Radiation therapy in Women with Large Breast

Patients with large breasts can be a challenge for the delivery of adjuvant radiation therapy:
- They have typically had higher acute and late toxicity as well as inferior cosmesis
One potential explanation for this:
- Is that they may have larger hot spots of increased dose compared to patients with smaller breasts
Several techniques have been devised to improve these hot spots and reduce toxicity:
- Intensity-modulated radiation therapy:
  - Has been shown in randomized trials to reduce acute and chronic toxicity:
    - With institutional data demonstrating reductions in toxicity in women with large breasts:
      - By reducing hot spots and improving homogeneity
Proton therapy:
- Is not widely utilized to deliver WBI with no data supporting improvement in toxicity in women with large breasts with WBI
Electrons:
- Are typically utilized in treating the chest wall or as part of a tumor bed boost and are not utilized to deliver WBI
Neutron therapy:
- Is limited in its availability and is not routinely used to deliver WBI

References:
- Donovan E, Bleakley N, Denholm E, et al; Breast Technology Group. Randomised trial of standard 2D radiotherapy (RT) versus intensity modulated radiotherapy (IMRT) in patients prescribed breast radiotherapy. Radiother Oncol. 2007;82:254-264.
- Hille-Betz U, Baske B, Bremer M, et al. Late radiation side effects, cosmetic outcomes, and pain in breast cancer patients after breast-conserving surgery and three-dimensional conformal radiotherapy: risk modifying factors. Strahlenther Onkol. 2016;192:8-16.
- Pignol JP, Olivotto I, Rakovitch E, et al. A multicenter randomized trial of breast intensity modulated radiation therapy to reduce acute radiation dermatitis. J Clin Oncol. 2008;26:2085-2092.
- Shah C, Wobb J, Grills I, Wallace M, Mitchell C, Vicini FA. Use of intensity modulated radiation therapy to reduce acute and chronic toxicities of breast cancer patients treated with traditional and accelerated whole breast irradiation. Pract Radiat Oncol. 2012;2:e45-51.

Published by Rodrigo Arrangoiz MS, MD, FACS, FSSO