Iodine-131 ablation therapy for a patient receiving peritoneal dialysis.
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.
Toubert
M E
ME
Department of Nuclear Medicine, H pital Saint-Louis, Paris, France. marie-elisabeth.toubert@sls.ap-hop-paris.fr
Michel
C
C
Metivier
F
F
Peker
M C
MC
Rain
J D
JD
D018265:Carcinoma, Papillary, Follicular / Q000150:complications / Q000532:radiotherapy*; D006207:Half-Life; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D007690:Polycystic Kidney Diseases / Q000150:complications / Q000628:therapy*; D011874:Radiometry; D013964:Thyroid Neoplasms / Q000150:complications / Q000532:radiotherapy*
D007457:Iodine Radioisotopes