Image-guided Stereotactic Biopsy Research Articles

Matching Quantitative MRI Parameters with Histological Features of Treatment-Naïve IDH Wild-Type Glioma.

Simple SummaryMRI plays an important role in the classification of structural brain changes and quantitative MRI can provide more and different information than conventional MRI. A comparison with neuropathological parameters helps to expand the understanding of (patho)physiological concepts but has hardly been carried out so far. In this prospective study, we correlated quantitative MRI data with histological features of 25 patients with isocitrate dehydrogenase (IDH) wild-type glioma. We found that the relative shortening of T1 relaxation time after the application of contrast agent was pronounced in the presence of tumor cells and vascular proliferates, indicating a disruption of the blood brain barrier (BBB). T2′ relaxation time, depending on local deoxyhemoglobin concentration, correlated with the vessel density but not with immunopositivity for endogenous markers of hypoxia.Quantitative MRI allows to probe tissue properties by measuring relaxation times and may thus detect subtle changes in tissue composition. In this work we analyzed different relaxation times (T1, T2, T2* and T2′) and histological features in 321 samples that were acquired from 25 patients with newly diagnosed IDH wild-type glioma. Quantitative relaxation times before intravenous application of gadolinium-based contrast agent (GBCA), T1 relaxation time after GBCA as well as the relative difference between T1 relaxation times pre-to-post GBCA (T1rel) were compared with histopathologic features such as the presence of tumor cells, cell and vessel density, endogenous markers for hypoxia and cell proliferation. Image-guided stereotactic biopsy allowed for the attribution of each tissue specimen to its corresponding position in the respective relaxation time map. Compared to normal tissue, T1 and T2 relaxation times and T1rel were prolonged in samples containing tumor cells. The presence of vascular proliferates was associated with higher T1rel values. Immunopositivity for lactate dehydrogenase A (LDHA) involved slightly longer T1 relaxation times. However, low T2′ values, suggesting high amounts of deoxyhemoglobin, were found in samples with elevated vessel densities, but not in samples with increased immunopositivity for LDHA. Taken together, some of our observations were consistent with previous findings but the correlation of quantitative MRI and histologic parameters did not confirm all our pathophysiology-based assumptions.

Comparison of Frame-Based Versus Frameless Image-Guided Intracranial Stereotactic Brain Biopsy: A Retrospective Analysis of Safety and Efficacy

A definitive diagnosis of brain lesions not amenable to surgery is mainly made by stereotactic needle biopsy. The diagnostic yield and safety of the frameless versus frame-based image-guided stereotactic techniques is unclear. Our objective was to evaluate the safety and accuracy of frameless versus frame-based stereotactic brain biopsy techniques. A total of 278 patients (153 men; mean age: 65.5 years) with intra-axial brain lesions underwent frame-based (n= 148) or frameless image-guided stereotactic brain biopsy (n= 130) using a minimally invasive twist drill technique during 2010-2016 at Sheba Medical Center. Demographic, imaging, and clinical data were retrospectively analyzed. The diagnostic yield (>90%) did not differ significantly between groups. Overall morbidity (6.8% vs. 8.5%), incidence of permanent neurologic deficits (2.1% vs. 1.6%), mortality rate (0.7% vs. 0.8%), and postoperative computed tomography-detected asymptomatic (14.2% vs. 16.1%) and symptomatic (2.0% vs. 1.6%) bleeding also did not differ significantly between the frame-based and frameless cohorts, respectively. The diagnostic yield and complication rates related to the biopsy technique were not significantly associated with sex, age, entry angle to the skull and skull thickness, lesion location or depth, or radiologic characteristics. Diagnostic yield was significantly associated with the mean lesion volume. Smaller lesions were less diagnostic than larger lesions in both techniques (P= 0.043 frame-based and P= 0.048 frameless). The frameless biopsy technique is as efficient as the frame-based brain biopsy technique with a low complication rate. Lesion volume was the only predictive factor of diagnostic yield. The minimally invasive twist drill technique is safe and efficient.

