Related Experiment Video
Updated: Mar 23, 2026
A New Technique for Treating Low-risk Prostate Cancer—Super Active Surveillance
Published on: November 7, 2025
Randomized Phase III Noninferiority Study Comparing Two Radiotherapy Fractionation Schedules in Patients With
W Robert Lee1, James J Dignam2, Mahul B Amin2
1W. Robert Lee and Bridget F. Koontz, Duke University Medical Center, Durham, NC; James J. Dignam, University of Chicago, Chicago, IL; Mahul B. Amin and Howard M. Sandler, Cedars-Sinai Medical Center; Daniel Low, University of California, Los Angeles, Los Angeles; Samantha A. Seaward, Kaiser Permanente Northern California, Santa Clara, CA; Deborah W. Bruner, Emory University, Atlanta, GA; Gregory P. Swanson, Baylor Scott & White Healthcare Temple Clinic, Temple, TX; Amit B. Shah, York Cancer Center, York; James J. Dignam and Rebecca Paulus, NRG Oncology Statistics and Data Management Center, Philadelphia, PA; David P. D'Souza, London Regional Cancer Program, London, Ontario; Ian S. Dayes, McMaster University, Hamilton, Ontario; Sergio L. Faria, McGill University Health Center, Montreal, Quebec, Canada; Jeff M. Michalski, Washington University School of Medicine, St Louis, MO; William A. Hall, Medical College of Wisconsin, Milwaukee, WI; Paul L. Nguyen, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA; Thomas M. Pisansky, Mayo Clinic, Rochester, MN; and Yuhchyau Chen, University of Rochester, Rochester, NY. w.robert.lee@duke.edu.
Purpose:
Conventional radiotherapy (C-RT) treatment schedules for patients with prostate cancer typically require 40 to 45 treatments that take place from > 8 to 9 weeks. Preclinical and clinical research suggest that hypofractionation-fewer treatments but at a higher dose per treatment-may produce similar outcomes. This trial was designed to assess whether the efficacy of a hypofractionated radiotherapy (H-RT) treatment schedule is no worse than a C-RT schedule in men with low-risk prostate cancer.
Patients And Methods:
A total of 1,115 men with low-risk prostate cancer were randomly assigned 1:1 to C-RT (73.8 Gy in 41 fractions over 8.2 weeks) or to H-RT (70 Gy in 28 fractions over 5.6 weeks). This trial was designed to establish (with 90% power and an α of .05) that treatment with H-RT results in 5-year disease-free survival (DFS) that is not worse than C-RT by more than 7.65% (H-RT/C-RT hazard ratio [HR] < 1.52).
Results:
A total of 1,092 men were protocol eligible and had follow-up information; 542 patients were assigned to C-RT and 550 to H-RT. Median follow-up was 5.8 years. Baseline characteristics were not different according to treatment assignment. The estimated 5-year DFS was 85.3% (95% CI, 81.9 to 88.1) in the C-RT arm and 86.3% (95% CI, 83.1 to 89.0) in the H-RT arm. The DFS HR was 0.85 (95% CI, 0.64 to 1.14), and the predefined noninferiority criterion that required that DFS outcomes be consistent with HR < 1.52 was met (P < .001). Late grade 2 and 3 GI and genitourinary adverse events were increased (HR, 1.31 to 1.59) in patients who were treated with H-RT.
Conclusion:
In men with low-risk prostate cancer, the efficacy of 70 Gy in 28 fractions over 5.6 weeks is not inferior to 73.8 Gy in 41 fractions over 8.2 weeks, although an increase in late GI/genitourinary adverse events was observed in patients treated with H-RT.
