Frameless free-hand navigation-guided biopsy for brain tumors: A simpler method with an endoscope holder

Context/Aims: Given the limitations of current navigation-guided brain biopsy methods, we aimed to introduce a novel method and validate its safety and accuracy. Setting and Design: This was a retrospective study of twenty consecutive patients who underwent brain biopsy at Shimane University Hospital, Japan. Subjects and Methods: Clinical records of 13 and 7 patients who underwent brain biopsy with the novel frameless free-hand navigation-guided biopsy (FFNB) method or a framed computed tomography-guided stereotactic biopsy (CTGB) method, respectively, were retrospectively reviewed. We compared age, sex, tumor location, histological diagnosis, maximum size of the tumor (target), depth from target to cortical surface on the same slice of CT or magnetic resonance imaging, operative position, anesthesia method, setup time for biopsy, incision-to-closure time, trial times for puncture, success rate, and complications in the two groups. Statistical Analysis: Fisher's exact test and the Wilcoxon rank-sum test were performed. Results: Clinical characteristics and lesion size did not differ significantly between the FFNB and CTGB groups. The depth of the target lesion was significantly greater in the CTGB group (P < 0.05). All FFNB and CTGB procedures reached and obtained the target tissue. The number of punctures and the average incision-to-closure time did not differ between the FFNB and CTGB groups. However, the preoperative setup time was significantly shorter using FFNB (P = 0.0003). No complications were observed in either group. Conclusions: FFNB was comparable with CTGB in terms of safety, accuracy, and operative duration. The preoperative setup time was shorter using FFNB. Therefore, FFNB is a feasible method for brain tumor biopsy.