Integrating multisector molecular characterization into personalized peptide vaccine design for patients with newly diagnosed glioblastoma

PURPOSE

Glioblastoma (GBM) patient outcomes remain poor despite multimodality treatment with surgery, radiation, and chemotherapy. There are few immunotherapy options due to the lack of tumor immunogenicity. Several clinical trials have reported promising results with cancer vaccines. To date, studies have used data from a single tumor site to identify targetable antigens, but this approach limits the antigen pool and is antithetical to the heterogeneity of GBM. We have implemented multisector sequencing to increase the pool of neoantigens across the GBM genomic landscape that can be incorporated into personalized peptide vaccines called NeoVax.

PATIENTS AND METHODS

Here, we report the findings of four subjects enrolled onto the NeoVax clinical trial (NCT0342209).

RESULTS

Immune reactivity to NeoVax neoantigens was assessed in peripheral blood mononuclear cells (PBMCs) pre- and post-NeoVax for subjects 1-3 using IFNg-ELISPOT assay. A statistically significant increase in IFNg producing T cells at the post-NeoVax time point for several neoantigens was observed. Furthermore, a post-NeoVax tumor biopsy was obtained from subject 3 and, upon evaluation, revealed evidence of infiltrating, clonally expanded T cells.

CONCLUSIONS

Collectively, our findings suggest NeoVax did stimulate expansion of neoantigen-specific effector T cells and provide encouraging results to aid in the development of future neoantigen vaccine-based clinical trials in patients with GBM. Herein, we demonstrate the feasibility of incorporating multisector sampling in cancer vaccine design and provide information on the clinical applicability of clonality, distribution, and immunogenicity of the neoantigen landscape in GBM patients.

Glioblastoma-infiltrating CD8+ T cells are predominantly a clonally expanded GZMK+ effector population

Recent clinical trials have highlighted the limited efficacy of T cell-based immunotherapy in patients with glioblastoma (GBM). To better understand the characteristics of tumor-infiltrating lymphocytes (TIL) in GBM, we performed cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) and single-cell RNA sequencing (scRNA-seq) with paired V(D)J sequencing, respectively, on TIL from two cohorts of patients totaling 15 patients with high grade glioma, including GBM or astrocytoma, IDH mutant, grade 4 (G4A). Analysis of the CD8+ TIL landscape reveals an enrichment of clonally expanded GZMK+ effector T cells in the tumor compared to matched blood, which was validated at the protein level. Furthermore, integration with other cancer types highlights the lack of a canonically exhausted CD8+ T cell population in GBM TIL. These data suggest that GZMK+ effector T cells represent an important T cell subset within the GBM microenvironment and which may harbor potential therapeutic implications.

A pilot study of lymphoscintigraphy with tracer injection into the human brain

Many groups have reported lymphatic and glymphatic structures in animal and human brains, but tracer injection into the human brain to demonstrate real-time lymphatic drainage and mapping has not been described. We enrolled patients undergoing standard-of-care resection or stereotactic biopsy for suspected intracranial tumors. Patients received peritumoral injections of 99mTc-tilmanocept followed by planar or tomographic imaging. Fourteen patients with suspected brain tumors were enrolled. One was excluded from analysis because of tracer leakage during injection. There was no drainage of 99mTc-tilmanocept to regional lymph nodes in any of the patients. On average, after correcting for radioactive decay, 70.7% (95% CI: 59.9%, 81.6%) of the tracer in the injection site and 78.1% (95% CI: 71.1%, 85.1%) in the whole-head on the day of surgery remained the morning after, with variable radioactivity in the subarachnoid space. The retained fraction was much greater than expected based on the clearance rate from non-brain injection sites. In this pilot study, the lymphatic tracer 99mTc-tilmanocept was injected into the brain parenchyma, and there was no drainage outside the brain to the cervical lymph nodes. Our work demonstrates an inefficiency of drainage from peritumoral brain parenchyma and highlights a therapeutic opportunity to improve immunosurveillance of the brain.

Neoadjuvant stereotactic radiosurgery for brain metastases: a new paradigm

OBJECTIVE

For patients with surgically accessible solitary metastases or oligometastatic disease, treatment often involves resection followed by postoperative stereotactic radiosurgery (SRS). This strategy has several potential drawbacks, including irregular target delineation for SRS and potential tumor "seeding" away from the resection cavity during surgery. A neoadjuvant (preoperative) approach to radiation therapy avoids these limitations and offers improved patient convenience. This study assessed the efficacy of neoadjuvant SRS as a new treatment paradigm for patients with brain metastases.

METHODS

A retrospective review was performed at a single institution to identify patients who had undergone neoadjuvant SRS (specifically, Gamma Knife radiosurgery) followed by resection of a brain metastasis. Kaplan-Meier survival and log-rank analyses were used to evaluate risks of progression and death. Assessments were made of local recurrence and leptomeningeal spread. Additionally, an analysis of the contemporary literature of postoperative and neoadjuvant SRS for metastatic disease was performed.

RESULTS

Twenty-four patients who had undergone neoadjuvant SRS followed by resection of a brain metastasis were identified in the single-institution cohort. The median age was 64 years (range 32-84 years), and the median follow-up time was 16.5 months (range 1 month to 5.7 years). The median radiation dose was 17 Gy prescribed to the 50% isodose. Rates of local disease control were 100% at 6 months, 87.6% at 12 months, and 73.5% at 24 months. In 4 patients who had local treatment failure, salvage therapy included repeat resection, laser interstitial thermal therapy, or repeat SRS. One hundred thirty patients (including the current cohort) were identified in the literature who had been treated with neoadjuvant SRS prior to resection. Overall rates of local control at 1 year after neoadjuvant SRS treatment ranged from 49% to 91%, and rates of leptomeningeal dissemination from 0% to 16%. In comparison, rates of local control 1 year after postoperative SRS ranged from 27% to 91%, with 7% to 28% developing leptomeningeal disease.

CONCLUSIONS

Neoadjuvant SRS for the treatment of brain metastases is a novel approach that mitigates the shortcomings of postoperative SRS. While additional prospective studies are needed, the current study of 130 patients including the summary of 106 previously published cases supports the safety and potential efficacy of preoperative SRS with potential for improved outcomes compared with postoperative SRS.

