An Ontario-led international clinical trial with 1,206 men with localized prostate cancer shows that compressing radiation treatments into four weeks from eight delivers similar outcomes.

The findings, published online in the Journal of Clinical Oncology, provide a new standard of care worldwide, which the participating centres have already adopted, says co-principal investigator Charles Catton, radiation oncologist, Princess Margaret Cancer Centre, University Health Network. Dr. Catton is also a Professor, Department of Radiation Oncology, University of Toronto.

"We conducted a randomized clinical trial looking at a way of improving radiation therapy for men with intermediate-risk prostate cancer. Using modern radiation therapy techniques that are very precise, we determined there was no noticeable difference between eight- and four-week treatment regimens in terms of cancer control or side effects of treatment," says Dr. Catton. The trial participants were followed for six years.

"In fact, for some men, the shorter regimen meant slightly fewer side effects (particularly regarding bowel function) and therefore improved quality of life. The compressed course of treatment is of great benefit to patients and also to the system in terms of being able to treat more patients in less time," he says. In Canada, 20,000 men are diagnosed with prostate cancer every year; many of whom have intermediate-risk disease that has not spread.

The trial was conducted with co-principal investigator Himu Lukka, radiation oncologist, Juravinski Cancer Centre, and Professor, Department of Oncology, McMaster University, and coordinated by the Ontario Clinical Oncology Group, Hamilton, Ontario. Twenty-seven cancer centres in Canada, Australia and France participated in the study, which began in 2005.

Dr. Catton says the trial further improved patient care by standardizing quality delivery of precision radiation techniques among participating institutions.

Article: Randomized Trial of a Hypofractionated Radiation Regimen for the Treatment of Localized Prostate Cancer, Charles N. Catton, Himu Lukka, Chu-Shu Gu, Jarad M. Martin, Stéphane Supiot, Peter W.M. Chung, Glenn S. Bauman, Jean-Paul Bahary, Shahida Ahmed, Patrick Cheung, Keen Hun Tai, Jackson S. Wu, Matthew B. Parliament, Theodoros Tsakiridis, Tom B. Corbett, Colin Tang, Ian S. Dayes, Padraig Warde, Tim K. Craig, Jim A. Julian, and Mark N. Levine, Journal of Clinical Oncology, doi: 10.1200/JCO.2016.71.7397, published online 15 March 2017.