Correspondence

¹¹C-Labeled Methionine and Evaluation of Malignant Pleural Mesothelioma

N Engl J Med 2007; 357:1982-1984November 8, 2007

Article

To the Editor:

Assessing responses to treatment on the basis of computed tomographic (CT) measurements in patients with malignant pleural mesothelioma is challenging because of the pattern of growth of this disease.1 There is evidence that ¹⁸F-fluorodeoxyglucose positron-emission tomography (FDG-PET) can detect the response of a tumor to chemotherapy or chemoradiotherapy early in the course of treatment.2 A few pilot studies have explored the role of FDG-PET in patients with malignant pleural mesothelioma who were treated with chemotherapy, with promising results.3 Nevertheless, the usefulness of FDG is limited by its uptake in inflammatory cells such as macrophages and activated lymphocytes, which can cause false positive findings in patients treated with palliative talc pleurodesis. False negative results in early epithelial malignant pleural mesothelioma have been reported.4

Measurement of the uptake of ¹¹C-labeled methionine has been useful for metabolic imaging of brain tumors.5 This uptake is related to the overexpression of the LAT-1 amino acid transporter. After administration, the tracer is incorporated into proteins, and imaging reflects the increased metabolic activity of the tumor.

We report the case of a 63-year-old woman with a histologically confirmed diagnosis of epithelial malignant mesothelioma of the left pleura. The results of a pretreatment FDG-PET CT study (Figure 1AFigure 1Axial CT and PET CT Images of the Chest.) were negative. She underwent a ¹¹C-labeled methionine PET CT study 2 weeks later. It showed diffuse uptake in the left anterior mediastinal pleura and two foci of pleural uptake in the para-aortic and left bronchial regions (Figure 1B). The patient received chemotherapy with pemetrexed (an inhibitor of folate synthesis) plus carboplatin. After two courses of therapy, a second ¹¹C-labeled methionine PET CT study showed very little uptake of the radiopharmaceutical agent (Figure 1C).

The detectable ¹¹C-labeled methionine uptake in a patient with malignant pleural mesothelioma who had an otherwise negative FDG-PET CT evaluation and the early reduction of this uptake during treatment suggest that metabolic imaging with ¹¹C-labeled methionine could be an alternative for the metabolic measurement of malignant pleural mesothelioma in patients with negative findings on FDG-PET scans.

Giovanni L. Ceresoli, M.D.
Arturo Chiti, M.D.
Armando Santoro, M.D.
Istituto Clinico Humanitas, 20089 Milan, Italy
giovanni_luca.ceresoli@humanitas.it

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Citing Articles (3)

Citing Articles

1. 1

   ROSLYN FRANCIS, TATIANA SEGARD, LAURENCE MORANDEAU. (2011) Novel molecular imaging in lung and pleural diseases. Respirology 16:8, 1173-1188
   CrossRef

2. 2

   Victor H. Gerbaudo, Sharyn I. Katz, Anna K. Nowak, Roslyn J. Francis. (2011) Multimodality Imaging Review of Malignant Pleural Mesothelioma Diagnosis and Staging. PET Clinics 6:3, 275-297
   CrossRef

3. 3

   Georgios T. STATHOPOULOS. (2011) Translational advances in pleural malignancies. Respirology 16:1, 53-63
   CrossRef