Standard radiation therapy for breast cancer after lumpectomy usually lasts about five weeks. Giving an additional higher dose of radiation to the lumpectomy area further reduces the risk of recurrence but extends the treatment time to six or six and a half weeks.
Accelerated radiation therapy with “hypofractionation” involves giving a higher dose of radiation on fewer days over only three weeks. Studies have shown that the risk of breast cancer recurrence is comparable between this approach and the standard five-week radiation schedule. However, it is not known if a radiation boost can be given at the same time as the accelerated radiation treatments.
The purpose of this Radiation Therapy Oncology Group study is to compare accelerated radiation with a daily radiation boost to standard radiation therapy with a boost added on after the five-week regimen is completed. Patients will be randomly assigned to one treatment schedule or the other. It is expected that the two treatments will be at least comparable in their effectiveness for reducing breast cancer recurrence, but the accelerated radiation schedule may be more convenient and save time and costs.