Randomized controlled trial of intensity-modulated radiotherapy for early breast cancer: 5-year results confirm superior overall cosmesis

J Clin Oncol. 2013 Dec 20;31(36):4488-95. doi: 10.1200/JCO.2013.49.7842. Epub 2013 Sep 16.

Abstract

Purpose: There are few randomized controlled trial data to confirm that improved homogeneity with simple intensity-modulated radiotherapy (IMRT) decreases late breast tissue toxicity. The Cambridge Breast IMRT trial investigated this hypothesis, and the 5-year results are reported.

Patients and methods: Standard tangential plans of 1,145 trial patients were analyzed; 815 patients had inhomogeneous plans (≥ 2 cm(3) receiving 107% of prescribed dose: 40 Gy in 15 fractions over 3 weeks) and were randomly assigned to standard radiotherapy (RT) or replanned with simple IMRT; 330 patients with satisfactory dose homogeneity were treated with standard RT and underwent the same follow-up as the randomly assigned patients. Breast tissue toxicities were assessed at 5 years using validated methods: photographic assessment (overall cosmesis and breast shrinkage compared with baseline pre-RT photographs) and clinical assessment (telangiectasia, induration, edema, and pigmentation). Comparisons between different groups were analyzed using polychotomous logistic regression.

Results: On univariate analysis, compared with standard RT, fewer patients in the simple IMRT group developed suboptimal overall cosmesis (odds ratio [OR], 0.68; 95% CI, 0.48 to 0.96; P = .027) and skin telangiectasia (OR, 0.58; 95% CI, 0.36 to 0.92; P = .021). No evidence of difference was seen for breast shrinkage, breast edema, tumor bed induration, or pigmentation. The benefit of IMRT was maintained on multivariate analysis for both overall cosmesis (P = .038) and skin telangiectasia (P = .031).

Conclusion: Improved dose homogeneity with simple IMRT translates into superior overall cosmesis and reduces the risk of skin telangiectasia. These results are practice changing and should encourage centers still using two-dimensional RT to implement simple breast IMRT.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Beauty*
  • Breast Neoplasms / pathology
  • Breast Neoplasms / radiotherapy*
  • Breast Neoplasms / surgery
  • Edema / etiology
  • Female
  • Follow-Up Studies
  • Humans
  • Logistic Models
  • Mastectomy, Segmental
  • Middle Aged
  • Neoplasm Staging
  • Odds Ratio
  • Patient Satisfaction
  • Photography
  • Pigmentation Disorders / etiology
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy, Adjuvant
  • Radiotherapy, Intensity-Modulated* / adverse effects
  • Radiotherapy, Intensity-Modulated* / methods
  • Telangiectasis / etiology
  • Treatment Outcome