Survival After Resection of Newly-Diagnosed Intracranial Grade II Ependymomas: An Initial Multicenter Analysis and the Logistics of Intraoperative Magnetic Resonance Imaging

OBJECTIVE

To identify factors, including the use of intraoperative magnetic resonance imaging (iMRI), impacting overall survival (OS) and progression-free survival (PFS) after resections of newly diagnosed intracranial grade II ependymomas performed across 4 different institutions.

METHODS

Analyses of a multicenter mixed retrospective/prospective database assessed the impact of patient, treatment, and tumor characteristics on OS and PFS. iMRI workflow and logistics were also outlined.

RESULTS

Forty-three patients were identified (mean age 25.4 years, mean follow-up 52.8 months). The mean OS was 52.8 ± 44.7 months. Univariate analyses failed to identify prognostic factors associated with OS, likely due to relatively shorter follow-up time for this less aggressive glioma subtype. The mean PFS was 43.7 ± 39.8 months. Multivariate analyses demonstrated that gross-total resection was associated with prolonged PFS compared to both subtotal resection (STR) (P = 0.005) and near-total resection (P = 0.01). Infratentorial location was associated with improved PFS compared to supratentorial location (P = 0.04). Log-rank analyses of Kaplan-Meier survival curves showed that increasing extent of resection (EOR) led to improved OS specifically for supratentorial tumors (P = 0.02) and improved PFS for all tumors (P < 0.001). Thirty cases (69.8%) utilized iMRI, of which 12 (27.9%) involved additional resection after iMRI. Of these, 8/12 (66.7%) resulted in gross-total resection, while 2/12 (16.7%) were near-total resection and 2/12 (16.7%) were subtotal resection. iMRI was not an independent prognosticator of PFS (P = 0.72).

CONCLUSIONS

Greater EOR and infratentorial location were associated with increased PFS for grade II ependymomas. Greater EOR was associated with longer OS only for supratentorial tumors. A longer follow-up is needed to establish prognostic factors for this cohort, including use of iMRI.

Multivariate analysis of associations between clinical sequencing and outcome in glioblastoma

BACKGROUND

Many factors impact survival in patients with glioblastoma, including age, Karnofsky Performance Status, postoperative chemoradiation, IDH1/2 mutation status, MGMT promoter methylation status, and extent of resection. High-throughput next-generation sequencing is a widely available diagnostic tool, but the independent impact of tumors harboring specific mutant genes on survival and the efficacy of extent of resection are not clear.

METHODS

We utilized a widely available diagnostic platform (FoundationOne CDx) to perform high-throughput next-generation sequencing on 185 patients with newly diagnosed glioblastoma in our tertiary care center. We performed multivariate analysis to control for clinical parameters with known impact on survival to elucidate the independent prognostic value of prevalent mutant genes and the independent impact of gross total resection.

RESULTS

When controlling for factors with known prognostic significance including IDH1/2 mutation and after multiple comparisons analysis, CDKN2B and EGFR mutations were associated with reduced overall survival while PTEN mutation was associated with improved overall survival. Gross total resection, compared to other extent of resection, was associated with improved overall survival in patients with tumors harboring mutations in CDKN2A, CDKN2B, EGFR, PTEN, TERT promoter, and TP53. All patients possessed at least one of these 6 mutant genes.

CONCLUSIONS

This study verifies the independent prognostic value of several mutant genes in glioblastoma. Six commonly found mutant genes were associated with improved survival when gross total resection was achieved. Thus, even when accounting for known predictors of survival and multiple mutant gene comparisons, extent of resection continues to be strongly associated with survival.

Endonasal Free Flap Reconstruction Combined With Draf Frontal Sinusotomy for Complex Cerebrospinal Fluid Leak: A Technical Report & Case Series

BACKGROUND

Frontal sinus cranialization with closure via bifrontal pericranial flaps is the gold standard for separating the nasofrontal recess from the intracranial cavity for posterior table defects. Despite the high success rate, cerebrospinal fluid (CSF) leak may persist and is particularly challenging when vascularized reconstructive options from the bicoronal incision are exhausted.

OBJECTIVE

To assess a novel endonasal technique using an adipofascial radial forearm free flap delivered to the frontal recess through a Draf sinusotomy to repair complex CSF leaks from the frontal sinus.

METHODS

A retrospective review of 3 patients (all male; ages 42, 43, and 69 yr) with persistent CSF leak despite frontal sinus cranialization and repair with bifrontal pericranium was performed. Etiology of injury was traumatic in 2 patients and iatrogenic in 1 patient after anaplastic meningioma treatment. To create space for the flap and repair the nasofrontal ducts, endoscopic Draf III (Case 1, 3) or Draf IIb left frontal sinusotomy (Case 2) was performed. The forearm flap was harvested, passed through a Caldwell-Luc exposure, and placed within the Draf frontal sinustomy. The flap vessels were tunneled to the left neck and anastomosed to the facial vessels by the mandibular notch.

RESULTS

Intraoperatively, the flaps were well-seated and provided a watertight seal. Postoperative hospital courses were uncomplicated. There were no new CSF leaks or flap necrosis at 12, 14, and 16 mo.

CONCLUSION

Endoscopic endonasal free flap reconstruction through a Draf procedure is a novel viable option for persistent CSF leak after failed frontal sinus cranialization.

Characterization of the Genomic and Immunological Diversity of Malignant Brain Tumors Through Multi-Sector Analysis

Despite some success in secondary brain metastases, targeted or immune-based therapies have shown limited efficacy against primary brain malignancies such as glioblastoma (GBM). While the intratumoral heterogeneity of GBM is implicated in treatment resistance, it remains unclear whether this diversity is observed within brain metastases and to what extent cancer-cell intrinsic heterogeneity sculpts the local immune microenvironment. Here, we profiled the immunogenomic state of 93 spatially distinct regions from 30 malignant brain tumors through whole exome, RNA, and TCR-sequencing. Our analyses identified differences between primary and secondary malignancies with gliomas displaying more spatial heterogeneity at the genomic and neoantigen level. Additionally, this spatial diversity was recapitulated in the distribution of T cell clones where some gliomas harbored highly expanded but spatially restricted clonotypes. This study defines the immunogenomic landscape across a cohort of malignant brain tumors and contains implications for the design of targeted and immune-based therapies against intracranial malignancies.

Bilateral Subthalamic Nucleus Deep Brain Stimulation in Elderly Patients With Parkinson Disease: A Case-Control Study

BACKGROUND

Subthalamic nucleus deep brain stimulation (STN DBS) is an effective adjunctive therapy for Parkinson disease. Studies have shown improvement of motor function but often exclude patients older than 75 yr.

