Evaluation of Dose Reduction of Cardiac Exposure Using Deep-inspiration Breath Hold Technique in Left-sided Breast Radiotherapy

Joo-Young Jung; Min-Joo Kim; Jae-Hong Jung; Seu-Ran Lee; Tae-Suk Suh

Article

Original Article

Korean Journal of Medical Physics 2013; 24(4): 278-283

Published online December 30, 2013

Evaluation of Dose Reduction of Cardiac Exposure Using Deep-inspiration Breath Hold Technique in Left-sided Breast Radiotherapy

좌측 유방암 방사선 치료에서 깊은 들숨 호흡법을 이용한 심장 선량 감소 평가

Joo-Young Jung^*†, Min-Joo Kim^*†, Jae-Hong Jung^*†‡, Seu-Ran Lee^*†, Tae-Suk Suh^*†

정주영^*†ㆍ김민주^*†ㆍ정재홍^*†‡ㆍ이스란^*†ㆍ서태석^*†

Author Info ⁺

^*Department of Biomedical Engineering, ^†Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul,^‡Department of Radiation Oncology, College of Medicine, Soonchunhyang University, Bucheon, Korea

*가톨릭대학교 의과대학 의공학교실, ^†생체의공학연구소, ^‡순천향대학교 의과대학 방사선종양학교실

Received: October 21, 2013; Accepted: December 14, 2013

Abstract

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Abstract

Breast cancer is the leading cause of cancer death in women worldwide and the number of women breast cancer patient was increased continuously. Most of breast cancer patient has suffered from unnecessary radiation exposure to heart, lung. Low radiation dose to the heart could lead to the worsening of preexisting cardiovascular lesions caused by radiation induced pneumonitis. Also, several statistical reports demonstrated that left-sided breast cancer patient showed higher mortality than right-sided breast cancer patient because of heart disease. In radiation therapy, Deep Inspiration Breath Hold (DIBH) technique which the patient takes a deep inspiration and holds during treatment and could move the heart away from the chest wall and lung, has showed to lead to reduction in cardiac volume and to minimize the unnecessary radiation exposure to heart during treatment. In this study, we investigated the displacement of heart using DIBH CT data compared to free-breathing (FB) CT data and radiation exposure to heart. Treatment planning was performed on the computed tomography (CT) datasets of 10 patients who had received lumpectomy treatments. Heart, lung and both breasts were outlined. The prescribed dose was 50 Gy divided into 28 fractions. The dose distributions in all the plans were required to fulfill the International Commission on Radiation Units and Measurement specifications that include 100% coverage of the CTV with ≥95% of the prescribed dose and that the volume inside the CTV receiving ＞107% of the prescribed dose should be minimized. Scar boost irradiation was not performed in this study. Displacement of heart was measured by calculating the distance between center of heart and left breast. For the evaluation of radiation dose to heart, minimum, maximum and mean dose to heart were calculated. The present study demonstrates that cardiac dose during left-sided breast radiotherapy can be reduced by applying DIBH breathing control technique.

KeywordsBreast cancer, Radiation dose to heart, Deep inspiration breath hold