Twenty-year follow-up of a randomized clinical trial of unilateral thyroid lobectomy with or without postoperative levothyroxine treatment.

Abstract

The aim of this study was to validate in 20-year follow-up (FU) the outcomes reported in World J Surg 2010; 34(6):1232-8 on recurrent nodular goiter in the contralateral thyroid lobe among patients after thyroid lobectomy (TL) for multinodular goiter (MNG) receiving versus not receiving postoperative prophylactic levothyroxine (LT4) treatment. Some 150 consenting patients underwent TL for MNG in 2000-2003. They were randomized to two groups, 75 patients each: (a) receiving prophylactic LT4 treatment postoperatively (dose range 75-125 microg/day to maintain thyroid-stimulating hormone values within 0.27-1.0mU/L), and (b) not receiving LT4. Sixty-month FU was extended to 240months for all the consenting patients. The primary outcome was prevalence of recurrent goiter. The secondary outcome was re-intervention rate for recurrent goiter. The outcomes were stratified according to individual iodine metabolism status assessed by urinary iodine excretion. During the 5-year FU (5 patients were lost) recurrent goiter was found in patients receiving versus not receiving LT4 in 1.4% versus 16.7% (p=0.001) whereas during 20-year FU (29 patients were lost) it was 3.3% versus 30.0% of patients, respectively (p=0.031). During 20-year FU 4.9% versus 30.0%, respectively, of patients receiving versus not receiving LT4 required contralateral thyroid lobe treatment/surgery (p=0.028). LT4 decreased recurrence rate among iodine-deficient patients (10.0% vs. 70.0%, respectively; p=0.037) but not among iodine-sufficient patients (0.0% vs. 10.0%, respectively; p=0.056). Twenty-year FU data confirmed that prophylactic LT4 treatment significantly decreased the recurrence of nodular goiter and the need for completion intervention/surgery, mostly among patients with iodine deficiency.