Impact of a rash management guide in patients receiving apalutamide for high-risk localized prostate cancer in the Apa-RP study.

BACKGROUND/OBJECTIVES: Based on the SPARTAN and TITAN studies, apalutamide is approved for patients with nonmetastatic castration-resistant and metastatic castration-sensitive prostate cancer. Skin rash was a common adverse reaction across indications. We hypothesized that earlier identification and intervention could improve rash outcomes. SUBJECTS/METHODS: A prespecified rash management guide outlining recommended skin care practices was provided to all patients enrolled in Apa-RP (NCT04523207). Rash-related safety data from Apa-RP were compared descriptively with data from SPARTAN and TITAN. RESULTS: Patients in Apa-RP experienced improved rash-related outcomes vs those in SPARTAN and TITAN. CONCLUSIONS: Increased vigilance and proactive management may reduce the incidence, severity, and duration of rash during apalutamide treatment.

Malignant Tumors Identified in Adult Polycystic Kidney Disease Can Be Derived from Both Proximal Tubular and Distal Tubular Origins.

Adult polycystic kidney disease (APKD) is a genetic disorder leading to premature renal dysfunction and failure. The prevalence of malignant renal tumors occurring in the APKD setting has been rarely reported. OBJECTIVE: To better characterize malignant renal tumors in nephrectomy specimens of APKD and apply modern pathologic evaluation. METHODS: We reviewed our database of APKD specimens over the past 11 years (from 2012 to 2023) for primary malignant tumors within the kidneys of APKD. RESULTS: Of 48 nephrectomy specimens with APKD evaluated, 10 malignant renal tumors were identified, indicating a prevalence of 20.8 % (10/48). These included three clear cell (cc) renal cell carcinomas (RCC) (ranging from 1 mm to 6.7 cm), three papillary RCCs (2.5, 3.5, and 14 cm with lymph node metastasis), two cases of clear cell papillary (CCP) RCC, one acquired cystic disease (ACD) with associated RCC (4 mm), and one urothelial adenocarcinoma. The urothelial adenocarcinoma was found near a tubulovillous adenoma in a collecting duct and stained positively for GATA3 and Uroplakin-2 but was negative for PAX8 & CDX2. The tumor showed extensive invasion into perirenal fatty tissue and the rectum. Next generating sequencing (NGS) analysis of the tumor showed mutations in TERT, RB1, TP53, ERBB2, and TET1 genes, further supporting its urothelial origin. CONCLUSIONS: We found a prevalence of 20.8%, which was higher than in previous reports of malignant renal tumors in patients who underwent resections for APKD. Renal tumors were mostly from damaged proximal tubular origins (clear cell or papillary RCC), but less commonly were from distal tubular or urothelial cells as well (clear cell papillary RCC and urothelial adenocarcinoma).

Association of Baseline Magnetic Resonance Imaging Prostate Imaging Reporting and Data System Score With Prostate Cancer Active Surveillance Early Biopsy Reclassification: Data From the Michigan Urological Surgery Improvement Collaborative (MUSIC).

PURPOSE: The purpose of our study was to evaluate the association of baseline MRI Prostate Imaging Reporting and Data System (PI-RADS) score with biopsy reclassification in a multicenter active surveillance (AS) cohort. MATERIALS AND METHODS: We identified men in the Michigan Urological Surgery Improvement Collaborative registry (46 hospital-based/academic/private practice urology groups) with National Comprehensive Cancer Network (NCCN) low-risk and favorable intermediate-risk prostate cancer who underwent MRI within 6 months before or after initial biopsy and enrolled in AS from June 2016 to January 2021. The primary objective was to determine the association of baseline MRI PI-RADS score (≥4 lesion) with reclassification to high-grade prostate cancer (≥grade group 3) on surveillance biopsy. Multivariable Cox proportional hazards regression models were constructed and adjusted for pathologic, MRI, and clinical/biopsy factors, with landmark time of 6 months from diagnostic biopsy. We included an interaction term between PI-RADS score and NCCN group in the Cox model. RESULTS: A total of 1491 men were included with median age 64 years (IQR: 59-69) with median follow-up 11.0 months (IQR: 6.0-23.0) after landmark. Baseline PI-RADS ≥ 4 lesion was associated with an increased hazard of biopsy reclassification (HR: 2.3 [95% CI: 1.6-3.2], P < .001), along with grade group 2 vs 1 (HR: 2.5 [95% CI: 1.7-3.7], P < .001), and increasing age (per 10 years; HR: 1.8 [95% CI: 1.4-2.4], P < .001). The interaction between NCCN risk group with MRI findings was not significant (P = .7). CONCLUSIONS: In this multicenter cohort study of real-world data, baseline MRI PI-RADS score was significantly associated with early biopsy reclassification in men undergoing AS with NCCN low- or favorable intermediate-risk prostate cancer.

