The first programme of assesment of occupational exposure due to intake of I-131 in the practice of nuclear medicine in venezuela

摘要

The amount of medical procedures on the Single Photon Emission Computerized Tomography(SPECT) and Positron Emission Tomography Computerized (PET/CT) practices has increased dramatically inVenezuela. Unfortunately, Venezuela lacks assessment experience on occupational exposure due to intakes ofradionuclide in nuclear medicine practices. The Venezuelan Scientific Investigations Institute (IVIC) incooperation with the Colombia National University-Sede Medellìn are developing the methodology toimplement in Venezuela the evaluation of the occupational exposure due to the intakes of Iodine-131 inconcordance with Safety Standards Series No RS-G-1.2 (IAEA). For this task, we selected four institutions asreference. The first institution is a business company dedicated to fractioning I-131 doses; the other threeinstitutions are health institutions which perform various diagnostic examinations involving intravenousadministration of radiopharmaceutical. In a three month period, every 15 days, seven technicians working inthese institutions were individually monitored according to the recommendation of the ICRP 78. Two types ofmeasurements were made: Direct measurements in the thyroid using a NaI(TI) crystal and indirect measurementsof urine samples collected for 24 hours. The Committed Effective Dose E(50) and Committed Equivalent DoseH(50) of workers was estimated running the AIDE code developed in the Region. The doses were comparedwith the following reference: levels: Investigation levels (IL_j), recording level (RL_j) and derived levels (DIL_j)established for this program according to Safety Guide No RS-G-1.2. Finally based on these results, we shouldtake a decision on the methodology for a national programme for assessment of occupational exposures due tointakes of I-131 in nuclear medicine practice.