Deep-seated Intracranial Lesions Research Articles

P11.73.B The diagnostic value of frame-based stereotactic biopsies in the age of precision oncology: A cross-sectional study

Abstract Background For non-resectable, eloquent, multifocal and deep-seated intracranial lesions, stereotactic frame-based biopsies can deliver a finite amount of tissue for neuropathology studies. With the increasing role of molecular genetics in the diagnostics of intracranial tumors, sufficient tissue for sequencing studies is of paramount importance. This study explored the rate of successful diagnosis after stereotactic frame-based biopsies of intracranial lesions in a high-throughput neurooncology center Material and Methods 145 consecutive patients undergoing frame-based stereotactic biopsies in 2020 and 2021 at our neurosurgical department were included in this retrospective analysis. Aspects of histological and molecular (methylomics, panel-sequencing) neuropathology analysis in addition to clinical and radiological variables were analyzed. Cases were classified as conclusive, likely-conclusive (sufficient diagnosis with non-satisfying sequencing information), and inconclusive neuropathological diagnosis. Results Of 145 cases analyzed, astrocytic tumors were suspected in n= 94 (67%) of patients. In n= 122 cases (84%), a conclusive diagnosis was possible. For 14 (11%) cases, a likely-conclusive diagnosis was established Diagnoses comprised mainly WHO 4 glioblastomas (56%), WHO 3 gliomas (2%) in addition to WHO 1 and 2 gliomas (n=7, 5%), CNS lymphomas (n=23, 16%), inflammatory diseases (n=10, 7%) and normal or reactive tissue (n=4, 3%). Methylomics were pivotal in providing an integrated diagnosis in 30% of the cases (panel sequencing in 14%). In n= 12 (8%) of the cases further testing was hindered by insufficient tissue sample DNA. Only in 3 out of 12 cases this resulted in a final inconclusive diagnosis. Conclusion Although stereotactic frame-based biopsies deliver a limited amount of tissue, they bear an excellent histopathological and molecular genetic diagnostic yield, with rare cases of missing molecular data or rarely insufficient diagnosis. Optimizing the number and representativeness of cell and DNA-rich stereotactic biopsy specimen might enhance the diagnostic and therapeutic potential of precision oncology even further.

SURG-09. Benefits of laser interstitial thermal therapy in the treatment of biopsy-proven radiation necrosis

IntroductionLaser interstitial thermal therapy (LITT) is a minimally-invasive treatment option often used for patients with deep-seated intracranial lesions. It has been implemented as a definitive treatment for radiation necrosis (RN), which occurs in 9–14% of patients after stereotactic radiosurgery (SRS) for brain metastases (BM). Medical management (MM) with steroids is a common first-line therapy, with variable response and numerous side effects, especially regarding immunotherapy.MethodsPatients with biopsy-proven RN after SRS for BM who received LITT or MM at two academic centers were retrospectively reviewed. Treatment failure was defined as radiographic progression that necessitated a change in management. Measurements of total (TLV) and contrast-enhancing lesion volume (ceLV) were obtained from MRI by semi-automated analysis using the BrainLab iPlan Cranial 3.0 software.ResultsSeventy-two patients were followed for 10.0 (4.2–25.1) months and 57 (79%) received LITT. Steroid cessation occurred at a median of 37 days post-LITT compared to 245 days after MM (p<0.01). On Kaplan-Meier analyses, there was no significant difference between the two groups in overall survival (LITT median of 15.2 months vs 11.6 months, p = 0.60) or freedom from local progression (13.6 months vs. 7.06 months), though LITT trended to show a benefit in both metrics. When controlled for follow-up duration, patients treated with LITT were three times more likely to be weaned off steroids prior to the study endpoint compared to those who were medically managed (p=0.003). The LITT cohort demonstrated a general radiographic trend of initially increased CeLV followed by contraction, with significant decreases from pre-operative at 10–12 months (p<0.01). The MM group did not demonstrate any statistically significant radiographic trends.ConclusionThese results suggest that LITT for RN significantly reduces the time to steroid cessation and characterize a stereotyped radiographic response to LITT. Future prospective studies will be important to their validation.

