Quality Assurance of Intensity Modulated Radiation Therapy: Site-Specific Results of Eulji University Hospital |
Sung Jin Kim, Mi Jo Lee, Seon Min Youn |
Department of Radiation Oncology, Eulji University Hospital, Eulji University College of Medicine, Daejeon, Korea. smyoun@eulji.ac.kr |
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ABSTRACT |
PURPOSE: To analyze our quality assurance (QA) data for intensity modulated radiation therapy (IMRT) according to treatment site and to possibly improve QA for IMRT in Hospital.
MATERIALS AND METHODS: We performed QA on 50 patients (head and neck, 28 patients; Breast, 14 patients; Pelvis, 8 patients) for IMRT. The calculated dose from RTP was compared with the measured value film, gamma index, and ionization chamber for dose measurement in each case.
RESULTS: The point dose measurement results in 45 of 50 patients showed good agreement with the calculation dose (+/-3%). The largest error measured thus far has been 3.60%, with a mean of only -0.17% (SD, 2.25%). Each treatment site showed an error rate of -0.13% (SD, 1.93%) for head and neck cases, -0.26% (SD, 2.79%) for breast cases, and -0.24% (SD, 2.44%) for pelvis cases. The gamma index verified with the error rate of head and neck cases (6%), breast (10%), and pelvis (6%), which corresponded to a tolerance of 3 mm (3% for the head and neck, 2%, for the breast 1% for the pelvis, and 0% in the region where the isodose curve was greater than 90%.
CONCLUSION: We recognize the cause of errors for each treatment site of IMRT QA and so we maximize our efforts to reduce error and increase accuracy. |
Key Words:
Intensity-modulated radiation therapy, Quality assurance, Error rate |
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