2Department of Nuclear Medicine, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul-Türkiye DOI : 10.5505/tjo.2022.3720 OBJECTIVE
In thyroid cancer, radioiodine is widely used for thyroid ablation with variable activity range 1110- 11100 MBq (30-300 mCi). The aim of this work was to evaluate the dose rate of the discharged patients and the impact of hydration on the patients whose dose rate is close to the discharging dose limit.
METHODS
A total of 303 patients undergoing 131 therapies were recruited in this study. Dose rate measurements
were performed 22?24 h after radioiodine uptake. The patients with a dose rate <30 µSv/h were discharged.
Whereas, those with a 30?40 ?Sv/h dose rate were asked to drink further 1.5-2 liters of water
for 4-6 h. Then, post-voiding dose rate measurements were repeated.
RESULTS
Consequently, the patients administered with 1111?2775 MBq (30-75 mCi) were discharged after 24 h.
Among the patients treated with 3700 MBq (100 mCi), 21/29 patients (72.4%) had a dose rate between
30 and 40 ?Sv/h and they were released within 4-6 h after drinking 1.5?2.0 liters of water. For the patients
treated with 5555 MBq (150 mCi), 23/32 patients (71.8%) whose dose rate between 30 and 40
µSv/h were similarly discharged after drinking extra 1.5?2.0 liters of water within 4?6 h. Moreover, the
patients who were subjected to 7400?11100 MBq (200?300 mCi) 131I therapy were not asked to drink
extra water as the dose rates measured at the end of 24 h were >40 ?Sv/h and they were discharged later.
CONCLUSION
Consequently, it was manifested that around 72% of thyroid cancer patients who underwent radioiodine
therapy had a dose rate level 30?40 ?Sv/h after 24 h and could be discharged early by drinking 1.5-2.0
liters of water within 4-6 h.