The Commissioning and Validation of EclipseTM Treatment Planning System on a Varian VitalBeamTM Medical Linear Accelerator for Photon and Electron Beams

Purpose: Commissioning of a linear accelerator is a process of acquiring a set of data used for patient treatment. This article presents the beam data measurement results from the commissioning of a VitalBeamTM linac. Materials and Methods: Dosimetric properties for 6,10, and 15 MV photon beams and 6, 9, 12, and 16 MeV electron beams have been performed. Parameters, including Percentage Depth Dose (PDD), depth dose profile, symmetry, flatness, quality index, output factors, and the vital data for Treatment Planning System (TPS) commissioning were measured. The imported data were checked by CIRS phantom accordingly to IAEA TRS-430, TECDOC. Eight different positions of CIRS phantom CT were planned and treated. Finally, the calculated dose at a determined position was compared with measuring data to TPS validation. Results: After comparing 84 points in a different plan, the 83 points were in agreement with the criteria, and just for one point in 15 MV failed. Conclusion: Commissioning of dose and field flatness and symmetry are in tolerance intervals given by Varian. This proves that the studied lines meet the specification and can be used in clinical practice with all available electron and photon energies.

Evaluation of Calculation Algorithms for photon Beam dose in Heterogeneous Medium

The success of the implementations of a radiotherapy treatment planning system is determined by the ability of the dose calculation algorithms to reproduce the algorithm input data, and in most cases the agreement was found within ±2%. Varian linear accelerator DMX, TPS Eclipse (version 10.33) is used and absolute dosimetry and relative dosimetry system (PTW, Freiburg, Germany) and 2D array were also used. The Calculation of Analytical Anisotropic Algorithm (AAA) is more accurate than the Pencil beam Algorithm (PBC) in heterogeneity medium in comparison with practical measurement. The extent of the effort required to carry out a validation study of the complexity of that described here precludes its use as a routine component of TPS commissioning. Our realistic recommendation is that commissioning includes tests aimed at confirming that raw beam data have been entered correctly and that the operation of the system is understood. Finally, the study tell us that the observed deviations between TPS calculated using Eclipse version 10.33 and measured dose in the present of heterogeneous medium are well within the tolerance levels and the study also show that the use of Eclipse (version 10.33) TPS, AAA algorithm records significant improvement than the previous TPS versions especially in the present of low density inhomogeneity.