Primary Leptomeningeal Gliomatosis in Children and Adults

Primary Leptomeningeal Gliomatosis in Children and Adults

Neurosurgery 78:343–352, 2016

Primary leptomeningeal gliomatosis (PLG) is a poorly recognized tumor of the central nervous system.

OBJECTIVE: To describe the histopathological, immunohistochemical, and molecular features of PLG.

METHODS: Results of our multicentric retrospective study of 6 PLG cases (3 pediatric and 3 adult) were compared with literature data.

RESULTS: The mean age was 54.7 years for adults and 8.7 years for children, with 3 males and 3 females. Clinical symptoms were nonspecific. Cerebrospinal fluid analyses showed a high protein level often associated with pleocytosis but without neoplastic cells. On neuroimaging, diffuse leptomeningeal enhancement and hydrocephalus were observed, except in 1 case. PLG was mostly misinterpreted as infectious or tumoral meningitis. The first biopsy was negative in 50% of cases. Histopathologically, PLG cases corresponded to 1 oligodendroglioma without 1p19q codeletion and 5 astrocytomas without expression of p53. No immunostaining for IDH1R132H and no mutations of IDH1/2 and H3F3A genes were found. Overall survival was highly variable (2-82 months) but seems to be increased in children treated with chemotherapy.

CONCLUSION: This study shows the difficulties of PLG diagnosis. The challenge is to achieve an early biopsy to establish a diagnosis and to begin a treatment, but the prognosis remains poor. PLG seems to have a different molecular and immunohistochemical pattern compared with intraparenchymal malignant gliomas.

Surgical assessment of the insula. Part 2: validation of the Berger-Sanai zone classification system for predicting extent of glioma resection

Insular glioma zone classification

J Neurosurg 124:482–488, 2016

Though challenging, maximal safe resection of insular gliomas enhances overall and progression-free survival and deters malignant transformation. Previously published reports have shown that surgery can be performed with low morbidity. The authors previously described a Berger-Sanai zone classification system for insular gliomas. Using a subsequent dataset, they undertook this study to validate this zone classification system for predictability of extent of resection (EOR) in patients with insular gliomas.

Methods The study population included adults who had undergone resection of WHO Grade II, III, or IV insular gliomas. In accordance with our prior published report, tumor location was classified according to the Berger-Sanai quadrant- style classification system into Zones I through IV. Interobserver variability was analyzed using a cohort of newly diagnosed insular gliomas and independent classification scores given by 3 neurosurgeons at various career stages. Glioma volumes were analyzed using FLAIR and T1-weighted contrast-enhanced MR images.

Results One hundred twenty-nine procedures involving 114 consecutive patients were identified. The study population from the authors’ previously published experience included 115 procedures involving 104 patients. Thus, the total experience included 244 procedures involving 218 patients with insular gliomas treated at the authors’ institution. The most common presenting symptoms were seizure (68.2%) and asymptomatic recurrence (17.8%). WHO Grade II glioma histology was the most common (54.3%), followed by Grades III (34.1%) and IV (11.6%). The median tumor volume was 48.5 cm3. The majority of insular gliomas were located in the anterior portion of the insula with 31.0% in Zone I, 10.9% in Zone IV, and 16.3% in Zones I+IV. The Berger-Sanai zone classification system was highly reliable, with a kappa coefficient of 0.857. The median EOR for all zones was 85%. Comparison of EOR between the current and prior series showed no change and Zone I gliomas continue to have the highest median EOR. Short- and long-term neurological complications remain low, and zone classification correlated with short-term complications, which were highest in Zone I and in Giant insular gliomas.

Conclusions The previously proposed Berger-Sanai classification system is highly reliable and predictive of insular glioma EOR and morbidity.

Patients with incidental WHO grade II glioma frequently suffer from neuropsychological disturbances

Plastic relocation of motor cortex in a patient with LGG (low grade glioma) confirmed by NBS (navigated brain stimulation)

Acta Neurochir (2016) 158:305–312

WHO grade II gliomas (low-grade glioma, LGG) are increasingly diagnosed in patients undergoing MRI for many conditions. These patients are classically considered asymptomatic because they do not experience seizures. Although it was previously demonstrated that symptomatic LGG patients frequently have neurocognitive disorders, the literature does not provide data on the neuropsychological status of patients with incidental LGG (iLGG).

Objective Our aim is to investigate whether neurocognitive impairments exist in a homogeneous iLGG population.

Methods We conducted an analysis of pretreatment neuropsychological assessments of patients with iLGG (histologically proven) admitted to our center from 2007 to 2014. We also obtained data on subjective complaints, tumor size and location.

Results Our study focused on 15 iLGG patients. Two thirds reported subjective complaints, mainly tiredness (40 %) and attentional impairment (33 %). Neurocognitive functions were disturbed in 60 % of patients; 53 % had altered executive functions, 20 % had working memory impairment, and 6 % had attentional disturbances. Only one patient with normal preoperative neuropsychological assessment experienced a deficit at the 3-month postoperative examination.

