Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Two years experience with quality assurance protocol for patient related Rapid Arc treatment plan verification using a two dimensional ionization chamber array. | Wagner and Vorwerk Radiation Oncology 2011 6 21 http content 6 1 21 RADIATION ONCOLOGY RESEARCH Open Access Two years experience with quality assurance protocol for patient related Rapid Arc treatment plan verification using a two dimensional ionization chamber array Daniela WagneP Hilke Vorwerkt Abstract Purpose To verify the dose distribution and number of monitor units MU for dynamic treatment techniques like volumetric modulated single arc radiation therapy - Rapid Arc - each patient treatment plan has to be verified prior to the first treatment. The purpose of this study was to develop a patient related treatment plan verification protocol using a two dimensional ionization chamber array MatriXX IBA Schwarzenbruck Germany . Method Measurements were done to determine the dependence between response of 2D ionization chamber array beam direction and field size. Also the reproducibility of the measurements was checked. For the patient related verifications the original patient Rapid Arc treatment plan was projected on CT dataset of the MatriXX and the dose distribution was calculated. After irradiation of the Rapid Arc verification plans measured and calculated 2D dose distributions were compared using the gamma evaluation method implemented in the measuring software OmniPro version IBA Schwarzenbruck Germany . Results The dependence between response of 2D ionization chamber array field size and beam direction has shown a passing rate of 99 for field sizes between 7 cm X 7 cm and 24 cm X 24 cm for measurements of single arc. For smaller and larger field sizes than 7 cm X 7 cm and 24 cm X 24 cm the passing rate was less than 99 . The reproducibility was within a passing rate of 99 and 100 . The accuracy of the whole process including the uncertainty of the measuring system treatment planning system linear accelerator and isocentric laser system in the treatment room was acceptable for treatment plan verification using gamma criteria of 3 and