Lateral Temporal Approach for Image-Guided Stereotactic Biopsy of Pineal Region Tumors

Biopsy of pineal region neoplasms is frequently accomplished by way of endoscopic transventricular access or using an image-guided, computer-assisted stereotactic approach. We evaluated a nonorthogonal lateral temporal approach for stereotactic biopsy of pineal region tumors as a variation of previously described stereotactic methods. Magnetic resonance imaging-guided frameless stereotaxy was used to plan and perform biopsies of pineal region tumors using a nonorthogonal trajectory extending from the superior or middle temporal gyri through the temporal stem, anterior to the atrium of the lateral ventricle, and posterior to the corticospinal tract. All patients had an uncomplicated postoperative course and remained at neurologic baseline. No parenchymal or ventricular hemorrhage was present on postoperative scans. A tissue diagnosis was obtained in all patients. This method appears to be a safe alternative to stereotactic biopsy using other trajectories and provides adequate tissue for definitive diagnosis.

Central Nervous System Infections Due to Aspergillus and Other Hyaline Molds.

Central nervous system infections due to Aspergillus spp and other hyaline molds such as Fusarium and Scedosporium spp are rare but fatal conditions. Invasion of the central nervous system (CNS) tends to occur as a result of hematogenous dissemination among immunocompromised patients, and by local extension or direct inoculation secondary to trauma in immunocompetent hosts. Efforts should be directed to confirm the diagnosis by image-guided stereotactic brain biopsy when feasible. Non-culture methods could be useful to support the diagnosis, but they have not been validated to be performed in cerebral spinal fluid. Treatment of these infections is challenging given the variable susceptibility profile of these pathogens and the penetration of antifungal agents into the brain.

Magnetic Resonance Imaging-guided Stereotactic Biopsy: A Review of 83 Cases with Outcomes.

Background:The purpose of this study was to determine the relationship between the radiological and histopathological distribution of the cerebral lesions diagnosed with stereotactic biopsy (STB) procedure and its outcomes.Materials and Methods:In the current study, a retrospective analysis of 83 patients that underwent the STB in our clinic from January 2011 to December 2015 was made. T1-weighted contrast-enhanced cranial magnetic resonance imaging examinations were performed on patients on whom Leksell stereotactic frame system was installed. The histopathological and the radiological data derived from the STB procedure were classified.Results:In terms of localization, glial tumor (56.6%) was the most common lesion in all regions, except for the multifocal lesions. Contrary to the common knowledge, lymphoma (14.4%) was found to be the most common lesion among multifocal lesions. The success of obtaining positive STB samples in the current series was 95.2% and the complication rate was 3.6%.Conclusion:Had a routine computed tomography scan been performed on each patient in this series, the number of clinically insignificant small intracerebral hematomas would have probably been higher. Nevertheless, the rate of the STB sampling accuracy and the complication rate were similar to those reported in the relevant literature.

Identifying Recurrent Malignant Glioma after Treatment Using Amide Proton Transfer-Weighted MR Imaging: A Validation Study with Image-Guided Stereotactic Biopsy.

To quantify the accuracy of amide proton transfer-weighted (APTw) MRI for identifying active glioma after treatment via radiographically guided stereotactic tissue validation.Experimental Design: Twenty-one patients who were referred for surgery for MRI features concerning for tumor progression versus treatment effect underwent preoperative APTw imaging. Stereotactic biopsy samples were taken from regions of interest with varying APTw signal intensities. The relationship between final clinical pathology and the histopathology of each of the 64 specimens was analyzed relative to APTw results. Analysis of confirmed recurrent tumor or treatment effect tissue was used to perform ROC analysis. Eighteen of 21 patients had recurrent tumor, and 3 had treatment effect on clinical pathology. In 12 patients, there were multiple histopathologic assignments confirmed within the same tumor. Of the 64 total specimens, 20 specimens were active glioma, 27 mixed active and quiescent glioma, and 17 quiescent/no identifiable tumor. APTw signal intensity and histopathologic assignment, cellularity, and proliferation index had significant positive correlations (R = 0.651, 0.580, and 0.458, respectively; all P < 0.001). ROC analysis with a 1.79% APTw intensity cutoff differentiated active from nonactive tumor (AUC of 0.881) with 85.1% sensitivity and 94.1% specificity. Analysis of clinical pathology showed the mean APTw intensity for each patient had 94.4% sensitivity and 100% positive predictive value for identifying recurrent glioma at this cutoff. APTw imaging hyperintensity may be a marker of active malignant glioma. It is able to distinguish between regions of heterogeneous abnormality on anatomic brain MRI with high sensitivity and specificity.

