Compassionate use of recombinant human thyrotropin to facilitate radioiodine therapy: case report and review of literature.
OBJECTIVE
To describe the use of recombinant human thyrotropin (thyroid-stimulating hormone) (rhTSH) to assist in radioiodine therapy in a patient with thyroid carcinoma who was unable to produce sufficient endogenous thyrotropin when hypothyroid and to review the related literature.


METHODS
The study patient underwent formal dosimetric analysis and received radioiodine in conjunction with rhTSH. Follow-up scanning studies were performed.


RESULTS
We found good localization of radioiodine on the posttherapy scans after administration of (131)I while the patient continued to receive thyroxine replacement after two intramuscularly administered injections of rhTSH. Some of his metastatic lesions disappeared and his serum thyroglobulin level decreased after the first rhTSH-assisted dose of (131)I was administered. His blood radioiodine clearance rate was unexpectedly more rapid in the hypothyroid state than when he was euthyroid (taking thyroxine) after administration of rhTSH. His whole-body clearance rate was more delayed when he was hypothyroid. Swelling of some of the metastatic thyroid cancer lesions developed when the patient was hypothyroid and after rhTSH was administered, the latter being much more rapid in onset.


CONCLUSIONS
Therapeutic doses of radioiodine can be delivered with the assistance of rhTSH administration while patients continue to take suppressive doses of thyroxine. Metastatic thyroid carcinoma lesions can swell rapidly after administration of rhTSH. The commercially available form of rhTSH is approved only for diagnostic use. Its safety and efficacy in assisting radioiodine therapy have not been fully determined.
Robbins
R J
RJ
Endocrinology Service, Memorial Hospital for Cancer and Allied Diseases, Memorial Sloan-Kettering Cancer Center, 1275 York Ave, New York, NY 10021, USA.
Voelker
E
E
Wang
W
W
Macapinlac
H A
HA
Larson
S M
SM
D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D001932:Brain Neoplasms / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D004357:Drug Synergism; D004645:Empathy; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D011994:Recombinant Proteins; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013972:Thyrotropin / Q000627:therapeutic use*; D013974:Thyroxine / Q000627:therapeutic use
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D013972:Thyrotropin; D013974:Thyroxine