Daily scans taken during prostate cancer radiotherapy may help doctors adjust treatment to reduce side effects, according to a recent study. Researchers used artificial intelligence to analyze routine images originally captured for patient positioning during radiotherapy sessions. They found these images could identify early changes linked to future rectal bleeding, a common side effect of the treatment.
The study was led by scientists from the University of Edinburgh, with contributions from the University of Cambridge and The Christie NHS Foundation Trust. Using machine learning tools, the team reviewed daily imaging data from 187 patients who received prostate radiotherapy. Their analysis revealed that patterns observed in single scans just one week into treatment were highly predictive of later rectal bleeding. When data from the first three weeks were combined, predictions became even more reliable.
Rectal bleeding occurs when healthy tissues near the prostate, such as the rectum, are exposed to radiation during therapy. Adaptive radiotherapy involves regularly updating treatment plans based on anatomical changes rather than using a fixed plan throughout therapy. However, current decisions do not account for subtle tissue patterns—referred to as radiomic features—that might indicate increased risk for side effects.
Researchers suggest that monitoring these features early in treatment could offer an opportunity to personalize or improve care without requiring new scans or technology.
Dr Zhuolin Yang, Research Fellow at the University of Edinburgh's Institute of Genetics and Cancer, stated: "The key result here is that early treatment imaging contains quantitative information about later toxicity risk, long before symptoms occur. This supports the idea that predictive biomarkers for adaptive radiotherapy may not require new scans or technology, only better use of the data we already collect."
Professor Bill Nailon, Clinical Scientist at Edinburgh Cancer Centre added: "This study gives a proof-of-concept that imaging collected for beam setup could support future adaptive workflows. Future trials and automation will be essential before approaches like this can be integrated into clinical decision-making."
Dr Hayley Luxton, Head of Research Impact at Prostate Cancer UK said: "Radiotherapy is a very common treatment used to cure prostate cancer. While very effective, the natural movement of the prostate and surrounding organs during treatment can lead to damage to the surrounding areas, causing bleeding and other side effects that can have a significant impact on men's lives.
"We know there's a need to make treatments kinder, so that's why in partnership with Movember and Garfield Weston Foundation we funded this research to identify which men are most likely to have these side effects and change their treatment plan early, avoiding these issues without compromising the effect on the cancer itself.
"While more research is needed in larger groups of men, this marks a great step forward in personalising radiotherapy to make it kinder and better for more men who need it."
The findings are published in Physics and Imaging in Radiation Oncology (https://doi.org/10.1016/j.phro.2025.100850). The researchers caution that further studies involving larger patient groups are needed before these methods become part of standard clinical practice.
