Manoj Kumar Pandeya* & Jayanty Ashokb
*aRadio Physicist cum RSO, Rajendra Institute of Medical Sciences, Jharkhand, Ranchi, India
bHead, University Dept. of Physics, Ranchi University Ranchi, Jharkhand, India
Received 20th October, 2012; Revised 25th November., 2012
Abstract : The authors have studied the Physical characteristic parameters of High Energy Electron Beams produced by Synergy Digital Linac with particular reference to percentage depth dose curves, beam profile, Uniformity index and virtual source to surface distances of multi electron energies 4, 6, 8, 10, 12 and 15 MeV electron beams. The measurements have been carried out through IBA RFA system in a Blue WP 2 (48 x 48 x 41) cm3 water phantom with reference detector CC 13SN 96850 and using a PPC 05 parallel plate ionization chamber at nominal source to surface distance.
Electron beam though follow the same trends observed by others (depending on the type of machines) yet estimated penumbra ranges were found to be slightly higher for all available energies and field sizes except 10 MeV electron beam for (10×10) cm2field size.
Energy deposition is dependent upon depth as well as the field size and has a medical relevance especially when the depth of tumour site is known. Normally 80% to 90% isodose level is said to have therapeutic relevance.
This type of study provides an input data for the treatment planning system i.e., delivery of dose at the site of interest (tumour) would give an idea for what kind of electron energy is needed before treating the patient and has the therapeutic relevance.
Keywords: Linear accelerator (Linac), electron beam, beam characteristics, range- energy parameters.
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