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Sandy Srinivas, MD
Sandy Srinivas, MD
Posted: Monday, September 11, 2023
Results of the randomized phase III NRG 0232 trial of 579 men with intermediate-risk prostate cancer indicated that adding external-beam radiation therapy (EBRT) to brachytherapy did not improve 5-year freedom from disease progression (the study’s primary endpoint) and, in fact, caused greater toxicity. Thus, brachytherapy alone should be considered a standard treatment in this scenario, stated Jeff M. Michalski, MD, MBA, of Washington University School of Medicine, St. Louis, Missouri, and colleagues in the Journal of Clinical Oncology.
The combination and brachytherapy-alone arms comprised 287 and 292 men, respectively (median patient age, 67 years). About two-thirds had clinical stage T1 disease, and 89.1% had both a prostate-specific antigen measurement of up to 10 ng/mL and a Gleason score of 7.
Using the American Society for Radiation Oncology calculation, the 5-year freedom from disease progression rate was 85.6% in the combination arm compared with 82.7% in the brachytherapy-alone arm (P = .18). According to the Phoenix definition, the 5-year freedom from disease progression rate was 88.0% with the combination compared with 85.5% with brachytherapy alone (P = .19). On the other hand, the 5-year cumulative incidence rate for late genitourinary or gastrointestinal grade 2 or greater toxicity was 42.8% in the combination arm compared with 25.8% in the brachytherapy-alone arm (P < .0001); the 5-year cumulative incidence rate for late genitourinary or gastrointestinal grade 3 or greater toxicity was 8.2% versus 3.8%, respectively (P = .006).
The patients in the combination arm received EBRT (45 Gy in 25 fractions) to the prostate and the seminal vesicles, followed by a brachytherapy prostate boost (110 Gy with iodine-125; 100 Gy with palladium-103). In the brachytherapy-alone arm, the patients received local radiation to the prostate alone (145 Gy with iodine-125; 125 Gy with palladium-103).
Disclosure: The study authors’ disclosure information can be found at ascopubs.org.
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