OBJECTIVE

To determine the safety and effectiveness of STN DBS in patients 75 yr and older.

METHODS

A total of 104 patients (52 patients >75 yr old, 52 patients <75 yr old) with STN DBS were paired and retrospectively analyzed. The primary outcome was change in Unified Parkinson Disease Rating Scale (UPDRS) subscale III at 1 yr postoperatively, OFF medication. Secondary outcomes were changes in UPDRS I, II, and IV subscales and levodopa equivalents. Complications and all-cause mortality were assessed at 30 d and 1 yr.

RESULTS

Both cohorts had significant improvements in UPDRS III at 6 mo and 1 yr with no difference between cohorts. Change in UPDRS III was noninferior to the younger cohort. The cohorts had similar worsening in UPDRS I at 1 yr, no change in UPDRS II, similar improvement in UPDRS IV, and similar levodopa equivalent reduction. There were similar numbers of postoperative intracerebral hemorrhages (2/52 in each cohort, more severe in the older cohort) and surgical complications (4/52 in each cohort), and mortality in the older cohort was similar to an additional matched cohort not receiving DBS.

CONCLUSION

STN DBS provides substantial motor benefit and reduction in levodopa equivalents with a low rate of complications in older patients, which is also noninferior to the benefit in younger patients. STN DBS remains an effective therapy for those over 75 yr.

Salvage therapies for radiation-relapsed isocitrate dehydrogenase-mutant astrocytoma and 1p/19q codeleted oligodendroglioma

Background

Optimal management for recurrent IDH-mutant glioma after radiation therapy (RT) is not well-defined. This study assesses practice patterns for managing recurrent IDH-mutant astrocytoma (Astro) and 1p/19q codeleted oligodendroglioma (Oligo) after RT and surveys their clinical outcomes after different salvage approaches.

Methods

Ninety-four recurrent Astro or Oligo patients after RT who received salvage systemic therapy (SST) between 2001 and 2019 at a tertiary cancer center were retrospectively analyzed. SST was defined as either alkylating chemotherapy (AC) or nonalkylating therapy (non-AC). Overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method from the start of SST. Multivariable analysis (MVA) was conducted using Cox regression analysis.

Results

Recurrent Oligo (n = 35) had significantly higher PFS (median: 3.1 vs 0.8 years, respectively, P = .002) and OS (median: 6.3 vs 1.5 years, respectively, P < .001) than Astro (n = 59). Overall, 90% of recurrences were local. Eight-three percent received AC as the first-line SST; 50% received salvage surgery before SST; approximately 50% with local failure >2 years after prior RT received reirradiation. On MVA, non-AC was associated with worse OS for both Oligo and Astro; salvage surgery was associated with improved PFS and OS for Astro; early reirradiation was associated with improved PFS for Astro.

Conclusions

Recurrent radiation-relapsed IDH-mutant gliomas represent a heterogeneous group with variable treatment approaches. Surgery, AC, and reirradiation remain the mainstay of salvage options for retreatment.

IgG4-Related Disease of the Skull and Skull Base-A Systematic Review and Report of Two Cases

OBJECTIVE

IgG4-related disease (IgG4-RD) is an inflammatory process that uncommonly can present in the skull base and calvarium and mimic a tumor but the nature of this condition is not well summarized in the neurosurgical literature.

METHODS

A review was performed of 2 cases of IgG4-RD in the skull base highlighting the diagnostic challenges with assessment of these skull base lesions, and a systematic review of relevant literature was carried out.

RESULTS

A systematic review of the literature conducted in accordance with PRISMA guidelines identified 113 articles, with 184 cases of IgG4-RD in the skull base or calvarium. The most commonly affected locations include the meninges, cavernous sinus, base of the posterior fossa, clivus, and mastoid bone. Headache, visual and auditory disturbances, cranial nerve dysfunction, and seizures were the most common presenting symptoms. Medical treatment was highly successful and most commonly consisted of corticosteroids coadministered with immunosuppressive agents such as rituximab. Prevalence seemed to be equal between sexes, and serum IgG4 levels were increased in 61% of patients. Delayed diagnosis and a need for multiple biopsies were reported in numerous cases. Two cases of skull base IgG4-RD from the authors' institution show the variable presentations of this disease. More invasive surgical biopsies were required in both cases, and corticosteroid treatment led to significant clinical improvement.

CONCLUSIONS

IgG4-RD is an uncommon condition with an increasing body of reported cases that can affect the skull base and calvarium and should be in the differential diagnosis, because delay in diagnosis and treatment may be common.

Using Histopathology to Assess the Reliability of Intraoperative Magnetic Resonance Imaging in Guiding Additional Brain Tumor Resection: A Multicenter Study

BACKGROUND

Intraoperative magnetic resonance imaging (iMRI) is a powerful tool for guiding brain tumor resections, provided that it accurately discerns residual tumor.

OBJECTIVE

To use histopathology to assess how reliably iMRI may discern additional tumor for a variety of tumor types, independent of the indications for iMRI.

METHODS

A multicenter database was used to calculate the odds of additional resection during the same surgical session for grade I to IV gliomas and pituitary adenomas. The reliability of iMRI for identifying residual tumor was assessed using histopathology of tissue resected after iMRI.

RESULTS

Gliomas (904/1517 cases, 59.6%) were more likely than pituitary adenomas (176/515, 34.2%) to receive additional resection after iMRI (P < .001), but these tumors were equally likely to have additional tissue sent for histopathology (398/904, 44.4% vs 66/176, 37.5%; P = .11). Tissue samples were available for resections after iMRI for 464 cases, with 415 (89.4%) positive for tumor. Additional resections after iMRI for gliomas (361/398, 90.7%) were more likely to yield additional tumor compared to pituitary adenomas (54/66, 81.8%) (P = .03). There were no significant differences in resection after iMRI yielding histopathologically positive tumor between grade I (58/65 cases, 89.2%; referent), grade II (82/92, 89.1%) (P = .98), grade III (72/81, 88.9%) (P = .95), or grade IV gliomas (149/160, 93.1%) (P = .33). Additional resection for previously resected tumors (122/135 cases, 90.4%) was equally likely to yield histopathologically confirmed tumor compared to newly-diagnosed tumors (293/329, 89.0%) (P = .83).

CONCLUSION

Histopathological analysis of tissue resected after use of iMRI for grade I to IV gliomas and pituitary adenomas demonstrates that iMRI is highly reliable for identifying residual tumor.

