Recombinant human thyrotropin-stimulated radioiodine therapy of large nodular goiters facilitates tracheal decompression and improves inspiration.

INTRODUCTION: The impact on tracheal anatomy and respiratory function of recombinant human (rh)TSH-stimulated (131)I therapy in patients with goiter is not clarified. METHODS: In a double-blinded design, patients (age 37-87 yr) with a large multinodular goiter (range, 99-440 ml) were randomized to placebo (n = 15) or 0.3 mg rhTSH (n = 14) 24 h before (131)I therapy. The smallest cross-sectional area of the trachea (SCAT; assessed by magnetic resonance imaging) and the pulmonary function were determined before, 1 wk, and 12 months after therapy. RESULTS: Data on goiter reduction have been reported previously. In the placebo group, no significant changes in the lung function or SCAT were found throughout the study. In the rhTSH group, a slight decrease was observed in the forced vital capacity 1 wk after therapy, whereas the mean individual change in SCAT was significantly increased by 10.5% (95% confidence interval = 0.9-20.0%). A further increase in SCAT to 117 +/- 36 mm(2) (P = 0.005 compared with 92 +/- 38 mm(2) at baseline) was seen at 12 months, corresponding to a mean of 31.4% (95% confidence interval = 16.0-46.8%). The expiratory parameters did not change significantly, whereas forced inspiratory flow at 50% of the vital capacity (FIF50%) increased from initially 3.34 +/- 1.33 liters/sec to ultimately 4.23 +/- 1.88 liters/sec (P = 0.015) in the rhTSH group, corresponding to a median increase of 24.6%. By 12 months, the relative improvements in FIF50% and in SCAT were inversely correlated to the respective baseline values (FIF50%: r = -0.47, P = 0.012; SCAT: r = -0.57, P = 0.001). CONCLUSION: On average, neither compression of the trachea nor deterioration of the pulmonary function was observed in the acute phase after rhTSH-augmented (131)I therapy. In the long term, tracheal compression is diminished, and the inspiratory capacity improved, compared with (131)I therapy alone.

The feasibility of high dose iodine 131 treatment as an alternative to surgery in patients with a very large goiter: effect on thyroid function and size and pulmonary function.

Some patients with very large goiters (>150 mL) are not candidates for surgery. We evaluated the feasibility of high dose 131I in such patients. Twenty-three patients (2 men and 21 women; median age, 67 yr; range, 42-86 yr) with very large goiter (8 toxic) were treated with calculated high dose 131I [median, 2281 megabecquerels (61.6 mCi); range, 988-4620 megabecquerels (26.7-124.9 mCi)]. During the 12-month observation period, goiter reduction and tracheal anatomy were monitored by magnetic resonance imaging, and the respiratory capacity was monitored by pulmonary function tests. Five patients (22%) developed hypothyroidism. Thyroid volumes were at baseline, after 1 week, and after 1 yr [mean +/- SEM, 311 +/- 28, 314 +/- 26 (P = NS), and 215 +/- 26 (P < 0.01) mL]. The relative changes 1 week after therapy ranged from -14.1% to 15.3%. After 1 yr the mean size was reduced by 33.9% (range, 13.5-61.4%). Only the initial goiter size showed a significant negative correlation to the percent reduction. The smallest cross-sectional area of the trachea decreased 9.2% within 1 week after treatment, but eventually emerged with a 17.9% larger area [mean +/- SEM, 84.3 +/- 4.8, 75.5 +/- 5.1 (P < 0.01), and 98.2 +/- 6.0 (P < 0.01) mm2]. The inspiratory parameter, FIF50%, improved after an initial insignificant decline [baseline therapy, after 1 week, after 3 months, and after 1 yr (mean +/- SEM), 2.37 +/- 0.24, 2.20 +/- 0.21 (P = NS), 2.51 +/- 0.23 (P = NS), and 2.76 +/- 0.25 (P = 0.01) L/s]. FIF50% correlated significantly with the smallest cross-sectional tracheal area (baseline, 1 week, and 1 yr: r = 0.74; P < 0.001, r = 0.63; P < 0.005, and r = 0.46; P < 0.05). Changes in tracheal anatomy did not correlate with changes in either lung dynamics or goiter size. In conclusion, very large goiters can be reduced by a third, on the average, with high dose 131I therapy without any initial clinically significant tracheal compression. Tracheal cross-sectional area as well as pulmonary inspiratory capacity improve. No serious adverse effects are seen.