Introduction: Despite radical resection and adjuvant therapy, progression and/or malignant transformation of insular gliomas is common. This study reports on repeat resection of insular gliomas for progression and/or malignant transformation at our institution.
Methods: All adult patients undergoing repeat resection of insular gliomas for progression and/or malignant transformation from 1997 to 2013 were included. Clinical and outcome data was collected. Gliomas were classified by location using a modified classification system and one independent scientist performed all volumetric analyses.
Results: Nineteen patients underwent repeat insular glioma resection for progression and/or malignant transformation. Of the 9 (47%) patients that underwent a transsylvian approach, the approach for the previous surgery was transsylvian in 4 patients and transcortical in 5 patients. Of the 10 (53%) patients that underwent a transcortical approach, the surgical approach for the previous surgery was transsylvian in 5 patients and transcortical in 5 patients. The median extent of resection (EOR) was 70%, with an EOR of =70% achieved in 58% of cases. EOR was lower for gliomas with a posterior insular component and/or medial extension. Permanent neurologic deficits occurred in two (10.5%) patients, both of which had posterior-medial gliomas. The median overall survival after repeat resection was 5.8 years for grade II gliomas, 3.8 years for grade III gliomas, and 10.2 months for grade IV gliomas. The median progression-free survival after repeat resection was 5.1 years for grade II gliomas, 1.5 years for grade III gliomas, and 0.6 years for grade IV gliomas.
Conclusions: While technically challenging, repeat insular glioma resection after previous resection and adjuvant therapy can be performed with low rates of morbidity and acceptable EOR, in select patients. Classification of tumors by location provides useful information regarding the achievable EOR and possible neurologic deficits.
Patient Care: Defines the role and outcomes of repeat insular glioma resections. Describes a clinically and surgically useful classification system. First report to define the survival of patients after repeat insular glioma resection for progression and/or malignant transformation.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of repeat insular glioma resection in select patients.