Routine individualised patient dosimetry using electronic portal imaging devices

摘要: Background and purpose: To analyse the results of routine EPID measurements for individualised patient dosimetry. Materials methods: Calibrated camera-based EPIDs were used to measure central field dose, which was compared with a dose prediction at level. For transit dosimetry, data calculated using transmission scatter, measured values. Furthermore, backprojected an in vivo value 5 cm depth water (D5) directly D5 from treatment planning system. Dose differences per session by weighting values number monitor units beam. Reported errors categorised analysed approximately 37,500 images 2511 patients during period 24 months. Results: Pre-treatment showed mean difference 0.0 ± 1.7% (1 SD). Transfer detected corrected prior first session. An accelerator output variation about 4% found between two weekly QC measurements. Patient dosimetry � 0.7 5.2% SD) 0.3 5.6% session, respectively. could be related set-up errors, organ motion, erroneous density corrections changes anatomy. Conclusions: can routinely accurately verify parameter transfer machine output. By applying more insight obtained respect different error sources influencing delivery patient. c 2007 Elsevier Ireland Ltd. All rights reserved. Radiotherapy Oncology 83 (2007) 65–75.