Effectiveness of Percutaneous Ethanol Injection in Benign Cold Thyroid Nodules: Five Years' Experience / 대한내분비학회지

ABSTRACT

BACKGROUND: Percutaneous ethanol injection therapy (PEI) which is performed with the guidance of ultrasonography has recently been used in patient who had benign cold thyroid nodules. We performed this study to analyze the long-term effects of PEI on benign cold thyroid nodules. METHOD: From September 1995 to September 2000, we treated 198 outpatients (12 men and 186 women, who had a mean age of 40.8 years, with a range of 15-71) who had benign cold thyroid nodules at the Asan Medical Center. The PEI was performed on 141 patients who had solitary nodules (SN) and on 57 patients who had prominent nodules or Questionable or typing error? multiple nodules (MN). All patients had fine needle aspirations (FNAs) at least twice which resulted in a diagnosis of the presence of a colloid nodule. Thyroid hormone was given to all patients along with TSH measurements. The thyroid hormone dose was titrated to correspond to TSH level of a low normal range. These patients were followed up for mean period of 37.6 months (range 18-60). Patients who were treated with PEI were classified into three groups according to their volume reduction a complete response (CR, which was above 90% in volume reduction), a partial response (PR, which was a 50-89%) reduction and No Response (which was below 50% or an increased size) groups. RESULTS: The overall pre-treatment volumes of the nodules were 15.7+/-19.8 mL. The overall post-treatment volumes were 2.4+/-2.6 mL and consisted of volume reductions of 70.1+/-17.1%. The results of PEI for all of the patients were a complete reduction (CR) in 34 cases (17.2%), a partial reduction (PR) in 142 cases (71.7%) and No Response in 22 patients (11.1%). In 141 patients in the SN group, in which there was a mean follow-up duration of 36.7+/-11.2 months, the volume reductions were 68.3+/-18.8%. CR was observed in 20 patients (14.2%), PR in 103 (73.0%) and No Response in 18 (12.8%). In twenty-two of the SN patients (22/141, 15.6%) we were able to discontinue the thyroid hormone suppressive therapy because those nodules had markedly decreased in volume after PEI without any further increase of nodule size during the follow-up period. In 57 patients in the MN group, over a mean follow-up durations of 37.1+/-11.4 months, the volume reductions were 74.3+/-12.1%. CR was observed in 14 patients (24.6%), PR in 39 (68.4%) and No Response occurred in 4 (7.0%). During the follow-up period after PEI, further volume reductions were observed for 36 months after thyroid hormone suppressive therapy in the Response Group. Differences in volume reductions between the SN and MN groups were not statistically significant but the volume reductions in patients who had a pre-treatment volume larger than 15 mL were higher than those in the smaller group (p<0.001). In the cases of the SN and MN groups, volume reductions did not correlate with either the amount of injected ethanol or the pre-treatment volumes, but the pre-treatment volumes correlated with post-treatment volumes in the patients who had SN (p<0.001, r=0.411) and MN (p<0.001, r=0.729). We observed mild, but transient complications in 32 patients (16.2%) during PEI which included a transient neck pain (n=27, 13.6%), a transient unilateral vocal cord palsy (n=4, 2.0%), and an abscess formation (n=1, 0.5%) which was cured. CONCLUSION: These results suggest that PEI is a feasible adjunctive therapy to use in thyroid hormone suppressive therapy for benign cold thyroid nodules