bluuebunny/crossref_metadata_2025_split huggingface dataset:
Results of volume-staged fractionated Gamma Knife radiosurgery for large complex arteriovenous malformations: obliteration rates and clinical outcomes of an evolving treatment paradigm
Authors: Franzin Alberto , Panni Pietro , Spatola Giorgio , Vecchio Antonella del , Gallotti Alberto L. , Gigliotti Carmen R. , Cavalli Andrea , Donofrio Carmine A. , Mortini Pietro 
Published: April 2019

OBJECTIVEThere are few reported series regarding volume-staged Gamma Knife radiosurgery (GKRS) for the treatment of large, complex, cerebral arteriovenous malformations (AVMs). The object of this study was to report the results of using volume-staged Gamma Knife radiosurgery for patients affected by large and complex AVMs.METHODSData from 20 patients with large AVMs were prospectively included in the authors' AVM database between 2004 and 2012. A staging strategy was used when treating lesion volumes larger than 10 cm3. Hemorrhage and seizures were the presenting clinical feature for 6 (30%) and 8 (40%) patients, respectively. The median AVM volume was 15.9 cm3 (range 10.1–34.3 cm3). The mean interval between stages (± standard deviation) was 15 months (± 9 months). The median margin dose for each stage was 20 Gy (range 18–25 Gy).RESULTSObliteration was confirmed in 8 (42%) patients after a mean follow-up of 45 months (range 19–87 months). A significant reduction (> 75%) of the original nidal volume was achieved in 4 (20%) patients. Engel Class I–II seizure status was reported by 75% of patients presenting with seizures (50% Engel Class I and 25% Engel Class II) after radiosurgery. After radiosurgery, 71.5% (5/7) of patients who had presented with a worsening neurological deficit reported a complete resolution or amelioration. None of the patients who presented acutely because of hemorrhage experienced a new bleeding episode during follow-up. One (5%) patient developed radionecrosis that caused sensorimotor hemisyndrome. Two (10%) patients sustained a bleeding episode after GKRS, although only 1 (5%) was symptomatic. High nidal flow rate and a time interval between stages of less than 11.7 months were factors significantly associated with AVM obliteration (p = 0.021 and p = 0.041, respectively). Patient age younger than 44 years was significantly associated with a greater than 75% reduction in AVM volume but not with AVM obliteration (p = 0.024).CONCLUSIONSAccording to the results of this study, volume-staged GKRS is an effective and safe treatment strategy for large, complex, cerebral AVMs for which microsurgery or endovascular approaches could carry substantially higher risks to the patient. Radiation doses up to 20 Gy can be safely administered. The time interval between stages should be shorter than 11.7 months to increase the chance of obliteration. High nidal flow and a patient age younger than 44 years were factors associated with nidus obliteration and significant nidus reduction, respectively.
The role of diffusion tensor imaging tractography for Gamma Knife thalamotomy planning
Authors: Gomes João Gabriel Ribeiro , Gorgulho Alessandra Augusta , de Oliveira López Amanda , Saraiva Crystian Wilian Chagas , Damiani Lucas Petri , Pássaro Anderson Martins , Salvajoli João Victor , de Oliveira Siqueira Ludmila , Salvajoli Bernardo Peres , De Salles Antônio Afonso Ferreira 
Published: April 2019

OBJECTIVEThe role of tractography in Gamma Knife thalamotomy (GK-T) planning is still unclear. Pyramidal tractography might reduce the risk of radiation injury to the pyramidal tract and reduce motor complications.METHODSIn this study, the ventralis intermedius nucleus (VIM) targets of 20 patients were bilaterally defined using Iplannet Stereotaxy Software, according to the anterior commissure–posterior commissure (AC-PC) line and considering the localization of the pyramidal tract. The 40 targets and tractography were transferred as objects to the GammaPlan Treatment Planning System (GP-TPS). New targets were defined, according to the AC-PC line in the functional targets section of the GP-TPS. The target offsets required to maintain the internal capsule (IC) constraint of < 15 Gy were evaluated. In addition, the strategies available in GP-TPS to maintain the minimum conventional VIM target dose at > 100 Gy were determined.RESULTSA difference was observed between the positions of both targets and the doses to the IC. The lateral (x) and the vertical (z) coordinates were adjusted 1.9 mm medially and 1.3 mm cranially, respectively. The targets defined considering the position of the pyramidal tract were more medial and superior, based on the constraint of 15 Gy touching the object representing the IC in the GP-TPS. The best strategy to meet the set constraints was 90° Gamma angle (GA) with automatic shaping of dose distribution; this was followed by 110° GA. The worst GA was 70°. Treatment time was substantially increased by the shaping strategy, approximately doubling delivery time.CONCLUSIONSRoutine use of DTI pyramidal tractography might be important to fine-tune GK-T planning. DTI tractography, as well as anisotropy showing the VIM, promises to improve Gamma Knife functional procedures. They allow for a more objective definition of dose constraints to the IC and targeting. DTI pyramidal tractography introduced into the treatment planning may reduce the incidence of motor complications and improve efficacy. This needs to be validated in a large clinical series.
Prognostic factors for melanoma brain metastases treated with stereotactic radiosurgery
Authors: Bian Shelly X. , Routman David , Liu Jonathan , Yang Dongyun , Groshen Susan , Zada Gabriel , Trakul Nicholas , Wong Michael K. , Yu Cheng , Chang Eric L. 
Published: April 2019

