The more radiation,  the better is usually the rule in cancer treatment, but high-dose radiation may not increase survival in patients with localized prostate cancer, a new study finds.

New technology has made it possible for prostate cancer patients to receive higher-dose radiation with fewer side effects but a new study shows that escalating the amount the patient receives isn't necessarily better, say researchers from Jefferson University in Philadelphia.

They analyzed data from 12 trials and looked at 6,884 men with localized prostate cancer, meaning that it had not spread outside the prostate gland. By pooling data from multiple clinical trials, the researchers were able to see trends that would not have been apparent in the individual studies.

In addition, instead of just focusing on prostate cancer antigen (PSA) test scores declined, they looked at the patient's long-term survival, as well as whether the cancer had metastasized, or spread.

Their findings showed that, although PSA levels decreased as patients received higher doses of radiation, neither the likelihood of the cancer spreading nor the patient's long-term survival was not impacted, they found.

"In the field of radiation oncology, we often assume that the highest dose that the body can tolerate will be most effective at killing cancer," says Dr. Robert Den, the study’s senior author. "Our results argue that this may not be the case, at least not with lower-risk prostate cancer patients,” he added of the study, which appears in the American Journal of Clinical Oncology.