title: Prone accelerated partial breast irradiation after breast-conserving surgery: five-year results of 100 patients.
abstract: OBJECTIVE
  To report the 5-year results of a prospective trial of three-dimensional conformal external beam radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation in the prone position.
  
  
  METHODS
  Postmenopausal patients with Stage I breast cancer with nonpalpable tumors <2 cm, negative margins and negative nodes, positive hormone receptors, and no extensive intraductal component were eligible. The trial was offered only after eligible patients had refused to undergo standard whole-breast radiotherapy. Patients were simulated and treated on a dedicated table for prone setup. 3D-CRT was delivered at a dose of 30 Gy in five 6-Gy/day fractions over 10 days with port film verification at each treatment. Rates of ipsilateral breast failure, ipsilateral nodal failure, contralateral breast failure, and distant failure were estimated using the cumulative incidence method. Rates of disease-free, overall, and cancer-specific survival were recorded.
  
  
  RESULTS
  One hundred patients were enrolled in this institutional review board-approved prospective trial, one with bilateral breast cancer. One patient withdrew consent after simulation, and another patient elected to interrupt radiotherapy after receiving two treatments. Ninety-eight patients were evaluable for toxicity, and, in 1 case, both breasts were treated with partial breast irradiation. Median patient age was 68 years (range, 53-88 years); in 55% of patients the tumor size was <1 cm. All patients had hormone receptor-positive cancers: 87% of patients underwent adjuvant antihormone therapy. At a median follow-up of 64 months (range, 2-125 months), there was one local recurrence (1% ipsilateral breast failure) and one contralateral breast cancer (1% contralateral breast failure). There were no deaths due to breast cancer by 5 years. Grade 3 late toxicities occurred in 2 patients (one breast edema, one transient breast pain). Cosmesis was rated good/excellent in 89% of patients with at least 36 months follow-up.
  
  
  CONCLUSIONS
  Five-year efficacy and toxicity of 3D-CRT delivered in prone partial breast irradiation are comparable to other experiences with similar follow-up.
authors.affiliation: Department of Radiation Oncology, New York University School of Medicine and Langone Medical Center, New York, NY 10016, USA. silvia.formenti@nyumc.org
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Formenti
authors.forename: Howard
authors.initials: H
authors.lastname: Hsu
authors.forename: Maria
authors.initials: M
authors.lastname: Fenton-Kerimian
authors.forename: Daniel
authors.initials: D
authors.lastname: Roses
authors.forename: Amber
authors.initials: A
authors.lastname: Guth
authors.forename: Gabor
authors.initials: G
authors.lastname: Jozsef
authors.forename: Judith D
authors.initials: JD
authors.lastname: Goldberg
authors.forename: J Keith
authors.initials: JK
authors.lastname: Dewyngaert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology / Q000532:radiotherapy* / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D016609:Neoplasms, Second Primary; D056888:Patient Positioning / Q000379:methods; D017698:Postmenopause; D016684:Prone Position; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000379:methods*; D047368:Tumor Burden
chemical_list: D018931:Antineoplastic Agents, Hormonal