title: Implementation of image-guided intensity-modulated accelerated partial breast irradiation : Three-year results of a phase II clinical study.
abstract: OBJECTIVE
  To report 3‑year results of accelerated partial breast irradiation (APBI) using image-guided intensity-modulated radiotherapy (IG-IMRT) following breast conserving surgery (BCS) for low-risk early invasive breast cancer.
  
  
  METHODS
  Between July 2011 and March 2014, 60 patients with low-risk early invasive breast cancer underwent BCS and were enrolled in this phase II prospective study. The total dose was 36.9 Gy (9 fractions of 4.1 Gy, two fractions/day). Patient setup errors were detected in LAT, LONG and VERT directions. Local tumour control, survival results, early and late side effects and cosmetic outcome were assessed.
  
  
  RESULTS
  At a median follow-up of 39 months, all patients were alive and neither locoregional nor distant failure occurred. One contralateral breast cancer and two new primary malignancies outside the breast were observed. No grade (G) 3-4 acute toxicity was detected. G1 and G2 erythema occurred in 21 (35%) and 2 (3.3%) patients, respectively; while G1 oedema was observed in 23 (38.8%) cases. G1 and G2 pain was reported by 6 (10%) and 2 (3.3%) patients, respectively. Among the late radiation side effects, G1 pigmentation or telangiectasia, G1 fibrosis and G1 asymptomatic fat necrosis occurred in 10 (16.7%), 7 (11.7%) and 3 (5%) patients, respectively. No ≥ G2 late toxicity was detected. Cosmetic outcome was excellent in 43 (71.7%) and good in 17 (28.3%) patients.
  
  
  CONCLUSIONS
  IG-IMRT is a reproducible and feasible technique for delivery of external beam APBI following BCS for treatment of low-risk, early-stage invasive breast carcinoma. In order to avoid toxicity, image guidance performed before each radiation fraction is necessary to minimize the PTV. Three-year results are promising, early and late radiation side-effects are minimal, and cosmetic results are excellent to good.
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary. meszarosnorbert@oncol.hu.
authors.forename: Norbert
authors.initials: N
authors.lastname: Mészáros
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Major
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Stelczer
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Zaka
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.|Department of Radiooncology and Radiotherapy, Landesklinikum, Wiener Neustadt, Austria.
authors.forename: Emőke
authors.initials: E
authors.lastname: Mózsa
authors.affiliation: Department of Breast and Sarcoma Surgery, National Institute of Oncology, Budapest, Hungary.
authors.forename: Dávid
authors.initials: D
authors.lastname: Pukancsik
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Takácsi-Nagy
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.
authors.forename: János
authors.initials: J
authors.lastname: Fodor
authors.affiliation: Center of Radiotherapy, National Institute of Oncology, Ráth György u. 7-9, 1122, Budapest, Hungary.
authors.forename: Csaba
authors.initials: C
authors.lastname: Polgár
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000401:mortality* / Q000628:therapy*; D003131:Combined Modality Therapy / Q000401:mortality / Q000706:statistics & numerical data; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D006814:Hungary / Q000453:epidemiology; D008137:Longitudinal Studies; D015412:Mastectomy, Segmental / Q000401:mortality* / Q000706:statistics & numerical data; D008875:Middle Aged; D015995:Prevalence; D011832:Radiation Injuries / Q000401:mortality* / Q000517:prevention & control; D020266:Radiotherapy, Conformal / Q000401:mortality* / Q000706:statistics & numerical data; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome
keywords: APBI; Breast cancer; Image-guided; Intensity modulated; Toxicity