The Impact of Polymerase Chain Reaction Urine Testing on Clinical Decision-Making in the Management of Complex Urinary Tract Infections.

While urinary polymerase chain reaction (PCR) testing is effective in organism identification in patients with complex urinary tract infections (cUTI), limited data exists on the clinical usefulness of this test. We serially surveyed physicians treating symptomatic patients with cUTI both at presentation and after PCR, and urine culture (UC) results were available to ascertain how the test results modified the therapy. A total of 96 unique surveys completed by 21 providers were included in the data analysis. The mean age for female and male patients was 69.4 ± 15.5 and 71.6 ± 12.7 years, respectively. The test positivity and line-item concordance for UC and PCR were consistent with prior reports. The PCR results modified or confirmed treatment in 59/96 (61.5%) and 25/96 (26.0%) of the cases, respectively, with 12/29 (41.4%) and 47/67 (70.1%) having negative and positive PCR results, respectively, resulting in treatment change (difference 28.7%, p < 0.01). Of these, 55/59 (57.3%) were alterations in the antibiotic regimen. PCR use to modify treatment was similar across providers and not statistically different when stratified by patient age, gender, or prior empiric therapy. In 31/59 (52.5%) of the cases, the PCR results modified the treatment where UC would not; conversely, UC would have modified the treatment in 3/37 (8.1%) of the cases where PCR did not (difference 44.4%, p < 0.01). We find that PCR test results are used by clinicians in managing cUTI, and use of this test provides an opportunity to improve antibiotic stewardship in this difficult-to-treat subset of patients.

Enhancing Therapeutic Efficacy and Safety of Immune Checkpoint Inhibition for Bladder Cancer: A Comparative Analysis of Injectable vs. Intravesical Administration.

Bladder cancer (BC) presents a significant global health burden, characterized by high recurrence rates post-initial treatment. Gender differences in BC prevalence and response to therapy emphasize the importance of personalized treatment strategies. While Bacillus Calmette-Guérin (BCG) remains a cornerstone of BC therapy, resistance poses a challenge, necessitating alternative strategies. Immune checkpoint inhibitors (ICIs) have shown promise, yet systemic toxicity raises concern. Intravesical administration of ICIs offers a potential solution, with recent studies demonstrating the feasibility and efficacy of intravesical pembrolizumab. Although systemic toxicity remains a concern, its localized administration may mitigate adverse events. Additionally, liposomal delivery of ICIs exhibits promises in enhancing drug penetration and reducing toxicity. Novel imaging modalities compatible with Vesical Imaging-Reporting and Data System (VI-RADS) and capable of predicting high-grade bladder cancer can aid the pre-operative shared decision making of patient and surgeon. Future research should focus on refining treatment approaches, optimizing dosing regimens, and leveraging advanced imaging techniques to improve patient outcomes. In conclusion, intravesical immunotherapy presents a promising avenue for BC treatment, offering enhanced therapeutic effectiveness while minimizing systemic toxicity. Continued research efforts are essential to validate these findings and optimize intravesical immunotherapy's role in BC management, ultimately improving patient outcomes.

Comparison of Polymerase Chain Reaction and Urine Culture in the Evaluation of Patients with Complex Urinary Tract Infections.

To compare organism identification using polymerase chain reaction (PCR) and urine culture (UC) in patients with complex urinary tract infections (cUTIs), we reviewed the results of 3395 patients seen during 2022 with cUTI who underwent concomitant PCR and UC testing. We compared the overall positivity rates as well as the ability of each test to identify fastidious organisms (FOs) and the presence of polymicrobial infections (PMOs) and conducted concordance analysis between the tests. PCR detected 36.4% more organisms than UC and was 20 and nearly 36 times more likely to detect PMOs and FOs, respectively. PCR identified 90.6% of organisms found in UC, whereas UC identified 40.7% of organisms found in PCR testing. We found that 62.4% of organisms found in PCR were not found in urine culture, while UC found 9.4% of organisms not identified in polymerase chain reaction. All these differences were statistically significant (p < 0.05). Although we found that PCR was superior to UC in overall pathogen detection, and detection of both PMOs and FOs, both identified potentially pathogenic organisms not found in the corresponding test. Our data strongly suggest that the evaluation of patients with cUTI is best accomplished using PCR in conjunction with UC.