Application of a Thrombin-Gelatin Matrix in the Management of Intractable Hemorrhage During Stereotactic Biopsy

Few studies have been published about percutaneous techniques for management of surgical bed hemorrhage during a stereotactic biopsy, a serious complication that may affect patient outcome. We describe the injection of a thrombin-gelatin matrix through the biopsy cannula as an effective method to arrest surgical bed bleeding that does not respond to conventional methods of hemostasis. We prospectively documented image-guided stereotactic brain biopsy procedures in 30 awake patients between July 2014 and July 2017 at our center. Among patients presenting with intractable surgical bed bleeding, a thrombin-gelatin matrix injection through the biopsy cannula was performed. Details of the injection technique, surgical outcome, and complications were recorded. Among 30 documented stereotactic brain biopsies, 3 (10%) had intractable surgical bed bleeding during the procedure. In all 3 cases, thrombin-gelatin matrix was injected, and an immediate arrest of hemorrhage was achieved. None of the patients required a craniotomy or further invasive measure to achieve hemostasis. No postoperative complications were recorded. Our preliminary results suggest that thrombin-gelatin matrix injection is a simple, safe, and effective stereotactic practice to manage persistent surgical bed bleeding that cannot be arrested by standard, conventional hemostatic methods.

Clinical application of multimodal image fusion in stereotactic biopsy of intracranial lesions

Objective To explore the clinical application of multimodal image fusion in stereotactic biopsy of intracranial lesions. Methods A total of 34 patients underwent multimodal image-guided stereotactic biopsy and were enrolled into this study from January to December 2016 at Department of Neurosurgery, the First Affiliated Hospital, College of Medicine, Zhejiang University. Images including PET/CT, 1H-MRS, BOLD-fMRI, DTI were fused with structural MRI for target confirmation and trajectory design. Framed stereotactic biopsy was performed in 14 patients and frameless stereotactic biopsy was performed in the other 20 patients. The diagnostic yield and complications of biopsy were assessed. Results Stereotactic biopsy was successfully performed in all cases including 32 with supratentorial lesions and 2 with infratentoria lesions. Post-biopsy pathology revealed glioma in 14 patients, lymphoma in 12, metastatic tumors in 6 and inflammatory demyelinating diseases in 2. The diagnostic yield was 100%. Post-biopsy CT confirmed the accuracy of biopsy targets. A small hematoma (< 5 ml) in target area was found in 1(2.9%, 1/34) patient without severe complications and no further operation was performed. There was no bleeding in any trajectory or newly-occurred neurological deficits. Conclusion Multimodal image fusion could provide anatomical, metabolic and functional information for stereotactic biopsy, increase diagnostic yield and reduce complications. Key words: Brain diseases; Biopsy; Stereotactic technology; Multimodal image fusion technique

Diagnostic performance of apparent diffusion coefficient parameters for glioma grading

This study was to evaluate the diagnostic performance of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) parameters derived from diffusion tensor imaging in the differentiation between grade II and III gliomas. The records of 60 patients (30 women, 30 men; mean age, 45.4years) suspected of having gliomas who underwent an ADC image-guided stereotactic biopsy were retrospectively reviewed. The values of FA and ADC were measured, and the sensitivity, specificity, accuracy and area under the curve (AUC) of those parameters were calculated based on the receiver operating characteristic curve analysis. A predictive diagnostic equation was also constructed and evaluated. Significant differences in minimum ADC values were found in the quantitative analysis between the grade III and II glioma groups. The sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), accuracy and AUC for identifying grade III and II gliomas at the optimum cut-off value of 0.895 × 10-3mm2/s of minimum ADC were 81.0, 89.1, 77.3, 91.1, 86.6 and 0.87, respectively. The predictive diagnostic equation was superior to the single minimum ADC indicator with a sensitivity of 90.5%, a specificity of 84.8%, a PPV of 73.1%, an NPV of 95.1%, and an accuracy of 86.6%, respectively. The study provides evidence that minimum ADC values have a superior diagnostic performance in differentiating grade III and II gliomas, and the predictive diagnostic equation may be helpful in the differentiation.

