title: Phase 2 trial of accelerated, hypofractionated whole-breast irradiation of 39 Gy in 13 fractions followed by a tumor bed boost sequentially delivering 9 Gy in 3 fractions in early-stage breast cancer.
abstract: OBJECTIVE
  To report a phase 2 trial of accelerated, hypofractionated whole-breast irradiation (AH-WBI) delivered as a daily dose of 3 Gy to the whole breast followed by a tumor bed boost.
  
  
  METHODS
  Two hundred seventy-six patients diagnosed with breast cancer (pT1-2 and pN0-1a) who had undergone breast-conserving surgery in which the operative margins were negative were treated with AH-WBI delivered as 39 Gy in 13 fractions of 3 Gy to the whole breast once daily over 5 consecutive working days, and 9 Gy in 3 sequential fractions of 3 Gy to a lumpectomy cavity, all within 3.2 weeks.
  
  
  RESULTS
  After a median follow-up period of 57 months (range: 27-75 months), the rate of 5-year locoregional recurrence was 1.4% (n=4), whereas that of disease-free survival was 97.4%. No grade 3 skin toxicity was reported during the follow-up period. Qualitative physician cosmetic assessments of good or excellent were noted in 82% of the patients at 2 months after the completion of AH-WBI. The global cosmetic outcome did not worsen over time, and a good or excellent cosmetic outcome was reported in 82% of the patients at 3 years. The mean pretreatment percentage breast retraction assessment was 12.00 (95% confidence interval [CI]: 11.14-12.86). The mean value of percentage breast retraction assessment increased to 13.99 (95% CI: 12.17-15.96) after 1 year and decreased to 13.54 (95% CI: 11.84-15.46) after 3 years but was not significant (P>.05).
  
  
  CONCLUSIONS
  AH-WBI consisting of 39 Gy in 13 fractions followed by a tumor bed boost sequentially delivering 9 Gy in 3 fractions can be delivered with excellent disease control and tolerable skin toxicity in patients with early-stage breast cancer after breast-conserving surgery.
authors.affiliation: Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
authors.forename: Ja Young
authors.initials: JY
authors.lastname: Kim
authors.forename: So-Youn
authors.initials: SY
authors.lastname: Jung
authors.forename: Seeyoun
authors.initials: S
authors.lastname: Lee
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Kang
authors.forename: Eun Sook
authors.initials: ES
authors.lastname: Lee
authors.forename: In Hae
authors.initials: IH
authors.lastname: Park
authors.forename: Keun Seok
authors.initials: KS
authors.lastname: Lee
authors.forename: Jungsil
authors.initials: J
authors.lastname: Ro
authors.forename: Nam Kwon
authors.initials: NK
authors.lastname: Lee
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Shin
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology / Q000528:radiation effects; D001943:Breast Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D011379:Prognosis; D011832:Radiation Injuries / Q000150:complications / Q000473:pathology; D012867:Skin / Q000473:pathology / Q000528:radiation effects