Delivering a shorter course of external-beam radiation therapy—with higher doses of radiation given at each visit—appears to be as effective for prostate cancer as the conventional approach to external-beam radiation therapy. These results were presented at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO).
Prostate cancer is the most commonly diagnosed cancer (other than skin cancer) in US men. Each year, more than 240,000 men are diagnosed with the disease. When the cancer is diagnosed at an early stage, treatment options include surgery, radiation therapy, and active surveillance (close monitoring but no treatment unless the cancer shows signs of worsening).
For men treated with external-beam radiation therapy, the treatment is typically delivered on a daily basis over several weeks. Researchers have speculated, however, that it may be possible to shorten the duration of external-beam radiation therapy by increasing the dose that is delivered each day. This approach is called hypofractionation. Although hypofractionation offers a more convenient approach to treatment, it’s necessary to establish that this approach is both safe and at least as effective as the conventional approach.
To compare hypofractionated and conventional external-beam radiation therapy, researchers conducted a study among 303 men with intermediate- or high-risk prostate cancer. Half the men received hypofractionated radiation therapy (delivered over 5.1 weeks) and half received conventional radiation therapy (delivered over 7.5 weeks).
In both study groups, radiation was delivered using a technique known as intensity-modulated radiation therapy (IMRT). This is a more recent approach to external-beam radiation therapy that allows for more precise delivery of radiation to the cancer.
Patients were followed for five years after treatment.
- Hypofractionation and conventional fractionation produced similar rates of cancer recurrence.
- Rates of bowel or rectal problems and unsatisfactory erections were also similar in the two groups.
- Bladder control problems were more common in the hypofractionated group.
These results suggest that hypofractionation may provide a more convenient but still effective approach to external-beam radiation therapy for intermediate- or high-risk prostate cancer.
Reference: Pollack A, Walker G, Buyyounouski M et al. Five year results of a randomized external beam radiotherapy hypofractionation trial for prostate cancer. Presented at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO). Miami Beach, FL, October 2-6, 2011. Abstract 1.