Joint Program in Nuclear Medicine
PET Imaging of Pleural Mesothelioma
Hossein Jadvar, MD, PhD
Alan J. Fischman, MD, PhD
March 16, 1999
A 67 year old male presented with cough and dyspnea. A chest radiograph
(not showm) revealed moderately large left pleural effusion. A chest MRI
(not shown) was also performed that showed contrast enhancement of the
left pleura. FDG PET imaging and thoracoscopy were then performed.
Coronal FDG PET: Attenuation-corrected imaging 45 minutes after intravenous
injection of 17 mCi FDG.
The series of coronal PET images, from anterior
(top left) to posterior (bottom right), show asymmetric abnormal hypermetabolism
surrounding the left hemithorax highly suspicious for malignancy.
The differential diagnosis for pleural disease is as follows:
Serofibrinous (TB, pneumonia, infarct, rheumatoid arthritis, uremia)
Hemorrhagic (bleeding dyscrasia, neoplasm)
Metastatic (lung cancer, breast cancer, ovarian cancer)
Primary (benign and malignant mesothelioma)
The patient underwent thoracoscopy with pleural biopsy followed by left
extrapleural pneumonectomy. Both the biopsy and the surgical specimen demonstrated
extensive malignant mesothelioma involving both parietal and visceral pleura.
Malignant mesothelioma is an uncommon tumor of mesothelial cells in the
pleura or peritoneum. It is associated with previous occupational exposure
to asbestos in 90% of cases with a lifetime risk of approximately 10% in
heavily exposed individuals at a long latent period of 25-45 years. Pleural
mesotheliomas spread diffusely over the lung surface, may invade the pulmonary
parenchyma, and can metastasize. Prognosis is very poor and mean survival
is usually less than two years after the initial diagnosis (1). Diagnosis
is difficult with CT, which often cannot differentiate between benign pleural
thickening and malignant mesothelioma. Thoracentesis and CT-guided biopsy
are invasive and may be inconclusive. Benard et al. evaluated the use of
FDG PET in the evaluation of malignant mesothelioma in 28 patients (2).
They determined that a specific uptake value (SUV) cutoff of 2.0 differentiates
between malignant and benign pleural disease with a sensitivity of 91%
and a specificity of 100% . In another study by the same group, the level
of metabolic activity (SUV > 3.5) was correlated inversely with survival
(3). Lowe et al. found a SUV cutoff of 2.5 to be useful in separating benign
from malignant pleural abnormality (4). However, two patients with active
infectious pleuritis also demonstrated increased FDG uptake. Bury et al.
reported similar findings for the value of PET in assessing patients with
pleural disease (5).
1. Robins SL, Cotran RS, Kumar V. Pathologic basis of disease. WB Saunders
2. Benard F, Sterman D, Smith RJ, et al. Metabolic imaging of malignant
pleural mesothelioma with fluorodeoxyglucose positron emission tomography.
Chest 1998; 114(3): 713-722.
3. Benard F, Alavi A, Sterman D, et al. The prognostic value of FDG-PET
imaging in malignant pleural mesothelioma. J Nucl Med 1998; 39(5): 81P.
4. Lowe VJ, Patz E, Harris L, et al. FDG-PET evaluation of pleural abnormalities.
J Nucl Med 1994; 35: 228P. (Abstr.)
5. Bury T, Paulus P, Weber T, et al. Evaluation of pleural diseases
by FDG-PET imaging: preliminary report. Eur J Nucl Med 1996; 23: 1186.
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