OBJECTIVE: To develop and implement a software based on the manual calculation algorithm for verification of the calculations in radiotherapy monitor units and to establish acceptance levels as a mechanism of quality assurance. MATERIALS AND METHODS: Data were obtained from Clinac 600C and 2100C Varian linear accelerators and the computerized treatment planning system used was CadPlan™. RESULTS: For the 6 MV beams the acceptance levels for deviations among the calculations of monitor units, divided by treatment area, were the following: breast (0.0% ± 1.7%), head and neck (1.5% ± 0.5%), hypophysis (-1.7% ± 0.5%), pelvis (2.1% ± 2.1%) and thorax (0.2% ± 1.3%). For the 15 MV beams the suggested level for pelvis in all the treatment techniques was (3.2% ± 1.3%). CONCLUSION: The present data are sufficient to justify the use of the software in the clinical practice as a tool for the quality assurance program.
Monitor units calculation; Quality assurance; Computerized treatment planning system
