Surgical management of periventricular glioma: decision-making and preoperative assessment of resectability

Objective. Periventricular gliomas (PVG) are deep-seated tumors with wide invasion into cerebral core structures accompanied by high rates of postoperative deterioration and early relapse. The purpose of this study was to define the preoperative neuroimaging signs as the factors determining the early postoperative outcome in patients with high-grade PVG. Materials and methods. The clinical records of 132 (50 females and 82 males) consecutive patients with a mean age 45.9 years (range 21–69) undergoing image-guided surgery for PVG at a single academic institution were retrospectively analyzed. There were 52 (39.4 %) WHO grade III gliomas, and 80 (60.6 %) of patients had WHO grade IV gliomas. Results. Postoperative median KPS score significantly raised from 67.4 to 82.0, as well as a number of patients with the KPS score ≥ 70: from 18 (13.6 %) to 109 (82.6 %) with p<0.01. The multivariate regression analysis revealed that poor postoperative functional status was associated with basal ganglia involvement (OR 2.75, 95% CI 0.93–8.09, p = 0.07), the higher EOR grade (OR 3.30, 95% CI 1.15–9.43, p = 0.03), and hydrocephalus (OR 5.08, 95% CI 1.49–17.35, p = 0.09). Total/subtotal resection was carried out in 84 (63.6 %) cases; in 48 (36.4 %) cases, the partial resection was performed. The multivariate logistic regression analysis revealed that three factors decreased the likelihood of total/subtotal resection in PVG: basal ganglia invasion (OR 0.18, 95% CI 0.06–0.55, p< 0.01), minor extraventricular part (OR 0.40, 95% CI 0.17–0.94, p = 0.04), and contralateral side extension (OR 0.38, 95% CI 0.16–0.92, p = 0.03). In contrast, the presence of tumor-associated cyst (OR 3,73, 95% CI 1.32–10.54, p = 0.01) increased odds of total/subtotal resection. The four-tear grading system of PVG integrating statistically identified factors of total/subtotal resection and risks of postoperative neurological deterioration was developed. The Kaplan-Meier analysis showed that overall median survival was 17.7 ± 1.9 months for patients with high-grade PVG. The survival analysis using Cox regression model revealed that age over 45 years (HR 1.77, 95% CI 1.06–2.99; p = 0.03) and higher tumor WHO grade (HR 2.24, 95% CI 1.27–3.95; p = 0.005) significantly decreased survival rates. Conclusions. The proposed grading system provides the possibility of preoperative evaluation of PVG resectability that in combination with 3D surgical planning and image-guided resection allows performing maximal safe resections and preventing of postoperative neurological deficits.