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Pet/Ct Findings Of Intramedullary And Intradural Extramedullary Spinal Tumors Using Fluorine-18-Fluorodeoxyglucose: An Aide To Diagnosis And Treatment Planning 2014

Category General Spine J. Diego Lozano Natalya Nagornaya Efrat Saraf-Lavi M. Judith Donovan Post Purpose We report the uptake of the glucose analog Fluorine-18 Fluorodeoxyglucose (18F-FDG) of intramedullary and intradural extramedullary spinal tumors and discuss the diagnostic utility of these findings. Materials & Methods 18F-FDG Positron Emission Tomography/Computed Tomography (PET/CT) and contrast enhanced magnetic resonance imaging (MRI) was performed in 4 patients with intramedullary tumors and in 1 patient with an intradural extramedullary tumor of the spine. The maximum standardized uptake value (SUVmax) of the different tumors was measured and compared with the findings of the surgical pathology and/or clinical diagnosis. 18F-FDG PET/CT and contrast enhanced MRI was performed in a patient with sarcoidosis with a focal lesion in his cervical cord. This case was included as an example of non tumoral condition with a focal cord lesion on MRI. Results Diagnosis of the intramedullary tumors was obtained via surgical pathology in 2 of the 4 cases. The first case corresponded to a WHO grade II/IV astrocytoma, SUVmax 8.26, centered at the conus (Fig. 1, 2). The second case corresponded to a thoracic cord ependymoma, SUVmax 4.48 (Fig. 3, 4). The third and fourth cases did not have surgical pathology of the spinal lesion per se; rather, these patients had diffuse lymphoma and biopsies were obtained from extra spinal lesions more amenable to biopsy. The third case then corresponded to a focal thoracic cord lesion, SUVmax 8.12, in a patient with HIV/AIDS and widespread lymphoma. The fourth case corresponded to a focal thoracic cord lesion, SUVmax 6.88, in a patient with diffuse large B-cell lymphoma. Pathology of the intradural extramedullary tumor consisted of metastatic pituitary adenocarcinoma which had leptomeningeal spread to the lumbar spinal canal, SUVmax 8.02. In contradistinction, the patient with sarcoidosis and a focal lesion in the cervical cord demonstrated slightly increased hypermetabolic activity, SUVmax 2.65, when compared to the SUVmax of the previously mentioned spinal tumors. Conclusion There was significant accumulation of 18-F-FDG by all of the 4 intramedullary tumors presented here with the highest SUVmax seen in the astrocytoma of the conus. The intradural extramedullary tumor also demonstrated significantly increased uptake of the radiotracer. Comparatively, the patient with sarcoidosis did not demonstrate significant radiotracer uptake of the lesion in the cervical cord. A correlation between highly aggressive tumor and markedly increased hypermetabolic activity is suggested. PET/CT could prove valuable in aiding in the diagnosis, prognosis, and surgical planning in those patients with spinal lesions and markedly elevated focal 18-F-FDG uptake as measured by SUVmax. 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