Patient-reported functional outcomes and oncological control after primary focal cryotherapy for clinically significant prostate cancer: A Phase II mandatory biopsy-monitored study.

INTRODUCTION: We report herein the impact of focal therapy (FT) on multi-domain functional outcomes in a Phase II prospective clinical trial (NCT04138914) in focal cryotherapy for clinically significant prostate cancer (csPCa). METHODS: The primary outcome was the detection of a ≥5 point deterioration in any of the four main expanded prostate index composite (EPIC) functional domains. Pretreatment multiparametric magnetic resonance imaging (mpMRI) and transperineal targeted and systematic saturation biopsy were used to select patients with prostate-specific antigen (PSA)≤20 ng/mL, Gleason grade group (GG) ≤4, mpMRI lesion volume ≤ 3 mL (for a single lesion) or ≤1.5 mL (where two lesions were present). Focal cryotherapy was performed with a minimum 5 mm margin around each target lesion. EPIC scores were obtained at baseline and posttreatment at 1, 3, 6, and 12 months. Mandatory repeat mpMRI and prostate biopsy were performed at 12 months to determine the infield and outfield recurrence. RESULTS: Twenty-eight patients were recruited. The mean age was 68 years, with PSA of 7.3 ng/mL and PSA density of 0.19 ng/mL2 . No Clavien-Dindo ≥3 complications occurred. Transient worsening of EPIC urinary (mean diff 16.0, p < 0.001, 95% confidence interval [CI]: 8.8-23.6) and sexual function scores (mean diff 11.0, p:0.005, 95% CI: 4.0-17.7) were observed at 1-month posttreatment, with recovery by Month 3. A subgroup who had ablation extending to the neurovascular bundle had a trend to delayed recovery of sexual function to Month 6. At 12-month repeat mpMRI and biopsy, 22 patients (78.6%) had no detectable csPCa. Of the six patients (21.4%) who had csPCa recurrences, four were GG2, one GG3, and one GG4. Four patients underwent repeat FT, one underwent radical prostatectomy, while the remaining one patient with low-volume GG2 cancer opted for active surveillance. CONCLUSION: FT using cryotherapy was associated with a transient deterioration of urinary and sexual function with resolution at 3 months posttreatment and with reasonable early efficacy in well-selected csPCa patients.

Palliative radiotherapy for bladder cancer: a systematic review and meta-analysis.

BACKGROUND/PURPOSE: The optimal dose fractionation for palliative radiotherapy (RT) in patients with symptomatic advanced bladder cancer is unclear. This study aimed to determine if a higher dose of RT was associated with improved symptoms response rates. METHODS: We searched PubMed, Central and Embase for eligible studies published from 1990 to 2019. The primary outcomes were symptoms response rates for hematuria, dysuria and frequency. Secondary outcomes included treatment-related adverse events and quality of life. RESULTS: We found one randomized, four prospective and eight retrospective non-comparative observational studies including 1320 patients who received palliative bladder radiotherapy for symptom relief. The dose fractionation schedules varied across studies ranging from 8 Gy single fraction to 60 Gy in 2 to 8 Gy per fraction. The pooled response rates for hematuria, dyuria and frequency symptoms were 74%, 58% and 71% respectively. A higher dose of RT was not associated with improved response rates of hematuria and frequency. However, a higher dose of RT was associated with a longer duration of hematuria response and reduced response of dysuria. Grade 3 gastrointestinal and genitourinary toxicity occurred in up to 26% of patients. Health-related quality of life (HRQOL) outcomes were reported in one study. CONCLUSION: This systematic review demonstrates that a higher dose of bladder RT was not associated with improved response rates of hematuria and frequency symptoms but was associated with reduced response of dysuria. Higher doses of bladder RT was associated with more durable hematuria response. Prospective studies to determine the effects of palliative bladder radiotherapy on HRQOL outcomes are warranted.

Dose-volume analysis of planned versus accumulated dose as a predictor for late gastrointestinal toxicity in men receiving radiotherapy for high-risk prostate cancer.

