STUDY ON VARIATION OF QUALITY ASSURANCE DATA OF A LINEAR ACCELERATOR AFTER THIRTEEN YEARS OPERATION FOR CANCER TREATMENT.

*Dr. Suvendu Kumar Sahoo and Dr. Rabinarayan Mukharjee

ABSTRACT

Quality Assurance data is very much useful which had got during commissioning of a linear accelerator (LINAC) for clinical and research purposes. The commissioned beam data obtained are treated as references and ultimately used for radiotherapy clinical treatment for cancer patients. The scientific procedure used for measuring data of LINAC at HCG Panda Curie Cancer Hospital, Cuttack, India has been described in detail in this article. The maximum beam energy of this LINAC is 6 MV for photons and 10 MeV for electrons. The approximate flux of the source are of the order 1015 photons/sec and 1018electrons/sec with a highest delivery dose rate of 300 cGy/min for photons and 200 cGy/min for electrons at the dose maximum point in the water phantom. Here we have measured a complete set of QA data as per present performance of LINAC and made a comparison with commissioned data which was got before thirteen years. Both complete set of measured data of the LINAC have been presented here. The current measured radiation data are within permissible limit as per Atomic Energy Regulatory Board (Mumbai), India guide lines. Hence this old linear accelerator can be used safely for clinical radiotherapy treatment for cancer patients and research purposes like material modification by irradiation.

Keywords: Linear Accelerator, Water Phantom, Flux, Radiotherapy.