High precision radiation therapy; is it warranted in high-risk prostate cancer?

This study aimed to evaluate the benefit associated with use of intensity-modulated radiation therapy (IMRT), a form of high precision radiation therapy.

IMRT is a novel radiation therapy option for patients with prostate cancer that has not yet spread (localized). IMRT may offer lower rates of treatment-related toxicity when compared with standard radiation therapy. However, some authors have questioned the survival benefit of active treatment for patients with localized prostate cancer as opposed to observation.

This article aimed to determine if IMRT use may enhance the chance of survival compared to observation for patients with localized prostate cancer.

42,483 patients with prostate cancer were included in this study. 54.8% of the patients were treated with observation and 45.2% were treated with IMRT. The average follow up time was 50 months. Patients within each group were divided into high risk or low/intermediate risk.

Overall, the percentage of patients who died directly as a result of prostate cancer at 8 years was 3.4% for those treated with IMRT compared to 4.1% for patients treated with observation, respectively. This indicated that the initial observation group had 1.8 times higher chance of dying from prostate cancer compared with IMRT group.

In patients with low/intermediate risk disease, IMRT was not associated with lower percentages of patients dying from prostate cancer compared with observation.

Instead, when focusing in high-risk disease patients, the percentage of patients dying from cancer at 8 years was 5.8% for IMRT compared to 10.4% for the observation group. This indicated that observation was associated with a 2.4-fold increase in the risk of dying from prostate cancer compared with IMRT in high risk patients.

The authors concluded that IMRT is associated with a survival benefit only in patients with high-risk disease.

Although the patient population was large, more precise characterization of intermediate- risk group was needed in this study.

If you are considering IMRT as a treatment option, please consult your doctor for potential health benefits and risks.