Comparison of 2D and 3D Gamma calculations for an IMRT QA phantom

[摘要] Gamma index pass rates were evaluated for an anthropomorphic phantom using both 2D and 3D calculations. The phantom was irradiated with the traditional dosimetry insert loaded with radiochromic film and TLD, and then with a 3D dosimetry insert. A comparison with the calculated dose distribution showed that both the PRESAGE® dosimeter and the film and TLD system agreed with the plan to within 5% using 2D gamma index criteria. The 3D gamma index showed a slightly higher pass rate than the 2D gamma index at 3%/3mm, and comparable pass rates using more generous constraints. The acceptable number of pixels passing the tighter constraints (3%/3mm) might be dependent upon the choice between a 2D calculation versus a 3D calculation.

[发布机构] Department of Radiation Physics, University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston; TX; 77030, United States^1;University of Texas at Houston, Graduate School of Biomedical Sciences, Houston; TX; 77030, United States^2;Rider University, Lawerenceville; NJ, United States^3;Heuris Pharma, LLC, 412 Sunset Rd., Skillman; NJ; 08558, United States^4

[关键词] Anthropomorphic phantoms;Dose distributions;Gamma indices;Pass rate;Radiochromic film