Background and purpose: Significant dose deviations have been reported between planned (DP) and accumulated (DA) dose in prostate radiotherapy. This study aimed to develop multivariate analysis (MVA) models associating Grade 1 and 2 gastrointestinal (GI) toxicity with clinical and DP or DA dosimetric variables separately. Materials and methods: Dose volume (DV) metrics were compared between DA and DP for 150 high-risk prostate cancer patients. MV models were generated from significant clinical and dosimetric variables (p < 0.05) at univariate level. Dose-based-region of interest (DB-ROI) metrics were included. Model performance was measured, and additional subgroup analysis were performed. Results: Rectal DA demonstrated a higher intermediate-high dose (V30-65 Gy and DB-ROI at 15-50 mm) compared to DP. Conversely, at the very high dose region, rectal DA (V75 Gy and DB-ROI at 5-10 mm) were significantly lower. In MVA, rectal DB-ROI at 10 mm was predictive for Grade ≥ 1 GI toxicity for DA and DP. Age, rectal DA for D0.03 cc, and rectal DP for DB-ROI 10 mm were predictors for Grade 2 GI toxicity. Subgroup analysis revealed that patients ≥ 72 years old and a rectal DA of ≥ 78.2 Gy were highly predictive of Grade 2 GI toxicity. Conclusions: The dosimetric impact of a higher dose rectal dose in DA due to volumetric changes was minimal and was not predictive of detrimental clinical toxicity apart from rectal D0.03 cc ≥ 78.2 Gy for Grade 2 GI toxicity. The use of the DB-ROI method can provide equivalent predictive power as the DV method in toxicity prediction.

Efficacy, toxicity, and quality-of-life outcomes of ultrahypofractionated radiotherapy in patients with localized prostate cancer: A single-arm phase 2 trial from Asia.

AIMS: Ultra-hypofractionated radiotherapy (UHF-RT) is widely utilized in men with localized prostate cancer (PCa). There are limited data in Asian cohorts. We report the outcomes of a single-arm, phase II trial of UHF-RT from an Asian center. METHODS: We recruited men with histologically confirmed, nonmetastatic localized PCa. UHF-RT regimens were 36.25 Gy (Cohort A) and 37.5 Gy (Cohort B) delivered in five fractions every other day over 1.5-2.5 weeks. Primary endpoint was physician-scored late genitourinary (GU) and gastrointestinal (GI) adverse events (AEs). Quality-of-life (QoL) was assessed by Expanded Prostate Cancer Index Composite (EPIC) at baseline, 1- and 2-year post-UHF-RT. RESULTS: Between March 2014 and August 2019, 105 men were recruited; four were subsequently excluded from analysis. Median age was 68.0 (Interquartile range (IQR): 63.8-73.0) years. 26 (24.8%) and 68 (64.8%) men had NCCN-defined low-and intermediate-risk PCa, respectively. No late ≥G3 GU or GI toxicities were reported in both cohorts. Peak incidence of acute ≥G2 GU AEs at 14 days post-UHF-RT was 23.6% (17/72) and 24.0% (6/25) in Cohorts A and B, respectively; ≥G2 GI AEs were observed in 9.7% (7/72) and 36.0% (9/25), respectively. Late ≥G2 GU and GI AEs occurred in 4.7% and 3.1% of Cohort A patients, and 5.0% in Cohort B at 12 months, with no AEs at 24 months. EPIC scores changed minimally across all domains. At a median follow-up of 44.9 months, we recorded one (1.3%) biochemical relapse by the Phoenix criteria (Cohort A). CONCLUSION: UHF-RT is well tolerated in Asian men and can be a recommended fractionation schema for localized PCa.

Serum testosterone levels and testosterone 'bounce' phenomenon predict response to novel anti-androgen therapies in castration-resistant prostate cancer.

