Ablation therapy in differentiated thyroid cancer with recombinant TSH.

This study is determing the rate of ablation failure in differentiated thyroid cancer patients using rhTSH instead of thyroid hormone withdrawal for stimulation of remnant tissue, using a fixed dosage of 3.7 GBq inT1b-T3 N0N1M0 patients.

N/A

Study procedures:

After total thyroidectomy and histological confirmation of differentiated thyroid cancer substitution therapy is started (levothyroxine) to reach a TSH level < 0.3 mU/l.



3-6 WEEKS post surgery:

Neck ultrasound (standard application) to confirm the absence of significant thyroid remnant and to screen for lymph nodes. Basal TSH and Tg measurement.



6 WEEKS post surgery:

0.9 mg rhTSH will be administered i.m. at 0 and 24 hours.
At 48 hours 3.7 GBq (100 mCi) I-131 will be administered.
Post treatment scan 7 - 10 days after I-131 application. TSH and Tg measurement at 48 hours. To ensure the I-deficient diet (according to the Dutch guidelines), the iodine excretion in a 24 hours urine will be measured (in µg/l,).



6 MONTHS post ablation therapy:

Neck ultrasound and FNA of suspected nodules (if positive consider re-surgery).



9 MONTHS post ablation therapy:

0.9 mg rhTSH will be administered i.m. at 0 and 24 hours (Monday and Tuesday). At 48 hrs 150 MBq (4 mCi) I-131 application (Wednesday). TSH and Tg measurement and WBS 72 hours (Friday) after administration of 150 MBq (4 mCi) I-131 (i.e. 120 hours after the first rhTSH). (In case of visible uptake on a planar view, then a SPECT view will be made if available).