Frameless Image-guided Stereotactic Brain Biopsy – Advantages, Limitations, and Technical Tips

Frameless Image-guided Stereotactic Brain Biopsy – Advantages, Limitations, and Technical Tips

Comparison among conventional and advanced MRI, 18F-FDG PET/CT, phenotype and genotype in glioblastoma.

Glioblastoma (GB) is a highly heterogeneous tumor. In order to identify in vivo the most malignant tumor areas, the extent of tumor infiltration and the sites giving origin to GB stem cells (GSCs), we combined positron emission tomography/computed tomography (PET/CT) and conventional and advanced magnetic resonance imaging (MRI) with histology, immunohistochemistry and molecular genetics. Prior to dura opening and tumor resection, forty-eight biopsy specimens [23 of contrast-enhancing (CE) and 25 of non-contrast enhancing (NE) regions] from 12 GB patients were obtained by a frameless image-guided stereotactic biopsy technique.The highest values of 2-[18F]-fluoro-2-deoxy-D-glucose maximum standardized uptake value (18F-FDG SUVmax), relative cerebral blood volume (rCBV), Choline/Creatine (Cho/Cr), Choline/N-acetylaspartate (Cho/NAA) and Lipids/Lactate (LL) ratio have been observed in the CE region. They corresponded to the most malignant tumor phenotype, to the greatest molecular spectrum and stem cell potential. On the contrary, apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in the CE region were very variable.18F-FDG SUVmax, Cho/Cr and Cho/NAA ratio resulted the most suitable parameters to detect tumor infiltration. In edematous areas, reactive astrocytes and microglia/macrophages were influencing variables.Combined MRI and 18F-FDG PET/CT allowed to recognize the specific biological significance of the different identified areas of GB.

Amide proton transfer-weighted magnetic resonance image-guided stereotactic biopsy in patients with newly diagnosed gliomas

PurposePathological assessment using World Health Organization (WHO) criteria is the gold standard for diagnosis of gliomas. However, the accuracy of diagnosis is limited by tissue sampling, particularly for infiltrating, heterogeneous tumours. We assessed the accuracy of amide proton transfer-weighted (APTw) magnetic resonance imaging (MRI)-guided tissue sampling to identify regions of high-grade glioma via radiographic-histopathologic correlation in patients with newly suspected glioma. Patients and methodsTwenty-four patients with previously undiagnosed gliomas underwent a volumetric APTw MRI prior to their first neurosurgical procedure. A total of 70 specimens were collected via APTw image-directed stereotactic biopsy. Cellularity, necrosis, proliferation and glioma WHO grade were analysed for all specimens and correlated with corresponding APTw signal intensities. ResultsThirty-three specimens displayed grade-II pathology, 14 grade-III, 15 grade-IV, and eight specimens revealed only peritumoural oedema. Multiple glioma grades were found within a single lesion in six patients. APTw signal intensities of the biopsied sites and the maximum APTw values across all biopsied sites in each patient were significantly higher for high-grade versus low-grade specimens. APTw signal intensities were significantly positively correlated with cellularity (R = 0.757) and proliferation (R = 0.538). Multiple linear regression analysis showed that tumour cellularity and proliferation index were the best predictors of APTw signal intensities. ConclusionAPTw imaging identified tumour areas of higher cellularity and proliferation, allowing identification of high-grade regions within heterogeneous gliomas. APTw imaging can be readily translated for more widespread use and can assist diagnostic neurosurgical procedures by increasing the accuracy of tumour sampling in patients with infiltrating gliomas.

