核医学と放射線治療

FDG PET/CT in Malignant Transformation of Peripheral Nerve Sheath Tumor in Known Case NF-1: A Case Report

Abstract

Sibu Jacob B, Kiran Kumar JK, Alok Dixit, Nirav Thaker R and Inder Talwar

Neurofibromatosis type 1 is an autosomal dominant disease. The worldwide estimated prevalence is 1 in 3000. Germline mutation in the NF1 tumor suppressor gene on long arm of chromosome 17 appears to be the causative factor. Patients with plexiformneurofibromasshows higher risk of transformation into malignant pathology also referred to as malignant peripheral nerve sheath tumors (MPNST). The relative lifetime risk is expected to be around 8-13%. Histology remains gold standard for diagnosing MPNST, but requires complete excision which is technically difficult. As a combined metabolic-anatomic method, PET/CT using the radiotracer 18F-FDG allows different parameters oftumours to be analysed simultaneously. It also helps to avoid unnecessary surgeries in benign cases. Hybrid PET/MRI will play a crucial role in future for evaluating nerve sheath tumours in NF1 patients by combining the pros of both the modalities.