Endocrine Abstracts

Introduction: Lack of radioiodine uptake in differentiated thyroid carcinoma (DTC) is a big diagnostic and therapeutic problem. This sign is associated with worse prognosis. In NRADTC patients with elevated thyreoglobulin levels with no evidence of disease in radioiodine scintigraphy, scintigraphy with the somatostatin analog labeled with ^99mTc seems to be an alternative imaging method.

Aim: Assessment of scintigraphy with the somatostatin analog labelled with technetium – ^99mTc-HYNIC-TATE in visualization of NRADTC.

Materials and method: Ten patients with metastatic NRADTC (6 with papillary thyroid carcinoma (PTC) and 4 with follicular thyroid carcinoma (FTC) underwent neck, chest and upper abdomen scintigraphy with ^99mTc-HYNIC-TATE produced by OBRI POLATOM Świerk/Poland.

Results: Pathological uptake of ^99mTc-HYNIC-TATE were found in metastatic lesions located in neck, mediastinum, lung and scapula in seven patients with DTC (6 PTC and 3 FTC). In two patient with PTC and metastatic lesions in neck, lung, mediastinum and mesentericum lymph nodes we found pathological uptake of ^99mTc-HYNIC-TATE only in neck and mediastinum (lung’s lesions was lower then 1 cm in CT, mesentericum lymph nodes metastases we found only in ¹⁸F-FDG PET/CT). In one patient with FTC we found pathological uptake in neck’s lymph nodes, mediastinum, lung and scapula but we didn’t find two metastatic lesions in the ribs (diagnosed in skeletal scintigraphy with ^99mTc-MDP). In one patient with local recurrence of FTC (in CT) there wasn^’t observed any pathological uptake of radiopreparation.

Conclusion: Non-radioiodine-avid differentiated thyroid carcinoma can be visualizated with ^99mTc-HYNIC-TATE scintigraphy. This method can be useful for qualification to surgery and/or further receptor radionuclide therapy.