Transparent Tubular Retractor in Cranial Surgery: A Retrospective Analysis

Abstract Introduction The fourth Industrial Revolution has touched nearly all aspects of neurosurgery and the newer tubular retractor systems are a testimony to this fact. They aid in providing better visualization with minimal damage to those neural structures, which happen to be innocent bystanders overlying the path of deep-seated lesions. In addition to providing better patient outcomes they are surgeon friendly with their ergonomic design and improved stability, thereby causing minimal fatigue, and aid in procedures requiring precision and perseverance. A retrospective study conducted at a single institute analyzed the efficacy of transparent tubular retractors during cranial surgery for deep-seated lesions. Materials and Methods This retrospective study was conducted between April 2015 and July 2018 in a single institute wherein 22 patents with various deep-seated intracranial lesions were operated using the transparent tubular retractor, View Site Brain Access System (VBAS, Vycor Medical Inc.). Observation Of the 22 cases, 45% were of spontaneous intracerebral hemorrhage; 27% were high-grade gliomas; and the rest were colloid cyst, cystic tumors, and metastatic tumors in equal proportion. Total tumor excision was achieved in 27%, while 90% excision was achieved in 45% cases. The overall complication rate was 13%. Conclusion The transparent tubular retractors contribute to minimal invasiveness by causing uniform distribution of retraction pressure and minimal disruption of fiber tracts. Their use has a definite role in improving surgical outcomes for deep-seated intracranial lesions.

Endoport-assisted surgical evacuation of a deep-seated cerebral abscess

Conventional surgical treatment for cerebral abscesses includes craniotomy or stereotactic aspiration. Deep-seated, large abscesses pose a challenge to neurosurgeons, due to the risk of injury to the cortex and white matter tracts secondary to the brain retraction necessary to access the lesion. The endoport is a tubular conduit that can be employed for minimally invasive approaches to deep-seated intracranial lesions, and it may reduce the length of dural opening, size of corticotomy, and retraction-related injury. In this technical note, we present the first report of an adult with a deep cerebral abscess which was successfully treated with endoport-assisted surgical evacuation. The endoport has been shown to be useful for the treatment of other intracranial pathologies, and we believe that this technology may be employed for the evacuation of appropriately selected cerebral abscesses.

Use of Tubular Retractor for Resection of Deep-Seated Cerebral Tumors and Colloid Cysts: Single Surgeon Experience and Review of the Literature.

Brain retraction is often required to develop a surgical corridor during the resection of deep-seated intracranial lesions. Traditional blade retractors distribute pressure asymmetrically and may case local tissue damage. Tubular retractors minimize this pitfall by distributing pressure evenly, which has been shown to translate to significant safety and efficacy data. Further qualified reports regarding the use of tubular retractors are of interest. We performed a retrospective analysis of 1 surgeon's experience with 20 cases of minimally invasive resection with the ViewSite Brain Access System (n= 7) and BrainPath (n= 13) systems. In addition, a comprehensive review of all published cases of tubular retractor systems used for resection of subcortical neoplastic, cystic, infectious, vascular, and hemorrhagic lesions was conducted. Of the 20 cases analyzed, gross total resection was achieved in 18, with an associated 10% immediate postoperative complication rate and 5% long-term complication rate. A comprehensive review of the literature showed 30 articles describing 536 cases of resection of deep neoplastic or colloid cysts with an overall complication rate of 9.1%. Tubular retractor systems have a favorable safety profile and are an important tool in the armamentarium of a neurosurgeon for the resection of deep intracranial lesions.

Magnetic Resonance Imaging-Guided Focused Laser Interstitial Thermal Therapy for Intracranial Lesions

BACKGROUND:Surgical treatments for deep-seated intracranial lesions have been limited by morbidities associated with resection. Real-time magnetic resonance imaging–guided focused laser interstitial thermal therapy (LITT) offers a minimally invasive surgical treatment option for such lesions.OBJECTIVE:To review treatments and results of patients treated with LITT for intracranial lesions at Washington University School of Medicine.METHODS:In a review of 17 prospectively recruited LITT patients (34-78 years of age; mean, 59 years), we report demographics, treatment details, postoperative imaging characteristics, and peri- and postoperative clinical courses.RESULTS:Targets included 11 gliomas, 5 brain metastases, and 1 epilepsy focus. Lesions were lobar (n = 8), thalamic/basal ganglia (n = 5), insular (n = 3), and corpus callosum (n = 1). Mean target volume was 11.6 cm3, and LITT produced 93% target ablation. Patients with superficial lesions had shorter intensive care unit stays. Ten patients experienced no perioperative morbidities. Morbidities included transient aphasia, hemiparesis, hyponatremia, deep venous thrombosis, and fatal meningitis. Postoperative magnetic resonance imaging showed blood products within the lesion surrounded by new thin uniform rim of contrast enhancement and diffusion restriction. In conjunction with other therapies, LITT targets often showed stable or reduced local disease. Epilepsy focus LITT produced seizure freedom at 8 months. Preliminary overall median progression-free survival and survival from LITT in tumor patients were 7.6 and 10.9 months, respectively. However, this small cohort has not been followed for a sufficient length of time, necessitating future outcomes studies.CONCLUSION:Early peri- and postoperative clinical data demonstrate that LITT is a safe and viable ablative treatment option for intracranial lesions, and may be considered for select patients.ABBREVIATION:LITT, laser interstitial thermal therapy

