cis-4-[18F]-Fluoro-l-proline fails to detect peripheral tumors in humans

Stoffels, Gabriele; Pauleit, Dirk; Haas, Rainer; Kobbe, Guido; Salber, Dagmar; Hamacher, Kurt; Coenen, Heinz H.; Langen, Karl-Josef

doi:10.1016/j.nucmedbio.2008.08.003

« Previous Next »Nuclear Medicine and Biology
Volume 35, Issue 8 , Pages 895-900, November 2008

cis-4-[¹⁸F]-Fluoro-l-proline fails to detect peripheral tumors in humans

Gabriele Stoffels
- Institute of Neuroscience and Biophysics-Medicine, Research Centre Jülich, D-52425 Jülich, FRG
Dirk Pauleit
- Institute of Neuroscience and Biophysics-Medicine, Research Centre Jülich, D-52425 Jülich, FRG
Rainer Haas
- Department of Oncology, Hematology, and Clinical Immunology, Heinrich-Heine-University Düsseldorf, FRG
Guido Kobbe
- Department of Oncology, Hematology, and Clinical Immunology, Heinrich-Heine-University Düsseldorf, FRG
Dagmar Salber
- C. & O. Vogt Institute of Brain Research, Heinrich-Heine-University Düsseldorf, FRG
Kurt Hamacher
- Institute of Neuroscience and Biophysics - Nuclear Chemistry, Research Centre Jülich, Jülich, FRG
Heinz H. Coenen
- Institute of Neuroscience and Biophysics - Nuclear Chemistry, Research Centre Jülich, Jülich, FRG
Karl-Josef Langen
- Institute of Neuroscience and Biophysics-Medicine, Research Centre Jülich, D-52425 Jülich, FRG
- Corresponding author. Fax: +49 2461 612820.

Received 30 May 2008; received in revised form 11 August 2008; accepted 26 August 2008.

Abstract

System A amino acid transport is increased in transformed and malignant cells. The amino acid 4-cis[¹⁸F]fluoro-l-proline (cis-[¹⁸F]FPro) has been shown to be a substrate of the System A amino acid carrier. In this pilot study, we investigated the diagnostic potential of cis-[¹⁸F]FPro in patients with various tumors in comparison with [¹⁸F]fluorodeoxyglucose-positron emission tomography (FDG-PET).

Methods

Eight patients (seven females, one male, age range 43–77 years) with large primary, recurrent or metastatic tumors of different histologies were included in this study. One patient had a recurrent non-Hodgkin lymphoma; two patients, metastatic colon or rectal cancer; one, a metastatic endometrial cancer; one, a multiple myeloma; one, an Ewing sarcoma; one, a metastatic breast cancer and one, a gastrointestinal stromal tumor. PET scans of the trunk were acquired at 1 h after intravenous injection of 400 MBq cis-[¹⁸F]FPro and compared to PET scans with [¹⁸F]FDG.

Results

None of the tumors or metastatic lesions in this series of patients demonstrated relevant uptake of cis-[¹⁸F]FPro. In contrast, all tumors with exception of the multiple myeloma showed an intensive uptake of [¹⁸F]FDG. The mean standardized uptake value of cis-[¹⁸F]FPro in the tumor or metastases was significantly lower than that of [¹⁸F]FDG uptake (1.7±0.6 vs. 5.7±3.0; n=8; P<.01).

Conclusion

Although other System A-specific tracers have shown relevant tumor uptake, cis-[¹⁸F]FPro fails to detect most types of human tumors. Based on these results, we cannot recommend a further evaluation of this tracer as a tumor-seeking agent.

Keywords: cis-4-[¹⁸F]fluoro-l-proline, Radiolabelled amino acids, Peripheral tumors, PET