OBJECTIVEStereotactic radiosurgery (SRS) is routinely used to treat brain metastases from melanoma due to their radioresistant nature. The median survival for these patients is 4–6 months, according to earlier studies. The aim of this study was to evaluate prognostic factors that influence survival in patients with metastatic melanoma to the brain treated with SRS.METHODSThis retrospective analysis included all patients with melanoma brain metastases treated with SRS at the University of Southern California between 1994 and 2015. For the entire cohort, the authors performed a multivariable Cox regression analysis with an end point of survival. Covariates included number of lesions, total intracranial tumor volume, age, sex, and treatment date prior to 2005 or 2005 onward.In the subset of patients with > 1 lesion, additional multivariable Cox regression was performed, with covariates of Karnofsky Performance Scale, Graded Prognostic Assessment, Recursive Partitioning Analysis, timing of metastases (synchronous/metachronous), change in lesion number, and previous whole-brain radiation therapy or resection in addition to the previously mentioned covariates. Overall survival (OS) was calculated from the day SRS was performed to the date of last follow-up or date of death.RESULTSA total of 401 patients were available for analysis. The median follow-up was 35.1 months for patients alive at the time of analysis, and the median OS was 7.7 months for the entire cohort (95% CI 6.7–8.3 months). In the entire cohort, greater number of brain lesions, higher total intracranial tumor volume, age > 50 years, treatment prior to 2005, and male sex were found to be statistically significant factors associated with worse survival. The strongest risk factors for decreased OS were tumor volume > 10 cm3 and ≥ 5 lesions, with hazard ratios for risk of death of 1.7 and 2.2, respectively. In the subset of patients with > 1 lesion, tumor volume > 10 cm3 and no resection were the only factors significantly associated with decreased OS, with hazard ratios of 1.9 and 2.0 (hazard ratio of 0.49 for resection), respectively.CONCLUSIONSThis study suggests that greater lesion number, higher intracranial tumor volume, older age, treatment prior to 2005, and male sex have prognostic significance for decreased OS in patients with melanoma brain metastases treated with SRS. Additionally, in the subset of patients with > 1 lesion, only higher total tumor volume and no resection were associated with worse survival.
Neurological and neuropsychological outcome after resection of craniopharyngiomas
Authors: Giese Henrik , Haenig Benjamin , Haenig Anna , Unterberg Andreas , Zweckberger Klaus 
Published: April 2019

