RT Journal A1 Formenti SC, DeWyngaert J T1 POsitioning during radiotherapy for breast cancer—reply JF JAMA JO JAMA YR 2013 FD January 9 VO 309 IS 2 SP 137 OP 137 DO 10.1001/jama.2012.56923 UL http://dx.doi.org/10.1001/jama.2012.56923 AB In Reply: We agree with Dr Sherr that the radiation dose to the left anterior descending (LAD) coronary artery may be relevant to the severity of late effects of heart irradiation in patients with breast cancer.1 Our prospective trial selected the treatment position based on the least volume of heart and lung included in the fields of breast irradiation when the patient was imaged in the supine vs prone positions. Dosimetric analysis in both positions was conducted for the first consecutive 100 patients, confirming that in-field volume is a reliable surrogate for dose.2