Program Information
Dosimetric Evaluation of Electron Total Skin Irradiation Using TLD
L Falahati1 , N Banaee2 , H Nedaie3*, (1) Department of Medical Physics and Biomedical Engineering, Faculty of Medicine and Radiation Oncology Research Centre, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran. (2) Department of Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. (3) Odette Cancer Centre, University of Toronto, Toronto, Canada.
Presentations
SU-I-GPD-T-58 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: Total skin electron beam therapy (TSEBT) is mainly used to treat Mycosis Fungoides and other superficial diseases. TSEBT can be implemented in three different treatment techniques, regarding patient setup in respect to the large electron fields: (a) standing patient techniques in which patient takes special positions of treatment in each session, (b) rotary techniques–this treatment is accompanied with simultaneous rotation and irradiation of the skin, and (c) translational techniques. The aim of this study is to evaluate some dosimetry parameters such as uniformity, surface dose and max depth dose with TLD in TSEBT.
Methods: Stationary and rotary methods were set on Varian linear accelerator, Clinac 2100C. To create a radiation field large enough and uniform, the SSD was set 400 cm. Electron beam energy was 6 MeV. The Skin dose values were obtained in 21 different points on the phantom surface.
Results: The results of dose uniformity in stationary technique were obtained as 10% and 2.6% in longitudinal and transverse axes, respectively. The measurements at rotational technique at the referred conditions showed a homogeneous total field with intensity variation of 10 % and 4% in the longitudinal and horizontal axes, respectively. The surface doses at stationary and rotational techniques were 91.95% and 96.12%, respectively. The maximum dose position points at stationary and rotational techniques were 0.6 and 0.3 cm under skin, respectively.
Conclusion: Based on the results of this study, stationary techniques is preferred for TSEBT. The main advantage of rotational techniques is reducing the time of treatment. The results also demonstrate that TLD should be routinely used in TSEBT treatment. Comprehensive treatment to Rando phantom showed that the uniformity is better at the trunk than in the mobile parts of the body, the soles of the feet, perineum region and scalp vertex should be treated in boost.
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