Three scans are better than two for follow-up: An automatic method for finding missed and misidentified lesions in cross-sectional follow-up of oncology patients.

PURPOSE: Missed and misidentified neoplastic lesions in longitudinal studies of oncology patients are pervasive and may affect the evaluation of the disease status. Two newly identified patterns of lesion changes, lone lesions and non-consecutive lesion changes, may help radiologists to detect these lesions. This study evaluated a new interpretation revision workflow of lesion annotations in three or more consecutive scans based on these suspicious patterns. METHODS: The interpretation revision workflow was evaluated on manual and computed lesion annotations in longitudinal oncology patient studies. For the manual revision, a senior radiologist and a senior neurosurgeon (the readers) manually annotated the lesions in each scan and later revised their annotations to identify missed and misidentified lesions with the workflow using the automatically detected patterns. For the computerized revision, lesion annotations were first computed with a previously trained nnU-Net and were then automatically revised with an AI-based method that automates the workflow readers' decisions. The evaluation included 67 patient studies with 2295 metastatic lesions in lung (19 patients, 83 CT scans, 1178 lesions), liver (18 patients, 77 CECT scans, 800 lesions) and brain (30 patients, 102 T1W-Gad MRI scans, 317 lesions). RESULTS: Revision of the manual lesion annotations revealed 120 missed lesions and 20 misidentified lesions in 31 out of 67 (46%) studies. The automatic revision reduced the number of computed missed lesions by 55 and computed misidentified lesions by 164 in 51 out of 67 (76%) studies. CONCLUSION: Automatic analysis of three or more consecutive volumetric scans helps find missed and misidentified lesions and may improve the evaluation of temporal changes of oncological lesions.

Stereotactic radiosurgery for brain metastases arising from gynecological malignancies: A retrospective treatment outcome analysis.

BACKGROUND: This retrospective study aims to assess the efficacy of stereotactic radiosurgery (SRS) in the treatment of brain metastases (BM) originating from gynecological cancers. It focuses on local control (LC), distant tumor control (DTC), and overall survival (OS). METHODS: The analysis comprised 18 individuals with gynecological-origin BM treated with SRS at the Hadassah Medical Center from 2004 to 2021. Statistical analyses evaluate factors impacting LC, DTC, and OS. RESULTS: A total of 36 BM of gynecological origin underwent SRS. The median age at the first SRS treatment was 60 years, with a median time of 24.5 months from the primary malignancy diagnosis to BM detection. The 12-month LC rate per patient was 84.6 %, and 5.6 % per BM. Only two instances of local recurrence were observed. The DTC at 12 months was 75 %, with a 29 % overall. Non-significant trends indicating a correlation with distant brain failure with increased cumulative volume and the occurrence of craniotomy before SRS. The median OS of the cohort was 16.5 months from SRS treatment. The 6, 12, 18, and 24-month survival rates were 77.8 %, 66.7 %, 50 %, and 22.2 % respectively. Higher number of BM was associated with lower OS (p = 0.046). On multivariate analysis, age was a significant factor for OS (p = 0.03), demonstrating that older age was associated with a more favorable prognosis. CONCLUSION: This study supports SRS effectiveness for treating BM from gynecological cancers and suggests similar outcomes to more common malignancies.

Two is better than one: longitudinal detection and volumetric evaluation of brain metastases after Stereotactic Radiosurgery with a deep learning pipeline.

PURPOSE: Close MRI surveillance of patients with brain metastases following Stereotactic Radiosurgery (SRS) treatment is essential for assessing treatment response and the current disease status in the brain. This follow-up necessitates the comparison of target lesion sizes in pre- (prior) and post-SRS treatment (current) T1W-Gad MRI scans. Our aim was to evaluate SimU-Net, a novel deep-learning model for the detection and volumetric analysis of brain metastases and their temporal changes in paired prior and current scans. METHODS: SimU-Net is a simultaneous multi-channel 3D U-Net model trained on pairs of registered prior and current scans of a patient. We evaluated its performance on 271 pairs of T1W-Gad MRI scans from 226 patients who underwent SRS. An expert oncological neurosurgeon manually delineated 1,889 brain metastases in all the MRI scans (1,368 with diameters > 5 mm, 834 > 10 mm). The SimU-Net model was trained/validated on 205 pairs from 169 patients (1,360 metastases) and tested on 66 pairs from 57 patients (529 metastases). The results were then compared to the ground truth delineations. RESULTS: SimU-Net yielded a mean (std) detection precision and recall of 1.00±0.00 and 0.99±0.06 for metastases > 10 mm, 0.90±0.22 and 0.97±0.12 for metastases > 5 mm of, and 0.76±0.27 and 0.94±0.16 for metastases of all sizes. It improves lesion detection precision by 8% for all metastases sizes and by 12.5% for metastases < 10 mm with respect to standalone 3D U-Net. The segmentation Dice scores were 0.90±0.10, 0.89±0.10 and 0.89±0.10 for the above metastases sizes, all above the observer variability of 0.80±0.13. CONCLUSION: Automated detection and volumetric quantification of brain metastases following SRS have the potential to enhance the assessment of treatment response and alleviate the clinician workload.