Conclusions For the first time to our knowledge, we suggest that numerous iLGG patients have neuropsychological impairments. Therefore, greater attention should be paid to objective neuropsychological assessment in iLGG because of the high prevalence of insidious cognitive deficits. Moreover, our original findings bring into question the traditional wait-andsee attitude in iLGG, mainly based on the erroneous dogma that these patients have no functional disturbances. Neuropsychological assessment is mandatory to select the best individualized therapeutic management with preservation of quality of life.

Delayed contrast-enhanced MRI for brain metastases

Delayed contrast-enhanced MRI for brain metastases

J Neurosurg 124:489–495, 2016

Contrast-enhanced MRI is the preeminent diagnostic test for brain metastasis (BM). Detection of BMs for stereotactic radiosurgery (SRS) planning may improve with a time delay following administration of a high-relaxivity agent for 1.5-T and 3-T imaging systems. Metastasis detection with time-delayed MRI was evaluated in this study.

Methods Fifty-three volumetric MRI studies from 38 patients undergoing SRS for BMs were evaluated. All studies used 0.1-mmol/kg gadobenate dimeglumine (MultiHance; Bracco Diagnostics) immediately after injection, followed by 2 more axial T1-weighted sequences after 5-minute intervals (final image acquisition commenced 15 minutes after contrast injection). Two studies were motion limited and excluded. Two hundred eighty-seven BMs were identified. The studies were randomized and examined separately by 3 radiologists, who were blinded to the temporal sequence. Each radiologist recorded the number of BMs detected per scan. A Wilcoxon signed-rank test compared BM numbers between scans. One radiologist determined the scan on which BMs were best defined. All confirmed, visible tumors were contoured using iPlan RT treatment planning software on each of the 3 MRI data sets. A linear mixed model was used to analyze volume changes.

Results The interclass correlations for Scans 1, 2, and 3 were 0.7392, 0.7951, and 0.7290, respectively, demonstrating excellent interrater reliability. At least 1 new lesion was detected in the second scan as compared with the first in 35.3% of subjects (95% CI 22.4%–49.9%). The increase in BM numbers between Scans 1 and 2 ranged from 1 to 10. At least 1 new lesion was detected in the third scan as compared with the second in 21.6% of subjects (95% CI 11.3%–35.3%). The increase in BM numbers between Scans 2 and 3 ranged from 1 to 9. Between Scans 1 and 3, additional tumors were seen on 43.1% of scans (increase ranged from 1 to 14). The median increase in tumor number for all comparisons was 1. There was a significant increase in number of BMs detected from Scan 1 to Scan 2 (p < 0.0367) and from Scan 1 to Scan 3 (p < 0.0264). In 34 of the 51 subjects (66.7%), the radiologist selected the third scan as the one providing the clearest tumor definition. There was an average 25.4% increase in BM volume between Scans 1 and 2 (p < 0.0001) and a 9% increase in BM volume between Scans 2 and 3 (p = 0.0001).

Conclusions In patients who are being prepared for SRS of BMs, delayed MRI after contrast injection revealed more targets that needed treatment. In addition, apparent treatment volumes increased with a time delay. To avoid missing tumors that could be treated at the time of planned SRS and resultant “treatment failures,” the authors recommend that postcontrast MR images be acquired between 10 and 15 minutes after injection in patients undergoing SRS for treatment of BMs.

Advanced MRI may complement histological diagnosis of lower grade gliomas and help in predicting survival

Advanced MRI may complement histological diagnosis of lower grade gliomas and help in predicting survival

J Neurooncol (2016) 126:279–288

MRI grading of grade II and III gliomas may have an important impact on treatment decisions. Occasionally, both conventional MRI (cMRI) and histology fail to clearly establish the tumour grade. Three cMRI features (no necrosis; no relevant oedema; absent or faint contrast enhancement) previously validated in 196 patients with supratentorial gliomas directed our selection of 68 suspected low-grade gliomas (LGG) that were also investigated by advanced MRI (aMRI), including perfusion weighted imaging (PWI), diffusion weighted imaging (DWI) and spectroscopy. All the gliomas had histopathological diagnoses.

Sensitivity and specificity of cMRI preoperative diagnosis were 78.5 and 38.5 %, respectively, and 85.7 and 53.8 % when aMRI was included, respectively. ROC analysis showed that cut-off values of 1.29 for maximum rCBV, 1.69 for minimum rADC, 2.1 for rCho/Cr ratio could differentiate between LGG and HGG with a sensitivity of 61.5, 53.8, and 53.8 % and a specificity of 54.7, 43 and 64.3 %, respectively. A significantly longer OS was observed in patients with a maximum rCBV\1.46 and minimum rADC[1.69 (80 vs 55 months, p = 0.01; 80 vs 51 months, p = 0.002, respectively). This result was also confirmed when cases were stratified according to pathology (LGG vs HGG). The ability of aMRI to differentiate between LGG and HGG and to predict survival improved as the number of aMRI techniques considered increased.

In a selected population of suspected LGG, classification by cMRI underestimated the actual fraction of HGG. aMRI slightly increased the diagnostic accuracy compared to histopathology. However, DWI and PWI were prognostic markers independent of histological grade.

