Published online by Cambridge University Press: 23 July 2018
The purpose of this study was to analyse the comparison of intensity-modulated radiation therapy quality assurance (IMRT QA) using Gafchromic® EBT3 film, Electronic portal imaging device (EPID) and MapCHECK®2.
Pretreatment authentication is the main apprehension in advanced radiation therapy treatment plans such as IMRT.
A total of 20 patients were planned on Eclipse treatment planning system using 6 and 15 MV separately.
Gamma index of EBT3 film results shows the following average passing rates: 97% for 6 MV and 96·6% for 15 MV using criteria of ±5% of 3 mm, ±3% of 3 mm and ±3% of 2 mm for brain. However, by using ±5% of 3 mm and ±3% of 3 mm criteria, the average passing rates were 95·4% on 6 MV and 95·2% on 15 MV for prostate. For EPID, the results show the average passing rates as 97·8% for 6 MV and 97·2% for 15 MV in for brain. In cases in which ±5% of 3 mm and ±3% of 3 mm were used, the average passing rates were 96·6% for 6 MVand 96·1% for 15 MV for prostate. MapCHECK®2 results show average passing rates of 96·4% for 6 and 96·2% for 15 MV, respectively, for brain using criteria of ±5% of 3 mm, ±3% of 3 mm and ±3% of 2 mm, whereas for ±5% of 3 mm and ±3% of 3 mm the average rates are 95·2% for 6 and 94·7% for 15 MV in prostate.
The EPID results are better than the other methods, and hence EPID can be used effectively for IMRT pretreatment verifications.