Internal dose escalation associated with increased local control for melanoma brain metastases treated with stereotactic radiosurgery

OBJECTIVE

The internal high-dose volume varies widely for a given prescribed dose during stereotactic radiosurgery (SRS) to treat brain metastases (BMs). This may be altered during treatment planning, and the authors have previously shown that this improves local control (LC) for non-small cell lung cancer BMs without increasing toxicity. Here, they seek to identify potentially actionable dosimetric predictors of LC after SRS for melanoma BM.

METHODS

The records of patients with unresected melanoma BM treated with single-fraction Gamma Knife RS between 2006 and 2017 were reviewed. LC was assessed on a per-lesion basis, defined as stability or a decrease in lesion size. Outcome-oriented approaches were utilized to determine optimal dichotomization for dosimetric variables relative to LC. Univariable and multivariable Cox regression analysis was implemented to evaluate the impact of collected parameters on LC.

RESULTS

Two hundred eighty-seven melanoma BMs in 79 patients were identified. The median age was 56 years (range 31-86 years). The median follow-up was 7.6 months (range 0.5-81.6 months), and the median survival was 9.3 months (range 1.3-81.6 months). Lesions were optimally stratified by volume receiving at least 30 Gy (V30) greater than or equal to versus less than 25%. V30 was ≥ and < 25% in 147 and 140 lesions, respectively. For all patients, 1-year LC was 83% versus 66% for V30 ≥ and < 25%, respectively (p = 0.001). Stratifying by volume, lesions 2 cm or less (n = 215) had 1-year LC of 82% versus 70% (p = 0.013) for V30 ≥ and < 25%, respectively. Lesions > 2 to 3 cm (n = 32) had 1-year LC of 100% versus 43% (p = 0.214) for V30 ≥ and < 25%, respectively. V30 was still predictive of LC even after controlling for the use of immunotherapy and targeted therapy. Radionecrosis occurred in 2.8% of lesions and was not significantly associated with V30.

CONCLUSIONS

For a given prescription dose, an increased internal high-dose volume, as indicated by measures such as V30 ≥ 25%, is associated with improved LC but not increased toxicity in single-fraction SRS for melanoma BM. Internal dose escalation is an independent predictor of improved LC even in patients receiving immunotherapy and/or targeted therapy. This represents a dosimetric parameter that is actionable at the time of treatment planning and warrants further evaluation.

Intraoperative MRI for newly diagnosed supratentorial glioblastoma: a multicenter-registry comparative study to conventional surgery

OBJECTIVE

Intraoperative MRI (iMRI) is used in the surgical treatment of glioblastoma, with uncertain effects on outcomes. The authors evaluated the impact of iMRI on extent of resection (EOR) and overall survival (OS) while controlling for other known and suspected predictors.

METHODS

A multicenter retrospective cohort of 640 adult patients with newly diagnosed supratentorial glioblastoma who underwent resection was evaluated. iMRI was performed in 332/640 cases (51.9%). Reviews of MRI features and tumor volumetric analysis were performed on a subsample of cases (n = 286; 110 non-iMRI, 176 iMRI) from a single institution.

RESULTS

The median age was 60.0 years (mean 58.5 years, range 20.5-86.3 years). The median OS was 17.0 months (95% CI 15.6-18.4 months). Gross-total resection (GTR) was achieved in 403/640 cases (63.0%). Kaplan-Meier analysis of 286 cases with volumetric analysis for EOR (grouped into 100%, 95%-99%, 80%-94%, and 50%-79%) showed longer OS for 100% EOR compared to all other groups (p < 0.01). Additional resection after iMRI was performed in 104/122 cases (85.2%) with initial subtotal resection (STR), leading to a 6.3% mean increase in EOR and a 2.2-cm3 mean decrease in tumor volume. For iMRI cases with volumetric analysis, the GTR rate increased from 54/176 (30.7%) on iMRI to 126/176 (71.5%) postoperatively. The EOR was significantly higher in the iMRI group for intended GTR and STR groups (p = 0.02 and p < 0.01, respectively). Predictors of GTR on multivariate logistic regression included iMRI use and intended GTR. Predictors of shorter OS on multivariate Cox regression included older age, STR, isocitrate dehydrogenase 1 (IDH1) wild type, no O 6-methylguanine DNA methyltransferase (MGMT) methylation, and no Stupp therapy. iMRI was a significant predictor of OS on univariate (HR 0.82, 95% CI 0.69-0.98; p = 0.03) but not multivariate analyses. Use of iMRI was not associated with an increased rate of new permanent neurological deficits.

CONCLUSIONS

GTR increased OS for patients with newly diagnosed glioblastoma after adjusting for other prognostic factors. iMRI increased EOR and GTR rate and was a significant predictor of GTR on multivariate analysis; however, iMRI was not an independent predictor of OS. Additional supporting evidence is needed to determine the clinical benefit of iMRI in the management of glioblastoma.

Impact of Intraoperative Magnetic Resonance Imaging and Other Factors on Surgical Outcomes for Newly Diagnosed Grade II Astrocytomas and Oligodendrogliomas: A Multicenter Study

BACKGROUND

Few studies use large, multi-institutional patient cohorts to examine the role of intraoperative magnetic resonance imaging (iMRI) in the resection of grade II gliomas.

OBJECTIVE

To assess the impact of iMRI and other factors on overall survival (OS) and progression-free survival (PFS) for newly diagnosed grade II astrocytomas and oligodendrogliomas.

METHODS

Retrospective analyses of a multicenter database assessed the impact of patient-, treatment-, and tumor-related factors on OS and PFS.

RESULTS

A total of 232 resections (112 astrocytomas and 120 oligodendrogliomas) were analyzed. Oligodendrogliomas had longer OS (P &lt; .001) and PFS (P = .01) than astrocytomas. Multivariate analyses demonstrated improved OS for gross total resection (GTR) vs subtotal resection (STR; P = .006, hazard ratio [HR]: .23) and near total resection (NTR; P = .02, HR: .64). GTR vs STR (P = .02, HR: .54), GTR vs NTR (P = .04, HR: .49), and iMRI use (P = .02, HR: .54) were associated with longer PFS. Frontal (P = .048, HR: 2.11) and occipital/parietal (P = .003, HR: 3.59) locations were associated with shorter PFS (vs temporal). Kaplan-Meier analyses showed longer OS with increasing extent of surgical resection (EOR) (P = .03) and 1p/19q gene deletions (P = .02). PFS improved with increasing EOR (P = .01), GTR vs NTR (P = .02), and resections above STR (P = .04). Factors influencing adjuvant treatment (35.3% of patients) included age (P = .002, odds ratio [OR]: 1.04) and EOR (P = .003, OR: .39) but not glioma subtype or location. Additional tumor resection after iMRI was performed in 105/159 (66%) iMRI cases, yielding GTR in 54.5% of these instances.

