PSMA-PET/mpMRI-guided focal dose-escalated stereotactic body radiotherapy for localized prostate cancer: study protocol for a prospective, randomized controlled trial.

Abstract

Stereotactic body radiotherapy (SBRT) is effective for localized prostate cancer, yet many recurrences originate from the intraprostatic tumor mass (ITM). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) and multiparametric magnetic resonance imaging (mpMRI) enable precise ITM localization and support focal dose escalation. This trial assesses whether PSMA-PET/mpMRI-guided boosting during SBRT improves biochemical control without excess toxicity. This is a single-center, prospective, randomized (1:1), controlled, open-label clinical trial conducted at Huashan Hospital, Fudan University. A total of 128 men with newly diagnosed localized prostate adenocarcinoma will be enrolled and randomized to receive either (1) standard SBRT (39 Gy in 6 fractions) or (2) PSMA-PET/mpMRI-guided focal dose-escalated SBRT (up to 48 Gy in 6 fractions). All participants will receive androgen deprivation therapy (ADT) according to National Comprehensive Cancer Network (NCCN) risk group and clinical practice. The primary endpoint is biochemical progression-free survival (PSA-PFS), defined by the Phoenix criteria. Secondary endpoints include local progression-free survival (LPFS), distant metastasis-free survival (DMFS), overall survival (OS), prostate cancer-specific survival (PCSS), toxicity (CTCAE v5.0), and patient-reported quality of life (EPIC-26 and SF-12). Survival outcomes will be analyzed using Kaplan-Meier estimates and compared via log-rank testing.Clinical trial registration:www.chictr.org.cnidentifier ChiCTR2500114310.