Functional outcome after repeat surgery of tumor progression or treatment-associated changes in high-grade glioma: Clinical and radiological predictors

Abstract Background Recurrence of high-grade glioma after primary treatment is inevitable. New contrast-enhancing lesions on follow-up MRI may indicate tumor progression, treatment-associated changes (TAC), or both. A repeated surgical procedure, either biopsy or resection, provides diagnostic clarity and therapeutic benefit, but carries risks. In the patient-specific decision to operate, current literature offers limited guidance on which patients may benefit. This study aimed to describe functional outcomes after repeat surgery of previously irradiated glioma, and to identify predictors of functional deterioration. Methods Single-center retrospective cohort study. Adults with diffuse glioma who underwent first-line radiotherapy and subsequent repeat surgery (biopsy or resection) for suspected high-grade radiological progression were included. Lesions were histologically classified as progression, TAC, or both. The primary endpoint was functional outcome 30 days postoperatively, expressed as decline of Karnofsky Performance Status (KPS). Logistic regression identified predictors of KPS decline. Survival was assessed with Kaplan-Meier and Cox regression. Results Of 166 patients, 37 (22.3%) experienced a KPS deterioration, 127 (76.5%) remained stable, and 2 (1.2%) improved. Rates of functional deterioration were similar after biopsies and resections. Preoperative steroid usage (odds ratio = 2.73, 95% confidence interval = 1.09-6.79, P = .031) was associated with KPS deterioration. Histological diagnosis was not associated with functional outcome (χ2, P = .361). Patients with deterioration had shorter median survival (4 vs 11 months, P < .001). Conclusions In this cohort, 22.3% of patients experienced functional decline 30 days after a repeat surgery (biopsy or resection). Preoperative steroid usage predicted deterioration. These findings may provide clinical guidance in identifying which patients will benefit from repeat surgery.