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AIM: To validate and implement Monte Carlo simulation using PRIMO code as a tool for checking the credibility of measurements in LINAC initial commissioning and routine Quality Assurance (QA). Relative and absolute doses of 6 MV photon beam from TrueBeam STx Varian Linear Accelerator (LINAC) were simulated and validated with experimental measurement, Analytical Anisotropic Algorithm (AAA) calculation, and golden beam. METHODS AND MATERIALS: Varian phase-space files were imported to the PRIMO code and four blocks of jaws were simulated to determine the field size of the photon beam. Water phantom was modeled in the PRIMO code with water equivalent density. Golden beam data, experimental measurement, and AAA calculation results were imported to PRIMO code for gamma comparison. RESULTS: PRIMO simulations of Percentage Depth Dose (PDD) and in-plane beam profiles had good agreement with experimental measurements, AAA calculations and golden beam. However, PRIMO simulations of cross-plane beam profiles have a better agreement with AAA calculation and golden beam than the experimental measurement. Furthermore, PRIMO simulations of absolute dose agreed well with experimental results with ±0.8% uncertainty. CONCLUSION: The PRIMO code has good accuracy and is appropriate for use as a tool to check the credibility of beam scanning and output measurement in initial commissioning and routine QA.
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BACKGROUND: To study the pattern of patient load, personnel and equipment resources from 30-years experience in Southern Thailand. MATERIALS AND METHODS: This retrospective study collected secondary data from the Division of Therapeutic Radiology and Oncology and the Songklanagarind Hospital Tumor Registry database, Faculty of Medicine, Prince of Songkla University, during the period of 1982-2012. RESULTS: The number of new patients who had radiation treatment gradually increased from 121 in 1982 to 2,178 in 2011. Shortages of all kinds of personnel were demonstrated as compared to the recommendations, especially in radiotherapy technicians. In 2011, Southern Thailand, with two radiotherapy centers, had 0.44 megavoltage radiotherapy machines (cobalt or linear accelerator) per million of population. This number is suboptimal, but could be managed cost-effectively by prolonging machine operating times during personnel shortages. CONCLUSIONS: This study identified a discrepancy between workload and resources in one medical school radiotherapy center in.