This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Kaira, K. Articles by Mori, M. Search for Related Content PubMed PubMed Citation Articles by Kaira, K. Articles by Mori, M.

Diagnostic Usefulness of Fluorine–18-–Methyltyrosine Positron Emission Tomography in Combination With ¹⁸F-Fluorodeoxyglucose in Sarcoidosis Patients^*

^* From the Department of Medicine and Molecular Science (Drs. Kaira, Yanagitani, Sunaga, Hisada, Ishizuka, and Mori), Department of Diagnostic Radiology and Nuclear Medicine (Drs. Oriuchi and Endo), and Thoracic and Visceral Organ Surgery (Dr. Otani), Gunma University Graduate School of Medicine, Showa-machi, Maebashi, Japan.

Correspondence to: Kyoichi Kaira, MD, Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Showa-machi, Maebashi, Gunma 371-8511, Japan; e-mail: kkaira1970{at}yahoo.co.jp

Abstract

Objectives: L-[3-¹⁸F]-–methyltyrosine (¹⁸F-FMT) is an amino-acid tracer for positron emission tomography (PET) and is used for tumor detection because malignant tumor cells accumulate ¹⁸F-FMT based on the increased expression of an amino-acid transporter. This study was conducted to investigate the usefulness of ¹⁸F-FMT PET in combination with fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) PET for the diagnosis of sarcoidosis in patients with suspected malignancy.

Setting: Twenty-four sarcoidosis patients with suspected malignancy underwent ¹⁸F-FDG and ¹⁸F-FMT PET. The study included 17 patients with extrapulmonary manifestation mimicking malignant disease (13 patients with systemic lymphadenopathy, 3 of them with concomitant hepatosplenic processes; 3 patients with hepatosplenic processes without concomitant lymphadenopathy; and 1 patient with multiple bone lesions), 3 patients with occurrence of bilateral hilar lymphadenopathy in cancer patients, and 4 patients with multiple nodules mimicking pulmonary metastasis.

Results: All patients showed increased uptake of ¹⁸F-FDG and no increase in the accumulation of ¹⁸F-FMT in their lymphadenopathy. Standardized uptake values (SUVs) of ¹⁸F-FDG and ¹⁸F-FMT were 5.01 ± 2.15 and 0.77 ± 0.24, respectively (mean ± SD). All extranodal lesions such as liver, spleen, and bone were visually positive on ¹⁸F-FDG PET and negative on ¹⁸F-FMT PET. No neoplasm was confirmed in all patients. In a control group of patients with lung cancer, SUVs for ¹⁸F-FDG and ¹⁸F-FMT were 6.34 ± 2.52 and 1.54 ± 0.82, respectively.

Conclusion: The uptake of ¹⁸F-FDG was positive in the sarcoid lesions, and therefore ¹⁸F-FDG PET could not differentiate sarcoidosis from malignant disease. Use of ¹⁸F-FMT PET in combination with ¹⁸F-FDG PET may be the effective method to distinguish sarcoidosis from malignancy.

Key Words: fluorine–18-–methyltyrosine • fluorodeoxyglucose • lung cancer • lymphadenopathy • malignancy • positron emission tomography • sarcoidosis

This article has been cited by other articles:

				A. S. Teirstein, J. Machac, O. Almeida, P. Lu, M. L. Padilla, and M. C. Iannuzzi Results of 188 Whole-Body Fluorodeoxyglucose Positron Emission Tomography Scans in 137 Patients With Sarcoidosis Chest, December 1, 2007; 132(6): 1949 - 1953. [Abstract] [Full Text] [PDF]