[CURRENT TRENDS IN ISRAELI NEUROSURGERY].

INTRODUCTION: In the current issue of the "Harefuah" journal, original research articles and review articles describe current trends in advanced innovative technologies implemented in neurosurgery departments in Israel in the last decade. The articles present the implications of these technologies on the quality and safety of care of neurosurgical patients. The leading current trends include the development of subspecialties within neurosurgery and the restructuring of departments to reflect this, the integration of inter- and intra-disciplinary collaborations into patient management, the development of minimally invasive techniques, the advancement of epilepsy and functional neurosurgery in Israel and the use of non-surgical therapeutics. Workflow methods and innovative technologies that improve treatment efficiency and patient safety that have been implemented are presented and discussed. The current issue reports on original research works carried out in the various departments in Israel and review articles on the relevant topics.

[GLIOBLASTOMA MULTIFORME AFTER STEREOTACTIC RADIOSURGERY TREATMENT FOR ARTERIO-VENOUS MALFORMATION].

INTRODUCTION: Stereotactic radiosurgery (SRS) is a minimally invasive option commissioned in the treatment of intracranial arteriovenous malformations (AVMs). As long-term follow-up data became available, some late adverse effects have been reported, including SRS-induced neoplasia. However, the exact incidence of this adverse effect is unknown. In this article we present and discuss the topic with an unusual case of a young patient who was treated with SRS for AVM and developed a malignant brain tumor.

Flow-diverter stents in the early management of acutely ruptured brain aneurysms: effective rebleeding protection with low thromboembolic complications.

OBJECTIVE: Flow-diverter stents (FDSs) are not generally used for the management of acutely ruptured aneurysms with associated subarachnoid hemorrhage (SAH). Herein, the authors present their experience with FDSs in this scenario, focusing on the antiplatelet regimen, perioperative management, and outcome. METHODS: The authors retrospectively reviewed their institutional database for the treatment and outcomes of all patients with acutely ruptured aneurysms and associated SAH from July 2010 to September 2018 who had received an FDS implant as stand-alone treatment within 4 days after diagnosis. The protocol with the use of flow diversion in these patients includes a low threshold for placement of external ventricular drains before stenting, followed by the administration of aspirin and clopidogrel with platelet testing before stent implantation. With this approach, the risk of hemorrhage and stent-related thrombus formation is limited. Demographic, clinical, technical, and imaging data were analyzed. RESULTS: Overall, 76 patients (61% females, mean age 42.8 ± 11.3 years) met the inclusion criteria. FDS implantation was performed a median of 2 days after diagnosis. On average, 1.05 devices were used per procedure. There was no procedural mortality directly attributed to the endovascular intervention. Procedural device-related clinical complications were recorded in a total of 6 cases (7.9%) and resulted in permanent neurological morbidity in 2 cases (2.6%). There was complete immediate aneurysm occlusion in 11 patients (14.5%), and persistent aneurysm filling was seen in 65 patients (85.5%). Despite this, no patient presented with rebleeding from the target aneurysm. There was an excellent clinical outcome in 62 patients (81.6%), who had a 90-day modified Rankin Scale score of 0-2. Among the 71 survivors, total or near-total occlusion was observed in 64/67 patients (95.5%) with a 3- to 6-month angiographic follow-up and in all cases evaluated at 12 months. Five patients (6.6%) died during follow-up for reasons unrelated to the procedure or new hemorrhage. CONCLUSIONS: Flow diversion is an effective therapeutic strategy for the management of select acutely ruptured aneurysms. Despite low rates of immediate aneurysm occlusion after FDS implantation, the device exerts an important protective effect. The authors' experience confirmed no aneurysm rerupture, high rates of delayed complete occlusion, and complication rates that compare favorably with the rates obtained using other techniques.

