99mTc-EDDA/HYNIC-TOC: a new 99mTc-labelled radiopharmaceutical for imaging somatostatin receptor-positive tumours; first clinical results and intra-patient comparison with 111In-labelled octreotide derivatives.

摘要: [111In-diethylene triamine penta-acetic acid-d-Phe1]-octreotide (DTPA-octreotide) scintigraphy has gained widespread acceptance as a diagnostic clinical procedure in oncology for imaging somatostatin receptor-positive tumours. However, indium-111 radiolabel several drawbacks, including limited availability, suboptimal gamma energy and high radiation burden to the patient. We have recently reported on preclinical development of 99mTc-EDDA/HYNIC-TOC, new octreotide derivative which showed promising results both vitro vivo. now report our initial experiences with this radiopharmaceutical ten oncological patients. The diagnoses were: carcinoid syndrome (n=5), thyroid cancer (n=3), pancreatic (n=1) pituitary tumour (n=1). biodistribution kinetics 99mTc-EDDA/HYNIC-TOC were compared those 111In-DTPA-octreotide six cases, 111In-DOTA-TOC five cases. With tracer tumours imaged within 15 min after injection highest target/non-target ratios 4 h injection. Tumour uptake persisted up 20 p.i. rate blood clearance was similar that but faster than 111In-DOTA-TOC, while urinary excretion lower 111In derivatives. Semi-quantitative region interest analysis produced higher tumour/organ (target/non-target) derivatives, especially relation heart muscle. Significantly more lesions could be detected 99mTc images. conclude shows better properties identification sites currently available 111In-labelled