"Much to our surprise, four weeks of treatment was actually associated with a lower rate of skin reactions and other side effects than the conventional seven-week course of treatment," says researcher Gary Freedman, MD, a radiation oncologist at Fox Chase Cancer Center in Philadelphia.
Additionally, the women given the short course did not require any more pain medication than usual and said they were highly satisfied with the cosmetic results, he tells WebMD.
"Every single woman we studied was pleased to be finished in four weeks," Freedman says. "We had no one who wished they had opted for the conventional method."
Same Dose, Shorter Time
The study, presented here at the 48th Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), involved 75 women treated with breast-sparing surgery followed by intensity modulated radiation therapy or IMRT.
In IMRT, multiple radiation beams are focused at the breast from many directions. A computerized program allows doctors to adjust both the strength and the intensity of the beams, so that more radiation is blasted at the tumor site and less is delivered to healthy surrounding tissue.
Additionally, the doctors added a radiation boost, a little each day, to the part of the breast where the tumor was removed.
Their outcomes were compared with published results from studies of women who received conventional external beam radiation therapy. That method involves aiming a beam of radiation, or X-ray, through the skin to the tumor site and surrounding tissue to kill cancer cells.
Because the women receive the same dosage of radiation regardless of the delivery method, the researchers had expected that there would be a trade-off, with the short, high-dose course resulting in more toxicity, Freedman tells WebMD.
Side Effects, Pain Acceptable
But that proved not to be the case. Among the findings:
Fewer than one in four of the women on IMRT developed moderate to severe redness or peeling of the skin in the breast area. In comparison, more than one in three women who received conventional radiation treatment in a large published study had these reactions, Freedman says.
By six weeks after treatment, none of the women on IMRT had anything worse than mild redness.
When women were asked to score the cosmetic results by comparing their treated breast with the untreated breast, the majority of women on IMRT rated the appearance of both breasts as good to excellent.
While women on IMRT said they were in more pain six weeks and eight months compared with before treatment, the pain was generally mild and the women did not require pain medication. By 20 months later, their pain was no worse than before treatment.
Phillip Devlin, MD, assistant professor of radiation oncology at Harvard Medical School, says that if confirmed in a well-designed study in which half the women get IMRT and half get conventional treatment, the findings will be change medical practice.
"If this holds up, we would want to offer all women the option of having the shorter therapy," he tells WebMD. "It would likely improve quality of life and access to care, as it means less time away from work and family."