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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Capello, A. Articles by de Jong, M. Search for Related Content PubMed PubMed Citation Articles by Capello, A. Articles by de Jong, M.

Peptide Receptor Radionuclide Therapy In Vitro Using [¹¹¹In-DTPA⁰]Octreotide

Department of Nuclear Medicine, Erasmus Medical Center, Rotterdam, The Netherlands

Peptide receptor radionuclide therapy (PRRT) using [¹¹¹In-DTPA⁰]octreotide (where DTPA is diethylenetriaminepentaacetic acid) is feasible because, besides -radiation, ¹¹¹In emits both therapeutic Auger and internal conversion electrons having a tissue penetration of 0.02–10 and 200–500 µm, respectively. The aim of this study was to investigate the therapeutic effects of [¹¹¹In-DTPA⁰]octreotide in a single-cell model including the effects of incubation time, radiation dose, and specific activity of [¹¹¹In-DTPA⁰]octreotide. Finally, we discriminated between the effects of the Auger electrons and internal conversion electrons in PRRT. Methods: An in vitro, colony-forming assay to study cell survival after PRRT using the sst subtype 2–positive rat pancreatic tumor cell line CA20948 was developed. Results: In this in vitro system [¹¹¹In-DTPA⁰]octreotide can control tumor growth to 0% survival, and the effects were dependent on incubation time, radiation dose, and specific activity used. Similar concentrations of ¹¹¹In-DTPA, which is not internalized into sst-positive tumor cells like [¹¹¹In-DTPA⁰]octreotide, did not influence tumor survival. Excess unlabeled octreotide (10^-6 mol/L) could decrease tumor cell survival to 60% of control; the addition of radiolabeled peptide ([¹¹¹In-DTPA⁰]octreotide [10^-9 mol/L] + 10^-6 mol/L octreotide) did not further decrease survival. Conclusion: These in vitro studies show that the therapeutic effect of ¹¹¹In is dependent on internalization, enabling the Auger electrons with their very short particle range to reach the nucleus. Our results also indicate that the PRRT effects were receptor mediated.

Key Words: [¹¹¹In-diethylenetriaminepentaacetic acid(0)]octreotide • Auger electrons • peptide receptor radionuclide therapy

This article has been cited by other articles:

				M. Cremonesi, M. Ferrari, L. Bodei, G. Tosi, and G. Paganelli Dosimetry in Peptide Radionuclide Receptor Therapy: A Review J. Nucl. Med., September 1, 2006; 47(9): 1467 - 1475. [Abstract] [Full Text] [PDF]

				A. Capello, E. P. Krenning, B. F. Bernard, W. A.P. Breeman, J. L. Erion, and M. de Jong Anticancer Activity of Targeted Proapoptotic Peptides J. Nucl. Med., January 1, 2006; 47(1): 122 - 129. [Abstract] [Full Text] [PDF]

				C. A. Boswell and M. W. Brechbiel Auger Electrons: Lethal, Low Energy, and Coming Soon to a Tumor Cell Nucleus Near You J. Nucl. Med., December 1, 2005; 46(12): 1946 - 1947. [Full Text] [PDF]

				M. Ginj, K. Hinni, S. Tschumi, S. Schulz, and H. R. Maecke Trifunctional Somatostatin-Based Derivatives Designed for Targeted Radiotherapy Using Auger Electron Emitters J. Nucl. Med., December 1, 2005; 46(12): 2097 - 2103. [Abstract] [Full Text] [PDF]

				A. Capello, E. P. Krenning, B. F. Bernard, W. A.P. Breeman, M. P. van Hagen, and M. de Jong Increased Cell Death After Therapy with an Arg-Gly-Asp-Linked Somatostatin Analog J. Nucl. Med., October 1, 2004; 45(10): 1716 - 1720. [Abstract] [Full Text] [PDF]