ANALISIS POSISI SUMBER RADIOAKTIF COBALT PADA PESAWAT TELETERAPI COBALT-60

Abstract

This research have a purpose to maintain and ensure the conditions of Cobalt-60 teletherapy in appropriate with tolerance limits AAPM (American Association of Physicists in Medicine) Task Group 40. In addition, this research also aimed to determine the accuracy of the position of radiation sources of Cobalt in Cobalt-60 teletherapy. This has been research at Radiotheraphy Installation on RSPAD Gatot Soebroto, Jakarta on April 30, 2010 and May 7, 2010. The research carried out by using Cobalt-60 teletherapy with energy 1,25 MeV. Using a measure of farmer detector type ionization chamber and electrometer namely Tandem dual channel electrometer. Phantom used is slab phantom with a thickness of 10 cm plate. Before measurements were carried out mechanical checks such as lamp radiation field with size variations 10 x 10 cm, 15 x 15 cm, 20 x 20 cm, and then measured the position of Cobalt source with a wide variety of radiation field 10 x 10 cm and 20 x 20 cm. It also carried variations collimator angle 90o and 270o. Results of measurement of light radiation field checking is within tolerance limit given by the American Association of Physicist in Medicine (AAPM) of ± 3 mm. For the measurement of the source position was also obtained values that are still within tolerance limits given by the American Association of Physicist in Medicine (AAPM) of ± 3% so that it can be said that the Cobalt-60 teletherapy in the Radiotheraphy Installation on RSPAD Gatot Subroto still in a state fit for use.