Single-Fraction SBRT Shows Promise in Localized Prostate Cancer, Meeting Primary Endpoint in Phase 1/2 Trial
核心洞察
A phase 1/2 trial found single-fraction 19-Gy SBRT achieved 92.9% 3-year biochemical relapse-free survival in men with localized prostate cancer (搜索).
Grade 2 genitourinary and gastrointestinal toxicity rates were low at 9.8% and 4.9%, respectively, with one case of grade 3 proctitis (搜索) reported.
Erectile dysfunction (搜索) increased from 21.4% at baseline to 38.4% at three years, representing the most notable quality-of-life impact.
A multicenter phase 1/2 clinical trial has demonstrated that a single high-dose fraction of stereotactic body radiotherapy (SBRT) can achieve encouraging biochemical control in men with localized prostate cancer (搜索), with acceptable toxicity and limited deterioration in quality of life.
The nonrandomized prospective study, led by Zilli and colleagues and published in JAMA Oncology, evaluated whether a single 19-Gy dose of prostate SBRT using urethra-sparing techniques could meet a predefined threshold for biochemical relapse-free survival (bRFS) while maintaining safety.
Trial Design and Patient Population
The study enrolled 45 men with low- or intermediate-risk prostate cancer (搜索), classified as International Society of Urological Pathology grade group 1 or 2, with no significant tumor involvement of the transitional zone. Of those enrolled, 43 received treatment according to protocol. Participants had a median age of 72 years and were followed for a median of 55.3 months.
All patients were treated with a single 19-Gy SBRT fraction, employing urethra-sparing techniques and real-time control of prostate movement during treatment delivery. The primary endpoint was 3-year bRFS.
Efficacy Results Meet Primary Endpoint
At three years, the estimated bRFS was 92.9% (95% CI, 85.4%–100%), successfully meeting the trial's primary endpoint. This result suggests that a single high-dose treatment may provide effective disease control in carefully selected patients with localized prostate cancer (搜索).
Toxicity Profile and Quality of Life
Treatment-related adverse events remained low throughout follow-up. At three years, grade 2 genitourinary (GU) adverse events occurred in 9.8% of patients, while grade 2 gastrointestinal (GI) events were reported in 4.9%. One patient experienced grade 3 proctitis (搜索) at 12 months.
Sexual function outcomes showed a more pronounced impact. Grade 2 or higher erectile dysfunction (搜索) increased from 21.4% at baseline to 38.4% at three years, representing the most notable treatment-related effect observed in the study.
Quality-of-life assessments demonstrated limited deterioration overall. Clinically meaningful changes were observed in GU scores in 14% of patients and in sexual scores in 28%. Gastrointestinal quality-of-life effects were minimal.
Cautious Interpretation and Next Steps
The authors concluded that single-fraction 19-Gy urethra-sparing SBRT appears feasible and well tolerated in carefully selected patients with localized prostate cancer (搜索). However, they emphasized that longer follow-up is required to determine whether this approach provides durable long-term cancer control.
"If confirmed in larger comparative studies, single-session SBRT could represent a further evolution in prostate cancer (搜索) radiotherapy, reducing treatment burden while maintaining oncological outcomes," the researchers noted.
The findings add to the growing body of evidence supporting abbreviated radiotherapy schedules in prostate cancer (搜索), though the single-fraction approach remains investigational pending longer-term data and comparative trials.