RADIOLOGICAL SURVEILLANCE AFTER RESECTION OF LOW GRADE DYSEMBRYOPLASTIC NEUROEPITHELIAL TUMOUR AND GANGLIOGLIOMA: HOW OFTEN AND FOR HOW LONG?

Abstract

Abstract AIMS Prolonged follow-up with imaging has costs both financial and psychological. We sought to review clinical and radiological follow-up for operated dysembryoplastic neuroepithelial tumour (DNET) and ganglioglioma in our unit. METHOD Retrospective review of patients diagnosed with WHO grade 1 DNET or ganglioglioma identified from our histopathology database over the last 20 years. RESULTS 44 patients were identified (DNET n=23, ganglioglioma n=21). Mean age at first surgery was 27.2 and 22.3 respectively. The median length of follow-up was 3.45 (0.84-13.9) years for DNET, and 5.03 (0.4-12.6) years for ganglioglioma. The majority of the patients had epilepsy (39/44, 88.6%) prior to surgery. Patients with DNET had 0.58 postoperative scans per year, whilst those with ganglioglioma had 1.17 scans per year. 11 (47.8%) DNET and 9 (42.9%) ganglioglioma patients had residual tumour after first surgery. None of the DNET patients had radiological change during follow-up. 9 (43%) patients with ganglioglioma had radiological change noted at least once during follow-up. 3 (13%) patients with DNET and 4 (19%) with ganglioglioma had further surgery for ongoing seizures due to residual tumour, but not for radiological progression. CONCLUSIONS Radiological change following tumour resection did not occur for DNET whereas it was more common for gangliogliomas. A reduction in postoperative imaging in our practice could be considered for operated low grade DNET and ganglioglioma, given that for all patients the indication for reoperation was seizures rather than tumour progression.