Novel approaches using radiation therapies

The updates of the Danish DBCG 82b trial and the British Columbia trial have confirmed a significant overall survival benefit with postoperative radiation therapy in patients with high-risk disease. These trials together with in-depth analyses of previous studies suggest that the mechanism of the survival benefit is eradication of subclinical locoregional deposits of tumor cells with a potential for further dissemination if left untreated. Despite these findings, several questions remain largely unanswered concerning the optimal way to integrate radiation therapy into routine clinical practice. For instance, which subgroups are likely to benefit from comprehensive treatment including the peripheral lymphatics as opposed to treatment of the breast/chest wall alone? The available randomized trials and overviews have convincingly demonstrated that it is essential to minimize long-term radiation side effects in the myocardium in order to achieve an overall survival benefit. An appropriate treatment technique is therefore essential. Individual treatment planning should be encouraged since some patients have an "unfavorable anatomy" with the heart located anteriorly in the mediastinum. Such patients may receive a high cardiac dose-volume even with conventional tangential field irradiation that does not include the internal mammary nodes.