Glioma surgery in eloquent areas: can we preserve cognition?

Surgery for low-grade glioma infiltrating the central cerebral region

Acta Neurochir (2016) 158:35–50

Cognitive preservation is crucial in glioma surgery, as it is an important aspect of daily life functioning. Several studies claimed that surgery in eloquent areas is possible without causing severe cognitive damage. However, this conclusion was relatively ungrounded due to the lack of extensive neuropsychological testing in homogenous patient groups. In this study, we aimed to elucidate the short-term and long-term effects of glioma surgery on cognition by identifying all studies who conducted neuropsychological tests preoperatively and postoperatively in glioma patients.

Methods We systematically searched the electronical databases Embase, Medline OvidSP, Web of Science, PsychINFO OvidSP, PubMed, Cochrane, Google Scholar, Scirius and Proquest aimed at cognitive performance in glioma patients preoperatively and postoperatively.

Results We included 17 studies with tests assessing the cognitive domains: language, memory, attention, executive functions and/or visuospatial abilities. Language was the domain most frequently examined. Immediately postoperatively, all studies except one, found deterioration in one or more cognitive domains. In the longer term (3–6/6–12 months postoperatively), the following tests showed both recovery and deterioration compared with the preoperative level: naming and verbal fluency (language), verbal word learning (memory) and Trailmaking B (executive functions).

Conclusions Cognitive recovery to the preoperative level after surgery is possible to a certain extent; however, the results are too arbitrary to draw definite conclusions and not all studies investigated all cognitive domains. More studies with longer postoperative follow-up with tests for cognitive change are necessary for a better understanding of the conclusive effects of glioma surgery on cognition.

Hypnosis for Awake Surgery of Low-grade Gliomas

Hypnosis for Awake Surgery of Low-grade Gliomas

Neurosurgery 78:53–61, 2016

Awake craniotomy with intraoperative electric stimulation is a reliable method for extensive removal of low-grade gliomas while preserving the functional integrity of eloquent surrounding brain structures. Although fully awake procedures have been proposed, asleep-awake-asleep remains the standard technique. Anesthetic contraindications are the only limitation of this method, which is therefore not reliable for older patients with high-grade gliomas.

OBJECTIVE: To describe and assess a novel method for awake craniotomy based on hypnosis.

METHODS: We proposed a novel hypnosedation procedure to patients undergoing awake surgery for low-grade gliomas in our institution between May 2011 and April 2015. Surgical data were retrospectively recorded. The subjective experience of hypnosis was assessed by 3 standardized questionnaires: the Cohen Perceived Stress Scale, the Posttraumatic Stress Disorder Checklist Scale, the Peritraumatic Dissociative Experience Questionnaire, and a fourth questionnaire designed specifically for this study.

RESULTS: Twenty-eight questionnaires were retrieved from 43 procedures performed on 37 patients. The Peritraumatic Dissociative Experience Questionnaire revealed a dissociation state in 17 cases. The Perceived Stress Scale was pathological in 8 patients. Two patients in this group stated that they would not accept a second hypnosedation procedure. The Posttraumatic Stress Disorder Checklist Scale revealed 1 case of posttraumatic stress disorder. Burr hole and bone flap procedures were the most frequently reported unpleasant events during opening (15 of 52 events).

CONCLUSION: The main findings of our study are the effectiveness of the technique, which in all cases allowed resection of the tumor up to functional boundaries, and the positive psychological impact of the technique in most of the patients.

Long-term outcomes after supratotal resection of diffuse low-grade gliomas

Long-term outcomes after supratotal resection of diffuse low-grade gliomas

Acta Neurochir (2016) 158:51–58

Total or subtotal surgical resection ofWHO grade II glioma (diffuse low-grade glioma, DLGG) can significantly increase survival. Moreover, a supratotal resection, i.e., an extended resection with a margin beyondMR imaging abnormalities, could decrease the risk of malignant transformation. Here, the goal is to analyze the long-term functional and oncological outcomes following supratotal resection for DLGG.

Methods Sixteen consecutive patients who underwent supratotal resection for a DLGG with a minimum follow-up of 8 years after surgery were included. The resection was continued up to functional cortical and subcortical structures defined by intrasurgical electrical mapping. The extent of resection was evaluated on postoperative FLAIR-weighted MR imaging. Data regarding clinicoradiological features, therapeutic management, and outcomes were analyzed.

Results Seven men and nine women (mean age, 41.3 years, range, 26–63 years) were included (seizure in 15 cases, one incidental discovery). All patients resumed a normal life after surgery (no neurological deficits, no epilepsy). The volume of postoperative cavity was larger than the preoperative tumor volume in the 16 patients. Neuropathological examination confirmed the diagnosis of WHO grade II glioma in all cases. No adjuvant treatment was administrated after resection. The mean duration of postoperative follow-up was 132 months (range, 97–198 months). There was no relapse in eight cases. Eight patients experienced tumor recurrence, with an average time to relapse of 70.3 months (range, 32–105 months), but without malignant transformation. Five of them have been retreated, with a reoperation (two cases), chemotherapy (three cases) and radiotherapy (two cases). All patients continue to enjoy a normal life.