OBJECTIVECraniopharyngiomas are rare and benign tumors of the sellar and/or parasellar region. Primary treatment involves resection followed by adjuvant radiotherapy. While the grade of resection was frequently analyzed following surgery, the neurological outcome and especially neuropsychological deficits and quality of life have been neglected for many decades. Therefore, the authors retrospectively analyzed their patient series and prospectively assessed neuropsychological outcome and quality of life following resection of craniopharyngiomas in adults.METHODSIn total, 71 patients (39 men and 32 women) with a mean age of 49 years were enrolled in the retrospective analysis. In addition, 36 of the 71 patients were included in the prospective arm of the study and underwent neurological and neuropsychological testing as well as quality of life (36-Item Short-Form Health Survey; SF-36) assessment. Factors influencing outcome were identified and correlations calculated.RESULTSResection was performed mostly using a pterional (41.6%, 47/113 surgical procedures) or bifrontal translamina terminalis (30.1%, 34/113 surgical procedures) approach. Following surgery, visual acuity was significantly improved (> 0.2 diopters) in 32.4% (23/71) of patients, or remained stable in 45.1% (32/71) of patients. During long-term follow up, 80.3% (57/71) of patients developed pituitary insufficiency, particularly involving the corticotropic and thyrotrophic axes. In total, 75% (27/36) of patients showed neuropsychological deviations in at least 1 test item. In particular, attentiveness, cognitive speed, and short-term memory were affected. Referring to the SF-36 score, quality of life was affected in both the mental and physical score in 19.4% (7/36) and 33.3% (12/36), respectively. The risk factors that were identified were a tumor volume larger than 9 cm3, tumor extension toward/into the third ventricle or the brainstem, and resection using a bifrontal translamina terminalis or left-sided approach.CONCLUSIONSThis study demonstrated that resection of craniopharyngiomas is frequently associated with postoperative neuropsychological deficits and hence an impaired quality of life. In addition to tumor size and extension toward/into the third ventricle or the brainstem, selection of the surgical approach may play a crucial role in the patient’s neuropsychological outcome and quality of life.
Effect of glycolysis inhibition by miR-448 on glioma radiosensitivity
Authors: Lan Fengming , Qin Qing , Yu Huiming , Yue Xiao 
Published: April 2019

OBJECTIVEAlthough glucose metabolism reengineering is a typical feature of various tumors, including glioma, key regulators of glycolytic reprogramming are still poorly understood. The authors sought to investigate whether glycolysis inhibition by microRNA (miR)–448 increases radiosensitivity in glioma cells.METHODSThe authors used glioma tissue samples from glioma patients, cells from glioblastoma (GBM) cell lines and normal human astrocyte cells, and subcutaneous tumor–bearing U87 cells in mice to examine the effects of signaling regulation by miR-448 in the response of glioma tissues and cells to radiation treatment. Techniques used for investigation included bioinformatics analyses, biochemical assays, luciferase reporter assays, and establishment of subcutaneous tumors in a mouse model. Glucose consumption, LDH activity, and cellular ATP were measured to determine the ability of glioma cells to perform glycolysis. Expression of HIF-1α was measured as a potential target gene of miR-448 in glycolysis.RESULTSmiR-448 was detected and determined to be significantly downregulated in both glioma tissues from glioma patients and GBM cell lines. Furthermore, miR-448 acted as a tumor-inhibiting factor and suppressed glycolysis in glioma by negatively regulating the activity of HIF-1α signaling and then interfering with its downstream regulators relative to glycolysis, HK1, HK2, and LDHA. Interestingly, overexpression of miR-448 increased the x-radiation sensitivity of glioma cells. Finally, in in vivo experiments, subcutaneous tumor–bearing U87 cells in a mouse model verified that high expression of miR-448 also enhanced glioma radiosensitivity via inhibiting glycolytic factors.CONCLUSIONSmiR-448 can promote radiosensitivity by inhibiting HIF-1α signaling and then negatively controlling the glycolysis process in glioma. A newly identified miR-448–HIF-1α axis acts as a potentially valuable therapeutic target that may be useful in overcoming radioresistance in glioma treatment.
Full tractography for detecting the position of cranial nerves in preoperative planning for skull base surgery: technical note
Authors: Jacquesson Timothee , Yeh Fang-Chang , Panesar Sandip , Barrios Jessica , Attyé Arnaud , Frindel Carole , Cotton Francois , Gardner Paul , Jouanneau Emmanuel , Fernandez-Miranda Juan C. 
Published: April 2019

