Evaluation of Targeted Image‑Guided Radiation Therapy Treatment Planning System by Use of American Association of Physicists in Medicine Task Group‑119 Test Cases

Mohsen Saeb, Daryoush Shahbazi‑ Gahrouei, Shahram Monadi

Abstract


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 flm was used for evaluating the IMRT plans and point dose
measured by a Pinpoint chamber positioned in slab phantom. The flm 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.


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