Study suggests three-week course of radiation therapy effective for breast cancer patients

American Society for Radiation OncologyNov 5 2009

According to a study presented November 4, 2009, at the 51st Annual Meeting of the American Society for Radiation Oncology (ASTRO), a shortened, more intensive course of radiation given to the whole breast, along with an extra dose of radiation given to the surgical bed of the tumor (concomitant boost), has been shown to result in excellent local control at a median follow up of two years after treatment with no significant side effects.

"The observations to date suggest that a three-week course of radiation therapy with concomitant boost results in outcomes comparable to that of a five to seven week course for early stage-breast cancers. Additional studies with a larger body of data and longer follow-up period will help establish whether this type of radiation treatment should be routinely used," Manjeet Chadha, M.D., lead author of the study and a radiation oncologist at the Beth Israel Medical Center in New York, said.

This shorter treatment, called accelerated hypofractionated whole breast irradiation, is an especially attractive option because women can receive a full course of radiation therapy in half the time -- three weeks of daily treatments vs. five to seven weeks. In addition, the cost of this treatment is lower relative to the cost of the standard whole breast radiation and is also less expensive than other new approaches, such as partial breast irradiation (breast brachytherapy).

"Studies from Europe and Canada have used accelerated schedules for breast radiation therapy with favorable results reported on longer follow up. In the U.S., however, there is limited data on this topic," Dr. Chadha said. "Additionally, the radiation therapy technique used in our study is different from previously published experiences. For each patient, we developed a conformal, personalized plan using three-dimensional dosimetry data derived from the patient specific CT scan images. Radiation treatment was delivered to the whole breast using an accelerated hypofractionated schedule, with the simultaneous delivery of a boost dose given to the precise location from which the tumor was removed."

Many women with early-stage breast cancer undergo breast conserving therapy. Typically, this means they first have surgery to remove the visible cancer (a lumpectomy), and then receive a course of radiation therapy to kill any microscopic cancer cells that may remain. The standard whole breast radiation treatment takes 15 to 30 minutes every day, Monday through Friday, for five to seven weeks.

Beginning in June 2004, researchers studied 112 women with early-stage breast cancer who received accelerated hypofractionated whole breast irradiation plus concomitant boost. The results were reported on 105 patients who had completed therapy and had a minimum six-month follow up. The patient group had small breast tumors that had not spread to the lymph nodes. Women with early-stage breast cancer who received chemotherapy or underwent radiation to the lymph nodes were excluded from the study. Patients were followed at regular intervals after completion of treatment.

Findings show that the cancer did not return to the original site or to the surrounding region in these women. The median follow-up of the study was two years. Survival was greater than 95 percent for patients with five years of follow up. The study also shows there were no significant physical or cosmetic side effects from the radiation treatment.

In an era of personalized care, Dr. Chadha emphasizes, "Women with early-stage breast cancer interested in this shorter course should ask their radiation oncologists about this option to evaluate whether it is suitable for their individual case."