CONCLUSION

EOR is a major determinant of OS and PFS for patients with grade II astrocytomas and oligodendrogliomas. Intraoperative MRI may improve EOR and was associated with increased PFS.

Characterization and validation of an intra-fraction motion management system for masked-based radiosurgery

Purpose

Characterize the intra‐fraction motion management (IFMM) system found on the Gamma Knife Icon (GKI), including spatial accuracy, latency, temporal performance, and overall effect on delivered dose.

Methods

A phantom was constructed, consisting of a three‐axis translation mount, a remote motorized flipper, and a thermoplastic sphere surrounding a radiation detector. An infrared marker was placed on the translation mount secured to the flipper. The spatial accuracy of the IFMM was measured via the translation mount in all Cartesian planes. The detector was centered at the radiation focal point. A remote signal was used to move the marker out of the IFMM tolerance and pause the beam. A two‐channel electrometer was used to record the signals from the detector and the flipper when motion was signaled. These signals determined the latency and temporal performance of the GKI.

Results

The spatial accuracy of the IFMM was found to be <0.1 mm. The measured latency was <200 ms. The dose difference with five interruptions was <0.5%.

Conclusion

This work provides a quantitative characterization of the GKI IFMM system as required by the Nuclear Regulatory Commission. This provides a methodology for GKI users to satisfy these requirements using common laboratory equipment in lieu of a commercial solution.

ESM-CT: a precise method for localization of DBS electrodes in CT images

BACKGROUND

Deep brain stimulation (DBS) of the subthalamic nucleus produces variable effects in Parkinson disease. Variation may result from different electrode positions relative to target. Thus, precise electrode localization is crucial when investigating DBS effects.

NEW METHOD

We developed a semi-automated method, Electrode Shaft Modeling in CT images (ESM-CT) to reconstruct DBS lead trajectories and contact locations. We evaluated methodological sensitivity to operator-dependent steps, robustness to image resampling, and test-retest replicability. ESM-CT was applied in 56 patients to study electrode position change (and relation to time between scans, postoperative subdural air volume, and head tilt during acquisition) between images acquired immediately post-implantation (DBS-CT) and months later (DEL-CT).

RESULTS

Electrode tip localization was robust to image resampling and replicable to within ∼ 0.2 mm on test-retest comparisons. Systematic electrode displacement occurred rostral-ventral-lateral between DBS-CT and DEL-CT scans. Head angle was a major explanatory factor (p < 0.001,Pearson's r = 0.46, both sides) and volume of subdural air weakly predicted electrode displacement (p = 0.02,r = 0.29:p = 0.1,r = 0.25 for left:right). Modeled shaft curvature was slightly greater in DEL-CT. Magnitude of displacement and degree of curvature were independent of elapsed time between scans.

COMPARISON WITH EXISTING METHODS

Comparison of ESM-CT against two existing methods revealed systematic differences in one coordinate (1 ± 0.3 mm,p < 0.001) for one method and in three coordinates for another method (x:0.1 ± 0.1 mm, y:0.4 ± 0.2 mm, z:0.4 ± 0.2 mm, p < 10^-10). Within-method coordinate variability across participants is similar.

CONCLUSION

We describe a robust and precise method for CT DBS contact localization. Application revealed that acquisition head angle significantly impacts electrode position. DBS localization schemes should account for head angle.

Internal dose escalation is associated with increased local control for non-small cell lung cancer (NSCLC) brain metastases treated with stereotactic radiosurgery (SRS)

Objective

To identify potentially actionable dosimetric predictors of local control (LC) for non-small cell lung cancer (NSCLC) brain metastases treated with single-fraction stereotactic radiosurgery (SRS).

Methods and materials

Patients with NSCLC brain metastases treated with single-fraction SRS were identified. Eligible patients had at least 1 follow-up magnetic resonance imaging scan and were without prior metastasectomy or SRS to the same lesion. LC and overall survival (OS) were estimated using the Kaplan-Meier method. The Cox proportional hazards model was used for univariate (UVA) and multivariate analysis (MVA). Receiver operating characteristic (ROC) analysis was used to identify optimal cut points for dose-volume histogram metrics relative to LC.

Results

A total of 612 NSCLC brain metastasis were identified in 299 patients with single-fraction SRS between 1999 and 2014. Median follow-up was 10 months. Median OS from time of SRS was 11 months. Overall LC was 75% and 66% at 1 and 2 years, respectively. On UVA, increasing dose by any measure was associated with improved LC. On MVA, volume receiving at least 32 Gy (V32; hazard ratio [HR], 0.069; P < .000), along with higher prescription isodose (HR, 0.953; P = .031) and lower volume (HR, 1.359; P < .000), were independent predictors of improved LC. ROC analysis demonstrated a V32 of 24% to be most predictive for LC. For the entire cohort, 1-year LC for V32 ≥24% was 89% versus 67% for V32 <24% (P = .000). Stratifying by volume, lesions ≤2 cm (n = 323) had a 1-year LC of 95% versus 82% (P = .005) for V32 above and below 24%, respectively. For lesions 2.1 to 3 cm (n = 211), 1-year LC was 79% versus 59% (P = .003) for V32 above and below 24%, respectively. Total tumor volume alone was predictive for OS.

Conclusions

Volume, prescription isodose line, and V32 are independent predictors of LC. V32 represents an actionable SRS treatment planning parameter for NSCLC brain metastases.

Radiation Therapy for Residual or Recurrent Atypical Meningioma: The Effects of Modality, Timing, and Tumor Pathology on Long-Term Outcomes

BACKGROUND

Optimal use of stereotactic radiosurgery (SRS) vs external beam radiation therapy (EBRT) for treatment of residual/recurrent atypical meningioma is unclear.

OBJECTIVE

To analyze features associated with progression after radiation therapy.

METHODS

Fifty radiation-naive patients who received SRS or EBRT for residual and/or recurrent atypical meningioma were examined for predictors of progression using Cox regression and Kaplan-Meier analyses.