[18F]-FDHT PET/CT as a tool for imaging androgen receptor expression in high-grade glioma.

BACKGROUND: G lioblastoma (GBM) is associated with poor overall survival. Recently, we showed that androgen receptor (AR) protein is overexpressed in 56% of GBM specimens and AR antagonists induced dose-dependent death in several GBM cell lines and significantly reduced tumor growth and prolonged the lifespan of mice implanted with human GBM. 16ß-18F-fluoro-5α-dihydrotestosterone ([18F]-FDHT) is a positron emission tomography (PET) tracer used to detect AR expression in prostate and breast cancers. This study was aimed at exploring the ability of [18F]-FDHT-PET to detect AR expression in high-grade gliomas. METHODS: Twelve patients with suspected high-grade glioma underwent a regular workup and additional dynamic and static [18F]-FDHT-PET/CT. Visual and quantitative analyses of [18 F]-FDHT kinetics in the tumor and normal brain were performed. Mean and maximum (max) standardized uptake values (SUVs) were determined in selected volumes of interest. The patients had surgery or biopsy after PET/CT. AR protein was analyzed in the tumor samples by western blot. Fold change in AR expression was calculated by densitometry analysis. Correlation between imaging and AR protein samples was determined. RESULTS: In six of the 12 patients, [18 F]-FDHT uptake was significantly higher in the tumor than in the normal brain. These patients also had increased AR protein expression within the tumor. Pearson correlation coefficient analysis for the tumor-to-control normal brain uptake ratio in terms of SUVmean versus AR protein expression was positive and significant (R = 0.84; P = .002). CONCLUSION: [18 F]-FDHT-PET/CT could identify increased AR expression in high-grade glioma.

VHL-Related Neuroendocrine Neoplasms And Beyond: An Israeli Specialized Center Real-Life Report.

OBJECTIVE: Von Hippel-Lindau (VHL) syndrome is a rare and complex disease. In 1996, we described a 3 generation VHL 2A kindred with 11 mutation carriers. We aim to share our experience regarding the long-term follow-up of this family and the management of all our other VHL patients focusing on frequently encountered neuroendocrine neoplasms: pheochromocytoma/paraganglioma and pancreatic neuroendocrine neoplasms (PNEN). METHODS: All VHL patients in follow-up at our tertiary center from 1980 to 2019 were identified. Clinical, laboratory, imaging, and therapeutic characteristics were retrospectively analyzed. RESULTS: We identified 32 VHL patients in 16 different families, 7/16 were classified as VHL 2 subtype. In the previously described family, the 4 initially asymptomatic carriers developed a neuroendocrine tumor; 7 new children were born, 3 of them being mutation carriers; 2 patients died, 1 due to metastatic PNEN-related liver failure. Pheochromocytoma was frequent (22/32), bilateral (13/22;59%), often diagnosed in early childhood when active screening was timely performed, associated with paraganglioma in 5/22, rarely malignant (1/22), and recurred after surgery in some cases after more than 20 years. PNEN occurred in 8/32 patients (25%), and was metastatic in 3 patients. Surgery and palliative therapy allowed relatively satisfactory outcomes. Severe disabling morbidities due to central-nervous system and ophthalmologic hemangiomas, and other rare tumors as chondrosarcoma in 2 patients and polycythemia in 1 patient were observed. CONCLUSION: A multidisciplinary approach and long-term follow-up is mandatory in VHL patients to manage the multiple debilitating morbidities and delay mortality in these complex patients.

Radiation-induced vascular malformations in the brain, mimicking tumor in MRI-based treatment response assessment maps (TRAMs).

•Of 310 brain tumors patients recruited, histology of 99 lesions was available.•Of those, 5 were histologically confirmed as radiation-induced malformations.•TRAMs cannot differentiate active tumor from vascular malformation.

The clinical characteristics of posttraumatic epilepsy following moderate-to-severe traumatic brain injury in children.

