The treatment of differentiated thyroid cancer (DCT) includes surgery followed by radioiodine treatment. In the follow-up of patients it is necessary to induce TSH elevation for the measurement of thyreoglobulin and/or total body scanning. There are two principal methods to obtain TSH elevation: 1) injection of recombinant human TSH , and 2) to stop L-thyroxin replacement for several (3-4) weeks. As use of recombinant TSH is rather expensive, this method is not feasible in many countries. The problem with stopping L-thyroxin is development of severe hypothyroidism for several weeks with concomitant symptoms and signs.~Current pilot study aims to induce the necessary TSH elevation by decreasing the L-thyroxin dose. The main hypothesis is that necessary TSH stimulation will be achieved during 4-6 weeks in majority of patients with fixed dose of L-thyroxin. Concomitantly, blood tests and symptoms and signs of hypothyroidism will be obtained to get information about possible deviations during treatment with low dose of thyroxin.
The treatment of differentiated thyroid cancer (DCT) includes surgery followed by radioiodine treatment. In the follow-up of patients it is necessary to induce TSH elevation to test for cancer recurrence. One of the options is to stop L-thyroxin replacement for several weeks. Current pilot study aims to induce the necessary TSH elevation by decreasing the L-thyroxin dose. The main hypothesis is that necessary TSH stimulation will be achieved during 4-6 weeks in majority of patients.