Intravesical liposomal tacrolimus for hemorrhagic cystitis: a phase 2a multicenter dose-escalation study.

BACKGROUND: Hemorrhagic cystitis (HC) is an inflammatory disease of the bladder with sustained hematuria for which there is currently no approved drug treatment. We evaluated a liposomal tacrolimus preparation (LP-10) in patients with refractory moderate to severe sterile HC. METHODS: This phase 2a dose-escalation study assessed the safety and efficacy of up to 2 intravesical instillations of LP-10 (2, 4, or 8 mg tacrolimus) in 13 patients with HC. Primary efficacy outcomes were changes from baseline in the number of bleeding sites on cystoscopy, microscopic urine analysis for red blood cells (RBCs), and hematuria on dipstick. Additional efficacy measures included urinary incontinence, frequency, and urgency on a 3-day diary and cystoscopy global response assessment (GRA). Blood samples for pharmacokinetic (PK) assessment were obtained in all patients. RESULTS: Intravesical LP-10 was well tolerated, with no treatment-related severe or serious adverse events (AEs) and only 3 drug-related AEs (artificial urinary sphincter malfunction, dysuria, and bladder spasms). LP-10 blood levels showed short durations of minimal systemic uptake. Treatment resulted in significant improvements in bleeding on cystoscopy, RBC counts in urine, hematuria on dipstick, and urinary incontinence. Bleeding on cystoscopy and urinary incontinence showed dose-dependent improvements that were more pronounced in the 4 mg and 8 mg dose groups. All dose groups showed a significant improvement in cystoscopy GRA. CONCLUSION: LP-10 was well tolerated, with clinically relevant efficacy seen in improvements in cystoscopic bleeding, hematuria, and urinary incontinence. The benefit-risk profile supports the further clinical development of LP-10 at a tacrolimus dose of 4 mg.

Clear cell renal cell carcinoma cells show diffuse expression of phagocytotic markers through the identification of lysosome-rich eosinophilic granules.

BACKGROUND: Paneth cell-like granules (PCLG) in clear cell renal cell carcinomas (RCC) have previously been reported but were not found to express neuroendocrine markers. This study was to investigate if the eosinophilic granules (so called PCLG) were enlarged lysosomes. METHODS: A retrospective review of 72 different renal tumors was conducted which included 42 clear cell RCC, 16 papillary RCC, 6 chromophobe RCC, 5 clear cell papillary RCC, 2 urothelial carcinomas and 1 unclassified RCC. All tumors were evaluated for the eosinophilic granules on hematoxylin and eosin-stained sections. In addition, PAS-D staining, immunohistochemical stains, and electron microscopy were performed. RESULTS: The eosinophilic granules were found in 19% (8 out of 42) clear cell RCC, but not in the other renal tumor types. The granules stained positively for PAS-D and were also positive for lysosomal protein markers CD68 and lysozyme. Electron microscopy revealed that the eosinophilic granules were smooth ball-shaped structures in the cytoplasm, ranging in size from 0.8 to 1.4 µm. The overall findings indicate that the eosinophilic granules were best correlated with lysosomes. CONCLUSIONS: The eosinophilic granules in clear cell RCC are expanded lysosomes, and this may be used as a unique feature for confirming the pathologic diagnosis of clear cell RCC. The findings further support the view that clear cell RCC have phagocytic capacity due to their containing abundant lysosomes in the cytoplasm.

A Proposal for the Comprehensive Care of Men on Androgen Deprivation Therapy: Recommendations From the Multidisciplinary Prostate Cancer 360 Working Group.

