Abstract
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Objectives: Malignant peripheral nerve sheath tumors (MPNSTs) arise from peripheral nerve or extra-neural soft tissue which exhibits high metastatic potential and poor prognosis. They can arise de-novo or through malignant transformation in Neurofibromatosis (NF-1). The purpose of our study is to evaluate role of FDG PET/CT in prognostication of MPNSTs.
Methods: We have performed a retrospective analysis in patients of MPNSTs who underwent 18F-FDG PET/CT imaging for staging as well as restaging. Standardised uptake values (SUVmax) were measured for each primary/recurrent lesion. Texture analysis parameters which were calculated using “radiomics” package (version 0.1.3) revealed first and second order statistics. PET/CT quantitative parameters were compared between the two groups, which were divided based on presence and absence of event (recurrence/progression). Student T-test test was applied for comparative analyses using the SPSS software package (version 23.0; IBM), with a significance level of 0.05.
Results: Thirty patients (17 males, 13 females; mean age 42.7 ±15.66 years) were enrolled in the study, 18F-FDG PET/CT was done for staging in 10 patients and restaging in 20 patients. Textural analysis showed more heterogeneity in lesions in high risk group with presence of recurrence or progression. SUV parameters and first order statistics showed no significant difference. Second order statistics revealed significantly higher contrast (p=0.041), dissimilarity (p=0.006) and entropy (p=0.048) in high risk group. However, homogeneity was higher in low risk group patients with no event (p=0.002).
Conclusions: 18F-FDG PET/CT can be used for prognostication in MPNSTs, as more heterogeneity was observed in lesions in patients with recurrence or progression, however further studies are warranted to validate the results.