Skin Toxicity in Early Breast Cancer Patients Treated with Field-In-Field Breast Intensity-Modulated Radiotherapy versus Helical Inverse Breast Intensity-Modulated Radiotherapy: Results of a Phase III Randomised Controlled Trial

Clin Oncol (R Coll Radiol). 2021 Jan;33(1):30-39. doi: 10.1016/j.clon.2020.07.005. Epub 2020 Jul 22.

Abstract

Aims: Skin toxicity is a common adverse effect of breast radiotherapy. We investigated whether inverse-planned intensity-modulated radiotherapy (IMRT) would reduce the incidence of skin toxicity compared with forward field-in-field breast IMRT (FiF-IMRT) in early stage breast cancer.

Materials and methods: This phase III randomised controlled trial compared whole-breast irradiation with either FiF-IMRT or helical tomotherapy IMRT (HT-IMRT), with skin toxicity as the primary end point. Patients received 50 Gy in 25 fractions and were assessed to compare skin toxicity between treatment arms.

Results: In total, 177 patients were available for assessment and the median follow-up was 73.1 months. Inverse IMRT achieved more homogeneous coverage than FiF-IMRT; erythema and moist desquamation were higher with FiF-IMRT compared with HT-IMRT (61% versus 34%; P < 0.001; 33% versus 11%; P < 0.001, respectively). Multivariate analysis showed large breast volume, FiF-IMRT and chemotherapy were independent factors associated with worse acute toxicity. There was no difference between treatment arms in the incidence of late toxicities. The 5-year recurrence-free survival was 96.3% for both FiF-IMRT and HT-IMRT and the 5-year overall survival was 96.3% for FiF-IMRT and 97.4% for HT-IMRT.

Conclusions: Our study showed significant reduction in acute skin toxicity using HT-IMRT compared with FiF-IMRT, without significant reduction in late skin toxicities. On the basis of these findings, inverse-planned IMRT could be used in routine practice for whole-breast irradiation with careful plan optimisation to achieve the required dose constraints for organs at risk.

Keywords: Acute toxicity; early stage breast cancer; forward field-in-field intensity-modulated radiotherapy; inverse-planned intensity-modulated radiotherapy; late toxicity.

Publication types

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

MeSH terms

  • Breast Neoplasms* / pathology
  • Breast Neoplasms* / radiotherapy
  • Disease-Free Survival
  • Female
  • Humans
  • Long Term Adverse Effects* / diagnosis
  • Long Term Adverse Effects* / etiology
  • Middle Aged
  • Neoplasm Staging
  • Radiodermatitis* / diagnosis
  • Radiodermatitis* / etiology
  • Radiodermatitis* / prevention & control
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted / methods
  • Radiotherapy, Intensity-Modulated* / adverse effects
  • Radiotherapy, Intensity-Modulated* / methods
  • Skin* / pathology
  • Skin* / radiation effects