Volumetric Assessment of Meningioma Resection: A Single-Center Experience in a Resource-Limited Setting

Precise assessment of the extent of resection (EOR) is fundamental in meningioma surgery. This study describes the use of volumetric analysis to quantify the EOR at a single tertiary center in Addis Ababa, Ethiopia, between January 1, 2020, and December 31, 2024. We reviewed 83 adult patients in a single-center retrospective study with histopathologically confirmed intracranial meningioma and available preoperative and early postoperative imaging (≤72 hours). Tumor volumes were segmented using 3D Slicer software, and the percentage EOR was calculated. Exploratory non-parametric tests assessed differences across selected clinical, radiological, and operative tumor characteristics. The study population showed a female predominance (2.8:1) and a mean age of 41.7 ± 10.8 years. Headache was the most reported presenting symptom (38.6%), and tumors were often large at presentation, with a median preoperative volume of 70.4 cm 3 . The overall median EOR was 93%, ranging from 25% to 100%. Lower median EOR was observed in tumors with bone involvement (r = 0.53, p < 0.001), skull base location (r = 0.38, p = 0.002) and those involving multiple neurovascular structures (ε 2 = 0.21, p = 0.002). The volumetric assessment demonstrated a wide variability in actual tumor removal despite identical operative grading among patients having Simpson Grade 4 resection (ε 2 = 0.81, p < 0.001). Open-source volumetric software offers a practical method for measuring resection extent in resource-limited settings. The variability observed within Simpson Grade 4 resections further highlights its potential role as a complementary tool for postoperative assessment and institutional surgical audit.