The technical report of three-dimension visualized image-guided stereotactic biopsy for lesions in pineal region and brain stem

Abstract

Objective To investigate the methodology, technical essential and significance of three-dimension visualized image-guided stereotactic biopsy(SB) for lesions in pineal region and brain stem. Methods A total of 88 cases of lesions in pineal region and brain stem underwent image-guided SB in our department were retrospectively studied. Frame-based and CAS-2 type frameless SBs were performed in 57 and 31 cases respectively. Pre-biopsy three-dimension visualized image reconstruction was performed by SB planning software and the structure related to possible trajectory in each image slice was confirmed. The most suitable trajectory was selected accordingly. For lesions in pineal region, anterior-frontal trans-tentorium cerebella hiatus trajectory for avoiding tentorial margin was used. For lesions in mesencephalon, posterior-frontal trans-lateral ventrical- thalamus trajectory via the vertical axis of brain stem was used. For pontal lesions , supra-occipital trans- pedunculus cerebellaris medius trajectory was used. Results Histological diagnosis was established in all 88 cases, which gave a high diagnostic yield (100%). Fifty-six lesions (64%) located in brain stem (middle brain and pons) and 32 (36%) in pineal region. In 56 brain stem lesions, there were 38 cases (68%) of glioma, 3(5%) lymphoma, 2(4%) neurodegenerative disease, 6(11%) multiple sclerosis and tumefactive demyelinating lesion, 2(4%) non-specific inflammation, 2(4%)brain infarct, 2(4%) brain metastases, and 1 (2%) radiation necrosis. For lesions in pineal region, there were 18 cases (56%) of germ cell tumor, 4(13%)glioma, 9 (28%) pineal cell tumor, and 1(3%) Wernicke encephalopathy. One case(1 %)died of biopsy-related hemorrhage. The neurological deficits became severe because of hemorrhage in 5 cases, the medical treatment was adopted in 3 cases(3%)and drainage in 2 (2%). Conclusions Stereotactic biopsy for lesions in pineal region and brain stem was a safe and effective procedure that could help for the selection of clinical management and provide important prognostic information. Three-dimension visualized image-guided technique could realize virtually individual visualized intuitionistic view of biopsy trajectory. It could remarkably improve the safety and decrease the operative complications. Key words: Stereotaxic techniques; Biopsy; Brain stem; Pineal region