Cardiopulmonary Substructure Doses are Not Correlated With Cardiorespiratory Fitness Among Breast Cancer Survivors Treated With Contemporary Radiation Therapy

Maria Thor; Jessica M Scott; Anne S Reiner; Linda Hong; Anthony F Yu; Aditya Apte; Beryl McCormick; Angelica Perez-Andujar; Catherine P Lee; Laura Cervino; Jenna Harrison; Xiaolin Liang; Prusha Patel; Lawrence T Dauer; Chaya S Moskowitz; Jonine L Bernstein

doi:10.1016/j.adro.2024.101613

Cardiopulmonary Substructure Doses are Not Correlated With Cardiorespiratory Fitness Among Breast Cancer Survivors Treated With Contemporary Radiation Therapy

Adv Radiat Oncol. 2024 Sep 30;9(12):101613. doi: 10.1016/j.adro.2024.101613. eCollection 2024 Dec.

Authors

Maria Thor¹, Jessica M Scott^{2

3}, Anne S Reiner⁴, Linda Hong¹, Anthony F Yu^{2

3}, Aditya Apte¹, Beryl McCormick⁵, Angelica Perez-Andujar¹, Catherine P Lee², Laura Cervino¹, Jenna Harrison², Xiaolin Liang⁴, Prusha Patel⁴, Lawrence T Dauer¹, Chaya S Moskowitz⁴, Jonine L Bernstein⁴

Affiliations

¹ Departments of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
² Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York.
³ Weill Cornell Medical College, New York, New York.
⁴ Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
⁵ Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York.

Abstract

Purpose: Breast cancer radiation therapy (RT) techniques have historically delivered mean heart doses (MHDs) in the range of 5 Gy, which have been found to predispose patients to cardiopulmonary toxicities. The purpose of this study was to apply artificial intelligence (AI) cardiac substructure auto-segmentation to evaluate the corresponding substructure doses, whether there are laterality- and technique-specific differences in these doses, and if the doses are significantly associated with cardiorespiratory fitness after state-of-the-art RT planning and delivery for breast cancer.

Methods and materials: Cardiopulmonary substructures were AI auto-segmented. Cardiorespiratory fitness was evaluated at a median of 2.3 (range, 1.1-9.8) years following RT from 2007 to 2021 among 65 breast cancer survivors. The associations between the mean dose to each of the 9 AI auto-segmented cardiopulmonary substructures, the contralateral, and the ipsilateral lung with cardiorespiratory fitness were evaluated using linear regression.

Results: The median MHD was 0.64 Gy (range, 0.12-7.1). Among the auto-segmented substructures, the highest mean doses were observed for the left ventricle (median, 0.88 Gy). The mean dose to each of the 11 structures was significantly higher for women treated with volumetric modulated arc therapy (MHD median, 3.8 Gy vs 0.57 Gy; P < .0001). Women with left-sided breast cancer had significantly higher MHDs (0.97 vs 0.38 Gy; P < .0001) due to higher doses in 3 of 4 cardiac chambers and also due to significantly higher pulmonary artery doses (median, 0.93 vs 0.32 Gy; P = .0003); women with right-sided breast cancer had significantly higher vena cava and right atrium doses (eg, right atrium median, 0.74 vs 0.29 Gy; P = .0002). No cardiopulmonary structure dose was significantly associated with reduced cardiorespiratory fitness after adjusting for age, chemotherapy agent, volumetric modulated arc therapy, RT position, and RT extent.

Conclusions: State-of-the-art breast cancer RT reduces cardiopulmonary dose, and there is a technique and cancer laterality RT dose dependence throughout the cardiopulmonary system.