Surgical biopsy techniques in neurosurgery: A four-year population-based study of frameless and frame-based procedures

• Both frameless and frame-based methods demonstrated comparable safety and efficacy. • The heterogeneous histology in radiologically suspected brain tumors further necessitates biopsy for definitive diagnosis and treatment guidance. • Robot-assisted biopsies and skull-mounted procedures proved significantly faster than craniotomies. Suspected malignant lesions in the brain unamenable for resection are most often biopsied to establish the histomolecular diagnosis, guiding further treatment. Herein, we compare the postoperative outcomes in terms of safety and diagnostic yield between traditional and more recent biopsy techniques utilized at our facility. Population-based patient data was collected from 2020 to 2023. Patients were subdivided depending on chosen surgical strategy. Data included clinical, radiological and surgical variables, in addition to histopathological diagnosis and post-operative treatment strategy. We identified 161 adult patients undergoing 163 biopsies; 101 robot-assisted biopsies, 35 frameless skull-mounted trajectory guided biopsies, 15 biopsies obtained via craniotomies, and 12 frame-based stereotactic biopsies. There was no significant difference in diagnostic yield between methods, ranging from 94.3 % in skull-mounted biopsies to 83.3 % in stereotactic biopsies. Glioblastomas were the most common diagnosis (55.2 %), but a plethora of malignancies were identified. The histopathological diagnosis was inconclusive in 19 patients (11.7 % of study population). Robot-assisted and skull-mounted procedures resulted in significantly shorter operating time compared to craniotomies (p < 0.001). There was no statistically significant difference in rate of complications between methods. Small postoperative hemorrhages were detected in 28.2 % of cases (median 6 mm), none required intervention. Subsequent oncologic treatment was administered to 91.7 % of patients with a conclusive histopathological diagnosis, compared to 73.7 % with an inconclusive diagnosis. Both frameless and frame-based methods demonstrated comparable safety and efficacy. Robot-assisted biopsy was the predominant method. Our findings further illustrate the large variety of histopathological diagnoses in patients presenting with radiologically suspected brain tumor, underscoring the importance of a biopsy to obtain a conclusive tissue diagnosis to guide treatment.