PURPOSE: Children with traumatic brain injury (TBI) are at increased risk of posttraumatic epilepsy (PTE); the risk increases according to TBI severity. We examined the long-term incidence and risk factors for developing PTE in a cohort of children hospitalised at one medical centre with moderate or severe TBI. METHODS: Moderate brain injury was classified as Glasgow Coma Score on Arrival (GCSOA) of 9-13, and severe brain injury as GCSOA ≤8. We collected demographics and clinical data from medical records and interviewed patients and parents at 5-11 years following the TBI event. RESULTS: During a median follow-up period of 7.3 years, 9 (9%) of 95 children with moderate-to-severe TBI developed PTE; 4 developed intractable epilepsy. The odds for developing PTE was 2.9 in patients with severe compared to moderate TBI. CT findings showed fractures in 7/9 (78%) of patients with PTE, compared to 40/86 (47%) of those without PTE (p = 0.09). Of the patients with fractures, all those with PTE had additional features on CT (such as haemorrhage, contusion and mass effect), compared to 29/40 (73%) of those without PTE. One of nine (11%) PTE patients and 10 of 86 (12%) patients without PTE had immediate seizures. Two (22%) children with PTE had their first seizure more than 2 years after the TBI. CONCLUSION: Among children with moderate or severe TBI, the presence of additional CT findings, other than skull fractures, seem to increase the risk of PTE. In our cohort, the occurrence of an early seizure did not confer an increased risk of PTE.

Prevalence, Characteristics, and Long-Term Prognosis of Epilepsy Associated with Pediatric Brain Tumors.

OBJECTIVE: We investigated the prevalence, onset, characteristics, and long-term course of epilepsy disease in children who underwent surgical intervention for diagnosed brain tumors. METHODS: We reviewed the medical records of children with diagnosed brain tumors who underwent surgery during 2004-2014 at the Hadassah Medical Center. All patients with epilepsy were invited to a clinical visit that included a neurologic examination. The primary outcome measures were neurologic status according to the Glasgow outcome score (GOS) and postoperative seizure outcome according to the Engel system. We compared clinical characteristics according to the timing of epilepsy onset. RESULTS: The mean follow-up was 49 months. Of 128 patients included in the study, 44 (34%) had seizures; 23 (18%) developed epilepsy after surgery. Of the 30 patients with epilepsy who survived, 21 (70%) are in Engel class I and 13% Engel are in class II. Forty-five percent of the children are classified as GOS 5. Children who developed epilepsy after surgery were more likely to be in GOS 1-2 than were those who had seizures before surgery (P = 0.0173). Children with seizures were more likely to have cortical tumors and less likely to have tumors of the posterior fossa (P < 0.001). Children who underwent gross total resection were less likely to have epilepsy (P < 0.001). CONCLUSIONS: We show a high incidence of epilepsy in the late course of pediatric brain tumor disease. In the long term, seizure outcome was excellent. However, postsurgical onset of epilepsy was associated with a less favorable neurologic outcome.

Computer-based radiological longitudinal evaluation of meningiomas following stereotactic radiosurgery.

PURPOSE: Stereotactic radiosurgery (SRS) is a common treatment for intracranial meningiomas. SRS is planned on a pre-therapy gadolinium-enhanced T1-weighted MRI scan (Gd-T1w MRI) in which the meningioma contours have been delineated. Post-SRS therapy serial Gd-T1w MRI scans are then acquired for longitudinal treatment evaluation. Accurate tumor volume change quantification is required for treatment efficacy evaluation and for treatment continuation. METHOD: We present a new algorithm for the automatic segmentation and volumetric assessment of meningioma in post-therapy Gd-T1w MRI scans. The inputs are the pre- and post-therapy Gd-T1w MRI scans and the meningioma delineation in the pre-therapy scan. The output is the meningioma delineations and volumes in the post-therapy scan. The algorithm uses the pre-therapy scan and its meningioma delineation to initialize an extended Chan-Vese active contour method and as a strong patient-specific intensity and shape prior for the post-therapy scan meningioma segmentation. The algorithm is automatic, obviates the need for independent tumor localization and segmentation initialization, and incorporates the same tumor delineation criteria in both the pre- and post-therapy scans. RESULTS: Our experimental results on retrospective pre- and post-therapy scans with a total of 32 meningiomas with volume ranges 0.4-26.5 cm[Formula: see text] yield a Dice coefficient of [Formula: see text]% with respect to ground-truth delineations in post-therapy scans created by two clinicians. These results indicate a high correspondence to the ground-truth delineations. CONCLUSION: Our algorithm yields more reliable and accurate tumor volume change measurements than other stand-alone segmentation methods. It may be a useful tool for quantitative meningioma prognosis evaluation after SRS.

