RESUMO
AIM: To assess late gastrointestinal (GI) and genitourinary (GU) side effects in patients with organ-confined unfavorable prostate cancer (PCa) treated with single dose ablative radiotherapy (SDRT). METHODS: Thirty patients enrolled in a single-arm prospective trial received 24 Gy SDRT to the whole prostate with urethra sparing and organ motion control delivered on a Linac platform with a 10MV FFF single partial arc. ADT was prescribed as per standard of care. Treatment-related acute and late GU and GI toxicities (CTCAE_v5 scale) and QoL outcomes (EORTC QLQ-PR25/C30, IPSS) were assessed at different time points. Minimal Important Difference (MID) was established as a change of >0.5 pooled SD from baseline. Statistical analysis included ANOVA test and logistic regression. RESULTS: Median follow-up was 18 months (range, 6-31), with no ≥G3 late side effects observed. G2 late GI and G2 late GU toxicities occurred in 1 and 2 patients, respectively. GI toxicity of any grade correlated with maximum rectal dose (P=0.021). Lower baseline QoL score (P=0.025), higher baseline IPSS score (P=0.049), acute GU toxicity (P=0.029), and acute urinary domain MID (P=0.045) predicted GU toxicity of any grade. In MVA, only baseline QoL score (OR, 0.95, P=0.031) and acute GU toxicity (OR, 8.4, P=0.041) remained significant. Significant QoL change was observed only in the urinary domain (P=0.005), with a median increase from 8 to 17. Late urinary MID correlated with acute urinary MID (P=0.003), acute QoL MID (P=0.029), acute GU toxicity (P=0.030), and lower baseline urinary score (P=0.033). In MVA, only acute urinary MID predicted late urinary MID (OR, 9.7, P=0.035). CONCLUSION: Our findings provide promising data on the feasibility and safety of 24 Gy whole gland SDRT with urethra sparing and organ motion control, in association with ADT and an adequate prophylactic medication, in organ confined unfavorable PCa. Long-term follow-up is needed to confirm these results.
RESUMO
BACKGROUND: The aim of this study was to investigate the feasibility of ultrahypofractionated radiotherapy to the prostate bed in patients with biochemical and/or clinical relapse following radical prostatectomy who were enrolled in the prospective, observational, multicentric POPART trial (NCT04831970). METHODS: Patients with post-radical prostatectomy PSA levels of ≥0.1-2.0 ng/mL and/or local relapse at PSMA PET/CT or multiparametric MRI were treated with Linac-based SBRT on the prostate bed up to a total dose of 32.5 Gy in five fractions every other day (EQD21.5 = 74.2 Gy). Maximum acute toxicity was assessed using the Common Terminology Criteria for Adverse Events version 5 scale. International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) and Prostate Cancer Index Composite for Clinical Practice (EPIC-CP) scores were assessed at baseline and during the follow-up. RESULTS: From April 2021 to June 2022, thirty men with a median age of 72 years (range 55-82) were enrolled in three centers. The median PSA level before RT was 0.30 ng/mL (range 0.18-1.89 ng/mL). At 3 months post-treatment, no GI or ≥2 GU side effects were reported; three patients (10%) experienced Grade 1 GU toxicity. No changes in ICIQ-SF or in the urinary domains of EPIC-CP were observed, while a transient worsening was registered in the bowel domain. At the same time point, all but two patients, who progressed distantly, were found to be biochemically controlled with a median post-treatment PSA level of 0.07 ng/mL (range 0-0.48 ng/mL). CONCLUSIONS: Our preliminary findings show that SBRT can be safely extended to the postoperative setting, without an increase in short-term toxicity or a significant decline in QoL. Long-term results are needed to confirm this strategy.