title: Two cases of thyroid carcinoma that were not stimulated by recombinant human thyrotropin.
abstract: Recombinant human TSH (rhTSH) is being widely used to monitor patients who were previously treated for differentiated thyroid cancers for evidence of recurrence. Its value lies in the avoidance of recurrent episodes of hypothyroidism in the follow-up protocols. rhTSH is also being evaluated as a potential therapeutic adjunct that would spare patients the experience of becoming hypothyroid when undergoing thyroid remnant ablation or treatment for metastases. In some centers, rhTSH is also used to support compassionate care of patients with advanced disease who cannot safely become hypothyroid. The (131)I uptake response to rhTSH, presently an off-label application, is expected to be similar to that of endogenously raised TSH levels. The two cases presented here are cautionary tales in which (131)I uptake by metastases was present under hypothyroid conditions, but absent in one patient and present in only a portion of the lesions in the other, with rhTSH stimulation.
authors.affiliation: Department of Nuclear Medicine, London Health Science Centre, London, Ontario, Canada N6A 4G5. al.driedger@lhsc.on.ca
authors.forename: A A
authors.initials: AA
authors.lastname: Driedger
authors.forename: N
authors.initials: N
authors.lastname: Kotowycz
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D011994:Recombinant Proteins / Q000009:adverse effects / Q000627:therapeutic use; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000532:radiotherapy*; D013972:Thyrotropin / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D007457:Iodine Radioisotopes; D011994:Recombinant Proteins; D013972:Thyrotropin