Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1835664 (TOC)
 2,763 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Indium- 111 labelled DTPA-D-Phe1-octreotide (DTPA-OC, OctreoScan) has been introduced into clinical routine for the detection of somatostatin receptor (SSTR)-positive tumours, which are predominantly of neuroendocrine origin. Potential further applications in other SSTR-positive cancers (e.g. small cell lung cancer, breast cancer, melanoma) have been limited mainly by the restricted availability and the high radionuclide costs. Previous attempts to introduce technetium-99m labelled analogues of octreotide have not been very successful in terms of the labelling procedure, in vivo biodistribution and/or tumour detection capabilities. The aim of this study was to assess the performance of the new 99mTc-labelled analogue HYNIC-D-Phe1-Tyr3-octreotide (HYNIC-TOC), using tricine as co-ligand, for the detection of SSTR-positive tumours in patients in comparison with 111In-DTPA-OC. Overall, 13 patients were examined using 99mTc-tricine-HYNIC-TOC. Twelve patients had proven SSTR-positive tumours, while one patient presented with an SSTR-negative tumour. In 9 of the 13 patients both tracers (99mTc-tricine-HYNIC-TOC and 111In-DTPA-OC) were used. Serial whole-body scans, spot views and/or single-photon emission tomography studies were performed. Images were qualitatively and semi-quantitatively (ROI analyses) evaluated. The biodistribution of 99mTc-tricine-HYNIC-TOC in patients showed high physiological uptake in kidneys, moderate uptake in liver and spleen and little uptake in the gut. The tracer showed predominantly renal and negligible hepatobiliary excretion. Known SSTR-positive tumour sites showed rapid and intense tracer accumulation. 99mTc-tricine-HYNIC-TOC demonstrated rapid tissue uptake within the first hour after injection and had basically no significant clearance (<20%) from normal or tumour tissue thereafter. In contrast, 111In-DTPA-OC showed continuous clearance from normal tissues as well as renal and very little hepatobiliary excretion. Nevertheless, the patterns of accumulation of 99mTc-tricine-HYNIC-TOC in tumours and normal organs were comparable to those of 111In-DTPA-OC. A lesion-by-lesion comparison showed comparable tumour detection capabilities in intrahepatic tumour sites and superior capabilities of 99mTc-tricine-HYNIC-TOC in respect of extrahepatic lesions. In conclusion, 99mTc-tricine-HYNIC-TOC shows promise as a tracer for SSTR imaging, given its favourable clinical characteristics (specific and high receptor affinity, good biodistribution, renal excretion, low radiation exposure, high imaging quality, on-demand availability) and cost-effectiveness. 99mTc-tricine-HYNIC-TOC allows earlier diagnosis (10 min-4 h) compared with 111In-DTPA-OC (4-24 h).
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PMID:Detection of somatostatin receptor-positive tumours using the new 99mTc-tricine-HYNIC-D-Phe1-Tyr3-octreotide: first results in patients and comparison with 111In-DTPA-D-Phe1-octreotide. 1108 50

The clinical usefulness of a new 99mTc-labeled somatostatin analogue has been studied from the standpoint of oncological diagnostics. The group of patients studied included 40 individuals with diagnosed malignant neoplasms (32 primary and 8 metastatic). Among the primary tumors were 7 pituitary adenomas (5 hormonally active and 2 inactive), 1 liposarcoma, 2 carcinoids, 1 breast carcinoma, and 21 cases of lung cancer (2 small cell and 19 non-small cell) were represented. The metastatic tumors consisted of: 3 malignant melanomas, 1 pheochromocytoma, 1 prostatic cancer, 1 leiomyosarcoma, 1 pancreatic carcinoma ectopically secreting ACTH, and 1 carcinoid of the thymus. The radiopharmaceutical, 99mTc-EDDA/HYNIC-octreotide, was i.v. administered at the activity of 740-925 MBq. The imaging was comprized of a whole-body scan and single photon emission computed tomography. Positive scintigrams were obtained in 4 of 5 hormonally active pituitary adenomas, in 1 of 2 cases of carcinoid, in liposarcoma, breast cancer, and all cases of small cell (SCLC) and non-small cell lung cancer (NSCLC). The neoplastic metastases were visualized in 2 of 3 cases of melanoma and in patients with pheochromocytoma, pancreatic carcinoma secreting ACTH, and thymic carcinoid. Scintigrams were negative in both hormonally inactive pituitary adenomas, in one case of metastatic malignant melanoma, leiomyosarcoma, and in cases of metastasis from the prostatic carcinomas. The results of this pilot study indicated that 99mTc-EDDA/HYNIC-TOC is a potentially useful radiopharmaceutical for the imaging of a wide range of primary and metastatic tumors. More detailed indications for the clinical usefulness of the new tracer for the imaging of selected tumor types require studies on much larger groups of patients. Special attention should be paid to the successful imaging of all cases of NSCLC.
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PMID:Clinical usefulness of 99mTc-EDDA/HYNIC-TOC scintigraphy in oncological diagnostics: a pilot study. 1518 7