INTRODUCTION: To promote comprehensive care of patients throughout the androgen deprivation therapy (ADT) prescribing process, the Prostate Cancer 360 (PC360) Working Group developed monitoring and management recommendations intended to mitigate or prevent ADT-associated adverse events. METHODS: The PC360 Working Group included 14 interdisciplinary experts with a dedicated clinical interest in prostate cancer and ADT management. The working group defined challenges associated with ADT adverse event management and then collaboratively developed comprehensive care recommendations intended to be practical for ADT prescribers. RESULTS: The PC360 Working Group developed both overarching recommendations for ADT adverse event management and specific recommendations across 5 domains (cardiometabolic, bone, sexual, psychological, and lifestyle). The working group recommends an interdisciplinary, team-based approach wherein the ADT prescriber retains an oversight role for ADT management while empowering patients and their primary and specialty care providers to manage risk factors. The PC360 recommendations also emphasize the importance of proactive patient education that involves partners or other support providers. Recommended monitoring and assessment tools, risk factor management, and patient counseling points are also included for the 5 identified domains, with an emphasis on lifestyle and behavioral interventions that can improve quality of life and reduce the risk for ADT-associated complications. CONCLUSIONS: Comprehensive care of patients receiving ADT requires early and ongoing coordinated management of a variety of health domains, including cardiometabolic, bone, sexual, psychological health. Patient education and primary care provider involvement should begin prior to ADT initiation and continue throughout treatment to improve patient and partner quality of life.

Cardiovascular Risk in Prostate Cancer Patients Using Luteinizing Hormone-Releasing Hormone Agonists or a Gonadotropin-Releasing Hormone Antagonist.

PURPOSE: Luteinizing hormone-releasing hormone (LHRH) agonists are believed to have higher cardiovascular risk relative to gonadotropin-releasing hormone (GnRH) antagonists. However, previous studies have not consistently demonstrated this. We used real-world clinical practice data to evaluate differences in major adverse cardiovascular events (MACE) risk between LHRH agonists compared to a GnRH antagonist following androgen deprivation therapy (ADT) initiation. MATERIALS AND METHODS: We performed a retrospective analysis of data in the Decision Resources Group (now Clarivate) Real World Evidence repository, which represents >300 million US patients from 1991 to 2020 across all US regions. Patients with prostate cancer who received at least 1 injection of ADT were included. The risks of MACE and all-cause mortality as independent endpoints were evaluated, Kaplan-Meier curves were constructed, and associations between MACE and all available confounding risk factors were evaluated by Cox regression analysis using Statistical Package for the Social Sciences. RESULTS: A total of 45,059 men with prostate cancer treated with ADT were analyzed. Overall, the risks of MACE and all-cause mortality were slightly lower in the first year after ADT initiation compared to subsequent years. MACE risk was higher for the GnRH antagonist compared to LHRH agonists (HR=1.62; 95% CI 1.21-2.18, P = .001). The risk of all-cause mortality was also higher for the GnRH antagonist vs LHRH agonists (HR=1.87; 95% CI 1.39-2.51, P < .001). CONCLUSIONS: The adjusted incidence of MACE was higher for men treated with the GnRH antagonist compared to the LHRH agonists. The demographic and risk factors with the greatest impact on MACE risk were higher age, baseline metastasis, oncology (vs urology) setting, personal MACE history, antagonist (vs agonist), tobacco history, White (vs Black) race, and lower BMI.

Development and Optimization of a Subtraction-Normalized Immunocyte Profiling Signature for Prostate Cancer Active Surveillance Risk Stratification.

PURPOSE: Less invasive decision support tools are desperately needed to identify occult high-risk disease in men with prostate cancer (PCa) on active surveillance (AS). For a variety of reasons, many men on AS with low- or intermediate-risk disease forgo the necessary repeat surveillance biopsies needed to identify potentially higher-risk PCa. Here, we describe the development of a blood-based immunocyte transcriptomic signature to identify men harboring occult aggressive PCa. We then validate it on a biopsy-positive population with the goal of identifying men who should not be on AS and confirm those men with indolent disease who can safely remain on AS. This model uses subtraction-normalized immunocyte transcriptomic profiles to risk-stratify men with PCa who could be candidates for AS. MATERIALS AND METHODS: Men were eligible for enrollment in the study if they were determined by their physician to have a risk profile that warranted prostate biopsy. Both training (n = 1017) and validation cohort (n = 1198) populations had blood samples drawn coincident to their prostate biopsy. Purified CD2+ and CD14+ immune cells were obtained from peripheral blood mononuclear cells, and RNA was extracted and sequenced. To avoid overfitting and unnecessary complexity, a regularized regression model was built on the training cohort to predict PCa aggressiveness based on the National Comprehensive Cancer Network PCa guidelines. This model was then validated on an independent cohort of biopsy-positive men only, using National Comprehensive Cancer Network unfavorable intermediate risk and worse as an aggressiveness outcome, identifying patients who were not appropriate for AS. RESULTS: The best final model for the AS setting was obtained by combining an immunocyte transcriptomic profile based on 2 cell types with PSA density and age, reaching an AUC of 0.73 (95% CI: 0.69-0.77). The model significantly outperforms (P < .001) PSA density as a biomarker, which has an AUC of 0.69 (95% CI: 0.65-0.73). This model yields an individualized patient risk score with 90% negative predictive value and 50% positive predictive value. CONCLUSIONS: While further validation in an intended-use cohort is needed, the immunocyte transcriptomic model offers a promising tool for risk stratification of individual patients who are being considered for AS.