Supraorbital Keyhole Approach for Excision of Tuberculum Sellae Meningiomas

Introduction: The main aim in surgery is to achieve the greatest therapeutic effect while causing the least iatrogenic injury. The evolution of microsurgical techniques with refined instrumentation and the enormous development of diagnostic tools enable neurosurgeons to treat different lesions through limited and specific keyhole approaches. The concept of keyhole surgery is based on careful study of diagnostic images to determine the anatomic windows that provide access to the lesion. Methods: During a 16-year period, from June 1994 to December 2010, 62 patients with tuberculum sellae meningiomas were treated using a supraorbital keyhole approach and endoscopic-assisted microsurgical technique. The most frequent presenting symptom was visual disturbance. Of the 28 patients with visual disturbances, 60% had marked visual improvement, 24% had no changes in visual function, and 16% had worsening of vision postoperatively. Results: Complete removal was achieved in 93% of cases. The postoperative complications associated with the approach were supraorbital hypoesthesia in three patients, palsy of the frontal branch of the facial nerve in two cases, hyposmia in one patient, wound-healing disturbances in one case, and subcutaneous CSF collection and leak in one patient. Conclusion: The supraorbital craniotomy allows a wide exposure of deep-seated intracranial lesions. It offers equal surgical possibilities with less approach-related morbidity owing to limited exposure of the cerebral surface and minimal brain retraction, contributing to improved postoperative results and shortened hospitalization times. The short skin incision within the eyebrow and careful soft tissue dissection result in a pleasing cosmetic outcome.

Surgical Options for Pineal Region Tumors

Surgical Options for Pineal Region Tumors

Robotic Digital Subtraction Angiography Systems Within the Hybrid Operating Room

Fully equipped high-end digital subtraction angiography (DSA) within the operating room (OR) environment has emerged as a new trend in the fields of neurosurgery and vascular surgery. To describe initial clinical experience with a robotic DSA system in the hybrid OR. A newly designed robotic DSA system (Artis zeego; Siemens AG, Forchheim, Germany) was installed in the hybrid OR. The system consists of a multiaxis robotic C arm and surgical OR table. In addition to conventional neuroendovascular procedures, the system was used as an intraoperative imaging tool for various neurosurgical procedures such as aneurysm clipping and spine instrumentation. Five hundred one neurosurgical procedures were successfully conducted in the hybrid OR with the robotic DSA. During surgical procedures such as aneurysm clipping and arteriovenous fistula treatment, intraoperative 2-/3-dimensional angiography and C-arm-based computed tomographic images (DynaCT) were easily performed without moving the OR table. Newly developed virtual navigation software (syngo iGuide; Siemens AG) can be used in frameless navigation and in access to deep-seated intracranial lesions or needle placement. This newly developed robotic DSA system provides safe and precise treatment in the fields of endovascular treatment and neurosurgery.

A simple trajectory guidance device that assists freehand and interactive image guided biopsy of small deep intracranial targets

