Establishment ofNational Diagnostic Reference Level for Renal Radiation Doses in Nuclear Medicine Departmentin Khartoum -Sudan

Abstract

A diagnostic reference level (DRL) is an investigational level used to identify unusual high radiation doses in Nuclear Medicine procedures. DRLs are suggested action levels above which a facility should review its methods and determine if acceptable image quality can be achieved at lower doses. In order to evaluate the radiological risk incurred by patients diagnosed at the Department of Nuclear Medicine (DNM), the high specific activity of 99mTc makes it suitable as a first pass agent, for multiple or sequential studies. 99mTcdiethylenetriaminepentaacetic acid (DTPA) is preferred to 99mTc -pertechnetate. DTPA has rapid renal excretion, making possible a repeat injection 20 min later. The aim of this study was the investigation of absorbed dose to the kidneys during technetium-99 m diethylenetriaminepentaacetic acid (99mTc-DTPA) kidney scan. A certain amount of radiopharmaceuticals was injected into each patient and was immediately imaged with dual-head gamma camera to calculate the activity through the conjugated view method. Patients who had been prepared for the kidney scan were divided to three groups. The first group (27.03 %) received dose less than 5 mCi, the second group (66.67 %) received 5.1-5.5 mCi and the third group (6.31 %) received dose over 5.5 mCi 99mTc-DTPA. The studies show that can image patient even have weight more than 80 kg by dose 2.8mCi.