%0 Journal Article %T Evaluation of a systemic change of Superficial X-ray tube characteristics %J Iranian Journal of Medical Physics %I Mashhad University of Medical Sciences %Z 2345-3672 %A Mohammadi, Mohammad %A Srinivasan, Kavitha %A Carrillo Serrano, Manuel %D 2018 %\ 12/01/2018 %V 15 %N Special Issue-12th. Iranian Congress of Medical Physics %P 213-213 %! Evaluation of a systemic change of Superficial X-ray tube characteristics %K Superficial X-Ray Therapy %K Quality Assurance %K Commissioning %R 10.22038/ijmp.2018.12830 %X Introduction: Very low, Low and Medium X-ray machines are used extensively for Superficial Radiation Therapy mostly used for Basal Cell, Squamous Cell Carcinoma, and Melanoma skin cancers. In most of cases, Superficial X-ray Therapy (SXRT) is preferred to Electron beams generated using a linear accelerator. SXRT tube characteristics may vary with the use of the machine for a long time. This study investigates the variation of machine output characteristics acquired during machine commissioning and applied for treatment planning system. Materials and Methods: A Gulmay D3150 Superficial Unit was used for all data collected. At the first stage, beam quality index, half Value Layer (HVL), radiation beam profiles in different depths for a range of applicator for all available applicators were collected. At the end, machine output was also compared with baseline established during the machine commissioning. Results: Result shows that there is a systemic variation of the beam quality index up to 4.3%. Although results are found to be within tolerance, but a systemic variation of the data acquired shows that machine characteristics are modified. Conclusion: As a systemic change of machine output is observed, based on data achieved, more detailed QA checks, annual QA program and re-commissioning of the machine for more accurate treatment is recommended. %U