Conclusions This is the first series demonstrating the prolonged impact of supratotal resection on malignant transformation of DLGG. These original data may suggest to remove a margin around the FLAIR-weighted MR imaging abnormalities in a more systematic manner for DLGG not involving eloquent structures.

Neurocognitive Changes Associated With Surgical Resection of Left and Right Temporal Lobe Glioma

Temporal lobe tumor

Neurosurgery 77:777–785, 2015

Little is known regarding the neurocognitive impact of temporal lobe tumor resection.

OBJECTIVE: To clarify subacute surgery-related changes in neurocognitive functioning (NCF) in patients with left (LTL) and right (RTL) temporal lobe glioma.

METHODS: Patients with glioma in the LTL (n = 45) or RTL (n = 19) completed comprehensive pre- and postsurgical neuropsychological assessments. NCF was analyzed with 2-way mixed design repeated-measures analysis of variance, with hemisphere (LTL or RTL) as an independent between-subjects factor and pre- and postoperative NCF as a within-subjects factor.

RESULTS: About 60% of patients with LTL glioma and 40% with RTL lesions exhibited significant worsening on at least 1 NCF test. Domains most commonly impacted included verbal memory and executive functioning. Patients with LTL tumor showed greater decline than patients with RTL tumor on verbal memory and confrontation naming tests. Nonetheless, over one-third of patients with RTL lesions also showed verbal memory decline.

CONCLUSION: In patients with temporal lobe glioma, NCF decline in the subacute postoperative period is common. As expected, patients with LTL tumor show more frequent and severe decline than patients with RTL tumor, particularly on verbally mediated measures. However, a considerable proportion of patients with RTL tumor also exhibit decline across various domains, even those typically associated with left hemisphere structures, such as verbal memory. While patients with RTL lesions may show even greater decline in visuospatial memory, this domain was not assessed. Nonetheless, neuropsychological assessment can identify acquired deficits and help facilitate early intervention in patients with temporal lobe glioma.

Prediction of Quality of Life and Survival After Surgery for Symptomatic Spinal Metastases

spinal metastasis

Neurosurgery 77:698–708, 2015

Surgery for symptomatic spinal metastases aims to improve quality of life, pain, function, and stability. Complications in the postoperative period are not uncommon; therefore, it is important to select appropriate patients who are likely to benefit the greatest from surgery. Previous studies have focused on predicting survival rather than quality of life after surgery.

OBJECTIVE: To determine preoperative patient characteristics that predict postoperative quality of life and survival in patients who undergo surgery for spinal metastases.

METHODS: In a prospective cohort study of 922 patients with spinal metastases who underwent surgery, we performed preoperative and postoperative assessment of EuroQol EQ-5D quality of life, visual analog score for pain, Karnofsky physical functioning score, complication rates, and survival.

RESULTS: The primary tumor type, number of spinal metastases, and presence of visceral metastases were independent predictors of survival. Predictors of quality of life after surgery included preoperative EQ-5D (P = .002), Frankel score (P , .001), and Karnofsky Performance Status (P , .001).

CONCLUSION: Data from the largest prospective surgical series of patients with symptomatic spinal metastases revealed that tumor type, the number of spinal metastases, and the presence of visceral metastases are the most useful predictors of survival and that quality of life is best predicted by preoperative Karnofsky, Frankel, and EQ-5D scores. The Karnofsky score predicts quality of life and survival and is easy to determine at the bedside, unlike the EQ-5D index. Karnofsky score, tumor type, and spinal and visceral metastases should be considered the 4 most important prognostic variables that influence patient management.

The Neurological Compromised Spine Due to Ewing Sarcoma. What First: Surgery or Chemotherapy?

The Neurological Compromised Spine Due to Ewing Sarcoma

Neurosurgery 77:718–725, 2015

The vertebral column is an infrequent site of primary involvement in Ewing sarcoma. Yet when Ewing sarcoma is found in the spine, the urge for decompression is high because of the often symptomatic compression of neural structures. It is unclear in alleviating a neurological deficit whether chemotherapy is preferred over decompressive laminectomy.

OBJECTIVE: To underline, in this case series, the efficiency of initial chemotherapy before upfront surgery in the setting of high-grade spinal cord or cauda equina compression of primary Ewing sarcoma.

METHODS: Fifteen patients with Ewing sarcoma primarily located in the spine were treated at our institution between 1983 and 2015. Localization, neurological deficit expressed as Frankel grade, and outcome expressed as Rankin scale before and after initial chemotherapy, the recurrence rate, and overall survival were evaluated. The multidisciplinary approach of 1 case will be discussed in detail.

RESULTS: Nine patients (60%) were female. The age at presentation was 15.0 ± 5.5 years (range: 0.9-22.8 years). Ten patients (67%) were initially treated with chemotherapy, and 1 patient (7%) was treated primarily with radiotherapy followed by chemotherapy. The remaining 4 patients (27%) were initially treated with decompressive surgery. All patients treated primarily nonsurgically improved neurologically at followup, showing the importance of chemotherapy as an effective initial treatment option.

