OUTCOME OF 309 PATIENTS WITH METASTATIC DIFFERENTIATED THYROID-CARCINOMA TREATED WITH RADIOIODINE

From 1969 to 1990 there were 309 patients with differentiated thyroid carcinoma (241 papillary and 68 follicular) treated with radioactive i odine for functioning node metastases alone (n = 191) or distant metas tases (n = 118) with or without node metastases. These patients repres ented 32.7% of 945 patients treated in our institution during the same period. Initial treatment included near-total thyroidectomy and I-131 ablation of postsurgical thyroid residue, followed by L-thyroxine sup pressive therapy. At the end of follow-up (mean 5.8 years), 146 patien ts (76.4%) in the group with nodal metastases were considered cured, a s assessed by clinical and laboratory evaluation including whole body scan (WBS) and serum thyroglobulin (Tg) levels; 32 patients (16.7%) ha d persistent disease. Loss of I-131 uptake in persistent metastatic le sions occurred in five patients (2.6%), and newly developed distant me tastases occurred in eight patients (4.2%). Of the patients with dista nt metastases, 36.4% were cured by I-131. Distant metastases from papi llary carcinomas had a higher cure rate than follicular carcinomas (p < 0.01). The metastases of four patients (5.2%) lost the property to t ake up radioiodine. Lung and bone metastases detectable by WBS but not by radiography were most likely to be cured by I-131. Th, overall sur vival at the end of follow-up was 95.8% in patients with only lymph no de metastases and 76.0% in those with distant metastases. Tumor-relate d deaths were 3.6% and 23.7%, respectively. Our data indicate that I-1 31 therapy is highly effective in the treatment of lymph node metastas es from differentiated thyroid carcinoma. To a variable extent, distan t metastases may also benefit from radioiodine therapy, definitive cur e being much more likely during the early phase of metastatic involvem ent.