Posttraumatic epilepsy: long-term follow-up of children with mild traumatic brain injury.

OBJECTIVE Posttraumatic epilepsy (PTE) is a known complication of traumatic brain injury (TBI). The true incidence of PTE in children is still uncertain, because most research has been based primarily on adults. This study aimed to determine the true incidence of PTE in a pediatric population with mild TBI (MTBI) and to identify risk factors for the development of epileptic events. METHODS Data were collected from electronic medical records of children 0-17 years of age, who were admitted to a single medical center between 2007 and 2009 with a diagnosis of MTBI. This prospective research consisted of a telephone survey between 2015 and 2016 of children or their caregivers, querying for information about epileptic episodes and current seizure and neurological status. The primary outcome measure was the incidence of epilepsy following TBI, which was defined as ≥ 2 unprovoked seizure episodes. Posttraumatic seizure (PTS) was defined as a single, nonrecurrent convulsive episode that occurred > 24 hours following injury. Seizures within 24 hours of the injury were defined as immediate PTS. RESULTS Of 290 children eligible for this study, 191 of them or their caregivers were reached by telephone survey and were included in the analysis. Most injuries (80.6%) were due to falls. Six children had immediate PTS. All children underwent CT imaging; of them, 72.8% demonstrated fractures and 10.5% did not demonstrate acute findings. The mean follow-up was 7.4 years. Seven children (3.7%) experienced PTS; of them, 6 (85.7%) developed epilepsy and 3 (42.9%) developed intractable epilepsy. The overall incidence of epilepsy and intractable epilepsy in this cohort was 3.1% and 1.6%, respectively. None of the children who had immediate PTS developed epilepsy. Children who developed epilepsy spent an average of 2 extra days in the hospital at the time of the injury. The mean time between trauma and onset of seizures was 3.1 years. Immediate PTS was not correlated with PTE. CONCLUSIONS In this analysis of data from medical records and long-term follow-up, MTBI was found to confer increased risk for the development of PTE and intractable PTE, of 4.5 and 8 times higher, respectively. As has been established in adults, these findings confirm that MTBI increases the risk for PTE in the pediatric population.

Clinical Significance of Long-Term Follow-Up of Children with Posttraumatic Skull Base Fracture.

OBJECTIVE: To assess the incidence of cerebrospinal fluid (CSF) leak and meningitis, and the need for prophylactic antibiotics, antipneumococcal vaccination, and surgical interventions, in children with a skull base fracture. METHODS: We reviewed the records of children with a skull base fracture who were admitted to our tertiary care center between 2009 and 2014. RESULTS: A total of 196 children (153 males), age 1 month to 18 years (mean age, 6 ± 4 years), were hospitalized with skull base fracture. Causes of injury were falls (n = 143), motor vehicle accidents (n = 34), and other (n = 19). Fracture locations were the middle skull base in 112 patients, frontal base in 62, and occipital base in 13. Fifty-four children (28%) had a CSF leak. In 34 of these children (63%), spontaneous resolution occurred within 3 days. Three children underwent surgery on admission owing to a CSF leak from an open wound, 3 underwent CSF diversion by spinal drainage, and 4 (2%) required surgery to repair a dural tear after failure of continuous spinal drainage and acetazolamide treatment. Twenty-eight children (14%) received prophylactic antibiotic therapy, usually due to other injuries, and 11 received pneumococcal vaccination. Two children developed meningitis, and 3 children died. Long-term follow up in 124 children revealed 12 children with delayed hearing loss and 3 with delayed facial paralysis. CONCLUSIONS: This is the largest pediatric series of skull base fractures reporting rates of morbidity and long-term outcomes published to date. The rate of meningitis following skull base fracture in children is low, supporting a policy of not administering prophylactic antibiotics or pneumococcal vaccine. Long-term follow up is important to identify delayed complications.

