[Optimization of 131I ablation in patients with differentiated thyroid carcinoma: comparison of early outcomes of treatment with 100 mCi versus 60 mCi].
BACKGROUND
The aim of this study was to compare the early outcomes between two groups of patients with differentiated thyroid carcinoma (DTC) who received 60 or 100 mCi of (131)I for remnant ablation.


METHODS
224 DTC patients with primary tumor > 1 cm of diameter or multifocal were randomised into prospective clinical trial. Patients with extrathyroideal extension of primary tumor and nodal metastases or M1 were not enrolled. 99 patients received 60 mCi, and 125--100 mCi of radioiodine as the first ablative dose.


RESULTS
The effectiveness of thyroid ablation was evaluated after one year, during endogenous TSH (thyroid stimulating hormone) stimulation, and after two years during Lthyroxine therapy. Whole body scintigraphy (WBS) was performed under thyroxine withdrawal and thyroglobulin serum level was assessed. Distant micrometastases were detected in 9.8% of patients by post-therapy WBS, 11 patients in group A treated with 60 mCi and 11 in group B treated with 100 mCi. In other patients no symptoms of persistent disease were detected. At one year follow up full remission was diagnosed in 176 patients: 76 in group A and 100 in group B. The remaining ones, 13.3% and 11.2% respectively, received the second course of (131)I for remnant ablation. There were no statistically significant differences in Tg (thyroglobulin) serum level either 12 or 24 months after 131I treatment.


CONCLUSIONS
Our evaluation of early efficacy of adjuvant radioiodine treatment in low risk DTC patients shows no differences between two radioiodine activities - 60 and 100 mCi in relation to thyroid ablation. Thus, the activity of 60 mCi is recommended.
Kukulska
Aleksandra
A
Department of Nuclear Medicine and Endocrine Oncology Comprehensive Cancer Center and M. Sklodowska-Curie Memorial Institute of Oncology, Branch Gliwice, Gliwice.
Krajewska
Jolanta
J
Roskosz
Józef
J
Handkiewicz-Junak
Daria
D
Jarzab
Michał
M
Paliczka
Ewa
E
Puch
Zbigniew
Z
Wygoda
Zbigniew
Z
Gubała
Elzbieta
E
Jarzab
Barbara
B
D018263:Adenocarcinoma, Follicular / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D002291:Carcinoma, Papillary / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage*; D008207:Lymphatic Metastasis; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy* / Q000601:surgery; D018365:Neoplasm, Residual; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome; D014915:Whole-Body Counting / Q000379:methods
D007457:Iodine Radioisotopes