CONCLUSION: Adequate and quick decompression of neural structures with similar results can be achieved by chemotherapy and radiotherapy, avoiding the local spill of malignant cells.

Subcortical anatomy as an anatomical and functional landmark in insulo-opercular gliomas

Subcortical anatomy as an anatomical and functional landmark in insulo-opercular gliomas

J Neurosurg 123:1081–1092, 2015

Little attention has been given to the functional challenges of the insular approach to the resection of gliomas, despite the potential damage of essential neural networks that underlie the insula. The object of this study is to analyze the subcortical anatomy of the insular region when infiltrated by gliomas, and compare it with the normal anatomy in nontumoral hemispheres.

Methods Ten postmortem human hemispheres were dissected, with isolation of the inferior fronto-occipital fasciculus (IFOF) and the uncinate fasciculus. Probabilistic diffusion tensor imaging (DTI) tractography was used to analyze the subcortical anatomy of the insular region in 10 healthy volunteers and in 22 patients with insular Grade II and Grade III gliomas. The subcortical anatomy of the insular region in these 22 insular gliomas was compared with the normal anatomy in 20 nontumoral hemispheres.

Results In tumoral hemispheres, the distances between the peri-insular sulci and the lateral surface of the IFOF and uncinate fasciculus were enlarged (p < 0.05). Also in tumoral hemispheres, the IFOF was identified in 10 (90.9%) of 11 patients with an extent of resection less than 80%, and in 4 (36.4%) of 11 patients with an extent of resection equal to or greater than 80% (multivariate analysis: p = 0.03).

Conclusions Insular gliomas grow in the space between the lateral surface of the IFOF and uncinate fasciculus and the insular surface, displacing and compressing the tracts medially. Moreover, these tracts may be completely infiltrated by the tumor, with a total disruption of the bundles. In the current study, the identification of the IFOF with DTI tractography was significantly associated with the extent of tumor resection. If the IFOF is not identified preoperatively, there is a high probability of achieving a resection greater than 80%.

Awake craniotomy to maximize glioma resection: methods and technical nuances over a 27-year period

awake craniotomy

J Neurosurg 123:325–339, 2015

Awake craniotomy is currently a useful surgical approach to help identify and preserve functional areas during cortical and subcortical tumor resections. Methodologies have evolved over time to maximize patient safety and minimize morbidity using this technique. The goal of this study is to analyze a single surgeon’s experience and the evolving methodology of awake language and sensorimotor mapping for glioma surgery.

Methods The authors retrospectively studied patients undergoing awake brain tumor surgery between 1986 and 2014. Operations for the initial 248 patients (1986–1997) were completed at the University of Washington, and the subsequent surgeries in 611 patients (1997–2014) were completed at the University of California, San Francisco. Perioperative risk factors and complications were assessed using the latter 611 cases.

Results The median patient age was 42 years (range 13–84 years). Sixty percent of patients had Karnofsky Performance Status (KPS) scores of 90–100, and 40% had KPS scores less than 80. Fifty-five percent of patients underwent surgery for high-grade gliomas, 42% for low-grade gliomas, 1% for metastatic lesions, and 2% for other lesions (cortical dysplasia, encephalitis, necrosis, abscess, and hemangioma). The majority of patients were in American Society of Anesthesiologists (ASA) Class 1 or 2 (mild systemic disease); however, patients with severe systemic disease were not excluded from awake brain tumor surgery and represented 15% of study participants. Laryngeal mask airway was used in 8 patients (1%) and was most commonly used for large vascular tumors with more than 2 cm of mass effect. The most common sedation regimen was propofol plus remifentanil (54%); however, 42% of patients required an adjustment to the initial sedation regimen before skin incision due to patient intolerance. Mannitol was used in 54% of cases. Twelve percent of patients were active smokers at the time of surgery, which did not impact completion of the intraoperative mapping procedure. Stimulation-induced seizures occurred in 3% of patients and were rapidly terminated with ice-cold Ringer’s solution. Preoperative seizure history and tumor location were associated with an increased incidence of stimulation- induced seizures. Mapping was aborted in 3 cases (0.5%) due to intraoperative seizures (2 cases) and patient emotional intolerance (1 case). The overall perioperative complication rate was 10%.

Conclusions Based on the current best practice described here and developed from multiple regimens used over a 27-year period, it is concluded that awake brain tumor surgery can be safely performed with extremely low complication and failure rates regardless of ASA classification; body mass index; smoking status; psychiatric or emotional history; seizure frequency and duration; and tumor site, size, and pathology.

The Effect of Timing of Concurrent Chemoradiation in Patients With Newly Diagnosed Glioblastoma

Relationship of glioblastoma multiforme to the subventricular zone is associated with survival

Neurosurgery 77:248–253, 2015

The effect of timing of initiation of concurrent radiation and chemotherapy after surgery on outcome of patients with glioblastoma (GBM) remains unclear.

