Standardization of Mean Lethal Dose (LD 50/30) of X -rays using Linear Accelerator (LINIAC) in Albino Wistar Rat Model Based on Survival Analysis Studies and Hematological Parameters.

This study aims at determining the dose of X-ray delivered through linear accelerator (LINIAC) that results in the 50 % survival of animals after an observation period of 30 days, following exposure to whole body irradiation in rat model. Animals were exposed to several doses of radiation (2, 4, 6, 8, 10 Gy) after which they were monitored for survival rate, overall behavior, diarrhoea and skin lesions. Animals of either sex were placed in a Perspex box restrainer and exposed to whole body irradiation of X -rays. Whole body Irradiation of X- rays was carried out by LINIAC accelerator. Radiation ranging from 2 to 10 Gy was delivered to rats with Dose rate of 3.5 Gy/min with field size of 40 × 40 cm2. Hematological parameters like total count, differential count and peripheral smear examination was carried out from the peripheral blood of the animals to complement with survival studies and compared with controls. Peripheral smear examination was done by Leishman’s staining method. Based on the results of our study, we report that the LD 50/30 of Wistar rats exposed to whole body irradiation of X–rays through linear accelerator was found to be 6.6 Gy. Whole body exposure of Ionizing radiation leads to complex cascades of syndromes which depends on the nature of radiation dose and quality. Establishing LD 50/30 in experimental animals will support further studies on the beneficial effects of the radio modulators that could probably reduce the morbidity and mortality in animals exposed to radiation.