OBJECTIVEDiffusion imaging tractography has allowed the in vivo description of brain white matter. One of its applications is preoperative planning for brain tumor resection. Due to a limited spatial and angular resolution, it is difficult for fiber tracking to delineate fiber crossing areas and small-scale structures, in particular brainstem tracts and cranial nerves. New methods are being developed but these involve extensive multistep tractography pipelines including the patient-specific design of multiple regions of interest (ROIs). The authors propose a new practical full tractography method that could be implemented in routine presurgical planning for skull base surgery.METHODSA Philips MRI machine provided diffusion-weighted and anatomical sequences for 2 healthy volunteers and 2 skull base tumor patients. Tractography of the full brainstem, the cerebellum, and cranial nerves was performed using the software DSI Studio, generalized-q-sampling reconstruction, orientation distribution function (ODF) of fibers, and a quantitative anisotropy–based generalized deterministic algorithm. No ROI or extensive manual filtering of spurious fibers was used. Tractography rendering was displayed in a tridimensional space with directional color code. This approach was also tested on diffusion data from the Human Connectome Project (HCP) database.RESULTSThe brainstem, the cerebellum, and the cisternal segments of most cranial nerves were depicted in all participants. In cases of skull base tumors, the tridimensional rendering permitted the visualization of the whole anatomical environment and cranial nerve displacement, thus helping the surgical strategy.CONCLUSIONSAs opposed to classical ROI-based methods, this novel full tractography approach could enable routine enhanced surgical planning or brain imaging for skull base tumors.
The post-aSAH syndrome: a self-reported cluster of symptoms in patients with aneurysmal subarachnoid hemorrhage
Authors: Haug Nordenmark Tonje , Karic Tanja , Røe Cecilie , Sorteberg Wilhelm , Sorteberg Angelika 
Published: April 2019

OBJECTIVEAlthough many patients recover to a good functional outcome after aneurysmal subarachnoid hemorrhage (aSAH), residual symptoms are very common and may have a large impact on the patient’s daily life. The particular cluster of residual symptoms after aSAH has not previously been described in detail and there is no validated questionnaire that covers the typical problems reported after aSAH. Many of the symptoms are similar to post-concussion syndrome, which often is evaluated with the Rivermead Post-Concussion Symptoms Questionnaire (RPQ). In the present study, the authors therefore performed an exploratory use of the RPQ as a template to describe post-aSAH syndrome.METHODSThe RPQ was administered to 128 patients in the chronic phase after aSAH along with a battery of quality-of-life questionnaires. The patients also underwent a medical examination besides cognitive and physical testing. Based on their RPQ scores, patients were dichotomized into a “syndrome” group or “recovery” group.RESULTSA post-aSAH syndrome was seen in 33% of the patients and their symptom burden on all RPQ subscales was significantly higher than that of patients who had recovered on all RPQ subscales. The symptom cluster consisted mainly of fatigue, cognitive problems, and emotional problems. Physical problems were less frequently reported. Patients with post-aSAH syndrome scored significantly worse on mobility and pain scores, as well as on quality-of-life questionnaires. They also had significantly poorer scores on neuropsychological tests of verbal learning, verbal short- and long-term memory, psychomotor speed, and executive functions. Whereas 36% of the patients in the recovery group were able to return to their premorbid occupational status, this was true for only 1 patient in the syndrome group.CONCLUSIONSApproximately one-third of aSAH patients develop a post-aSAH syndrome. These patients struggle with fatigue and cognitive and emotional problems. Patients with post-aSAH syndrome report more pain and reduced quality of life compared to patients without this cluster of residual symptoms and have larger cognitive deficits. In this sample, patients with post-aSAH syndrome were almost invariably excluded from return to work. The RPQ is a simple questionnaire covering the specter of residual symptoms after aSAH. Being able to acknowledge these patients’ complaints as a defined syndrome using the RPQ should help patients to accept and cope, thereby alleviating possible secondary distress produced.
Validation of a freehand technique for cortical bone trajectory screws in the lumbar spine
Authors: Tan Zachary , McLachlin Stewart , Whyne Cari , Finkelstein Joel 
Published: April 2019