Idiopathic bilateral occlusion of the foramen of Monro: An unusual entity with varied clinical presentations.

We review our experience with four patients who presented to our Medical Center from 2005-2015 with adult idiopathic occlusion of the foramen of Monro (FM). All patients underwent CT scanning and MRI. Standard MRI was performed in each patient to rule out a secondary cause of obstruction (T1-weighted without- and with gadolinium, T2-weighted, fluid-attenuated inversion recovery [FLAIR] and diffusion-weighted imaging [DWI] protocols). When occlusion of the FM appeared to be idiopathic, further high-resolution MRI with multiplanar reconstructions for evaluation of stenosis or an occluding membrane at the level of the FM was performed (T1-weighted without- and with gadolinium, T2-weighted 3D turbo spin-echo). Occlusion of the FM was due to unilateral stenosis and septum pellucidum deviation in two patients, to an occluding membrane in one, and to bilateral stenosis in one patient. Urgent surgical intervention is mandatory when there are signs of increased intracranial pressure while asymptomatic patients may be managed conservatively. In this patient series, truly bilateral stenotic obstruction of the FM was best managed with ventriculoperitoneal shunt and patients with membranous obstruction or unilateral stenosis with septum deviation were treated endoscopically.

Evaluation of the necessity of hospitalization in children with an isolated linear skull fracture (ISF).

OBJECTIVE: The prevalence of skull fractures after mild head trauma is 2 % in children of all ages and 11 % in children younger than 2 years. The current standard management for a child diagnosed with an isolated skull fracture (ISF), in our institute, is hospitalization for a 24-h observation period. Based on data from the literature, less than 1 % of all minor head injuries require neurosurgical intervention. The main objective of this study was to evaluate the risk of neurological deterioration of ISF cases, in order to assess the need for hospitalization. METHODS: We reviewed the medical charts of 222 children who were hospitalized from 2006 to 2012 with ISF and Glascow Coma Scale-15 at the time of arrival. We collected data regarding demographic characteristics, mechanism of injury, fracture location, clinical symptoms and signs, need for hospitalization, and need for repeated imaging. Data was collected at three time points: at presentation to the emergency room, during hospitalization, and 1 month after admission, when the patients' parents were asked about the course of the month following discharge. RESULTS: None of the 222 children included in the study needed neurosurgical intervention. All were asymptomatic 1 month after the injury. Two children underwent repeated head CT due to persistence or worsening of symptoms; these CT scans did not reveal any new findings and did not lead to any intervention whatsoever. CONCLUSION: Children arriving at the emergency room with a minor head injury and isolated skull fracture on imaging studies may be considered for discharge after a short period of observation. Discharge should be considered in these cases provided the child has a reliable social environment and responsible caregivers who are able to return to the hospital if necessary. Hospital admission should be reserved for children with neurologic deficits, persistent symptoms, suspected child abuse, or when the parent is unreliable or is unable to return to the hospital if necessary. Reducing unnecessary hospitalizations can prevent emotional stress, in addition to saving costs for the child's family and the health care system.

Review of controversies in management of non-benign meningioma.

Meningiomas are one of the most common brain tumors. World Health Organisation (WHO) Grade II and Grade III meningiomas are grouped together as non-benign meningioma (NBM). There are several controversies surrounding NBM management, including the significance of extent of resection and the efficacy of post-operative radiation and drug treatment. We reviewed the literature to develop recommendations for management of NBM. The questions we sought to answer were: Does gross total resection (GTR) improve patient outcome? Is radiation therapy (RT) warranted after complete or after incomplete resection of NBM? What drug therapies have been proven to improve outcome in patients with NBM? We found that GTR improves outcome in WHO Grade II meningioma, and should be attempted whenever considered safe. GTR correlates less closely to outcome in Grade III meningioma compared to subtotal resection (STR). Extreme measures to completely resect Grade III meningioma are not warranted. RT following GTR of Grade II meningioma does not improve patient outcome, and may be reserved for recurrence. RT improves outcome following STR of Grade II meningioma. RT improves outcome after resection of Grade III meningioma. No drug therapy has been shown to improve outcome in NBM. This review elucidates recommendations for some of the controversies involving NBM.

Ventriculoperitoneal shunt malfunction caused by proximal catheter fat obstruction.

