HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Anderson, C. J. Articles by McCarthy, D. W. Search for Related Content PubMed PubMed Citation Articles by Anderson, C. J. Articles by McCarthy, D. W.

⁶⁴Cu-TETA-Octreotide as a PET Imaging Agent for Patients with Neuroendocrine Tumors

Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri

⁶⁴Cu (half-life, 12.7 h; ß⁺, 0.653 MeV [17.4%]; ß^-, 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.

Key Words: ⁶⁴Cu • octreotide • PET • ¹¹¹In