OBJECTIVE: To further explore this issue, we analyzed 4 clinical trials for patients newly diagnosed with GBM receiving concurrent and adjuvant temozolomide.

METHODS: The cohort study included 198 adult patients with newly diagnosed supratentorial GBM who were enrolled from 2004 to 2010 in 4 clinical trials consisting of radiation plus temozolomide and an experimental agent. The interval to initiation of therapy was determined from the time of surgical resection. The partitioning deletion/ substitution/addition algorithm was used to determine the cutoff points for timing of chemoradiation at which there was a significant difference in overall survival (OS) and progression-free survival (PFS).

RESULTS: The median wait time between surgery and initiation of concurrent chemoradiation was 29.5 days (range, 7-56 days). A short delay in chemoradiation administration (at 30-34 days) was predictive of prolonged OS (hazard ratio [HR]: 0.63, P = .03) and prolonged PFS (HR: 0.68, P = .06) compared with early initiation of concurrent chemoradiation (<30 days), after adjusting for protocol and baseline prognostic variables including extent of resection by multivariate analysis. A longer delay to chemoradiation beyond 34 days was not associated with improved OS or PFS compared with early initiation (HR: 0.94, P = .77 and HR: 0.91, P = .63, respectively).

CONCLUSION: A short delay in the start of concurrent chemoradiation is beyond the classic paradigm of 4 weeks post-resection and may be associated with prolonged OS and PFS.

Adverse radiation effect after stereotactic radiosurgery for brain metastases

Adverse radiation effect after stereotactic radiosurgery for brain metastases- incidence, time course, and risk factors

J Neurosurg 123:373–386, 2015

The authors sought to determine the incidence, time course, and risk factors for overall adverse radiation effect (ARE) and symptomatic ARE after stereotactic radiosurgery (SRS) for brain metastases.

Methods All cases of brain metastases treated from 1998 through 2009 with Gamma Knife SRS at UCSF were considered. Cases with less than 3 months of follow-up imaging, a gap of more than 8 months in imaging during the 1st year, or inadequate imaging availability were excluded. Brain scans and pathology reports were reviewed to ensure consistent scoring of dates of ARE, treatment failure, or both; in case of uncertainty, the cause of lesion worsening was scored as indeterminate. Cumulative incidence of ARE and failure were estimated with the Kaplan-Meier method with censoring at last imaging. Univariate and multivariate Cox proportional hazards analyses were performed.

Results Among 435 patients and 2200 brain metastases evaluable, the median patient survival time was 17.4 months and the median lesion imaging follow-up was 9.9 months. Calculated on the basis of 2200 evaluable lesions, the rates of treatment failure, ARE, concurrent failure and ARE, and lesion worsening with indeterminate cause were 9.2%, 5.4%, 1.4%, and 4.1%, respectively. Among 118 cases of ARE, approximately 60% were symptomatic and 85% occurred 3–18 months after SRS (median 7.2 months). For 99 ARE cases managed without surgery or bevacizumab, the probabilities of improvement observed on imaging were 40%, 57%, and 76% at 6, 12, and 18 months after onset of ARE. The most important risk factors for ARE included prior SRS to the same lesion (with 20% 1-year risk of symptomatic ARE vs 3%, 4%, and 8% for no prior treatment, prior whole brain radiotherapy [WBRT], or concurrent WBRT) and any of these volume parameters: target, prescription isodose, 12-Gy, or 10-Gy volume. Excluding lesions treated with repeat SRS, the 1-year probabilities of ARE were < 1%, 1%, 3%, 10%, and 14% for maximum diameter 0.3–0.6 cm, 0.7–1.0 cm, 1.1–1.5 cm, 1.6–2.0 cm, and 2.1–5.1 cm, respectively. The 1-year probabilities of symptomatic ARE leveled off at 13%–14% for brain metastases maximum diameter > 2.1 cm, target volume > 1.2 cm3, prescription isodose volume > 1.8 cm3, 12-Gy volume > 3.3 cm3, and 10-Gy volume > 4.3 cm3, excluding lesions treated with repeat SRS. On both univariate and multivariate analysis, capecitabine, but not other systemic therapy within 1 month of SRS, appeared to increase ARE risk. For the multivariate analysis considering only metastases with target volume > 1.0 cm3, risk factors for ARE included prior SRS, kidney primary tumor, connective tissue disorder, and capecitabine.

Conclusions Although incidence of ARE after SRS was low overall, risk increased rapidly with size and volume, leveling off at a 1-year cumulative incidence of 13%–14%. This study describes the time course of ARE and provides risk estimates by various lesion characteristics and treatment parameters to aid in decision-making and patient counseling.

Outcomes in Reoperated Low-Grade Gliomas

OUTCOMES IN REOPERATED LOW-GRADE GLIOMAS

Neurosurgery 77:175–184, 2015

Low-grade gliomas (LGGs) comprise a diverse set of intrinsic brain tumors that correlate strongly with survival. Data on the effect of reoperation are sparse.

OBJECTIVE: To evaluate the effect of reoperation on patients with LGG.

