Room: Exhibit Hall
Purpose: The aim of this research was to analyze the dose verification results of 924 IMRT plans, and verify the relationship between gamma pass rate and the location of lesions, the total number of MU and the largest area of the dose in Shandong cancer hospital.
Methods: The 924 actual implementation IMRT plans in the Varian Trilogy accelerator were retrospectively analyzed. All of the actual treatment plan and verification plan were designed using Varian Eclipse planning system. The actual implementation plan will be transplanted to the water phantom. The derived fluence will compared with actual measured fluence by gamma analysis with 3mm3% standard.
Results: 924 patients were divided into brain, head and neck, chest, abdomen, pelvic, breast six sites, of which 22 not pass at the first time, the remaining gamma pass rate above 98% on average. There was a correlation between the treatment site with gamma through rate correlation (P=0.022, r=0.78); The total number of MU and the gamma pass rate has a correlation (P = 0, r=-0.986), and is negatively correlated; the largest area and the acquisition dose rate had no correlation (P=0.065, r=0.535).
Conclusion: The treatment site is related to the gamma pass rate and the total MU. When using mapcheck for dose verification, the gamma pass rate is high, and only a few results need to be analyzed.
Not Applicable / None Entered.
TH- External beam- photons: Quality Assurance - Linear accelerator