Authors: Javaid Ali , Shoab Shah , Abdul Samad , Imadullah Tariq , Ghufran Biradr , Muhammad Sohail , Irum Naz Memon , Attia Gul , Israr Ahmad

Abstract

Background: Radiation workers have reported that some errors during measurement of radioiodine-131 activities have been observed, which may result poor quality images, greater radioactive waste and financial burden in the hospital. The purpose of this retrospective study was to estimate the net percent errors in radioiodine-131 activities during administration to thyroid patients and give some fruitful suggestions to reduce such errors.

Methods: We included180 random patients i.e. thirty for each advised activity of 3 mCi, 15 mCi, 20 mCi, 25 mCi, 30 mCi and 150 mCi in this study from January 2019 to June 2022. All the recommended activities were measured with CRC-25R dose calibrator. The percent difference in the measured & prescribed activities and percent difference in the measured & residual activities were estimated. Finally, the net percent errors in administered activities were measured for all patients.

Results: The net percent error in recommended activities of 3 mCi, 15 mCi, 20 mCi, 25 mCi, 30 mCi & 150 mCi and administered activities were [6.73 (-32.7, 20.95) ± 11.15] %, [3.91 (-3.85, 8.77) ± 2.94] %, [3.63 (-2.39, 7.79) ± 2.51] %, [3.55 (-0.65, 10.67) ±2.6] %, [2.93 (-1.98, 6.78) ± 1.89] % & [0.88 (-1.04, 2.68) ±0.87] % respectively.

Conclusion: This study concludes that the patients receive approximately 6.73%, 3.91%, 3.63 %, 3.55 %, 2.93 % and 0.88 % less activities than the aforementioned activities respectively. The net percent error in radioiodine-131 activities is not alarming, but needs to be adjusted in order to ensure high quality images and optimum dose delivery.

Keywords: Radioiodine-131, residual activity, thyroid disorder, thyroid carcinoma