LGG-07. LOW-GRADE GLIOMA COMBINATION CHEMOTHERAPY MAY BE EFFECTIVE IN BRAF V600E CODON-MUTATED OPTIC PATHWAY GANGLIOGLIOMAS

Abstract Gangliogliomas (GG) are low-grade mixed glial/neuronal tumors typically seen in children and young adults. They commonly arise in the cerebrum, cerebellum and brainstem and are often associated with seizures. Management is typically surgical. Adjuvant radiation therapy is occasionally used, but primary treatment with chemotherapy is not considered standard. Very rarely, GG involves the optic pathway, with this location being rarely amenable to surgery, threatens vision and mandates creative treatment approaches. Many GG have mutations in the BRAF proto-oncogene, critical for regulating the MAP kinase/ERKs signaling pathway which affects cell division and differentiation. METHODS/ A 4-year-old boy presented with a many-year history of abnormal eye movements and progressive visual decline. Ophthalmologic examination revealed esotropia, optic atrophy and poor visual acuity. MRI scanning revealed an extensive bilateral infiltrative tumor involving the optic pathway, hypothalamus, thalami, midbrain and temporal lobes. An image-guided stereotactic biopsy revealed a typical WHO grade 1 ganglioglioma and tumor cell pyrosequencing revealed a BRAF codon 600 (V600E) mutation. There was no clinical or imaging evidence of NF1. Given the tumor’s unresectability and the reticence to use ionizing radiation therapy at such a young age, combination chemotherapy using carboplatin and vincristine was started. Tumor extent and contrast enhancement decreased dramatically during the one year chemotherapy journey and ophthalmologic parameters stabilized. The management of GG is typically surgical, with careful use of radiation therapy for select circumstances. Chemotherapy is not typically considered an effective therapy. However, this case suggests that GG can be chemosensitive, to standard low-grade glioma chemotherapy. The presence of the BRAF V600E mutation is common in GG and may afford a therapeutic management strategy for select cases, using BRAF inhibitors such as vemurafenib and dabrafenib. We recommend the ongoing reporting of novel treatment strategies for challenging-site GG and suggest BRAF analysis for such tumors.

Intraoperative real-time MRI-guided stereotactic biopsy followed by laser thermal ablation for progressive brain metastases after radiosurgery

Stereotactic radiosurgery is one of the treatment options for brain metastases. However, there are patients who will progress after radiosurgery. One of the potential treatments for this subset of patients is laser ablation. Image-guided stereotactic biopsy is important to determine the histopathological nature of the lesion. However, this is usually based on preoperative, static images, which may affect the target accuracy during the actual procedure as a result of brain shift. We therefore performed real-time intraoperative MRI-guided stereotactic aspiration and biopsies on two patients with symptomatic, progressive lesions after radiosurgery followed immediately by laser ablation. The patients tolerated the procedure well with no new neurologic deficits. Intraoperative MRI-guided stereotactic biopsy followed by laser ablation is safe and accurate, providing real-time updates and feedback during the procedure.

Microrecording and image-guided stereotactic biopsy of deep-seated brain tumors.

Image-guided stereotactic brain tumor biopsy cannot easily obtain samples of small deep-seated tumor or selectively sample the most viable region of malignant tumor. Image-guided stereotactic biopsy in combination with depth microrecording was evaluated to solve such problems. Operative records, MRI findings, and pathological specimens were evaluated in 12 patients with small deep-seated brain tumor, in which image-guided stereotactic biopsy was performed with the aid of depth microrecording. The tumors were located in the caudate nucleus (1 patient), thalamus (7 patients), midbrain (2 patients), and cortex (2 patients). Surgery was performed with a frameless stereotactic system in 3 patients and with a frame-based stereotactic system in 9 patients. Microrecording was performed to study the electrical activities along the trajectory in the deep brain structures and the tumor. The correlations were studied between the electrophysiological, MRI, and pathological findings. Thirty-two patients with surface or large brain tumor were also studied, in whom image-guided stereotactic biopsy without microrecording was performed. The diagnostic yield in the group with microrecording was 100% (low-grade glioma 4, high-grade glioma 4, diffuse large B-cell lymphoma 3, and germinoma 1), which was comparable to 93.8% in the group without microrecording. The postoperative complication rate was as low as that of the conventional image-guided method without using microelectrode recording, and the mortality rate was 0%, although the target lesions were small and deep-seated in all cases. Depth microrecording revealed disappearance of neural activity in the tumor regardless of the tumor type. Neural activity began to decrease from 6.3 ± 4.5 mm (mean ± SD) above the point of complete disappearance along the trajectory. Burst discharges were observed in 6 of the 12 cases, from 3 ± 1.4 mm above the point of decrease of neural activity. Injury discharges were often found at 0.5-1 mm along the trajectory between the area of decreased and disappeared neural activity. Close correlations between electrophysiological, MRI, and histological findings could be found in some cases. Image-guided stereotactic biopsy performed using depth microrecording was safe, it provided accurate positional information in real time, and it could distinguish the tumor from brain structures during surgery. Moreover, this technique has potential for studying the epileptogenicity of the brain tumor.

