The estimation of body organs absorbed dose induced by 99mTc –MDP radiopharmaceutical in the patients undergoing bone scan by NCAT phantom and GATE Monte Carlo code

Background: Methylene diphosphonate (MDP) is used to bone scan. This combination is absorbed by the bone tissue and is excreted by the kidneys and bladder. The aim of this study is to estimation of body organs absorbed dose induced by 99mTc –MDP radiopharmaceutical in the patients undergoing bone scan by specific dosimetry and GATE Monte Carlo codeMethods: Twenty female patients who referred to the nuclear medicine department for bone disorders were examined. Three planar images were taken at intervals of 1, 3 and 5 hours and one SPECT image was taken in 3 hours after injection. By using the GATE Monte Carlo simulation method, the absorbed dose of their organs was calculated. The NCAT phantom was used as a weakening map in the GATE code simulation method.Results: The average absorbed dose induced by 99mTc -MDP by using Gate Monte Carlo simulation for bladder wall, spleen, ovaries, muscles, lungs, bones, liver, kidneys, heart wall and rest of body were (0.07±0.013), (0.0048±0.00019), (0.0055±0.00045), (0.0027±0.00001), (0.0026±0.00018), (0.0047±0.00023), (0.0033±0.00012), (0.047±0.0094), (0.0026±0.00012) and (0.0032±0.00015) respectively.Conclusion: The organs that received the highest absorption dose after the bladder and kidneys were respectively ovaries, spleen, bones, liver, muscles, heart wall and lungs. One of the reasons for the different absorption of radioiodine in the organs of these patients is that these patients referred to the nuclear medicine department for a variety of reasons for bone scan.

کلیدواژه ها:

Absorbed dose ، Monte Carlo code ، patient specific dosimetry