Prone positioning (lying face-down) was associated with a reduced amount of irradiated lung and heart compared with supine positioning (lying on the back) among patients undergoing radiotherapy for breast cancer.

Although adjuvant radiotherapy to the breast contributes to improved outcomes in persons with breast cancer after breast-preservation surgery, whole breast radiotherapy is associated with damage to the heart and lung, increased cardiovascular mortality, and the development of lung cancer, acknowledged Silvia C. Formenti, MD, of the New York University School of Medicine, New York, and colleagues in a JAMA research letter (2012;308[9]:861-863). These consequences, the risks of which remain 15 to 20 years after treatment, occur when patients receive radiotherapy while supine. However, preliminary data suggest that prone positioning reduces radiation exposure to the heart and lung.

Formenti’s group compared the volume of heart and lung within the radiation fields in a prospective study of 200 patients with right breast cancer and 200 patients with left breast cancer who underwent two computed-tomography simulation scans, first supine and then prone. The investigators learned 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% of the patients with left breast cancer.

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Formenti and fellow researchers called for a multi-institutional prospective trial with outcome measures 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,” they wrote.