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

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

Image-Guided Stereotactic Biopsy for the Brain Lesions: 2,315 Case Reports

Image-Guided Stereotactic Biopsy for the Brain Lesions: 2,315 Case Reports

Stereotactic biopsy used in the diagnosis of hypothalamus lesions

Objective To analyze the use of stereotactic biopsy in the diagnosis of hypothalamus lesions,which could be an alternative method for cases with diagnostic problems.Methods Two cases of hypothalamus syndrome with a mass in the area of hypothalamus were presented.By image-guided stereotactic biopsy,correct diagnosis was made.Results These 2 cases diagnosed was granulomatous inflammation and embryonic germ cell tumor respectively,without any biopsy-related complications.The features of disease were improved after corresponding treatment.Similar reports published since 2001 were then reviewed.86％-99％ patients can be diagnosed pathologically by stereotactic biopsy,with accuracy rates of 79％-96.7％.The overall biopsy-related complications were found in less than 5 ％ of total patients.Conclusions Stereotactic biopsy is a safe and reliable way for making pathological diagnosis and may help selecting appropriate management for hypothalamus lesions. Key words: Hypothalamus lesions; Stereotactic biopsy; Etiological diagnosis

Hemorrhage after Stereotactic Biopsy from Intra-Axial Brain Lesions: Incidence and Avoidance

With the introduction of stereotactic surgery in humans by Spiegel and Wycis in 1947 and the great advances in neuroimaging, image-guided stereotactic brain biopsy is the mainstay for diagnosis of intrinsic deep-seated brain lesions. Stereotactic biopsy is usually safe, and the reported rate of complications is minimal, with mortality being reported in less than 1% and significant morbidity occurring in less than 5%. The complication most often encountered after stereotactic biopsy is hemorrhage. A total of 150 patients (84 male and 66 female) with the mean age of 52.8 years having intra-axial brain lesions were included in the study. Image-guided (114 computed tomography [CT] and 36 magnetic resonance imaging [MRI]) stereotactic biopsy were performed by a specialized stereotactic neurosurgeon. Routine preoperative coagulation studies were performed in all patients. A workstation with multiplanar trajectory planning software was used. Serial biopsies were done with Sedan-type side cutting needle. Any detectable bleeding was analyzed by CT within 4 hours after procedure. All medical charts, laboratory results, preoperative imaging studies, and postoperative imaging studies were reviewed. A conclusive histopathological diagnosis was achieved in 147 patients (98%). In 7 patients (4.7%), hemorrhage was detected in post-biopsy CT scan (3.3% asymptomatic and 1.4% symptomatic). Hemorrhage occurred in patients with highly malignant tumors. There was no mortality. Using multiplanar image-guided trajectory planning and a small biopsy needle decreases the incidence of post-biopsy hemorrhage. Neurologically intact patients with no hemorrhage in post-biopsy CT scan could safely be discharged home at the same operative day.

Image-guided stereotactic biopsy of pineal region tumour using CT venography in patient with a pacemaker: A technical note

Image-guided stereotactic biopsy of pineal region tumours requires careful appreciation of neuroanatomy and avoidance of the deep cerebral venous system. A patient with a pineal region lesion obstructing the third ventricle and causing obstructive hydrocephalus required stereotactic biopsy after cerebrospinal fluid (CSF) diversion. The presence of a pacemaker precluded MR Venography. Fine-cut CT Venography was performed in its stead and merged with image guidance software, and a trajectory was planned avoiding the venous anatomy. Stereotactic biopsy was successfully performed without complication, revealing a pineocytoma.