THYROID VOLUME REDUCTION FOLLOWING RADIOI ODINE THERAPY IN PATIENTS WITH AUTONOMOUS GOITER AND GRAVES-DISEASE

Aim: It is well known that radioiodine therapy (RITh) leads to a signi ficant thyroid volume reduction (TVR). But until now only little data has been presented due to the course of time and the extent of TVR. Me thod: Therefore the data of 33 patients with Graves' disease IGD), 36 patients with multifocal (MAG) and 31 with solitary (SAG) autonomous g oitre were analyzed retrospectively Results: All the patients showed a highly significant (p <0.001) TVR, which continued up to 1 year after RITh. Receiving equal effective radiation doses, the extent of TVR wa s significantly greater for GD than for MAG. This difference developed within six weeks up to 3 months after RITh. Conclusion: This observat ion suggests that the underlying thyroid disease affects the therapeut ic effect of RITh and may be partially explained by the total suppress ion of non-autonomous thyroid tissue in AG at the time of RITh. In pat ients with SAG with a 1.7 times higher effective radiation dose than i n MAG relative TVR was about 1.6 times stronger in SAG than in MAG. Th is demonstrates a direct relation between the effective radiation dose and the extent of the TVR after RITh.