FDG-Avid Intrathecal Inflammation Following Administration of Intrathecal Methotrexate.
Intrathecal methotrexate is a standard option for central nervous system-directed therapy in patients with stage III and IV diffuse large B-cell lymphoma. We present a case of a 50-year-old man with stage IV diffuse large B-cell lymphoma with widespread lymphomatous involvement including the central nervous system, who received 7 doses of intrathecal methotrexate via Ommaya catheter. Posttherapy F-FDG-PET/CT imaging demonstrated diffuse, intense intrathecal FDG avidity, without correlative findings on MR spinal imaging. FDG avidity resolved on follow-up. These PET/CT findings are most consistent with methotrexate-induced thecal inflammation, which needs to be distinguished from intrathecal malignancy.
From the Department of Radiology, Memorial Sloan Kettering Cancer Center; and Department of Radiology, Weill Cornell Medical College, New York, NY.
Molly P
MP
Hogan
Joseph
J
Osborne
Gary A
GA
Ulaner
D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects*; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy; D008297:Male; D008727:Methotrexate / Q000009:adverse effects*; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D013122:Spinal Diseases / Q000000981:diagnostic imaging*
D000964:Antimetabolites, Antineoplastic; D008727:Methotrexate