Dosimetric comparison between three-dimensional conformal radiotherapy followed by electron beam boost and volumetric modulated arc therapy using concomitant boost for the heart and cardiac segments in patients with left-sided breast cancer at risk for radiation-induced cardiac toxicity.

Abstract

PURPOSE:

We aimed to compare dosimetric parameters between three-dimensional conformal radiation therapy followed by electron beam boost (3D-CRT + EB) and volumetric modulated arc therapy using simultaneous integrated boost (SIB-VMAT) in left-sided breast cancer patients.

METHODS:

This study included 57 patients with left-sided breast cancer who underwent SIB-VMAT. All patients had a computed tomography-based maximum heart distance of ≥ 1 cm and were prescribed a dose of 42.56 Gy/16 fractions to the planning target volume and a concomitant-boosted target dose of 53.2 Gy or 51.2 Gy. The 3D-CRT + EB plan was retrospectively created for the purpose of comparison using tangential fields with field-in-field technique followed by electron beam irradiation.

RESULTS:

The doses to the clinical target volume significantly improved in the SIB-VMAT plans. All dosimetric parameters for the left anterior descending coronary artery (LAD) and LAD middle position (LAD mid) in the SIB-VMAT plans were significantly lower than those for 3D-CRT + EB plans (P < 0.01), while the doses to the heart, lung, contralateral breast and non-target tissue were decreased in the 3D-CRT + EB plans compared with those in the SIB-VMAT plans (e.g., 1.9 Gy vs. 2.9 Gy; P < 0.001 for the mean dose of heart).

CONCLUSIONS:

SIB-VMAT significantly improved the dose to the target while reducing the doses to the LAD and LAD mid, whereas 3D-CRT + EB significantly decreased the doses to the heart and other organs at risk in patients with left-sided breast cancer at risk for radiation-induced coronary artery disease.

• Authors: Yu Murakami, Yuki Murakami, Tatsuya Kamima, Masahiko Oguchi, Natsumi Abo, Taro Takahashi, Masahiro Kaneko, Masahiro Nakano, Fumiyasu Matsubayashi, Arisa Harada, Senzo Taguchi, Takeo Hashimoto, Yasuo Yoshioka
• Journal: Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) (Phys Med) Vol. 95 Pg. 126-132 (Mar 2022) ISSN: 1724-191X [Electronic] Italy
• PMID: 35158316 (Publication Type: Journal Article)
• Copyright: Copyright © 2022 Associazione Italiana di Fisica Medica e Sanitaria. Published by Elsevier Ltd. All rights reserved.

Topics

• Breast Neoplasms (etiology, radiotherapy)
• Cardiotoxicity (etiology)
• Electrons
• Female
• Humans
• Organs at Risk
• Radiotherapy Dosage
• Radiotherapy Planning, Computer-Assisted (methods)
• Radiotherapy, Conformal (adverse effects, methods)
• Radiotherapy, Intensity-Modulated (adverse effects, methods)
• Retrospective Studies
• Unilateral Breast Neoplasms (radiotherapy)