Assessment of Dose Calculation Accuracy of Monaco Treatment Planning System for Effective Wedge Angle in Internal Wedged Fields using Two Different Analytical Methods.

Abstract

Background: In radiotherapy, the accuracy of dose calculation systems plays a key role in the treatment of cancer patients.

Objective: The current research aimed to evaluate the dose calculation accuracy of Monaco Treatment Planning System (TPS) in estimating the Effective Wedge Angle (EWA) using two different mathematical methods: Elekta formula and ICRU-24 formula.

Material and methods: In this experimental study, EWAs for different field sizes (5×5, 10×10, 15×15, 20×20, 25×25, and 30×30 cm²) at standard angles (15°, 30°, 45°, and 60°) were computed by the Monaco TPS using two different analytical methods. The practical EWAs were measured according to the conditions outlined in the Elekta formula and the ICRU-24 formula, and these measurements were compared with the results derived from the TPS.

Results: The planned and measured EWAs are consistent with the Elekta formula, and the error value was less than ±0.5 in all radiation fields and EWAs. In the ICRU-24 formula, the maximum deviation was ±2.6° between the computational and practical EWAs.

Conclusion: The Elekta-based analytical method demonstrates a good agreement between planned and measured EWAs, while the ICRU-24 formula exhibited the greatest discrepancies.