title: DEGRO practical guidelines: radiotherapy of breast cancer I: radiotherapy following breast conserving therapy for invasive breast cancer.
abstract: OBJECTIVE
  The aim of the present paper is to update the practical guidelines for postoperative adjuvant radiotherapy of breast cancer published in 2007 by the breast cancer expert panel of the German Society for Radiooncology (Deutsche Gesellschaft für Radioonkologie, DEGRO). The present recommendations are based on a revision of the German interdisciplinary S-3 guidelines published in July 2012.
  
  
  METHODS
  A comprehensive survey of the literature concerning radiotherapy following breast conserving therapy (BCT) was performed using the search terms "breast cancer", "radiotherapy", and "breast conserving therapy". Data from lately published meta-analyses, recent randomized trials, and guidelines of international breast cancer societies, yielding new aspects compared to 2007, provided the basis for defining recommendations according to the criteria of evidence-based medicine. In addition to the more general statements of the DKG (Deutsche Krebsgesellschaft), this paper addresses indications, target definition, dosage, and technique of radiotherapy of the breast after conservative surgery for invasive breast cancer.
  
  
  RESULTS
  Among numerous reports on the effect of radiotherapy during BCT published since the last recommendations, the recent EBCTCG report builds the largest meta-analysis so far available. In a 15 year follow-up on 10,801 patients, whole breast irradiation (WBI) halves the average annual rate of disease recurrence (RR 0.52, 0.48-0.56) and reduces the annual breast cancer death rate by about one sixth (RR 0.82, 0.75-0.90), with a similar proportional, but different absolute benefit in prognostic subgroups (EBCTCG 2011). Furthermore, there is growing evidence that risk-adapted dose augmentation strategies to the tumor bed as well as the implementation of high precision RT techniques (e.g., intraoperative radiotherapy) contribute substantially to a further reduction of local relapse rates. A main focus of ongoing research lies in partial breast irradiation strategies as well as WBI hypofractionation schedules. The potential of both in replacing normofractionated WBI has not yet been finally clarified.
  
  
  CONCLUSIONS
  After breast conserving surgery, no subgroup even in low risk patients has yet been identified for whom radiotherapy can be safely omitted without compromising local control and, hence, cancer-specific survival. In most patients, this translates into an overall survival benefit.
authors.affiliation: Department of Radiotherapy and Radiation Oncology, LKH Salzburg, Paracelsus Medical University Hospital, Muellner Haupstr. 48, Salzburg, Austria, F.Sedlmayer@salk.at.
authors.forename: F
authors.initials: F
authors.lastname: Sedlmayer
authors.forename: M-L
authors.initials: ML
authors.lastname: Sautter-Bihl
authors.forename: W
authors.initials: W
authors.lastname: Budach
authors.forename: J
authors.initials: J
authors.lastname: Dunst
authors.forename: G
authors.initials: G
authors.lastname: Fastner
authors.forename: P
authors.initials: P
authors.lastname: Feyer
authors.forename: R
authors.initials: R
authors.lastname: Fietkau
authors.forename: W
authors.initials: W
authors.lastname: Haase
authors.forename: W
authors.initials: W
authors.lastname: Harms
authors.forename: R
authors.initials: R
authors.lastname: Souchon
authors.forename: F
authors.initials: F
authors.lastname: Wenz
authors.forename: R
authors.initials: R
authors.lastname: Sauer
mesh_terms: D001943:Breast Neoplasms / Q000628:therapy*; D003131:Combined Modality Therapy / Q000592:standards; D005260:Female; D005858:Germany; D006801:Humans; D015412:Mastectomy, Segmental / Q000592:standards*; D008495:Medical Oncology / Q000592:standards*; D009361:Neoplasm Invasiveness; D018714:Radiotherapy, Adjuvant / Q000592:standards; D020266:Radiotherapy, Conformal / Q000592:standards*