Frameless image guided stereotactic systems are rapidly becoming incorporated into routine neurosurgical practice. In our unit, the Elekta Viewing Wand has been applied to a comprehensive range of neurosurgical procedures, including pituitary, posterior fossa, skull base, atlantoaxial, and epilepsy surgery. The system allows a minimally invasive surgical exposure and provides instant and continual navigational information during surgery. Subjective studies have shown this intraoperative information to facilitate the surgeon's perception of anatomic relations and identification of structures, thus improving surgical safety. Furthermore, in comparison to traditional stereotactic frames, the frameless system has been reported to reduce operative time. The technology involves the use of a localizing mechanical arm to which a pointer or biopsy probe is attached. This localizing arm is hand-held and is therefore only as steady as the surgeon's hand. This precludes the use of the Viewing Wand for functional procedures and for the safe biopsy of small, deep-seated intracranial lesions. Both types of procedures are very dependent on a steady linear approach to the target for a successful outcome. We have designed a simple guidance device that eliminates the risk of unwanted drift or angular movements of the probe as it is advanced toward the target. When used with the Viewing Wand, this device guides the wand biopsy probe along a predetermined, fixed linear trajectory to the intracranial target. We report the successful use of the fixed trajectory guidance device (FTGD) with the Elekta Viewing Wand in a series of 12 patients.

A Simple Trajectory Guidance Device that Assists Freehand and Interactive Image Guided Biopsy of Small Deep Intracranial Targets

Frameless image guided stereotactic systems are rapidly becoming incorporated into routine neurosurgical practice. In our unit, the Elekta Viewing Wand has been applied to a comprehensive range of neurosurgical procedures, including pituitary, posterior fossa, skull base, atlantoaxial, and epilepsy surgery. The system allows a minimally invasive surgical exposure and provides instant and continual navigational information during surgery. Subjective studies have shown this intraoperative information to facilitate the surgeon's perception of anatomic relations and identification of structures, thus improving surgical safety. Furthermore, in comparison to traditional stereo-tactic frames, the frameless system has been reported to reduce operative time. The technology involves the use of a localizing mechanical arm to which a pointer or biopsy probe is attached. This localizing arm is hand-held and is therefore only as steady as the surgeon's hand. This precludes the use of the Viewing Wand for functional procedures and for the safe biopsy of small, deep-seated intracranial lesions. Both types of procedures are very dependent on a steady linear approach to the target for a successful outcome. We have designed a simple guidance device that eliminates the risk of unwanted drift or angular movements of the probe as it is advanced toward the target. When used with the Viewing Wand, this device guides the wand biopsy probe along a predetermined, fixed linear trajectory to the intracranial target. We report the successful use of the fixed trajectory guidance device (FTGD) with the Elekta Viewing Wand in a series of 12 patients.

The stereotaxic retractor in computer-assisted stereotaxic microsurgery. Technical note.

The authors describe a cylindrical retractor that is attached to a standard stereotaxic frame. This retractor provides a route for stereotaxic procedures and exposure of and a reference structure for the computer-assisted removal of deep-seated intracranial lesions defined stereotaxically by computerized tomography and magnetic resonance imaging.

Results of Computer-Assisted Stereotactic Laser Resection of Deep-Seated Intracranial Lesions

A computer-assisted stereotactic system has been developed for the precise resection of deep-seated intracranial neoplasms. After the tumor volume is reconstructed from computed tomographic and magnetic resonance imaging data, a computer-monitored, stereotactically directed carbon dioxide laser is used to vaporize the intracranial tumor. A computer graphics terminal is used to monitor the position of the laser in relationship to the planar slices through the tumor, which are reformatted orthogonally to the surgical plane of view. This procedure produced satisfactory postoperative neurologic results in 36 of the 41 patients who underwent treatment. The system provides precise surgical control in three-dimensional space for the safe resection of substantial amounts (as assessed by postoperative computed tomography) of intra-axial neoplasms.

Surgical Options for Patients With Deep-Seated Brain Tumors: Computer-Assisted Stereotactic Biopsy

The histologic nature of deep-seated intracranial lesions can be determined by using a computer-assisted stereotactic biopsy technique. The procedures are performed with use of local anesthesia. A data base consisting of stereotactic computed tomographic scans and stereotactic cerebral angiography is acquired. Target coordinates and trajectory approach angles are calculated by using a computer system in the operating room. Since July 1984, 36 patients with a variety of pathologic lesions in various intracranial sites have undergone this procedure at our institution. Of the 36 patients thought to have neoplastic lesions preoperatively, 6 were found to have nonneoplastic lesions, information that was of importance in the therapeutic management of these patients. Of the 30 patients with tumors, 24 had astrocytomas of various grades, 3 had metastatic lesions, and an additional 3 had lymphomas. Computer-assisted stereotactic biopsy with arteriographic control is an accurate and relatively safe method of determining the histologic nature of any suspicious intracranial lesion.