SBRT Shows Lower Biochemical Failure and Acute GU Toxicity Than HDR-BT in Intermediate-Risk Prostate Cancer: JAMA
Canada: Researchers have found in a post hoc pooled analysis using prospective data that stereotactic body radiotherapy (SBRT) was associated with significantly lower biochemical failure rates and fewer acute genitourinary adverse events compared with high-dose-rate brachytherapy (HDR-BT), with no significant difference in late patient-reported quality of life.
The findings, published in JAMA Network Open, were reported by Cristian Udovicich of the Odette Cancer Centre at Sunnybrook Health Sciences Centre, Toronto, Canada, and colleagues. The investigators compared long-term outcomes of SBRT and HDR-BT monotherapy in men with intermediate-risk prostate cancer, an area where direct prospective comparisons have been lacking.
This study was a post hoc pooled analysis of individual patient data from five prospective clinical trials conducted between 2010 and 2018. Eligible participants included men with intermediate-risk prostate cancer treated with either five- or two-fraction SBRT or two-fraction HDR-BT, without the use of androgen deprivation therapy. Statistical analyses were completed in 2024.
A total of 247 men met the inclusion criteria, including 180 treated with SBRT and 67 who received HDR-BT. The median follow-up duration was 9.5 years, allowing for robust long-term outcome assessment. The primary endpoint was biochemical failure (BCF), along with clinician-reported adverse events and patient-reported quality of life measures.
The following were the key findings:
- Biochemical failure rates were significantly higher in the HDR-BT group compared with the SBRT group.
- At five years, biochemical failure occurred in 7.8% of patients treated with HDR-BT versus 3.0% of those treated with SBRT.
- At 10 years, biochemical failure increased to 38.0% in the HDR-BT group compared with 10.4% in the SBRT group.
- Acute grade 2 or higher genitourinary adverse events were more common with HDR-BT, affecting nearly three-quarters of patients, compared with just over half in the SBRT group.
- No significant differences were observed in other acute or late adverse events between the two groups.
- Long-term patient-reported quality of life outcomes were similar for SBRT and HDR-BT.
The authors note that this represents one of the first long-term comparisons of SBRT and HDR-BT using pooled prospective data. While acknowledging the limitations inherent in post hoc analyses, the findings suggest that SBRT may offer improved biochemical control with fewer acute urinary side effects, without compromising long-term quality of life.
"Overall, these results may help guide shared decision-making for men with intermediate-risk prostate cancer considering radiation therapy options, further supporting the role of SBRT as an effective treatment strategy in this population," the authors concluded.
Reference:
Udovicich C, Cheung P, Chu W, et al. SBRT vs HDR Brachytherapy for Intermediate-Risk Prostate Cancer. JAMA Netw Open. 2026;9(2):e260146. doi:10.1001/jamanetworkopen.2026.0146
Next Story