RESULTS

Thirty-two patients (64%) received adjuvant radiation after subtotal resection, 12 patients (24%) received salvage radiation after progression following subtotal resection, and 6 patients (12%) received salvage radiation after recurrence following gross total resection. Twenty-one patients (42%) received SRS (median 18 Gy), and 7 (33%) had tumor progression. Twenty-nine patients (58%) received EBRT (median 54 Gy), and 13 (45%) had tumor progression. Whereas tumor volume (P = .53), SRS vs EBRT (P = .45), and adjuvant vs salvage (P = .34) were not associated with progression after radiation therapy, spontaneous necrosis (hazard ratio [HR] = 82.3, P < .001), embolization necrosis (HR = 15.6, P = .03), and brain invasion (HR = 3.8, P = .008) predicted progression in univariate and multivariate analyses. Tumors treated with SRS/EBRT had 2- and 5-year actuarial locoregional control rates of 91%/88% and 71%/69%, respectively. Tumors with spontaneous necrosis, embolization necrosis, and no necrosis had 2- and 5-year locoregional control rates of 76%, 92%, and 100% and 36%, 73%, and 100%, respectively (P < .001).

CONCLUSION

This study suggests that necrosis may be a negative predictor of radiation response regardless of radiation timing or modality.

ABBREVIATIONS

AM, atypical meningiomaEBRT, external beam radiation therapyGTR, gross total resectionLC, locoregional controlOS, overall survivalPOE, preoperative embolizationRT, radiation therapySRS, stereotactic radiosurgerySTR, subtotal resection.

Postoperative seizure freedom does not normalize altered connectivity in temporal lobe epilepsy

OBJECTIVES

Specific changes in the functional connectivity of brain networks occur in patients with epilepsy. Yet whether such changes reflect a stable disease effect or one that is a function of active seizure burden remains unclear. Here, we longitudinally assessed the connectivity of canonical cognitive functional networks in patients with intractable temporal lobe epilepsy (TLE), both before and after patients underwent epilepsy surgery and achieved seizure freedom.

METHODS

Seventeen patients with intractable TLE who underwent epilepsy surgery with Engel class I outcome and 17 matched healthy controls took part in the study. The functional connectivity of a set of cognitive functional networks derived from typical cognitive tasks was assessed in patients, preoperatively and postoperatively, as well as in controls, using stringent methods of artifact reduction.

RESULTS

Preoperatively, functional networks in TLE patients differed significantly from healthy controls, with differences that largely, but not exclusively, involved the default mode and temporal/auditory subnetworks. However, undergoing epilepsy surgery and achieving seizure freedom did not lead to significant changes in network connectivity, with postoperative functional network abnormalities closely mirroring the preoperative state.

SIGNIFICANCE

This result argues for a stable chronic effect of the disease on brain connectivity, with changes that are largely "burned in" by the time a patient with intractable TLE undergoes epilepsy surgery, which typically occurs years after the initial diagnosis. The result has potential implications for the treatment of intractable epilepsy, suggesting that delaying surgical intervention that may achieve seizure freedom may lead to functional network changes that are no longer reversible by the time of epilepsy surgery.

Management of atypical cranial meningiomas, part 1: predictors of recurrence and the role of adjuvant radiation after gross total resection

BACKGROUND

Indications for external beam radiation therapy (EBRT) for atypical meningiomas (AMs) remain unclear.

OBJECTIVE

To analyze features associated with recurrence in AM patients after gross total resection (GTR) and to assess the relative benefit of EBRT in a retrospective cohort study.

METHODS

One hundred fifty-one primary AMs after GTR (88 female patients; median follow-up, 45.0 months) were examined for possible predictors of recurrence (age, sex, location, volume, bone involvement, brain invasion). The Fisher exact and Wilcoxon rank-sum tests were used to analyze the association between these predictors and use of EBRT. The impact on recurrence for these predictors and EBRT was analyzed with Kaplan-Meier and Cox regression.

RESULTS

Of 151 patients, 13 (8.6%) experienced recurrence after GTR (median, 47.0 months). Multivariate analysis identified elevated mitotic index (P = .007) and brain invasion (P = .002) as predictors of recurrence. Larger volume (P = .96) was not associated with recurrence but was more likely to prompt EBRT (P = .001). Recurrences occurred in 11 of 112 with GTR (9.8%; median, 44 months) and 2 of 39 with GTR/EBRT (5.1%; median, 133 months). The 2-, 5-, and 10-year progression-free survival rates after GTR vs GTR/EBRT were 97%, 86%, and 68% vs 100%, 100%, and 78%. Kaplan-Meier analysis demonstrated no difference in progression-free survival or overall survival after GTR vs GTR/EBRT (P = .8, P > .99).

CONCLUSION

Brain invasion and high mitotic rates may predict recurrence. After GTR of AMs, EBRT appears not to affect progression-free survival and overall survival, suggesting that observation rather than EBRT may be indicated after GTR.

A CDC20-APC/SOX2 Signaling Axis Regulates Human Glioblastoma Stem-like Cells

Glioblastoma harbors a dynamic subpopulation of glioblastoma stem-like cells (GSCs) that can propagate tumors in vivo and is resistant to standard chemoradiation. Identification of the cell-intrinsic mechanisms governing this clinically important cell state may lead to the discovery of therapeutic strategies for this challenging malignancy. Here, we demonstrate that the mitotic E3 ubiquitin ligase CDC20-anaphase-promoting complex (CDC20-APC) drives invasiveness and self-renewal in patient tumor-derived GSCs. Moreover, CDC20 knockdown inhibited and CDC20 overexpression increased the ability of human GSCs to generate brain tumors in an orthotopic xenograft model in vivo. CDC20-APC control of GSC invasion and self-renewal operates through pluripotency-related transcription factor SOX2. Our results identify a CDC20-APC/SOX2 signaling axis that controls key biological properties of GSCs, with implications for CDC20-APC-targeted strategies in the treatment of glioblastoma.

Simpson Grade I-III Resection of Spinal Atypical (World Health Organization Grade II) Meningiomas is Associated With Symptom Resolution and Low Recurrence

BACKGROUND:

Because of their rarity, outcomes regarding spinal atypical meningiomas (AMs) remain unclear.

OBJECTIVE:

To describe the recurrence rate and postoperative outcomes after resection of spinal AMs, and to discuss an appropriate resection strategy and adjuvant therapy for spinal AMs.

METHODS:

Data from all patients who presented with spinal AMs to 2 tertiary referral centers between 1998 and 2013 were obtained by chart review.

