Radiooncological Aspects Regarding Multimodal Primary Treatment of Breast Cancer – a Review

Locoregional percutaneous radiation therapy (RT) is an integral part of a multimodal curative therapeutic concept in non-invasive and locally-limited invasive breast cancer. Large prospective randomized clinical trials and recent meta-analyses have demonstrated that RT is a major independent prognostic factor with a positive influence on local and locoregional tumor control after mastectomy and after breast-conserving surgery (BCS). RT improves local and locoregional control, independent of systemic antineoplastic therapy. Local recurrence rate is reduced by two thirds, the overall long-term reduction of local recurrence measures >20%. Rate of survival and quality of life are improved by this increased rate of tumor control. Depending upon the primary stage and related to an interval of 20 years, significant improvements achieved by RT range between 5-10%. After breast-conserving surgery, RT improves the prognosis, and long-term results are equal to those after mastectomy. Application of a total dose of 50-50.4 Gy in 1.8-2.0 Gy fractions, 5 times per week, is the considered standard therapy for irradiation of whole breast after BCS, chest wall or locoregional lymphatics, respectively. Delivery of fewer, larger fractions, reduction of target volume for RT after BCS as well as different intra- and postoperative radiation techniques (brachytherapy, electron beams and others) or more precise definition of patients who might benefit from different locoregional lymph node irradiation are currently in the focus of radiooncological investigations regarding primary treatment of breast cancer patients. Current topics concerning the application of RT are possible interactions with potentially cardiotoxic systemically administered antineoplastic drugs, questions of sequence of therapies thereby as well as the combination with oncoplastic surgery. These aspects and further developments in RT of breast cancer will be described in detail in this article.