Ventriculoperitoneal (VP) shunt placement is the mainstay of treatment for hydrocephalus, yet shunts remain vulnerable to a variety of complications. Although fat droplet migration into the subarachnoid space and cerebrospinal fluid pathways following craniotomy has been observed, a VP shunt obstruction with fat droplets has never been reported to our knowledge. We present the first reported case of VP shunt catheter obstruction by migratory fat droplets in a 55-year-old woman who underwent suboccipital craniotomy for removal of a metastatic tumor of the left medullocerebellar region, without fat harvesting. A VP shunt was inserted 1month later due to communicating hydrocephalus. The patient presented with gait disturbance, intermittent confusion, and pseudomeningocele 21days after shunt insertion. MRI revealed retrograde fat deposition in the ventricular system and VP shunt catheter, apparently following migration of fat droplets from the fatty soft tissue of the craniotomy site. Spinal tap revealed signs of aseptic meningitis. Steroid treatment for aseptic "lipoid" meningitis provided symptom relief. MRI 2months later revealed partial fat resorption and resolution of the pseudomeningocele. VP shunt malfunction caused by fat obstruction of the ventricular catheter should be acknowledged as a possible complication in VP shunts after craniotomy, even in the absence of fat harvesting.

Supraciliary keyhole craniotomy for anterior frontal lesions in children.

Treatment for anterior frontal space occupying lesions such as epidural hematoma, vascular malformations or brain tumors, have typically involved invasive craniotomies. This method often requires large incisions with wide exposure and may be associated with high morbidity rates. The basis for the "keyhole" method is that a minimally invasive craniotomy is often sufficient for exposing large areas deep in tissue, and may limit exposure and decrease surgically related morbidity while enabling adequate removal and decompression. The supraciliary method includes a cut above the eyebrow and a small craniotomy to uncover the base of the frontal lobe and the orbital roof. We demonstrate our experience with this method. We identified children who were operated via the supraciliary approach between January 2009 and December 2013, and gathered their pre- and post-operative clinical and radiological statistics. Fourteen patients were identified. Pathologies included tumors, abscesses and epidural hematomas. Nine were operated due to epidural hematoma, two due to tumors, two due to brain abscesses, and one for anterior encephalocele. No significant peri-operative or post-operative complications were observed. Long-term follow-up shows that the surgical scars were nearly invisible. The supraciliary approach is a safe, effective and elegant technique for treating lesions in the anterior skull base. The method should be weighed alongside traditional methods on a case-by-case basis.

Delayed contrast extravasation MRI: a new paradigm in neuro-oncology.

BACKGROUND: Conventional magnetic resonance imaging (MRI) is unable to differentiate tumor/nontumor enhancing tissues. We have applied delayed-contrast MRI for calculating high resolution treatment response assessment maps (TRAMs) clearly differentiating tumor/nontumor tissues in brain tumor patients. METHODS: One hundred and fifty patients with primary/metastatic tumors were recruited and scanned by delayed-contrast MRI and perfusion MRI. Of those, 47 patients underwent resection during their participation in the study. Region of interest/threshold analysis was performed on the TRAMs and on relative cerebral blood volume maps, and correlation with histology was studied. Relative cerebral blood volume was also assessed by the study neuroradiologist. RESULTS: Histological validation confirmed that regions of contrast agent clearance in the TRAMs >1 h post contrast injection represent active tumor, while regions of contrast accumulation represent nontumor tissues with 100% sensitivity and 92% positive predictive value to active tumor. Significant correlation was found between tumor burden in the TRAMs and histology in a subgroup of lesions resected en bloc (r(2) = 0.90, P < .0001). Relative cerebral blood volume yielded sensitivity/positive predictive values of 51%/96% and there was no correlation with tumor burden. The feasibility of applying the TRAMs for differentiating progression from treatment effects, depicting tumor within hemorrhages, and detecting residual tumor postsurgery is demonstrated. CONCLUSIONS: The TRAMs present a novel model-independent approach providing efficient separation between tumor/nontumor tissues by adding a short MRI scan >1 h post contrast injection. The methodology uses robust acquisition sequences, providing high resolution and easy to interpret maps with minimal sensitivity to susceptibility artifacts. The presented results provide histological validation of the TRAMs and demonstrate their potential contribution to the management of brain tumor patients.