BACKGROUND: The relevance of continuous testosterone (TT) monitoring in castration-resistant prostate cancer (CRPC) remains in question. OBJECTIVE: To determine if TT levels before and during novel anti-androgen therapies (NAAT), and the TT 'bounce' phenomenon may predict treatment response in CRPC. MATERIALS AND METHODS: From 2014 through 2018, we identified 92 CRPC patients treated with either Abiraterone or Enzalutamide from a prospectively maintained cancer registry. The TT levels measured before and during NAAT were correlated with the oncological outcomes, determined by PSA response (% change), PSA progression-free survival (PFS) and overall survival (OS). RESULTS AND LIMITATIONS: At CRPC, 58 (63.0%) and 34 (37.0%) patients opted for Abiraterone and Enzalutamide respectively. Median TT levels at CRPC status before and during NAAT were 10.37 ng/dl and 20.46 ng/dl respectively. PSA response was superior in patients with a higher TT before NAAT (P:0.048, median difference: 18.22%, 95% CI 0.70 - 40.37) and longer time to CRPC (P: 0.041, median difference: 15.31%, 95% CI 1.84 -34.84), with a trend towards lower TT during NAAT (P: 0.062). Over a follow up of 33.0 months, 65 patients (70.7%) developed PSA progression. PSA PFS was longer in patients with higher TT before NAAT (16.3 vs. 10.8 months; P: 0.023), lower TT during NAAT (17.0 vs. 9.1 months; P: 0.001), and longer time to CRPC (13.4 vs. 8.0 months; P: 0.032). Importantly, better OS was observed in lower TT during NAAT (45.0 vs. 33.0 months; P:0.029) and longer time to CRPC (43.0 vs. 31.0 months; P: 0.025). The TT 'bounce' phenomenon was observed in 28 patients (33.3%), and was associated with a poorer PSA response (P: 0.029, median difference: 18.90%, 95% CI 3.83 - 41.45), shorter PSA PFS (8.6 vs 15.2 months, P: 0.002) and shorter OS (29.0 vs. 45.0 months, P: 0.012). CONCLUSION: In CRPC patients, TT behaviors before and during NAAT, and the 'bounce' phenomenon continue to predict treatment response and could guide clinical decisions.

The implementation of an advanced practice radiation therapy (APRT) program in Singapore.

BACKGROUND: The exploration of Advanced Practiced Radiation Therapists (APRTs) development in Singapore started in 2011. This study aims to provide an overview of the development of the APRT roles, and to discuss the approaches used to develop and implement these roles in Singapore. MATERIALS AND METHODS: A mixed methods approach was used in the development of the APRT program. A literature review was carried out to define the APRT scope of practice and core responsibilities. A competency and assessment framework were setup to assess the core competency areas. With this framework, a structured 1-year residency training program was developed. RESULTS: The scope of practice and core responsibilities of APRTs were defined with five proposed advanced practice profiles being successfully validated. A competency framework was set up to assess the core competency domains: clinical, technical and professional competencies, research, education and leadership. A 4-point scoring system was developed for the competency assessment based on two criteria; the frequency with which RTTs would demonstrate competency, and the ability of performing the task competently. A 1-year structured APRT residency program was developed and implemented. The programme consisted of structured lectures, and clinical practice-based modules where APRT residents receive structured mentoring under a mentorship program. CONCLUSION: The APRT program in Singapore employed an evidence-based implementation process that tested the feasibility of a new practice model. Multidisciplinary involvements, mentorship and clinical training were important factors for the success of the APRT program.

Navigating the challenges of the COVID-19 outbreak: Perspectives from the radiation oncology service in Singapore.

In December 2019, pneumonia of unknown cause was reported by China to WHO. The outbreak was found to be caused by a coronavirus which was officially named "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), and the disease caused by it was named 'COVID-19'. The first case in Singapore was confirmed on 23rd January 2020. With lessons learnt from the SARS epidemic in 2003 and the H1N1 flu pandemic in 2009, Singapore was much better prepared to deal with the virus outbreak. The government has taken swift measures to contain and break the chain of transmission. Healthcare workers face the challenge of keeping patients and staff safe from the disease. There is a higher risk of mortality of COVID-19 in cancer patients and hence unique considerations for a radiation oncology department operating in an infectious disease outbreak. This article is the recommendations and adapted workflow from the two National Cancer Centres in Singapore with the endorsement by the working committee of the Chapter of Radiation Oncology, Academy of Medicine, Singapore. It highlights the challenges that radiation oncology departments in Singapore face and the appropriate recommended responses. This includes interventions, business continuity plans and workflow in managing a COVID-19 positive patient on radiotherapy.

