ABSTRACT
PURPOSE: To evaluate the impact on the radiation protection policies of the radiocontaminants in Samarium-153 ethylenediamine tetramethylene phosphonate ((153)Sm-EDTMP). METHODS: The internal contamination of patients treated with (153)Sm-EDMTP for palliation of painful disseminated multiple bone metastases due to long-lived impurities was assessed by direct measurements. These measurements were coupled with dose-rate measurements close to their bodies and spectroscopic analysis of the residual activity in post-treatment radiopharmaceutical vials. RESULTS: Whole-body counting carried out in six patients showed a 30-81-kBq europium -152 plus europium-154 contamination. The 0.85 mean (152)Eu- to -(154)Eu activity ratio obtained by direct counting was similar to that assessed by analysis of post-treatment residual activities in twelve radiopharmaceutical vials following radiopharmaceutical injection. CONCLUSIONS: The long-lived radiocontaminants in the patient's bodies and the treatment wastes require modifications of the applicable radiation protection policies.
Subject(s)
Bone Neoplasms/complications , Europium/chemistry , Organometallic Compounds/chemistry , Organometallic Compounds/therapeutic use , Organophosphorus Compounds/chemistry , Organophosphorus Compounds/therapeutic use , Pain Management , Palliative Care , Radioisotopes/chemistry , Gamma Rays , Humans , Radiation Dosage , Radiation Protection , Radiochemistry , Radiopharmaceuticals/chemistry , Whole-Body CountingABSTRACT
The aim of the study was to control occupational exposure during the removal of radioactive reactor components from a Greek research reactor pool. The method comprised the prediction of the radiation levels, the design of special shielding structures and the occupational dose assessment. Activation calculations were performed using the FISPACT code to predict the source term. Monte Carlo simulations using MCNP code were utilized to estimate the ambient dose equivalent rates. The results of the calculations were verified by measurements and were found to be in good agreement. Thermoluminescence dosemeter (TLD) and electronic personal dosemeter (EPD) were implemented to measure the radiation exposure of the workers. The total collective dose of 14 participating workers was 0.15 man mSv. The maximum individual effective dose was 0.02 mSv, and the maximum extremity equivalent dose was 0.09 mSv. The discussed method provides a useful tool enabling work planning during reactor decommissioning and renovation activities ensuring that exposures will be maintained ALARA.
Subject(s)
Occupational Exposure/prevention & control , Radiation Monitoring/instrumentation , Radiation Monitoring/methods , Radiation Protection/methods , Radiometry/instrumentation , Thermoluminescent Dosimetry/instrumentation , Computer Simulation , Equipment Design , Humans , Materials Testing , Monte Carlo Method , Neutrons , Nuclear Reactors , Radiation Dosage , Radioisotopes/analysis , Radiometry/methods , Thermoluminescent Dosimetry/methodsABSTRACT
A prototype multidetector shadow-shield whole-body counter is presented to be used as a monitor of internal contamination and as a tool in clinical research. The counter is equipped with 16 NaI(Tl) detectors located in the central region of a shielded tunnel surrounding the subject to be measured. The accuracy of the counting efficacy predictions was tested in a group of adults with various body shapes and sizes using X-ray absorptiometry. The precision of the total body potassium measurements allows the use of the counter in clinical follow-up studies.
