Usefulness of 18F-FDG PET/CT in the detection of neurolymphomatosis

Abstract

Purpose: Neurolymphomatosis (NL) is an uncommon complication of lymphoma and leukemia. Few data have been reported regarding the utilization of fluorine-18 fluorodeoxyglucose PET/computed tomography (F-FDG PET/CT) in this disease. The aim of this study was to assess the role of F-FDG PET/CT in the diagnosis of NL.

Patients and methods: Eight patients who suffered from NL due to lymphoma or leukemia were studied. The diagnosis of NL lesions was established according to ;the combination of neurologic symptoms, and imaging techniques including MRI and PET/CT, and/or analysis of cerebrospinal fluid, pathology, and clinical follow-up.

Results: Eight patients with lymphoma or leukemia were diagnosed with NL during or after treatment. F-FDG PET/CT was positive in all eight patients. A total of 19 NL lesions were detected by F-FDG PET/CT. Morphological abnormality was seen in seven of 19 lesions on the syn-modality CT. However, all lesions were F-FDG avid with a maximum standardized uptake value of 6.42 ± 3.02, and presented with linear and nodular hypermetabolic patterns. There was a significant difference in the detection of NL lesions between PET and syn-modality CT [100% (19/19) vs. 36.8% (7/19), χ=14.74, P<0.001]. The NL lesions were located predominantly in the nerve root of the thoracic and lumbar segments (63.2%). In four patients, PET/CT was performed after treatment and was useful for assessing the treatment response.

Conclusion: F-FDG PET/CT is a sensitive imaging modality for the detection of NL lesions. Further research involving more patients is needed to confirm our findings.