Toubert M E, Michel C, Metivier F, Peker M C, Rain J D
Department of Nuclear Medicine, H pital Saint-Louis, Paris, France.
Clin Nucl Med. 2001 Apr;26(4):302-5. doi: 10.1097/00003072-200104000-00004.
The authors describe a patient with follicular thyroid carcinoma who was receiving continuous ambulatory peritoneal dialysis to manage end-stage renal disease. To deliver radioiodine therapy to ablate thyroid remnants safely and under optimal conditions, the behavior of 37 MBq (1 mCi) I-131 was followed daily for 3 days. Blood activity and total body count decreased with a half-life of 100 hours (4.17 days). The daily iodide removal rate, estimated as a percentage of the total administrated activity, was low: 5.3% to 8.6% in peritoneal dialysate and 1.3% to 2.2% in urine. The thyroid uptake, measured using a probe, was 2.4% to 2.1% from day 1 to day 3 and 1.9% later at day 8. The volume of thyroid remnants was determined by ultrasonography to be 0.6 g. The patient received a reduced ablative I-131 dose of 814 MBq (22 mCi). Radiation emitted from the patient after I-131 therapy, monitored using a radiation monitor probe located at a distance of 1 meter, decreased with an effective half-life of 70 hours (2.9 days). The integration of the curve from t = 0 showed a level always less than 25 microSv/hour as early as 24 hours after treatment. Because the iodine removal rate is continuous but low in a case of peritoneal dialysis, smaller therapeutic doses must be administered to deliver maximal radiation to residual thyroid tissue while minimizing excessive radiation exposure to patients, their families, and medical staff.
作者描述了一名患有滤泡性甲状腺癌的患者，该患者正在接受持续性非卧床腹膜透析以治疗终末期肾病。为了在安全且最佳的条件下进行放射性碘治疗以消融甲状腺残余组织，对37 MBq（1 mCi）的I - 131的行为进行了为期3天的每日跟踪。血液活度和全身计数以100小时（4.17天）的半衰期下降。每日碘清除率（以总给药活度的百分比估算）较低：腹膜透析液中为5.3%至8.6%，尿液中为1.3%至2.2%。使用探头测量的甲状腺摄取率在第1天至第3天为2.4%至2.1%，在第8天后期为1.9%。通过超声检查确定甲状腺残余组织的体积为0.6 g。该患者接受了降低剂量的814 MBq（22 mCi）的I - 131消融治疗。使用位于1米远处的辐射监测探头监测I - 131治疗后患者发出的辐射，其以70小时（2.9天）的有效半衰期下降。从t = 0开始的曲线积分显示，早在治疗后24小时，水平就始终低于25微希沃特/小时。由于在腹膜透析的情况下碘清除率持续但较低，必须给予较小的治疗剂量，以便在将最大辐射传递至残余甲状腺组织的同时，将患者、其家人和医护人员所遭受的过度辐射暴露降至最低。
