Radioiodine treatment of metastatic differentiated thyroid cancer in patients on L-thyroxine, using recombinant human TSH.
OBJECTIVE
This study tested the hypothesis that administration of human recombinant thyroid-stimulating hormone (rhTSH: Thyrogen, thyrotropin alpha) could promote iodine-131 ((131)I) uptake in the therapy for metastatic or locally invasive differentiated thyroid cancer (DTC), obviating L-thyroxine suppressive therapy (L-T4) withdrawal and hypothyroidism in patients with advanced disease.


METHODS
Twelve totally (or almost completely) thyroidectomized adults, nine of whom had received earlier therapy after L-T4 withdrawal, underwent (131)I treatment while euthyroid on L-T4, after rhTSH administration. Nine underwent diagnostic whole-body scanning (WBS) after two consecutive daily i.m. injections (0.9 mg) of rhTSH. They then received an identical second course of rhTSH to promote therapeutic (131)I uptake. Post-therapy WBS was performed one week later. Three patients received only rhTSH (131)I therapy.


RESULTS
Administration of rhTSH promoted (131)I uptake in all patients, as demonstrated by post-therapy WBS. Administration of rhTSH also promoted a significant increase in serum thyroglobulin (Tg) concentrations. According to the most recent measurements, 3-12 months after therapy, serum Tg levels fell in four, and stabilized in two out of eleven patients. Upon additional rhTSH-WBS 8 months post-study, a reduction in one metastatic site was noted in one patient. The rhTSH was well tolerated, with mild, transient fever and/or nausea occurring in only a minority of patients. Individuals with bone metastases experienced degrees of peritumoral pain and swelling that were similar (though more short-lived) to those seen in the same or other patients after L-T4 withdrawal.


CONCLUSIONS
Administration of rhTSH is a safe, successful tool for inducing (131)I uptake in local and metastatic DTC lesions, and avoids L-T4 withdrawal, preserving metabolic homeostasis and preventing the debilitating effects of hypothyroidism.
Lippi
F
F
Department of Endocrinology and Metabolism, Section of Endocrinology, University of Pisa, Via Paradisa 2, 56124 Pisa, Italy. flippi@endoc.med.unipi.it
Capezzone
M
M
Angelini
F
F
Taddei
D
D
Molinaro
E
E
Pinchera
A
A
Pacini
F
F
D000368:Aged; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000378:metabolism* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000628:therapy; D013965:Thyroidectomy; D013972:Thyrotropin / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D013974:Thyroxine / Q000008:administration & dosage / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed; D014915:Whole-Body Counting
D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D013972:Thyrotropin; D013954:Thyroglobulin; D013974:Thyroxine