Postmastectomy Radiation Therapy Planning After Immediate Implant-based Reconstruction Using the European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice Consensus Guidelines for Target Volume Delineation

Clin Oncol (R Coll Radiol). 2021 Jan;33(1):20-29. doi: 10.1016/j.clon.2020.09.004. Epub 2020 Sep 26.

Abstract

Aims: To evaluate how common radiation therapy techniques perform in the setting of the new European Society for Radiotherapy and Oncology-Advisory Committee in Radiation Oncology Practice (ESTRO-ACROP) delineation recommendations for immediate breast reconstruction (IBR).

Materials and methods: Seven Danish radiation therapy centres and six international European centres participated in this project. Two breast cancer cases (one left-sided and one right-sided) with a retropectoral implant were chosen for radiation therapy planning using deep-inspiration breath-hold. Target volumes were delineated according to ESTRO-ACROP delineation recommendations. The centres were asked to plan the cases using any radiation therapy technique according to the Danish Breast Cancer Group plan objectives.

Results: In total, 35 treatment plans were collected. Half of the submitted plans, for both the left-sided and the right-sided case, used the field-in-field (FiF) technique (nine for each), a quarter used volumetric arc radiation therapy (VMAT; five for right-sided, four for left-sided) and the remaining quarter was a mix of inverse intensity-modulated radiation therapy (IMRT), helicoidal therapy and hybrid (combined open fields and VMAT) techniques. Mean clinical target volume doses were in the range 99-102% of the prescribed dose. The median FiF mean heart dose (MHD) for right-sided radiation therapy was 1 Gy (range 0.8-3.7) and 5.2 Gy for left-sided radiation therapy (range 2.2-6.5). For right-sided radiation therapy, the median VMAT MHD was 3.42 Gy, for IMRT was 2.3 Gy and for helicoidal therapy was 5.1 Gy. For left-sided radiation therapy, the median VMAT MHD was 6.3 Gy, for IMRT was 7.8 Gy and for helicoidal therapy was 7.3 Gy.

Conclusions: Different radiation therapy techniques could be used to plan radiation therapy in the setting of IBR. FiF provided good coverage with acceptable organ at risk doses. The best dose distribution results as a trade-off between the objectives of target volume coverage and high-dose organ at risk inclusion. The radiation therapy technique affects the interplay between these objectives.

Trial registration: ClinicalTrials.gov NCT03730922.

Keywords: Breast cancer; ESTRO-ACROP; implant; mastectomy; radiation; reconstruction; treatment planning.

Publication types

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

MeSH terms

  • Breast Implantation / methods
  • Breast Neoplasms* / epidemiology
  • Breast Neoplasms* / pathology
  • Breast Neoplasms* / radiotherapy
  • Breast Neoplasms* / surgery
  • Europe / epidemiology
  • Female
  • Guideline Adherence
  • Humans
  • Mastectomy / methods
  • Organs at Risk
  • Patient Care Planning / organization & administration
  • Patient Care Planning / standards*
  • Postoperative Care / methods
  • Postoperative Care / standards
  • Practice Guidelines as Topic
  • Radiation Injuries / prevention & control*
  • Radiation Oncology / standards*
  • Radiotherapy Dosage / standards*
  • Radiotherapy Planning, Computer-Assisted / methods*
  • Radiotherapy, Intensity-Modulated / methods

Associated data

  • ClinicalTrials.gov/NCT03730922