RESULTS:

From 102 patients with spinal meningioma, 20 AM tumors (7 cervical, 11 thoracic, 2 thoracolumbar) were identified in 18 patients (median age, 50 years [range, 19-75] at time of resection; 11% male; median follow-up, 32 months [range, 1-179] after resection). Before resection, patients had sensory deficits (70%), pain (70%), weakness (60%), ataxia (50%), spasticity (65%), and incontinence (35%). One tumor presented asymptomatically. Simpson grade I, II, III, and IV resection were achieved in 3 (15%), 13 (65%), 2 (10%), and 2 (10%) tumors, respectively. One patient that underwent Simpson grade III resection received adjuvant radiation therapy. After Simpson grade I-III or gross total resection, no tumors recurred (0%; confidence interval, 0%-17.6%). After Simpson grade IV resection, 1 tumor recurred (50%; confidence interval, 1.3%-98.7%). With the exception of 1 patient who had bilateral paraplegia perioperatively, all other patients experienced improvement of preoperative symptoms after surgery (median time, 3.6 months [range, 1-13] after resection).

CONCLUSION:

Despite published cases suggesting an aggressive clinical course for spinal AMs, this series of spinal AMs reports that gross total resection without adjuvant radiation therapy resulted in symptom resolution and low recurrence.

Predictors of individual tumor local control after stereotactic radiosurgery for non-small cell lung cancer brain metastases

PURPOSE

To evaluate local control rates and predictors of individual tumor local control for brain metastases from non-small cell lung cancer (NSCLC) treated with stereotactic radiosurgery (SRS).

METHODS AND MATERIALS

Between June 1998 and May 2011, 401 brain metastases in 228 patients were treated with Gamma Knife single-fraction SRS. Local failure was defined as an increase in lesion size after SRS. Local control was estimated using the Kaplan-Meier method. The Cox proportional hazards model was used for univariate and multivariate analysis. Receiver operating characteristic analysis was used to identify an optimal cutpoint for conformality index relative to local control. A P value <.05 was considered statistically significant.

RESULTS

Median age was 60 years (range, 27-84 years). There were 66 cerebellar metastases (16%) and 335 supratentorial metastases (84%). The median prescription dose was 20 Gy (range, 14-24 Gy). Median overall survival from time of SRS was 12.1 months. The estimated local control at 12 months was 74%. On multivariate analysis, cerebellar location (hazard ratio [HR] 1.94, P=.009), larger tumor volume (HR 1.09, P<.001), and lower conformality (HR 0.700, P=.044) were significant independent predictors of local failure. Conformality index cutpoints of 1.4-1.9 were predictive of local control, whereas a cutpoint of 1.75 was the most predictive (P=.001). The adjusted Kaplan-Meier 1-year local control for conformality index ≥ 1.75 was 84% versus 69% for conformality index <1.75, controlling for tumor volume and location. The 1-year adjusted local control for cerebellar lesions was 60%, compared with 77% for supratentorial lesions, controlling for tumor volume and conformality index.

CONCLUSIONS

Cerebellar tumor location, lower conformality index, and larger tumor volume were significant independent predictors of local failure after SRS for brain metastases from NSCLC. These results warrant further investigation in a prospective setting.

Management of Atypical Cranial Meningiomas, Part 2

BACKGROUND:

The efficacies of adjuvant stereotactic radiosurgery (SRS) and external beam radiation therapy (EBRT) for atypical meningiomas (AMs) after subtotal resection (STR) remain unclear.

OBJECTIVE:

To analyze the clinical, histopathological, and radiographic features associated with progression in AM patients after STR.

METHODS:

Fifty-nine primary AMs after STR were examined for predictors of progression, including the impact of SRS and EBRT, in a retrospective cohort study.

RESULTS:

Twenty-seven patients (46%) progressed after STR (median, 30 months). On univariate analysis, spontaneous necrosis positively (hazard ratio = 5.2; P = .006) and adjuvant radiation negatively (hazard ratio = 0.3; P = .009) correlated with progression; on multivariate analysis, only adjuvant radiation remained independently significant (hazard ratio = 0.3; P = .006). SRS and EBRT were associated with greater local control (LC; P = .02) and progression-free survival (P = .007). The 2-, 5-, and 10-year actuarial LC rates after STR vs STR/EBRT were 60%, 34%, and 34% vs 96%, 65%, and 45%. The 2-, 5-, and 10-year actuarial progression-free survival rates after STR vs STR/EBRT were 60%, 30%, and 26% vs 96%, 65%, and 45%. Compared with STR alone, adjuvant radiation therapy significantly improved LC in AMs that lack spontaneous necrosis (P = .003) but did not improve LC in AMs with spontaneous necrosis (P = .6).

CONCLUSION:

Adjuvant SRS or EBRT improved LC of AMs after STR but only for tumors without spontaneous necrosis. Spontaneous necrosis may aid in decisions to administer adjuvant SRS or EBRT after STR of AMs.

Biopsy of the superficial cortex: predictors of effectiveness and outcomes

BACKGROUND

Brain biopsies of superficial cortex are performed for diagnosis of neurological diseases, but preoperative predictors of successful diagnosis and risks are lacking.

OBJECTIVE

We evaluated effectiveness and outcomes of superficial cortical biopsies and determined preoperative predictors of diagnosis, outcomes, morbidities, and mortality.

METHODS

A single-institution retrospective analysis of 170 patients who underwent open brain biopsies of superficial cortex was performed. Clinical predictors of effectiveness and outcomes were determined using univariate/multivariate analyses and a system for risk-benefit stratification was created and tested.

RESULTS

Brain biopsies led to successful diagnosis in 122 of 170 (71.8%) and affected management in 97 of 170 (57.1%) cases. Factors increasing the odds of diagnostic pathology included age older than 45 years (odds ratio [OR]: 2.67, 95% confidence interval [CI]: 1.34-5.27, P < .01), previous cancer diagnosis (OR: 3.64, 95% CI: 1.69-7.85, P < .001), focal (OR: 3.90, 95% CI: 1.91-8.00, P < .001) and enhancing (OR: 5.03, 95% CI: 2.41-10.52, P < .001) lesions on magnetic resonance imaging, biopsy of specific lesions on magnetic resonance imaging (OR: 9.34, 95% CI: 4.29-20.33, P < .001), and use of intraoperative navigation (OR: 6.59, 95% CI: 3.04-14.28, P < .001). Brain biopsies led to symptomatic intracranial hemorrhage, seizures, other significant morbidities, and perioperative mortality in 12.4%, 16.2%, 37.1%, and 8% of cases, respectively. Risk of postoperative intracranial hemorrhage was increased by a history of aspirin use (OR: 2.51, 95% CI: 1.23-5.28, P < .05) and age older than 60 years (OR: 2.66, 95% CI: 1.36-5.18, P < .01).

