Devoted to diagnostic and interventional spine imaging and therapeutics


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. Further investigation with a larger number of patients is required. References 1. Alavi A, Kramer E, Wegener W, Alavi J. Magnetic resonance and fluorine-18 deoxyglucose imaging in the investigation of a spinal cord tumor. Journal of nuclear medicine : official publication, Society of Nuclear Medicine. Mar 1990;31(3):360-364. 2. Gilardi L, Vassallo S, Colandrea M, Travaini LL, Paganelli G. Intramedullary spinal cord metastases from breast cancer: detection with (18)F-FDG PET/CT. Ecancermedicalscience. 2013;7:329. 3. Imani F, Boada FE, Lieberman FS, Davis DK, Deeb EL, Mountz JM. Comparison of proton magnetic resonance spectroscopy with fluorine-18 2-fluoro-deoxyglucose positron emission tomography for assessment of brain tumor progression. Journal of neuroimaging : official journal of the American Society of Neuroimaging. Apr 2012;22(2):184-190. 4. Kawase Y, Yamamoto Y, Kameyama R, Kawai N, Kudomi N, Nishiyama Y. Comparison of 11C-methionine PET and 18F-FDG PET in patients with primary central nervous system lymphoma. Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging. Dec 2011;13(6):1284-1289. 5. Meltzer CC, Townsend DW, Kottapally S, Jadali F. FDG imaging of spinal cord primitive neuroectodermal tumor. Journal of nuclear medicine : official publication, Society of Nuclear Medicine. Jul 1998;39(7):1207-1209. 6. Metser U, Lerman H, Blank A, Lievshitz G, Bokstein F, Even-Sapir E. Malignant involvement of the spine: assessment by 18F-FDG PET/CT. Journal of nuclear medicine : official publication, Society of Nuclear Medicine. Feb 2004;45(2):279-284. 7. Mettler FA, Jr., Huda W, Yoshizumi TT, Mahesh M. Effective doses in radiology and diagnostic nuclear medicine: a catalog. Radiology. Jul 2008;248(1):254-263. 8. Mostardi PM, Diehn FE, Rykken JB, et al. Intramedullary Spinal Cord Metastases: Visibility on PET and Correlation with MRI Features. AJNR. American journal of neuroradiology. Jul 25 2013. 9. Prabhakar HB, Rabinowitz CB, Gibbons FK, O'Donnell WJ, Shepard JA, Aquino SL. Imaging features of sarcoidosis on MDCT, FDG PET, and PET/CT. AJR. American journal of roentgenology. Mar 2008;190(3 Suppl):S1-6. 10. Tomura N, Ito Y, Matsuoka H, et al. PET findings of intramedullary tumors of the spinal cord using [18F] FDG and [11C] methionine. AJNR. American journal of neuroradiology. Jun-Jul 2013;34(6):1278-1283. 11. Wilmshurst JM, Barrington SF, Pritchard D, et al. Positron emission tomography in imaging spinal cord tumors. Journal of child neurology. Jul 2000;15(7):465-472.