title: 99mTc-EDDA/HYNIC-TOC and (18)F-FDG in thyroid cancer patients with negative (131)I whole-body scans.
abstract: Several studies have reported on the expression of somatostatin receptors in patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate the imaging abilities of a recently developed technetium-99m labelled somatostatin analogue, (99m)Tc-EDDA/HYNIC-TOC ((99m)Tc-TOC), in terms of precise localisation of disease. The study population comprised 54 patients (24 men, 30 women; age range 22-90 years) with histologically confirmed DTC who presented with recurrent or persistent disease as indicated by elevated Tg levels after initial treatment. All patients were negative on the iodine-131 post-therapy whole-body scans. Fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) was performed in a subgroup of 36 patients. The study population consisted of two groups: Group A ( n=22) comprised patients with disease recurrence as shown by elevated Tg levels but without detectable pathology. In group B ( n=32), pre-existing lesions were known. Among the 54 cases, SSTR scintigraphy was true positive in 33 (61.1%), true negative in 4 (7.4%) and false negative in 17 (31.5%) cases, which resulted in a sensitivity of 66%. A total of 138 tumour foci were localised in 33 patients. The fraction of true positive (99m)Tc-TOC findings was positively correlated ( P<0.01) with elevated Tg levels (higher than 30 ng/ml). Despite two false positive findings, analysis on a lesion basis demonstrated better diagnostic efficacy with (18)F-FDG PET ( P<0.001); however, it also revealed substantial agreement between the imaging techniques [Cohen's kappa of 0.62 (0.47-0.78)]. In conclusion, scintigraphy with (99m)Tc-TOC might be a promising tool for treatment planning; it is easy to perform and showed sufficient accuracy for localisation diagnostics in thyroid cancer patients with recurrent or metastatic disease.
authors: Department of Nuclear Medicine, University of Innsbruck, Innsbruck, Austria. michael.gabriel@uklibk.ac.at
authors: Michael
authors: M
authors: Gabriel
authors: Franz
authors: F
authors: Froehlich
authors: Clemens
authors: C
authors: Decristoforo
authors: Christian
authors: C
authors: Ensinger
authors: Eveline
authors: E
authors: Donnemiller
authors: Elisabeth
authors: E
authors: von Guggenberg
authors: Dirk
authors: D
authors: Heute
authors: Roy
authors: R
authors: Moncayo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D017481:Receptors, Somatostatin / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology
chemical_list: D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; C487389:technetium 99m EDDA-HYNIC-Tyr(3)-octreotide; D019788:Fluorodeoxyglucose F18; D013954:Thyroglobulin