Purpose: single-staged stereotactic radiosurgery (SRS) is an established part of the multimodal treatment in neuro-oncology. Radiation necrosis after high-dose irradiation is a known complication, but there is a lack of evidence about the risk factors. The aim of this study was to evaluate possible risk factors for radiation necrosis in patients undergoing radiosurgery. Methods: patients treated with radiosurgery between January 2004 and November 2020 were retrospectively analyzed. The clinical data, imaging and medication were gathered from electronic patient records. The largest diameter of the tumors was measured using MRI scans in T1 weighted imaging with gadolinium and the edema in T2 weighted sequences. The diagnosis of a radiation necrosis was established analyzing imaging criteria combined with clinical course or pathologically confirmed by subsequent surgical intervention. Patients developing radiation necrosis detected after SRS were compared to patients without evidence of an overshooting irradiation reaction. Results: 388 patients were included retrospectively, 61 (15.7%) of whom developed a radiation necrosis. Median follow-up was 24 (6–62) months with a radiation necrosis after 8 (6–12) months. The most frequent tumors were metastases in 47.2% of the cases, followed by acoustic neuromas in 32.2% and meningiomas in 13.4%. Seventy-three (18.9%) patients already underwent one or more previous radiosurgical procedures for different lesions. The mean largest diameter of the tumors amounted to 16.3 mm (±6.1 mm). The median—80%—isodose administered was 16 (14–25) Gy. Of the radiation necroses, 25 (43.1%) required treatment, in 23 (39.7%) thereof, medical treatment was applied and in 2 (3.4%) cases, debulking surgery was performed. In this study, significantly more radiation necroses arose in patients with higher doses (HR 1.3 [CI 1.2; 1.5], p < 0.001) leading to a risk increment of over 180% between a radiation isodose of 14 and 20 Gy. The maximum diameter was a second significant risk factor (p = 0.028) with an HR of 1065 for every 1 mm increase in multivariate analysis. Conclusion: large diameter and high doses were reliable independent risk factors leading to more frequent radiation necroses, regardless of tumor type in patients undergoing radiosurgery. Alternative therapeutic procedures may be considered in lesions with large volume and an expected high radiation doses due to the increased risk of developing radiation necrosis.

Conventional microscopes have certain limitations in terms of posture and ergonomics. Monitor-based exoscopes could solve this problem and thereby lead to less work-related sick leave for surgeons. The aim of this study was to assess the ergonomics, usability, and neurosurgeon's comfort of a novel three-dimensional head-mounted display-based exoscope in a standardized setting. 34 neurosurgeons participated in a workshop on the exoscope, which features a head-mounted display and a head gesture-triggered control panel. After completion of a custom-made 10-step microsurgical exercise, image quality and comfort were assessed using a questionnaire. The participants' posture during the exercise was analyzed using a video motion analysis software. 34 participants (median neurosurgical experience: 6 years) were included. The median time to complete the exercise was 12 ​min [IqR 9.4, 15.0]. Younger participants (p ​= ​0.005) and those with video game experience (p ​= ​0.03) had a significantly steeper learning curve. The median overall satisfaction was at 80% in general and 82% for image quality. The median upper body as well as the median head coronal displacement from the neutral axis were 0°. Participants with less microsurgical experience showed less head/body displacement during the exercise (p ​= ​0.01). Using the microsurgical training tool, we were able to depict a steep learning curve with a sufficient learnability of the most relevant commands. The exoscope excelled in usability, image quality as well as in ergonomic and favorable posture and could thus become an alternative to conventional microscopes due to the potentially elevated surgeons' comfort.

Background: The Clinical Frailty Scale (CFS) describes the general level of fitness or frailty and is widely used in geriatric medicine, intensive care and orthopaedic surgery. This study was conducted to analyze, whether CFS could be used for patients with high-grade glioma. Methods: Patients harboring high-grade gliomas, undergoing first resection at our center between 2015 and 2020 were retrospectively evaluated. Patients’ performance was assessed using the Rockwood Clinical Frailty Scale and the Karnofsky Performance Scale (KPS) preoperatively and 3–6 months postoperatively. Results: 289 patients were included. Pre- as well as postoperative median frailty was 3 CFS points (IqR 2–4) corresponding to “managing well”. CFS strongly correlated with KPS preoperatively (r = − 0.85; p < 0.001) and at the 3–6 months follow-up (r = − 0.90; p < 0.001). The reduction of overall survival (OS) was 54% per point of CFS preoperatively (HR 1.54, CI 95% 1.38–1.70; p < 0.001) and 58% at the follow-up (HR 1.58, CI 95% 1.41–1.78; p < 0.001), comparable to KPS. Patients with IDH mutation showed significantly better preoperative and follow-up CFS and KPS (p < 0.05). Age and performance scores correlated only mildly with each other (r = 0.21…0.35; p < 0.01), but independently predicted OS (p < 0.001 each). Conclusion: CFS seems to be a reliable tool for functional assessment of patients suffering from high-grade glioma. CFS includes non-cancer related aspects and therefore is a contemporary approach for patient evaluation. Its projection of survival can be equally estimated before and after surgery. IDH-mutation caused longer survival and higher functionality.

