基于MPPG 5.a的国产TAICHI加速器TPS模型验收与调试OA

Objective To verify the accuracy of dose calculation of the beam model established by the domestic TAICHI equipment in the RayStation treatment planning system,so that the equipment can better serve the treatment of clinical patients.Methods Based on the reports of MPPG 5.a and TG119 released by the American Association of Medical Physics,the model dose calculation model of the TAICHI equipment was verified,including PDD curves,Profile curves,TG119,and clinical case verification,etc.Results The gamma pass rates of 2 mm/2%from the basal field of different source skins at shallow depths(0-20 cm)were basically close to 100%.The results at deep depths(25 cm underwater)were worse than those at shallow depths,but the mean value was still above 93%.The dose deviation results at all points were less than 2%(after small field correction).Therefore,the beam current in the model was basically consistent with the actual output of the equipment.The results of gamma pass rates at both point doses and area doses of intensity modulated radiation therapy(IMRT)and volumetric modulated arc therapy(VMAT)for TG119 test cases were much better than the standards required by the TG119 report.The average deviation results of planned point dose verification for clinical patients in IMRT and VMAT were 0.48%and 0.47%respectively,and the gamma pass rates of 2 mm/2%and 3 mm/3%in surface dose tests were 95.58%,99.46%and 96.75%,99.30%respectively.All the results met the clinical needs.The end-to-end lung tests of IMRT and VMAT passed,and the point dose deviations were-0.495%and-2.602%respectively.Conclusion After being verified by the MPPG 5.a and TG119 systems,the results of domestic TAICHI meet and far exceed the reporting requirements and standards,conform to clinical requirements,and can be used to optimize the treatment plans of clinical patients.For cases with poor deep fitting,more attention is needed in the subsequent modeling process.