METHODS: Fifty-two consecutive patients with reoperated LGGs treated at the University of Washington between 1986 and 2004 were identified and evaluated in a retrospective analysis.

RESULTS: The average overall survival (OS) for this cohort was 12.95 ± 0.96 years. The overall 10-year survival rate was 57%. The absence of any residual tumor at either the first or second operation was associated with significantly increased OS. Negative prognostic variables for OS included the use of upfront radiation and pathology at recurrence. The average overall progression-free survival to the first recurrence (PFS1) was 6.23 ± 0.51 years. Positive prognostic factors for improved PFS1 included the use of upfront radiation therapy. Variables not associated with differences in PFS1 included the use of upfront chemotherapy, enhancement, pathology, extent of resection, the presence of residual tumor, and Karnofsky Performance Scale score <80. The average overall progression-free survival to the second recurrence was 2.73 ± 0.39 years. Pathology at recurrence was associated with significant differences in progression-free survival to the second recurrence, as was extent of resection at time of first recurrence, and Karnofsky Performance Scale score <80.

CONCLUSION: This is among the largest studies to assess variables associated with outcome in patients with reoperated LGG. Reresection appears to provide significant benefit, and extent of resection remains the strongest predictor of OS.

Posterior thoracic corpectomy with cage reconstruction for metastatic spinal tumors

mini-open and open transpedicular corpectomy

J Neurosurg Spine 23:217–227, 2015

Spinal metastases most commonly affect the vertebral bodies of the spinal column, and spinal cord compression is an indication for surgery. Commonly, an open posterior approach is employed to perform a transpedicular costotransversectomy or lateral extracavitary corpectomy. Because of the short life expectancies in patients with metastatic spinal disease, decreasing the morbidity of surgical treatment and recovery time is critical. One potential approach to decreasing morbidity is utilizing minimally invasive surgery (MIS). Although significant advances have been made in MIS of the spine, data supporting the utility of MIS are still emerging. This study compared outcomes of patients who underwent mini-open versus traditional open transpedicular corpectomy for spinal metastases in the thoracic spine.

Methods A consecutive cohort from 2006 to 2013 of 49 adult patients who underwent thoracic transpedicular corpectomies for spinal metastases was retrospectively identified. Patients were categorized into one of 2 groups: open surgery and mini-open surgery. Mini-open transpedicular corpectomy was performed with a midline fascial incision over only the corpectomy level of interest and percutaneous instrumentation above and below that level. The open procedure consisted of a traditional posterior transpedicular corpectomy. Chi-square test, 2-tailed t-test, and ANOVA models were employed to compare perioperative and follow-up outcomes between the 2 groups.

Results In the analysis, there were 21 patients who had mini-open surgery and 28 patients who had open surgery. The mean age was 57.9 years, and 59.2% were male. The tumor types encountered were lung (18.3%), renal/bladder (16.3%), breast (14.3%), hematological (14.3%), gastrointestinal tract (10.2%), prostate (8.2%), melanoma (4.1%), and other/unknown (14.3%). There were no significant intergroup differences in demographics, comorbidities, neurological status (American Spinal Injury Association [ASIA] grade), number of corpectomies performed, and number of levels instrumented. The open group had a mean operative time of 413.6 minutes, and the mini-open group had a mean operative time of 452.4 minutes (p = 0.329). Compared with the open group, the mini-open group had significantly less blood loss (917.7 ml vs 1697.3 ml, p = 0.019) and a significantly shorter hospital stay (7.4 days vs 11.4 days, p = 0.001). There was a trend toward a lower perioperative complication rate in the mini-open group (9.5%) compared with the open group (21.4%), but this was not statistically significant (p = 0.265). At follow-up, there were no significant differences in ASIA grade (p = 0.342), complication rate after the 30-day postoperative period (p = 0.999), or need for surgical revision (p = 0.803). The open approach had a higher overall infection rate of 17.9% compared with that in the mini-open approach of 9.5%, but this was not statistically significant (p = 0.409).

Conclusions The mini-open transpedicular corpectomy is associated with less blood loss and shorter hospital stay compared with open transpedicular corpectomy. The mini-open corpectomy also trended toward lower infection and complication rates, but these did not reach statistical significance.

Survival in patients treated for anaplastic meningioma

Anaplastic meningioma

J Neurosurg 123:23–30, 2015

While most meningiomas are benign, 1%–3% display anaplastic features, with little current understanding regarding the molecular mechanisms underlying their formation. In a large single-center cohort, the authors tested the hypothesis that two distinct subtypes of anaplastic meningiomas, those that arise de novo and those that progress from lower grade tumors, exist and exhibit different clinical behavior.

Methods Pathology reports and clinical data of 37 patients treated between 1999 and 2012 for anaplastic meningioma at Memorial Sloan–Kettering Cancer Center (MSKCC) were retrospectively reviewed. Patients were divided into those whose tumors arose de novo and those whose tumors progressed from previously documented benign or atypical meningiomas.

