Commissioning and early experience with a new generation low-energy linear accelerator in zahedan

Introduction: Since commissioning beam data are treated as a reference and ultimately used by treatment planning systems, it is vitally important that the collected data are of the highest quality to avoid dosimetric and patient treatment errors that may subsequently lead to a poor radiation outcome. Beam data commissioning should be performed with appropriate knowledge and proper tools and should be independent of the person collecting the data. low-energy linear accelerator was introduced in the clinical area by ELEKTA Medical Systems. This machine was first installed in Sistan and Baluchestan state in 2016. The aim of the present contribution was to report experience about its commissioning and first year results from clinical operation. Materials and Methods: In this research, we used water phantom model DoseviewTM 3D version1.2 and A19 and A28 ion chambers. Commissioning data, beam characteristics and the modeling into the treatment planning system were summarized. . Finally, since the system is capable of delivering Threaetment dose with 6 Mev of energy , a summary of the tests performed for such modality to assess itsperformance in preclinicalsettings and during clinical usage was included. Results: The absorbed dose according to the TRS398 protocol in the absolute dosimetry was D = 0.010042Gy                /              Mu. In a relative dosimetry, PDD was calculated at different depths and fields, results at 10 cm depth for field 10 × 10 was equal to 0.661 and for the field 30 × 30 at the same depth of 10 cm was equal to 0.690. Also Measurements were made to determine the flatness and symmetry in different fields at a depth of 10cm. For example, the flatness in field 10×10 at depth of 10cm was 3.7 and its Asymmetry value was -0.7%. Conclusion: The results of the commissioning tests and of the first period of clinical operation, resulted meeting specifications and having good margins respect to tolerances. Linac was put into operation for all deliverytechniques; in particular, as shown by the pre-treatment quality assurance results, it enabledaccurate and safedelivery of 3D planning.