Measurement of the radiation dose passed through the spinal cord at dorsal part of the neck during treatment of Thyrotoxicosis diseases by radioactive iodine 131I

Abstract

Many studies have shown that there is a temporal side effects and chronic side effects during treatment with radioactive 131I for the thyrotoxicosis diseases common and the percentage of the dominant effects is less than 3% this includes spinal cord effects and leukemia .Our point of view is that this side effect may be due to γ-ray radiated from the decay of 131I .By analysis of the decay scheme and using TLDs dosimeters ,the γ – ray radiation dose from the frontal and dorsal side of the neck was measured .The dosimeters were fixed on the back side of the neck and in front of the central part of the thyroid gland , such that it measures γ-rays which penetrate the neck tissues , neck vertebral and the spinal cord. A difference of 27.6% between the reading of frontal and the back dosimeter .This indicates occurance of absorption by the neck tissue.We find also that for the same disease and for the different cases, there is no direct relation between the taken iodine dose and the transmitted dose this may due to the difference in the absorbed dose which depends on the degree of enlargement