68Gallium-labelled PSMA-PET/CT as a diagnostic and clinical decision-making tool in Asian prostate cancer patients following prostatectomy.

OBJECTIVE: Prostate cancers (PCa) in Asian individuals are molecularly distinct from those found in their Caucasian counterparts. There is no risk stratification tool for Asian men with rapid biochemical recurrence (BCR) following radical prostatectomy (RadP). This study aims to assess the detection rate of 68Ga-prostate-specific membrane antigen-positron emission tomography/computed tomography (PSMA-PET/CT) for diagnosis of clinical recurrence and as a treatment decision making tool in Asian patients with BCR post-RadP. METHODS: 68Ga PSMA-PET and CT body with/without bone scan [conventional workup (CWU)] were performed in 55 Asian patients with BCR within 36 months post-RadP. Two blinded reviewers assessed the images. Detection rates of 68Ga PSMA-PET/CT were evaluated, and impact on management was reviewed by comparison with CWU. RESULTS: Median time to BCR post-RadP was 8.1 months. Detection rate for 68Ga PSMA-PET/CT was 80% (44/55). A positive scan was significantly associated with increasing prostate-specific antigen (PSA) level [odds ratio (OR) = 1.13 (95% CI 1.05-1.30), P = 0.017], but not with higher Gleason grade or shorter PSA doubling time. Compared to CWU, 68Ga PSMA-PET/CT detected an additional 106 lesions in 33/44 patients with a positive scan, resulting in a change in management in 25/44 (56.8%) patients: 10 to hormonal therapy (HT) and whole pelvis radiotherapy (RT) in addition to bed RT, and 15 to palliative HT alone. CONCLUSIONS: In the present report, we demonstrated the diagnostic and treatment decision utility of 68Ga PSMA-PET/CT in Asian men with rapid BCR. Detection of small volume nodal and systemic recurrences at low PSA levels (< 1.0 ng/mL) highlights the role of the tool in assigning patients to treatment intensification with HT-RT or palliative HT in polymetastatic disease.

Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons.

PURPOSE: To evaluate the dosimetric impact and plan robustness of using Pencil Beam Scanning (PBS) in patients that requires prophylactic pelvic lymph nodes (PLNs) irradiation for prostate cancer. MATERIAL AND METHODS: Five intermediate to high-risk prostate patients previously treated using volumetric modulated arc therapy (VMAT), were selected for this study. Comparative proton radiotherapy plans were generated, where a three-field intensity modulated proton therapy (IMPT) plan was for the phase 1 planning target volume (PTV1) with PLNs. A technique with two posterior oblique fields using single field uniform dose (SFUD) was used for phase 2 (PTV2) volume, that comprises of the prostate and proximal seminal vesicles (Pro + proxSVs). Plan evaluation was performed on PTV coverage and dose to the organs at risk (OARs) using VMAT plans as a baseline (BL). Robust analysis on clinical target volume (CTV) coverage for the PBS plans was simulated with a 3 and 5 mm setup errors and a 3.5% range uncertainty. RESULTS: For target coverage, PTV1 and PTV2 showed negligible differences with a comparable homogeneity index (HI) values for both modalities. Proton plans produced a statistically significant lower mean dose to the bladder (32.5 Gy(RBE) vs. 46.5 Gy) and rectum (33.6 Gy(RBE) vs. 42.7 Gy). Dose to the bladder and rectum was equivalent at the high dose region. For the bowel cavity, the mean dose for proton plans were 45% lower compared to VMAT plans. Similarly, proton plans were able to achieve an overall reduction in integral dose for both treatment phase. CTV coverage remained high with all the simulated setup and range errors. CONCLUSIONS: Proposed beam geometries for PTV1 and PTV2 proton plans presented good treatment accuracy with similar target coverage as the VMAT plans. Better sparing of OARs was achieved at the low-medium dose region for the proton plans.