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

This Article 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Delaloye, A. B. Articles by Schubiger, P. A. Search for Related Content PubMed PubMed Citation Articles by Delaloye, A. B. Articles by Schubiger, P. A.

Comparison of Copper-67- and Iodine-125-Labeled Anti-CEA Monoclonal Antibody Biodistribution in Patients with Colorectal Tumors

Departments of Nuclear Medicine and Surgery, Institute of Biochemistry, University of Lausanne, Lausanne; Division of Radiopharmacy, Paul Scherrer Institute, Villigen, Switzerland

Correspondence: For correspondence or reprints contact: Angelika Bischof Delaloye, MD, Nuclear Medicine Department, Centre Hospitalier Universitaire Vaudois, CH-1011 Lausanne, Switzerland.

ABSTRACT

Copper-67 has comparable beta-particle emissions to that of ¹³¹I, but it displays more favorable gamma emission characteristics for application in radioimmunotherapy (RIT). This study investigates the potential of ⁶⁷C-labeled monoclonal antibody (MAb) 35 for RIT of colorectal carcinoma. Methods: Biokinetics of simultaneously injected ⁶⁷C- and ¹²⁵I-labeled MAb35 were studied in six patients scheduled for surgery of primary colorectal cancer. Results: Whole-body clearance (T_1/2)of ⁶⁷C, estimated from sequential anterior and posterior whole-body scans and corrected for decay of ⁶⁷C, was 41 hr. Serum clearance of ⁶⁷C was faster (27.41 hr) than that of ¹²⁵I(38.33 hr). Mean tumor uptake of the ⁶⁷C-labeled compound (0.0133 %ID/g) exceeded that of ¹²⁵I(0.0095 %ID/g), and tumor-to-blood ratios were higher for ⁶⁷C than for ¹²⁵I, with averages of 6.07 and 2.41, respectively. The average ⁶⁷C/¹²⁵I ratio was 1.9 for tumor uptake, 0.7 for blood and 2.6 for tumor-to-blood ratios. Nonspecific liver uptake of ⁶⁷C as calculated from whole-body scans was high in four patients, up to 25% of residual whole-body activity at 48 hr, but did not increase with time. We also observed some nonspecific bowel activity, as well as moderate to high uptake in benign polyps. Conclusion: Copper-67-labeled MAb35 is more favorable than its radioiodine-labeled counterpart for RIT of colorectal carcinoma due to higher tumor-to-blood ratios, but the problem of nonspecific liver and bowel uptake must first be overcome. The absolute accumulation of activity in tumor remains low, however, so the probability of cure with this compound alone is questionable. The use of ⁶⁷C as one component of a multimodality adjuvant treatment seems to remain the most appropriate application for RIT.

Key Words: anti-CEA • monoclonal antibodies • radioimmunotherapy • copper-67 • iodine-125 • colorectal carcinoma

This article has been cited by other articles:

				J. Grunberg, I. Novak-Hofer, M. Honer, K. Zimmermann, K. Knogler, P. Blauenstein, S. Ametamey, H. R. Maecke, and P. A. Schubiger In vivo Evaluation of 177Lu- and 67/64Cu-Labeled Recombinant Fragments of Antibody chCE7 for Radioimmunotherapy and PET Imaging of L1-CAM-Positive Tumors Clin. Cancer Res., July 15, 2005; 11(14): 5112 - 5120. [Abstract] [Full Text] [PDF]

				G. L. DeNardo, D. L. Kukis, S. Shen, D. A. DeNardo, C. F. Meares, and S. J. DeNardo 67Cu- versus131I-Labeled Lym-1 Antibody: Comparative Pharmacokinetics and Dosimetry in Patients with Non-Hodgkin's Lymphoma Clin. Cancer Res., March 1, 1999; 5(3): 533 - 541. [Abstract] [Full Text] [PDF]