The role of postmastectomy radiation in the treatment of early stage breast cancer: back to the future.

Oncologists once downplayed the adjuvant role of radiotherapy after mastectomy. A decade ago, lacking a survival benefit, studies demonstrating late fatal myocardial infarctions nearly put a stop to any referrals of postoperative high-risk women to radiation oncology. The potential survival benefits of adjuvant radiotherapy may be overshadowed by inadequate technique leading to late cardiac deaths. Is it possible to cover the chest wall, internal mammary lymph chain, supraclavicular, and, where indicated, the axillary nodes and keep the dose to the coronary arteries and the lung to well within tolerance? A modern five-field comprehensive technique can deliver less cardiac and lung irradiation than the standard three-field technique, i.e. supraclavicular field matched to broad tangential fields. Linear accelerators with 4 megavolt (MV) to 6 MV photons, a full spectrum (6 MV to 20 MV) of electron energies, and meticulous computerized treatment planning based on multiple computed tomography planes allow an experienced physics/dosimetry team to treat all target sites while wrapping the dose around critical normal tissues.Whether to offer postmastectomy radiation to women with one to three positive nodes after adjuvant chemotherapy treatment has been the subject of intense discussion since the publication of two major randomized prospective trials. Although before these studies radiotherapy after mastectomy was an established treatment for women with four or more positive axillary nodes, existing data did not justify its use in patients with less extensive nodal involvement. Now, with results from these studies showing improved survival after radiotherapy in all node-positive premenopausal and perimenopausal women, with perhaps its greatest benefit in women with 1-3 positive nodes, practice patterns are again shifting toward strong consideration of treatment in women with less tumor nodal involvement.