With the rising life expectancy and availability of neuroimaging, increased number of older patients will present with diffuse and anaplastic gliomas. The aim of our study was therefore to investigate age-related prognostic clinical, neuropathological and radiological features of lower-grade gliomas. All consecutive patients with diffuse or anaplastic glioma WHO grade 2 and 3 who underwent first tumor resection between 2010 and 2018, were selected from the institutional neuro-oncological database and evaluated. The mean age of 55 males and 44 females was 46 years (SD ± 16). Wild-type IDH1 (p = 0.012), persistent nuclear ATRX expression (p = 0.012) and anaplasia (p < 0.001) were significantly associated with higher age. The CE volume before resection was found to be increased in older patients (r = 0.42, p < 0.0001), and CE rate was higher in the IDH wild-type population only (p = 0.02). The extent of resection did not differ with age. Overall, one year of life resulted in a PFS reduction of 9 days (p = 0.047); in IDH sub-group analysis, this dependency was confirmed only in wild-type tumors (p = 0.05). OS was significantly reduced in older patients (p = 0.033). In conclusion, behavior and prognosis of WHO grade 2 and 3 glioma were unfavorable in correlation to patient’s age, even if the extent of resection was comparable. Older age imparted a poorer PFS and higher CE rate only in the IDH wild-type population.

OBJECTIVE: Cranioplasty (CP) is a crucial procedure after decompressive craniectomy and has a significant impact on neurological improvement. Although CP is considered a standard neurosurgical procedure, inconsistent data on surgery-related complications after CP are available. To address this topic, the authors analyzed 502 patients in a prospective multicenter database (German Cranial Reconstruction Registry) with regard to early surgery-related complications. METHODS: Early complications within 30 days, medical history, mortality rates, and neurological outcome at discharge according to the modified Rankin Scale (mRS) were evaluated. The primary endpoint was death or surgical revision within the first 30 days after CP. Independent factors for the occurrence of complications with or without surgical revision were identified using a logistic regression model. RESULTS: Traumatic brain injury (TBI) and ischemic stroke were the most common underlying diagnoses that required CP. In 230 patients (45.8%), an autologous bone flap was utilized for CP; the most common engineered materials were titanium (80 patients [15.9%]), polyetheretherketone (57 [11.4%]), and polymethylmethacrylate (57 [11.4%]). Surgical revision was necessary in 45 patients (9.0%), and the overall mortality rate was 0.8% (4 patients). The cause of death was related to ischemia in 2 patients, diffuse intraparenchymal hemorrhage in 1 patient, and cardiac complications in 1 patient. The most frequent causes of surgical revision were epidural hematoma (40.0% of all revisions), new hydrocephalus (22.0%), and subdural hematoma (13.3%). Preoperatively increased mRS score (OR 1.46, 95% CI 1.08–1.97, p = 0.014) and American Society of Anesthesiologists Physical Status Classification System score (OR 2.89, 95% CI 1.42–5.89, p = 0.003) were independent predictors of surgical revision. Ischemic stroke, as the underlying diagnosis, was associated with a minor rate of revisions compared with TBI (OR 0.18, 95% CI 0.06–0.57, p = 0.004). CONCLUSIONS: The authors have presented class II evidence–based data on surgery-related complications after CP and have identified specific preexisting risk factors. These results may provide additional guidance for optimized treatment of these patients.

Purpose: The Clinical Frailty Scale (CFS) evaluates patients’ level of frailty on a scale from 1 to 9 and is commonly used in geriatric medicine, intensive care and orthopedics. The aim of our study was to reveal whether the CFS allows a reliable prediction of overall survival (OS) in patients after surgical treatment of brain metastases (BM) compared to the Karnofsky Performance Score (KPS). Methods: Patients operated for BM were included. CFS and KPS were retrospectively assessed pre- and postoperatively and at follow-up 3–6 months after resection. Results: 205 patients with a follow-up of 22.8 months (95% CI 18.4–27.1) were evaluated. CFS showed a median of 3 (“managing well”; IqR 2–4) at all 3 assessment-points. Median KPS was 80 preoperatively (IqR 80–90) and 90 postoperatively (IqR 80–100) as well as at follow-up after 3–6 months. CFS correlated with KPS both preoperatively (r = − 0.92; p < 0.001), postoperatively (r = − 0.85; p < 0.001) and at follow-up (r = − 0.93; p < 0.001). The CFS predicted the expected reduction of OS more reliably than the KPS at all 3 assessments. A one-point increase (worsening) of the preoperative CFS translated into a 30% additional hazard to decease (HR 1.30, 95% CI 1.15–1.46; p < 0.001). A one-point increase in postoperative and at follow-up CFS represents a 39% (HR 1.39, 95% CI 1.25–1.54; p < 0.001) and of 42% risk (HR 1.42, 95% CI 1.27–1.59; p < 0.001). Conclusion: The CFS is a feasible, simple and reliable scoring system in patients undergoing resection of brain metastasis. The CFS 3–6 months after surgery specifies the expected OS more accurately than the KPS.