Radiation therapy to the breast contributes to improved outcomes in breast cancer patients after breast preservation surgery. “However, whole breast radiotherapy is associated with damage to the heart and lung, increased cardiovascular mortality, and lung cancer development, with risks that remain 15 to 20 years after treatment. These consequences occur when breast cancer patients are treated supine [lying on their back]. Preliminary data on prone positioning [lying face downward] suggest that radiation exposure to the heart and lung can be reduced compared with supine positioning with similar efficacy,” writes Silvia C. Formenti, M.D., of the New York University School of Medicine, New York, and colleagues.
As reported in a Research Letter, the authors conducted a study to test the hypothesis that prone positioning is superior to standard supine positioning, comparing the volume of heart and lung within the radiation field. The prospective study included breast cancer patients who underwent 2 computed tomography (CT) simulation scans, first supine and next prone. Two hundred patients per stratum (left and right breast cancer) were enrolled. The researchers found that prone positioning was associated with a reduction in the amount of irradiated lung in all patients and in the amount of heart volume irradiated in 85 percent of patients with left breast cancer. “The study is limited to a single institution. A multi-institutional prospective trial with outcome measures is warranted to confirm these findings. If prone positioning better protects normal tissue adjacent to the breast, the risks of long-term deleterious effects of radiotherapy may be reduced.”