Dose to the liver and spleen in pediatric patients undergoing technetium-99m sulfur colloid scans

Quantitative conjugate view external counting techniques were applied to determine radiation dose to the liver and spleen in pediatric patients undergoing 99mTc-sulfur colloid (Tc-SC) liver scans. The effective half-life of 99mTc-SC was 5.8 +/- 0.23 hours and 5.2 +/- 0.68 hours in the liver and spleen, respectively. Dose per administered activity ranged from 0.34 to 0.63 rad/mCi (92 to 170 muGy/MBq) for the liver and 0.35 to 1.96 rad/mCi (95.0 to 530.0 muGy/MBq) for the spleen. The spleen to liver dose ratio ranged from 1.0 to 4.9. These values are compared with results extrapolated from published adult data to the pediatric population.