Adherence to Hormonal Therapies in Prostate Cancer.

INTRODUCTION: Hormonal therapy is the standard of care in prostate cancer treatment. The approval of the first oral androgen deprivation therapy, relugolix, to treat prostate cancer patients provides an opportunity to review adherence to oral and injectable/implantable hormonal therapies to aid patients and physicians in making informed decisions. METHODS: A PubMed search for available literature on adherence to hormonal therapy in prostate cancer was conducted, including published data on relugolix. RESULTS: Adherence to oral antiandrogen therapy was above 90% by medication possession ratio in several studies worldwide and from 75% to 91% by proportion of days covered. For injectable/implantable androgen deprivation therapy, adherence to treatment ranged from 71% to 95%. In general, 60% and 29% of injections were reported to be delayed by more than 1 week and 2 weeks, respectively, with some patients experiencing testosterone increases (tests above 50 ng/dL). Although real-world data on adherence to relugolix are currently unavailable, pharmacokinetic/pharmacodynamics models demonstrated that, if necessary, treatment interruption up to 7 days would still maintain testosterone suppression levels. CONCLUSIONS: In general, adherence to hormonal therapy is high in prostate cancer. Studies revealed that adherence to injectable androgen deprivation therapy dosing schedules is important to maintain castrate levels. Pharmacokinetic/pharmacodynamics models showed that relugolix treatment interruption up to 7 days had minimal impact on testosterone suppression levels.

Safety, Tolerability, and Preliminary Efficacy of TAR-200 in Patients With Muscle-invasive Bladder Cancer Who Refused or Were Unfit for Curative-intent Therapy: A Phase 1 Study.

PURPOSE: Half of patients with muscle-invasive bladder cancer worldwide may not receive curative-intent therapy. Elderly or frail patients are most affected by this unmet need. TAR-200 is a novel, intravesical drug delivery system that provides sustained, local release of gemcitabine into the bladder over a 21-day dosing cycle. The phase 1 TAR-200-103 study evaluated the safety, tolerability, and preliminary efficacy of TAR-200 in patients with muscle-invasive bladder cancer who either refused or were unfit for curative-intent therapy. MATERIALS AND METHODS: Eligible patients had cT2-cT3bN0M0 urothelial carcinoma of the bladder. TAR-200 was inserted for 4 consecutive 21-day cycles over 84 days. The primary end points were safety and tolerability at 84 days. Secondary end points included rates of clinical complete response and partial response as determined by cystoscopy, biopsy, and imaging; duration of response; and overall survival. RESULTS: Median age of the 35 enrolled patients was 84 years, and most were male (24/35, 68.6%). Treatment-emergent adverse events related to TAR-200 occurred in 15 patients. Two patients experienced treatment-emergent adverse events leading to removal of TAR-200. At 3 months, complete response and partial response rates were 31.4% (11/35) and 8.6% (3/35), respectively, yielding an overall response rate of 40.0% (14/35; 95% CI 23.9-57.9). Median overall survival and duration of response were 27.3 months (95% CI 10.1-not estimable) and 14 months (95% CI 10.6-22.7), respectively. Progression-free rate at 12 months was 70.5%. CONCLUSIONS: TAR-200 was generally safe, well tolerated, and had beneficial preliminary efficacy in this elderly and frail cohort with limited treatment options.

