The published studies confirming the safety and efficacy of
rhTSH for diagnostic purposes have led to an increased interest in its use for preparation for radioiodine (RI) dose administration in patients with recurrent or persistent differentiated
thyroid carcinoma (DTC). In order to establish the efficacy of RI
therapy after
rhTSH, we have reviewed 39
rhTSH-aided radioiodine treatment in a series of 28 DTC patients. Patients were divided into two groups: GI (n=17), with previous thyroid bed uptake and undetectable
thyroglobulin (Tg) levels under
levothyroxine treatment and GII (n=11), with proven metastatic local or distant disease. Median follow-up after the first
rhTSH-aided radioiodine treatment was 32 +/- 13 months (range 8 to 54 months). Sixteen patients (94%) in GI were rendered disease free and one patient was shown to have persistent disease. In GII, the post
therapy whole body scan showed pathological uptakes in all cases: in four patients in lungs, in four in mediastinum and in three in lateral neck. In two patients with mediastinum uptake, Tg levels were undetectable after
rhTSH. In the follow-up, two patients with lateral neck uptake were rendered disease free, four patients died (three due to
thyroid cancer) and five out of the remaining patients have persistent disease. In conclusion,
rhTSH aided
therapy was helpful to eliminate normal thyroid bed remnants in 16/17 (94%) patients (GI).
rhTSH stimulated Tg was undetectable in two patients with mediastinal
metastasis. We believe that
rhTSH is a good alternative to
levothyroxine withdrawal for the treatment of DTC with radioactive
iodine, increasing the quality of life in these patients. Caution should be recommended in the follow-up of unselected DTC patients only with stimulated Tg levels.