ASSESSMENT OF SCATTER RADIATION DOSE BY TLD MEASUREMENT INCLUDING SKIN DOSE THYROID & CONTRALATERAL BREAST DOSE IN MAMMOGRAPHY PATIENTS

Abstract

This study will be the first in the country to measure the scatter dose received in contralatrral breast and thyroid, during mammography by thermoluminescent dosimeters (TLD The measurement of skin dose is very important in breast mammography and radiation protection …organs is necessary Radiation dosimetry is fundamental in Medical Physics, involving patients and phantom dosimetry. Inboth cases thermoluminescence dosimetry (TLD) is the most appropriate technique for measuring the absorbed dose. In this paper thermoluminescence dosimeter GR-200 was used for thyroid and breast skin dose measurements. Results are presented and discussed.

<strong>Materials and Methods:</strong> we used the types of thermoluminescence dosimeter crystal, and each time in completely similar standardized conditions.. TLD crystals were calibrated against SSDL (Secondary Standard Dosimetry Laboratory) Farmer chamber of Iran Institute of Atomic Energ and aniling., an overall check of basic calibration mammography, cristals placed in each area of breast and thyroid lobes, and the amount of the exposed X-ray injected was accurately recorded, and after reading the capsules in the physics laboratory, the scatter dose of each capsule was obtained and by applying physical coefficients, including calibration, the adsorbed dose rate was reported.

<strong>Results:</strong> According to the results, the absorbed dose in both thyroid organ and the breast outside the radiation field in oblique view and the fact that under normal conditions of breast screening without any additional radiation, magnifying, etc., which includes 4 craniocaudal and oblique views the absorption dose is significant, therefore, the radiation of these organs and choosing the protection techniques and shielding is essential and very important.