Prone-Position Breast Radiation Avoids Heart, Lung Exposure
(HealthDay News) – For most women with breast cancer, prone positioning during computed tomography (CT) simulation scans correlates with a reduction in the amount of heart and lung irradiation, according to a research letter published in the Sept 5 issue of the Journal of the American Medical Association.
To examine whether prone positioning is superior to supine positioning, Silvia C. Formenti, MD, from the New York University School of Medicine in New York City, and colleagues compared the volume of heart and lung within the radiation field in a prospective cohort of patients with Stage 0–IIA breast cancer. Participants underwent two CT simulation scans each, one supine and one prone.
Of the 400 patients accrued, approximately 60% were eligible for inclusion in the study. The researchers found that, in all patients, compared with supine positioning, prone positioning correlated with reduced in-field lung volumes (an 86.2% reduction for right breast cancer and a 91.1% reduction for left breast cancer). The prone position also correlated with a reduction of in-field heart volumes compared with supine positioning for patients with left breast cancer (85.7% reduction). But, the supine position correlated with less in-field heart volume in 15% of patients with left breast cancer (mean difference, 6.15cm³). Regardless of breast volume, these reductions were statistically significant (with the exception of heart in women with breast size less than 750cm³).
"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 patients with left breast cancer," the authors write.