Dosimetric comparison of deep-inspiration breath-hold and free-breathing treatment delivery techniques for left-sided breast cancer using 3D surface tracking

Winston Vuong; Rupen Garg; Daniel J Bourgeois; Suhong Yu; Varun Sehgal; Parima Daroui

doi:10.1016/j.meddos.2018.06.002

Dosimetric comparison of deep-inspiration breath-hold and free-breathing treatment delivery techniques for left-sided breast cancer using 3D surface tracking

Med Dosim. 2019;44(3):193-198. doi: 10.1016/j.meddos.2018.06.002. Epub 2018 Aug 3.

Authors

Winston Vuong¹, Rupen Garg¹, Daniel J Bourgeois², Suhong Yu³, Varun Sehgal¹, Parima Daroui⁴

Affiliations

¹ Department of Radiation Oncology, Chao Family Comprehensive Cancer Center, University of California, IR, USA.
² Department of Radiation Oncology, Mary Bird Perkins Cancer Center.
³ Department of Radiation Oncology, Boston Medical Center.
⁴ Department of Radiation Oncology, Chao Family Comprehensive Cancer Center, University of California, IR, USA. Electronic address: pdaroui@uci.edu.

PMID: 30078605
DOI: 10.1016/j.meddos.2018.06.002

Abstract

Introduction: While radiation therapy has been shown to increase local control and overall survival for breast cancer, late cardiac toxicity remains a concern. Morbidity and mortality have been shown to increase proportionally to the mean heart dose. Deep inspiration breath-hold (DIBH) can reduce heart dose compared to free-breathing (FB) by increasing the heart-to-chest wall distance, especially in left-sided breast cancer. We present our clinical experience with DIBH in left breast and chest-wall irradiation using 3D optical surface tracking.

Materials & methods: 29 patients were treated with DIBH using a surface tracking system that provides a real time 3D surface image of the patient. Comparisons of maximum and mean heart dose, heart-chest wall separation, and the percentage of lung volume that receives 20 or more Gy (V20) between the DIBH and hypothetical FB treatment plans were conducted with the Student's t-test. Correlation coefficients were also calculated for heart-chest wall separation, heart volume, and lung volume.

Results: Comparing DIBH and FB plans showed a decrease in mean and maximum heart doses in all patients. Individual mean heart doses decreased by an average of 1.12 Gy, and the average mean heart dose for DIBH plans was significantly lower than corresponding FB plans (1.02 vs. 2.12 Gy; p < 0.0001). Maximum heart dose decreased by an average of 11.88 Gy and was significantly lower in DIBH versus FB plans (28.33 vs. 43.7 Gy; p = 0.0001). The average difference in heart to chest-wall separation between DIBH and FB images was 2.41 cm. DIBH left lung volume and measured increases in volume on inspiration inversely correlated with maximum heart dose (R = 0.39) and left lung V20 (R = 0.32).

Conclusions: DIBH with 3D surface tracking can significantly benefit patients with left sided disease by limiting the mean and maximum heart dose. DIBH appears to viably reduce heart dose for left-breast cancer patients and thus potentially reduce long-term complications without prolonging treatment delivery.

Keywords: Breast cancer; Deep inspiration breath-hold; Dose reduction; Free-breathing; Heart dose; RT.

Publication types

Comparative Study

MeSH terms

Adult
Aged
Aged, 80 and over
Breath Holding*
Female
Heart / radiation effects
Humans
Middle Aged
Radiotherapy Dosage*
Radiotherapy Planning, Computer-Assisted / methods*
Unilateral Breast Neoplasms / radiotherapy*