RT Journal Article SR Electronic T1 64Cu-TETA-Octreotide as a PET Imaging Agent for Patients with Neuroendocrine Tumors JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 213 OP 221 VO 42 IS 2 A1 Carolyn J. Anderson A1 Farrokh Dehdashti A1 P. Duffy Cutler A1 Sally W. Schwarz A1 Richard Laforest A1 Laura A. Bass A1 Jason S. Lewis A1 Deborah W. McCarthy YR 2001 UL http://jnm.snmjournals.org/content/42/2/213.abstract AB 64Cu (half-life, 12.7 h; β+, 0.653 MeV [17.4%]; β−, 0.579 MeV [39%]) has shown potential as a radioisotope for PET imaging and radiotherapy. 111In-diethylenetriaminepentaacetic acid (DTPA)-d-Phe1-octreotide (OC) was developed for imaging somatostatin-receptor–positive tumors using conventional scintigraphy. With the advantages of PET over conventional scintigraphy, an agent for PET imaging of these tumors is desirable. Here, we show that 64Cu-TETA-OC (where TETA is 1,4,8,11-tetraazacyclotetradecane-N,N′,N′′,N′′′-tetraacetic acid) and PET can be used to detect somatostatin-receptor–positive tumors in humans. Methods: Eight patients with a history of neuroendocrine tumors (five patients with carcinoid tumors and three patients with islet cell tumors) were imaged by conventional scintigraphy with 111In-DTPA-OC (204–233 MBq [5.5–6.3 mCi]) and by PET imaging with 64Cu-TETA-OC (111 MBq [3 mCi]). Blood and urine samples were collected for pharmacokinetic analysis. PET images were collected at times ranging from 0 to 36 h after injection, and the absorbed doses to normal organs were determined. Results: In six of the eight patients, cancerous lesions were visible by both 111In-DTPA-OC SPECT and 64Cu-TETA-OC PET. In one patient, 111In-DTPA-OC showed mild uptake in a lung lesion that was not detected by 64Cu-TETA-OC PET. In one patient, no tumors were detected by either agent; however, pathologic follow-up indicated that the patient had no tumors. In two patients whose tumors were visualized with 111In-DTPA-OC and 64Cu-TETA-OC, 64Cu-TETA-OC and PET showed more lesions than 111In-DTPA-OC. Pharmacokinetic studies showed that 64Cu-TETA-OC was rapidly cleared from the blood and that 59.2% ± 17.6% of the injected dose was excreted in the urine. Absorbed dose measurements indicated that the bladder wall was the dose-limiting organ. Conclusion: The high rate of lesion detection, sensitivity, and favorable dosimetry and pharmacokinetics of 64Cu-TETA-OC indicate that it is a promising radiopharmaceutical for PET imaging of patients with neuroendocrine tumors.