OBJECTIVEThe cortical bone trajectory (CBT) technique for pedicle screw placement has gained popularity among spinal surgeons. It has been shown biomechanically to provide better fixation and improved pullout strength compared to a traditional pedicle screw trajectory. The CBT technique also allows for a less invasive approach for fusion and may have lower incidence of adjacent-level disease. A limitation of the current CBT technique is a lack of readily identifiable and reproducible visual landmarks to guide freehand CBT screw placement in comparison to the well-defined identifiable landmarks for traditional pedicle screw insertion. The goal of this study was to validate a safe and intuitive freehand technique for placement of CBT screws based on optimization of virtual CBT screw placement using anatomical landmarks in the lumbar spine. The authors hypothesized that virtual identification of anatomical landmarks on 3D models of the lumbar spine generated from CT scans would translate to a safe intraoperative freehand technique.METHODSCustomized, open-source medical imaging and visualization software (3D Slicer) was used in this study to develop a workflow for virtual simulation of lumbar CBT screw insertion. First, in an ex vivo study, 20 anonymous CT image series of normal and degenerative lumbar spines and virtual screw insertion were conducted to place CBT screws bilaterally in the L1–5 vertebrae for each image volume. The optimal safe CBT trajectory was created by maximizing both the screw length and the cortical bone contact with the screw. Easily identifiable anatomical surface landmarks for the start point and trajectory that best allowed the reproducible idealized screw position were determined. An in vivo validation of the determined landmarks from the ex vivo study was then performed in 10 patients. Placement of virtual “test” cortical bone trajectory screws was simulated with the surgeon blinded to the real-time image-guided navigation, and the placement was evaluated. The surgeon then placed the definitive screw using image guidance.RESULTSFrom the ex vivo study, the optimized technique and landmarks were similar in the L1–4 vertebrae, whereas the L5 optimized technique was distinct. The in vivo validation yielded ideal, safe, and unsafe screws in 62%, 16%, and 22% of cases, respectively. A common reason for the nonidealized trajectories was the obscuration of patient anatomy secondary to severe degenerative changes.CONCLUSIONSCBT screws were placed ideally or safely 78% of the time in a virtual simulation model. A 22% rate of unsafe freehand trajectories suggests that the CBT technique requires use of image-guided navigation or x-ray guidance and that reliable freehand CBT screw insertion based on anatomical landmarks is not reliably feasible in the lumbar spine.
Predictors of endoscopic third ventriculostomy ostomy status in patients who experience failure of endoscopic third ventriculostomy with choroid plexus cauterization
Authors: Hale Andrew T. , Stanton Amanda N. , Zhao Shilin , Haji Faizal , Gannon Stephen R. , Arynchyna Anastasia , Wellons John C. , Rocque Brandon G. , Naftel Robert P. 
Published: April 2019

OBJECTIVEAt failure of endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC), the ETV ostomy may be found to be closed or open. Failure with a closed ostomy may indicate a population that could benefit from evolving techniques to keep the ostomy open and may be candidates for repeat ETV, whereas failure with an open ostomy may be due to persistently abnormal CSF dynamics. This study seeks to identify clinical and radiographic predictors of ostomy status at the time of ETV/CPC failure.METHODSThe authors conducted a multicenter, retrospective cohort study on all pediatric patients with hydrocephalus who failed initial ETV/CPC treatment between January 2013 and October 2016. Failure was defined as the need for repeat ETV or ventriculoperitoneal (VP) shunt placement. Clinical and radiographic data were collected, and ETV ostomy status was determined endoscopically at the subsequent hydrocephalus procedure. Statistical analysis included the Mann-Whitney U-test, Wilcoxon rank-sum test, t-test, and Pearson chi-square test where appropriate, as well as multivariate logistic regression.RESULTSOf 72 ETV/CPC failures, 28 patients (39%) had open-ostomy failure and 44 (61%) had closed-ostomy failure. Patients with open-ostomy failure were older (median 5.1 weeks corrected age for gestation [interquartile range (IQR) 0.9–15.9 weeks]) than patients with closed-ostomy failure (median 0.2 weeks [IQR −1.3 to 4.5 weeks]), a significant difference by univariate and multivariate regression. Etiologies of hydrocephalus included intraventricular hemorrhage of prematurity (32%), myelomeningocele (29%), congenital communicating (11%), aqueductal stenosis (11%), cyst/tumor (4%), and other causes (12%). A wider baseline third ventricle was associated with open-ostomy failure (median 15.0 mm [IQR 10.3–18.5 mm]) compared to closed-ostomy failure (median 11.7 mm [IQR 8.9–16.5 mm], p = 0.048). Finally, at the time of failure, patients with closed-ostomy failure had enlargement of their ventricles (frontal and occipital horn ratio [FOHR], failure vs baseline, median 0.06 [IQR 0.00–0.11]), while patients with open-ostomy failure had no change in ventricle size (median 0.01 [IQR −0.04 to 0.05], p = 0.018). Previous CSF temporizing procedures, intraoperative bleeding, and time to failure were not associated with ostomy status at ETV/CPC failure.CONCLUSIONSOlder corrected age for gestation, larger baseline third ventricle width, and no change in FOHR were associated with open-ostomy ETV/CPC failure. Future studies are warranted to further define and confirm features that may be predictive of ostomy status at the time of ETV/CPC failure.