Background: Different computational methods have been used for the prediction of X-ray spectra and beam quality in diagnostic radiology. The purpose of this study was to compare X-ray beam qualities based on half-value layers (HVLs) determined through measurements and computational model estimations. Methods: The HVL estimations calculated by IPEM78 (Spectrum Processor of the Institute of Physics and Engineering in Medicine’s Report 78) and SpekCalc software were compared with those determined through measurements. In this study, the HVLs of both Philips (Phil) (Philips Healthcare, Best, NL) and General Electric Company (GE) (GE Global Research, Niskayuna, US) diagnostic range X-ray machines (50 kVp to 125 kVp) were evaluated. Results: In the HVL estimations, SpekCalc and IPEM78 showed maximum differences of 10% and 9%, respectively, compared with direct measurements. Both models provided means and SDs of HVLs that were within 5% of the HVL measurements of GE and Phil machines. Conclusion: Both computational models provide an alternative method for estimating the HVL of diagnostic range X-ray. These models are user-friendly in predicting HVLs, which are used to characterise the quality of the X-ray beam, and these models provide predictions almost instantly compared with experimental measurements.

This is a retrospective study, the organ doses of the bladder and the rectum were compared between routine PLATO V14.2.3 (Nucletron B.V., Veenendaal, The Netherlands) and newer version software Oncentra MasterPlan (OMP) V4.3 (Nucletron B.V., Veenendaal, The Netherlands) treatment planning systems (TPS). The treatment data of 32 intracavitary brachytherapy patients at Hospital Universiti Sains Malaysia from January 2010 to June 2015 were used. These data sets were used for catheter reconstruction for both PLATO and OMP TPS followed by independent verification using Excel. There was no significant difference in mean doses to organs at risk (OARs) that calculated by both TPS (p>0.05). The mean percentage of doses calculated by PLATO TPS for bladder and rectum were 66.58 ± 27.42% and 46.27 ± 14.47%, respectively. While, the mean percentage of doses for bladder and rectum calculated by OMP TPS were 65.68 ± 24.24% and 46.46 ± 16.66%, respectively. The mean percentage difference in doses comparison between independent verification calculation and PLATO TPS was 1.96 ± 6.00% and then became 6.37 ± 5.17% when it was compared with OMP TPS. Overall, the dose calculation differences for both versions of TPS were within the range recommended by Nuclear Regulatory Commission (NRC). The dose calculations of the two treatment planning systems showed good agreement and both could be used in planning intracavitary brachytherapy for cervical cancer. Whereas, Excel based independent verification is suitable to be implemented as routine dose verification programme prior to treatment delivery.