[The LISA trial-a- randomized, double-blind, placebo-controlled four-arm study of 1,000 patients with nodular goiter in Germany. Study Design and first results of feasibility].

Background: Although levothyroxine is the mostly prescribed medicament in Germany, its therapeutic effectiveness in nodular goiter was never studied in a randomized, double-blind trial with sufficient power. Thus, in May 2004 a TSH-adapted (TSH: thyroid-stimulating hormone), randomized, doubleblind, placebo-controlled four-arm (placebo [P] vs. levothyroxine [T] vs. iodine [I] vs. levothyroxine + iodine [TI]) multicenter study was started in Germany (LISA study).

Patients And Methods: Based on former retrospective and prospective studies, it was calculated that a sufficient statistical power (> 80%) would be achieved with 250 patients in each arm. The primary endpoint of the trial is the 1-year change of ultrasonographically measured total volume of all nodules. Secondary criteria are volume of goiter, number of nodules, and echogenic structure of nodules. While the study is kept strictly double-blind, the dose of levothyroxine in the T and TI groups is adapted once according to 3-month TSH measurements (target range 0.2-0.8 mU/l).

Results: Up to now (1 year after beginning), 305 patients have been included. TSH adaptation could be performed without compromising the double-blind character of the study with good results: about 90% of the patients reached the TSH target range.

Conclusion: Unblinded results are to be expected in 2007.