed by men of European ancestry (EA) and those residing in zip codes associated with a higher median household income. The cost-effectiveness analysis demonstrated that [18F]DCFPyL PET/CT should be considered as an alternative to anti-3-[18F]FACBC PET/CT and standard of care imaging for prostate cancer staging. [18F]DCFPyL PET/CT is a new imaging modality to evaluate PC patients with higher sensitivity and specificity in detecting disease than other prostate specific imaging studies. Despite this, access may be inequitable. This discrepancy will need to be addressed proactively as the distribution network of the radiotracer includes both academic and non-academic sites nationwide.