Program Information
Estimation of Dose Distributions with Different Types of Breast Implants in Various Radiation Treatment Techniques for Breast Cancer
M Lee1,2*, J Jung1,2,3 , S Lee1,2 , , S Kim 4, Y Cho 4, I Lee4, T Suh1,2 (1) Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea (2) Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul, Korea (3) Department of Radiation Oncology, College of Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea (4) Department of Radiation Oncology, Gangnam Severance Hospital, Seoul, Korea
Presentations
SU-F-T-314 (Sunday, July 31, 2016) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose:This study investigates the effects of different kinds and designs of commercialized breast implants on the dose distributions in breast cancer radiotherapy under a variety of conditions.
Methods:The dose for the clinical conventional tangential irradiation, Intensity Modulated Radiation Therapy (IMRT), volumetric modulated arc therapy (VMAT) breast plans was measured using radiochromic films and stimulated luminescence dosimeter (OSLD). The radiochromic film was used as an integrating dosimeter, while the OSLDs were used for real-time dosimetry to isolate the contribution of dose from individual segment. The films were placed at various slices in the Rando phantom and between the body and breast surface OSLDs were used to measure skin dose at 18 positions spaced on the two (right/left) breast. The implant breast was placed on the left side and the phantom breast was remained on the right side. Each treatment technique was performed on different size of the breasts and different shape of the breast implant. The PTV dose was prescribed 50.4 Gy and V47.88≥95%.
Results:In different shapes of the breast implant, because of the shadow formed extensive around the breast implant, dose variation was relatively higher that of prescribed dose. As the PTV was delineated on the whole breast, maximum 5% dose error and average 3% difference was observed averagely. VMAT techniques largely decrease the contiguous hot spot in the skin by an average of 25% compared with IMRT. The both IMRT and VMAT techniques resulted in lower doses to normal critical structures than tangential plans for nearly all dose analyzation.
Conclusion:Compared to the other technique, IMRT reduced radiation dose exposure to normal tissues and maintained reasonable target homogeneity and for the same target coverage, VMAT can reduce the skin dose in all the regions of the body.
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