A new strategy for prostate cancer at the Centre hospitalier de l’Université de Montréal (CHUM) not only detects the disease more effectively, but also attacks it with greater precision. A phase III clinical trial is currently underway, but the results obtained so far are so promising that the CHUM has decided to change its approach immediately. “It’s a combination of two things that happened at about the same time, namely new, much more powerful imaging (and) more precise radiotherapy techniques,” said Dr. Cynthia Ménard, head of the CHUM’s radiation oncology department. “So yes, it’s really a game changer.” The new strategy is based on the use of a highly sophisticated form of imaging called prostate-specific membrane antigen positron emission tomography, or PSMA PET. PSMA PET works by detecting the presence of a protein, PSMA, on the surface of cancer cells. By guiding and intensifying radiation therapy, a press release stated, “this approach significantly improves failure-free survival without increasing side effects or altering the patient’s quality of life.” After 37 months of follow-up, patients who received PSMA PET-guided treatment had half as many relapses as those receiving standard treatment. This technology makes it possible to detect prostate cancer and any metastases (even micro-metastases) in the smallest corners of the body, and thus to proceed with extremely targeted radiation therapy, according to the study’s lead author, Dr. Collin Beliveau, a resident physician in radiation oncology. “This is a significant advance (in being able) to reduce recurrence in the future by better guiding and personalizing radiation therapy treatments with new, more accurate imaging,” he said. But that’s not all, said Dr. Ménard: this imaging also makes it possible to detect cancers that would otherwise have gone unnoticed, at least for the time being. “When we tried to find out what percentage of patients had lesions completely outside the field that we would have treated if we hadn’t had the information, it was over 30 per cent,” she said. “That’s a significant number of patients who would have been missed with standard treatment.” After a follow-up period of just over three years, Dr. Ménard added, “it is clear that there is a big difference between the two groups of patients, those who survive without recurrence and those who do not.” The main obstacle at the moment, she added, is access, “since not all centres have access to imaging.” In addition, in the face of possible delays, we will have to ask ourselves whether it is appropriate to wait, because “standard treatment is preferable to no treatment.” “This study allows us to personalize treatment for each patient,” said Dr. Belliveau. “Before, we either treated everything to be sure we didn’t miss anything, or we didn’t treat enough and missed a lesion, so we weren’t necessarily offering the best treatment. But with PET PSMA, we’re pretty confident that we’re targeting exactly the right spot.” The findings of phase II of this clinical trial were recently published in the medical journal JAMA Oncology. This report by The Canadian Press was first published in French on Oct. 27, 2025.