Results Overall, the median age at diagnosis was 59 years and 57% of patients were female. Most patients (38%) underwent 2 craniotomies (range 1–5 surgeries) aimed at gross-total resection (GTR; 59%), which afforded better survival when compared with subtotal resection according to Kaplan-Meier estimates (median overall survival [OS] 3.2 vs 1.3 years, respectively; p = 0.04, log-rank test). Twenty-three patients (62%) presented with apparently de novo anaplastic meningiomas. Compared with patients whose tumors had progressed from a lower grade, those patients with de novo tumors were significantly more likely to be female (70% vs 36%, respectively; p = 0.04), experience better survival (median OS 3.0 vs 2.4 years, respectively; p = 0.03, log-rank test), and harbor cerebral hemispheric as opposed to skull base tumors (91% vs 43%, respectively; p = 0.002).

Conclusions Based on this single-center experience at MSKCC, anaplastic meningiomas, similar to glial tumors, can arise de novo or progress from lower grade tumors. These tumor groups appear to have distinct clinical behavior. De novo tumors may well be molecularly distinct, which is under further investigation. Aggressive GTR appears to confer an OS advantage in patients with anaplastic meningioma, and this is likely independent of tumor progression status. Similarly, those patients with de novo tumors experience a survival advantage likely independent of extent of resection.

Magnetic resonance spectroscopy detection of high lipid levels in intraaxial tumors without central necrosis: a characteristic of malignant lymphoma

Magnetic resonance spectroscopy detection of high lipid levels in intraaxial tumors without central necrosis- a characteristic of malignant lymphoma
J Neurosurg 122:1370–1379, 2015

The differentiation of malignant lymphomas from gliomas or malignant gliomas by conventional MRI can be difficult. The authors studied Gd-enhanced MR images to obtain a differential diagnosis between malignant lymphomas and gliomas without central necrosis or cystic changes and investigated the diagnostic value of single-voxel proton MR spectroscopy (1H-MRS) using different parameters, including lipid levels.
Methods This was a retrospective study of patients with primary malignant CNS lymphoma (n = 17) and glioma (n = 122 [Grades I, II, III, and IV in 10, 30, 33, and 49 patients, respectively]) who were treated between 2007 and 2013. The authors focused on 15 patients with homogeneously enhanced primary malignant CNS lymphomas and 7 homogeneously enhanced gliomas. Images of all the included tumors were acquired with 1H-MRS at 3 T, and the diagnoses were histologically confirmed.
Results Using a short echo time 1H-MRS, large lipid peaks were observed in all 17 patients with a malignant lymphoma, in 39 patients (79.6%) with a Grade IV glioma, and in 10 patients (30.3%) with a Grade III glioma. A focus on homogeneously enhanced tumors revealed large lipid peaks in 15 malignant lymphomas that were free of central necrosis on Gd-enhanced T1-weighted images. Conversely, in the 7 homogeneously enhanced gliomas (glioblastoma and anaplastic astrocytoma, n = 2 each; anaplastic oligodendroglioma, diffuse astrocytoma, and pilomyxoid astrocytoma, n = 1 each), lipid peaks were small or absent.
Conclusions Large lipid peaks on 1H-MRS images of tumors without central necrosis were characteristic of malignant lymphomas. Conversely, small or absent lipid peaks in intraaxial tumors without central necrosis were strongly suggestive of glioma.

Topographical Risk Factor Analysis of New Neurological Deficits Following Precentral Gyrus Resection

Topographical Risk Factor Analysis of New Neurological Deficits Following Precentral Gyrus Resection

Neurosurgery 76:714–720, 2015

Precentral gyrus resections (PGRs) have been regarded as excessively hazardous interventions because of the risk of postoperative major neurological complications.

OBJECTIVE: To evaluate the neurological deterioration that follows PGRs and to assess the topographical risk factors associated with these morbidities.

METHODS: We reviewed 33 consecutive patients who experienced pharmacologically intractable epilepsy and underwent PGR with intraoperative cortical stimulation and mapping while under awake anesthesia. The etiological diagnoses were brain neoplasm in 26 patients (78.8%), cortical lesion in 4 (12.1%), and no lesion in 3 (9.1%). The mean follow-up period was 62.6 months (range, 12-146 months). All topographical analyses of the resected quadrant area were performed based on postoperative magnetic resonance images.

RESULTS: After PGR, 22 patients (66.7%) experienced neurological worsening, including 5 permanent deficits (15.2%) and 17 transient deficits (51.5%). Permanent deficits included 2 instances of weakness, 1 dysarthria, 1 dysesthesia, and 1 fine-movement disturbance of the hand. While the neurological risk for anterior lower quadrant PGR was 20.0% (1/5), the risk for posterior upper quadrant PGR was 100.0% (10/10). The anterior upper and posterior lower quadrant PGR caused neurological deteriorations in 60.0% (6/10) and 62.5% (5/8) of the patients, respectively. In a multivariate analysis, PGR of the posterior and upper quadrant sections were significant risk factors for post-PGR neurological deteriorations (P = .022 and 0.030, respectively).

CONCLUSION: The posterior upper quadrant of the precentral gyrus was vulnerable to post-resective neurological impairment.