Saeb Mohsen, Shahbazi-Gahrouei Daryoush, Monadi Shahram
Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
J Med Signals Sens. 2018 Apr-Jun;8(2):95-100.
This study aimed to evaluate the overall accuracy of the beam commissioning criteria of targeted image-guided radiation therapy (TiGRT) treatment planning system (TPS) based on the American Association of Physicists in Medicine (AAPM) Task Group Report 119 (TG-119).
The work was performed using 6 MV energy LINAC with a variable dose rate of 200 MU/min which equipped with the high-quality external TiGRT dynamic multileaf collimator model H. The AAPM TG-119 intensity-modulated radiation therapy (IMRT) commissioning tests are composed of two preliminary tests and four clinical test cases. The clinical tests consisted of mock prostate, mock head and neck, C-shaped target, and multitarget. EDR2 film was used for evaluating the IMRT plans and point dose measured by a Pinpoint chamber positioned in slab phantom. The film analysis was done with the Sun Nuclear Corporation patient software. The dose prescription for each fraction was 200 cGy in mock prostate, mock head and neck, C-shaped target, and multitarget. Dose distributions were analyzed using gamma criteria of 3% and 2% dose difference (DD) and 3 and 2 mm distance to agreement.
In all test cases, the gamma criteria for 2%/2 and 3%/3 were found to be 94% and 98%, respectively. Results showed that the average gamma criteria result was in the range of 99.1% to 93% (3%/3, 2%/2) overall test cases.
Findings were favorable and in some tests were comparable with the other studies. The dose point values were within the mean values of the range reported by TG-119. Overall, the TiGRT TPS is needed to apply IMRT technique in radiation therapy centers.
本研究旨在根据美国医学物理学家协会（AAPM）任务组报告119（TG - 119）评估靶向图像引导放射治疗（TiGRT）治疗计划系统（TPS）射束调试标准的总体准确性。
使用配备高质量外部TiGRT动态多叶准直器型号H的6兆伏能量直线加速器进行此项工作，其可变剂量率为200 MU/分钟。AAPM TG - 119调强放射治疗（IMRT）调试测试由两项初步测试和四个临床测试病例组成。临床测试包括模拟前列腺、模拟头颈部、C形靶区和多靶区。使用EDR2胶片评估IMRT计划，并通过置于平板模体中的Pinpoint电离室测量点剂量。胶片分析使用Sun Nuclear Corporation患者软件进行。在模拟前列腺、模拟头颈部、C形靶区和多靶区中，每个分次的剂量处方为200 cGy。使用3%和2%剂量差异（DD）以及3毫米和2毫米距离一致性的伽马标准分析剂量分布。
在所有测试病例中，发现2%/2毫米和3%/3毫米伽马标准分别为94%和98%。结果表明，在所有测试病例中，平均伽马标准结果在99.1%至93%（3%/3毫米，2%/2毫米）范围内。
研究结果良好，在某些测试中与其他研究相当。剂量点值在TG - 119报告范围的平均值内。总体而言，放射治疗中心需要TiGRT TPS来应用IMRT技术。
