Examination of the somatostatin receptor status in non-medullary thyroid cancer

Aim: Recent in-vitro and in-vivo studies demonstrated a somatostatin recept or expression in some non-medullary thyroid carcinomas. In this study we in vestigated the somatotatin receptor status for this particular tumor entity in a larger patient group. Subject and methods: We compared 131-iodine wit h 111-In-pentetreotide scans in 24 patients with metastasizing, non-medulla ry thyroid cancer. The findings were correlated with other imaging modaliti es. Additionally, Lye performed receptor autoradiography in one patient, oc treotide therapy in another patient and administration of 90-Y- and 111-In- DOTATOC in 2 consecutive patients. Results: In the 15 patients with papilla ry or follicular carcinoma, 111-In-pentetreotide was inferior to 131-I in 8 /15, equal in 1/15, and superior in 6/15 patients. In 8/9 of the patients w ith Hurthle cell carcinoma, metastases showed a 111-In-pentetreotide accumu lation of various intensity, while 131-iodine scans were negative except fo r one patient. 111-In-pentetreotide was equal or superior compared to 201-T l or 99m-Tc-sestamibi, but for the most part inferior in comparison with 18 -F-FDG-PET. The findings of 111-In-pentetreotide scintigraphy correlated we ll with the receptor autoradiography and the accumulation of DOTATOC, but n ot with the therapeutic effect of "cold" octreotide on the thyroid cancer m etastases. Conclusions: Several metastases of papillary and follicular carc inoma, and the majority of Hurthle cell cancer metastases can express somat ostatin receptors. 111-In-pentetreotide scintigraphy is a promising tool fo r localization of metastases especially in Hurthle cell cancer or if PET is not available, and may be useful for selection of possible candidates, if therapeutic effective beta-emitting somatostatin analogues will be availabl e for routine application.