Journal List > Prog Med Phys > v.26(4) > 1098487

Prog Med Phys. 2015 Dec;26(4):234-240. Korean.
Published online December 31, 2015.
Copyright © 2015 Korean Society of Medical Physics
Comparison of Dosimetric Parameters of Patient with Large and Pendulous Breast Receiving Breast Radiotherapy in the Prone versus Supine Position
Sun Young Moon,* Myonggeun Yoon,* Weon Kuu Chung, Mijoo Chung, Dong Oh Shin, and Dong Wook Kim
*Department of Bio-convergence Engineering, Korea University, Korea.
Department of Radiation Oncology, Kyung Hee University Hospital at Gangdong, Korea.
Department of Radiation Oncology, Kyung Hee University Hospital, Seoul, Korea.

Co-correspondence: Dong Wook Kim. (Email: ), Tel: 82-2-440-7398, Fax: 82-2-440-7393
Received December 01, 2015; Revised December 18, 2015; Accepted December 19, 2015.

This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


The purpose of this study is to analyze dosimetric parameters of patient with large and pendulous breast receiving breast radiotherapy in the prone versus supine position. The patient underwent computed tomography simulation in both prone and supine position. The homogeneity index (HI), conformity index (CI), coverage index (CVI) to the left breast as planning target volume (PTV) and the doses to the lung, heart, and right breast as organ at risk (OAR) were compared by using dose-volume histogram. The lifetime attributable risk (LAR) according to the prone and supine position was measured for the lung and right breast. The HI, CI of the PTV decreased 21.7%, 6.49%, respectively and the CVI increased 10.8% with the prone position. The mean and maximum dose to the left lung decreased 91.6%, 87.0%, respectively and the volume parameters also decreased over 99% with the prone position. The parameters to the right lung were same regardless of the position. The mean and maximum dose to the heart decreased 51.6%, 14.2% with the prone position. But the mean and maximum dose to the right breast increased unlike the other OARs. The LARs to the lung decreased 80.3% (left), 24.2% (right) but the LAR to the right breast doubled with the prone position. The prone position is a favorable alternative for irradiation of breast in patients with large and pendulous breasts.

Keywords: Large breast; Breast cancer; Prone position; Radiotherapy


Fig. 1
Dose-volume histogram of the patient; (a) Prone (b) Supine. PTV: red, right lung: blue, left lung: bluish green, right breast: green, heart: plum.
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Fig. 2
CT image of the patient; (a) Prone (b) Supine.
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Table 1
HI, CI, CVI of the left breast according to the patient's position.
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Table 2
Parameters of the OAR according to the patient's position.
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Table 3
LAR of the OAR according to the patient's position.
Click for larger image


This work was supported by the General Researcher Program (NRF-2015R1D1A1A09056828), the Nuclear Safety Research Program (Grant No. 1403019) of the Korea Radiation Safety Foundation.

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