The value of 18F-FDG PET/CT in the diagnosis of secondary malignant peripheral nerve lesion

Objective: To investigate the characteristics and diagnostic value of 18F-fluorodeoxyglucose (FDG) PET/CT in patients with secondary malignant peripheral nerve lesions. Methods: 18F-FDG PET/CT studies of 8 cases of secondary malignant peripheral nerve lesions confirmed by histopathology or follow-up were analyzed retrospectively. The maximum standardized uptake value (SUVmax) of infiltrating peripheral nerves and contralateral normal peripheral nerves was measured and compared with their morphological appearances on CT. Paired student t-test was performed by SPSS 10.0. Results: Twelve secondary malignant peripheral nerve lesions with high 18F-FDG metabolism were found in 8 cases. On PET imaging, the lesions distributed along the neurovascular tissues or intervertebral foramina with appearances resembling those of fibre bundles, radices or nodes on PET but no density differences with the surrounding soft tissue or fat planes on CT. The SUVmax was 6.86 ± 3.87. The contralateral normal peripheral nerves showed no abnormal 18F-FDG uptake with a SUVmax of 1.10 ±0.46, which was significantly different from that of the secondary malignant peripheral nerve lesions (t = 9.231, P<0.001). Conclusion: 18F-FDG PET/CT may be useful in locating the secondary malignant peripheral nerve lesions and in assessing its regional infiltration. (authors)