Combination Treatment with Sipuleucel-T and Abiraterone Acetate or Enzalutamide for Metastatic Castration-Resistant Prostate Cancer: STAMP and STRIDE Trials.

PURPOSE: We present long-term outcomes from 2 randomized studies [STAMP (with abiraterone, NCT01487863) and STRIDE (with enzalutamide, NCT01981122)] that were performed to study the impact of sequential or concurrent administration of androgen receptor-targeting agents (ARTAs) on sipuleucel-T immune response and overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: Sipuleucel-T was administered per current prescribing information. Results from STRIDE are presented together with updated STAMP results. Survival status of patients was updated using demographic information to query the National Death Index (NDI). Kaplan-Meier methodology was used to analyze survival. RESULTS: Updated data reduced patient censoring in each study compared with the original analyses; the 95% confidence intervals (CIs) for OS are now estimable. Updated median OS (95% CI) is 33.3 (24.1-40.7) months for STAMP and 32.5 (26.0-45.1) months for STRIDE. There was no notable impact on median OS [HR, 0.727 (0.458-1.155); P = 0.177, reference = STRIDE]. OS with sequential administration was similar to concurrent administration [NDI update: HR, 0.963 (0.639-1.453); P = 0.845, reference = concurrent arm]. Sipuleucel-T potency, measured as antigen-presenting cell (APC) activation, was higher in subsequent infusions compared with the first infusion. Humoral responses (IgG + IgM antibody titers) to PA2024 and prostatic acid phosphatase were significantly elevated versus baseline. No new safety signals were observed. CONCLUSIONS: Median OS was consistent regardless of whether the agents were administered sequentially or concurrently, including after NDI update. Results suggest that sipuleucel-T induces an immunologic prime-boost effect after initial sipuleucel-T exposure, even when combined with ARTAs.

Niraparib with Abiraterone Acetate and Prednisone for Metastatic Castration-Resistant Prostate Cancer: Phase II QUEST Study Results.

Niraparib (NIRA) is a highly selective inhibitor of poly (adenosine diphosphate-ribose) polymerase, PARP1 and PARP2, which play a role in DNA repair. The phase II QUEST study evaluated NIRA combinations in patients with metastatic castration-resistant prostate cancer who were positive for homologous recombination repair gene alterations and had progressed on 1 prior line of novel androgen receptor-targeted therapy. Results from the combination of NIRA with abiraterone acetate plus prednisone, which disrupts androgen axis signaling through inhibition of CYP17, showed promising efficacy and a manageable safety profile in this patient population.

Normal Tissue Integral Dose as a Result of Prostate Radiation Therapy: A Quantitative Comparison Between High-Dose-Rate Brachytherapy and Modern External Beam Radiation Therapy Techniques.

Purpose: Quantification of integral radiation dose delivered during treatment for prostate cancer is lacking. We performed a comparative quantification of dose to nontarget body tissues delivered via 4 common radiation techniques: conventional volumetric modulated arc therapy, stereotactic body radiation therapy, pencil-beam scanning proton therapy, and high-dose-rate brachytherapy. Methods and Materials: Plans for each radiation technique were generated for 10 patients with typical anatomy. For brachytherapy plans, virtual needles were placed to achieve standard dosimetry. Standard planning target volume margins or robustness margins were applied as appropriate. A "normal tissue" structure (entire computed tomography simulation volume minus planning target volume) was generated for integral dose computation. Dose-volume histogram parameters for targets and normal structures were tabulated. Normal tissue integral dose was calculated by multiplying normal tissue volume by mean dose. Results: Normal tissue integral dose was lowest for brachytherapy. Pencil-beam scanning protons, stereotactic body radiation therapy, and brachytherapy resulted in 17%, 57%, and 91% absolute reductions compared with standard volumetric modulated arc therapy, respectively. Mean nontarget tissues receiving 25%, 50%, and 75% of the prescription dose were reduced by 85%, 76%, and 83% for brachytherapy relative to volumetric modulated arc therapy, by 79%, 64%, and 74% relative to stereotactic body radiation therapy, and 73%, 60%, and 81% relative to proton therapy. All reductions observed using brachytherapy were statistically significant. Conclusions: High-dose-rate brachytherapy is an effective technique for reducing dose to nontarget body tissues relative to volumetric modulated arc therapy, stereotactic body radiation therapy, and pencil-beam scanning proton therapy.