DIFFERENTIATED THYROID CARCINOMA ONE YEAR AFTER ABLATION

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 459-496-Thyroid Neoplasia & Case Reports
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-473
Sandra Melanzi*1, Ines Bucci2, Fabrizio Febo1, Cesidio Giuliani2, Giorgio Napolitano2, Valerio Di Francesco3 and Angelo Di Nicola3
1University of Chieti, Chieti, Italy, 2University of Chieti-Pescara, Chieti, Italy, 3Nuclear Medicine, Pescara, Italy
Differentiated thyroid carcinoma has a very favourable prognosis in more than 90% of patients. This is especially true in those patients who have been classified at “low risk” after surgery and I131 treatment. Aim of our study was to compare the risk of recurrence, based on ATA guidelines, after radioiodine ablation with the evaluation of TSH-stimulated Thyroglobulin (Tg) levels and whole-body scintigraphy 1 year afterwards. 390 patients (293 F, 97 M, age 14-85 years) have been I131 treated from 2007 to 2011; 329 were papilary carcinomas, 51 follicular and in 10 patients coexistence of both follicular and papillary carcinomas was diagnosed. 168 cases had a maximum diameter  ≤1 cm, while in 222 patients  it was > 1 cm. According to ATA guidelines, 242 patients have been classified in the “low” risk group, 126 in the “intemediate” and 22 in  the “high” risk group.

207 patients, (124 “low”, 77 “intermediate” and 6 “high” risk), were again evaluated after 1 year with whole-body scintigraphy and Tg levels (plus Tg-Ab) after stimulation with Thyrogen or LT4 suspension. Tg was < 1 ng/ml in 174 patients and ≥ 1ng/ml in 33; Tg-Ab levels were positive in 9 patients with Tg <1 ng/ml and in 3 of theese thyroid scan was positive. Patients were considered “not free” from disease if their stimulated-Tg  levels were ≥1 ng/ml or if, when Tg-Ab were positive, thyroid scan showed I131 uptake. 17 (13.7%) patients in the “low “ risk group, 15 (19.4%) in the “intermediate” group and 3 (50%) in the “high” risk were “not free” from disease. Of particular interest in the “low” risk group, 3 patients had Tg levels >15 ng/ml and 2 (with positive Tg-Ab) showed I131 uptake at the thyroid scan, thus showing persistence/recurrence of disease. Our data show that a significant percentage of patients in the “low” risk group cannot be considered “free” from disease 1 year after I131ablation; these data suggest that caution is requested in the follow up of “low” risk patients too, and might have implications in the therapeutic goal before TSH-stimulated Tg and whole-body scintigraphy is performed.

Nothing to Disclose: SM, IB, FF, CG, GN, VD, AD

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm