To report on the results of a phase II randomized trial of moderately hypofractionated (MH) versus conventionally fractionated (CF) radiotherapy to the prostate with elective nodal irradiation (ENI).
This was a single-centre prospective phase II randomized study. Patients with high-risk disease (cT3, PSA >20 ng/mL, or Gleason score 8-10) were eligible. Patients were randomized to either MH using a simultaneous integrated boost (68 Gy in 25 fractions to prostate; 48 Gy to pelvis) or CF (46 Gy in 23 fractions with a sequential boost to the prostate of 32 Gy in 16 fractions), with long-term androgen deprivation therapy (ADT). The primary endpoint was grade ≥2 acute gastrointestinal (GI) and genitourinary (GU) toxicity (CTCAE v3.0). Secondary endpoints included late GI and GU toxicity, quality of life, and oncologic outcomes.
180 patients enrolled: 90 were randomized to and received MH and 90 to CF. Median follow-up was 67.4 months. Seventy-five (41.7%) patients experienced a grade ≥2 acute GI and/or GU toxicity, including 34 (37.8%) in the MH and 41 (45.6%) in the CF arms, respectively (p=0.29). Late grade ≥2 GI (p=0.07) and GU (p=0.25) toxicity was not significantly different between arms, however, late grade ≥3 GI toxicity was worse in the MH group (p=0.01). There were no statistically significant quality of life differences between the two treatments. There were no statistically significant differences observed in cumulative incidence of biochemical failure (p=0.71) or distant metastasis (p=0.31), and overall survival (p=0.46).
MH to the prostate and pelvis with ADT for men with high-risk localized prostate cancer was not significantly different than CF with regards to acute toxicity, quality of life and oncologic efficacy. However, late grade ≥3 late GI toxicity was more common in the MH arm.
International journal of radiation oncology, biology, physics. 2023 Nov 16 [Epub ahead of print]
Rachel M Glicksman, Andrew Loblaw, Gerard Morton, Danny Vesprini, Ewa Szumacher, Hans T Chung, William Chu, Stanley K Liu, Chia-Lin Tseng, Rohann Correa, Andrea Deabreu, Alexandre Mamedov, Liying Zhang, Patrick Cheung
Department of Radiation Oncology, University of Toronto, Toronto, Canada; Princess Margaret Cancer Centre, University Health Network, Toronto, Canada., Department of Radiation Oncology, University of Toronto, Toronto, Canada; Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Canada., London Health Sciences Centre, London, Canada., Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Canada., Department of Radiation Oncology, University of Toronto, Toronto, Canada; Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Canada. Electronic address: .