CONCLUSION

Effectiveness and risk of morbidity/mortality can be estimated preoperatively for patients undergoing open brain biopsies of the superficial cortex. Older age and specific imaging characteristics increase the odds of diagnostic biopsy. Conversely, older age and aspirin use increases the risk of postoperative complications.

A retrospective analysis of survival and prognostic factors after stereotactic radiosurgery for aggressive meningiomas

BACKGROUND

While most meningiomas are benign, aggressive meningiomas are associated with high levels of recurrence and mortality. A single institution's Gamma Knife radiosurgical experience with atypical and malignant meningiomas is presented, stratified by the most recent WHO classification.

METHODS

Thirty-one patients with atypical and 4 patients with malignant meningiomas treated with Gamma Knife radiosurgery between July 2000 and July 2011 were retrospectively reviewed. All patients underwent prior surgical resection. Overall survival was the primary endpoint and rate of disease recurrence in the brain was a secondary endpoint. Patients who had previous radiotherapy or prior surgical resection were included. Kaplan-Meier and Cox proportional hazards models were used to estimate survival and identify factors predictive of recurrence and survival.

RESULTS

Post-Gamma Knife recurrence was identified in 11 patients (31.4%) with a median overall survival of 36 months and progression-free survival of 25.8 months. Nine patients (25.7%) had died. Three-year overall survival (OS) and progression-free survival (PFS) rates were 78.0% and 65.0%, respectively. WHO grade II 3-year OS and PFS were 83.4% and 70.1%, while WHO grade III 3-year OS and PFS were 33.3% and 0%. Recurrence rate was significantly higher in patients with a prior history of benign meningioma, nuclear atypia, high mitotic rate, spontaneous necrosis, and WHO grade III diagnosis on univariate analysis; only WHO grade III diagnosis was significant on multivariate analysis. Overall survival was adversely affected in patients with WHO grade III diagnosis, prior history of benign meningioma, prior fractionated radiotherapy, larger tumor volume, and higher isocenter number on univariate analysis; WHO grade III diagnosis and larger treated tumor volume were significant on multivariate analysis.

CONCLUSION

Atypical and anaplastic meningiomas remain difficult tumors to treat. WHO grade III diagnosis and treated tumor volume were significantly predictive of recurrence and survival on multivariate analysis in aggressive meningioma patients treated with radiosurgery. Larger tumor size predicts poor survival, while nuclear atypia, necrosis, and increased mitotic rate are risk factors for recurrence. Clinical and pathologic predictors may help identify patients that are at higher risk for recurrence.

Codeletions at 1p and 19q predict a lower risk of pseudoprogression in oligodendrogliomas and mixed oligoastrocytomas

BACKGROUND

Pseudoprogression (PsP) occurs at a higher rate in glioblastoma multiforme with a methylated MGMT promoter-a subset with increased sensitivity to chemoradiotherapy and better overall prognosis. In oligodendroglioma (OG) and oligoastrocytoma (OA), presence of 1p/19q codeletions is highly predictive of response to treatment and is often associated with the methylated MGMT promoter; hence, this study queries whether the presence of 1p/19q codeletions in OG/OA correlates with a higher rate of PsP following therapy.

METHODS

A retrospective analysis was performed on all OG/OA in a database of patients with brain tumors who underwent resection of their tumor since 1998. Eighty-eight cases (37 with and 51 without 1p/19q codeletions) met inclusion criteria, and their patient data were analyzed to determine whether the presence of 1p/19q codeletions was associated with PsP and survival.

RESULTS

OG/OA (World Health Organization grades II and III) with 1p/19q codeletions had a significantly improved survival (P = .041). Multivariate analysis found that PsP occurred less frequently in OG/OA with 1p/19q codeletions compared with tumors without codeletions (odds ratio, 0.047; 95% confidence interval, 0.005-0.426; P = .0066). The rate of PsP was 19% for the entire cohort, 31% for tumors without codeletions, and 3% for tumors with codeletions. When early posttreatment contrast enhancement developed in tumors with 1p/19q codeletions, it occurred exclusively in tumors that were histologically OA and not OG.

CONCLUSION

Codeletions of 1p/19q are a marker of good prognosis but are unexpectedly associated with a lower likelihood of PsP. PsP does not correlate with sensitivity to treatment and improved survival in OG/OA.

Survival following gamma knife radiosurgery for brain metastasis from breast cancer

Background

Breast cancer is the second most common cause of brain metastases in the United States. Although breast cancer induced brain metastases represent an incurable condition, some patients experience prolonged survival. In this retrospective study, we examine a cohort of patients with brain metastases from breast cancer treated with Gamma Knife stereotactic radiosurgery to identify factors that predict better outcomes.

Methods

A retrospective database of 100 patients treated for brain metastases due to breast cancer via Gamma Knife radiosurgery (GKS) from July 1998 through March 2009 was reviewed. Patients who received radiosurgery as sole treatment, as a planned boost after whole brain radiotherapy or surgical resection, or as salvage after prior whole brain radiation therapy (WBRT) or surgical resection were included. Prognostic factors identified to be significant for survival in previous brain metastasis studies were analyzed for significance by univariate and multivariate Cox analysis.

Results

Overall, the median brain progression-free survival time was 7.1 months and the median survival time was 12.3 months. No prognostic variables were significant for brain progression-free survival. For patients treated with a planned GKS after WBRT, GKS as sole treatment, GKS salvage after WBRT, GKS boost after surgery, or GKS for surgical salvage the median survival times (MSTs) were as follows: 12.2 months, 12.4 months, 9.5 months, 27.6 months and 33.4 months respectively. Differences between the groups were not significant (p = 0.06); however, GKS boost after surgery and GKS for salvage after surgery did have a trend toward better overall survival.

The MST for patients of age <65 years was 14.5 months, compared to age ≥65 which was 7.7 months (p = 0.06) and remained a significant prognostic factor for overall survival on multivariate analysis. The MST for patients with a single lesion was 16.9 months, not significantly different than the MST of 14.5 months for patients with 2–3 lesions. However patients with >3 lesions had a MST of 5.9 months, which was significantly worse. Breast cancer subtype as approximated by biomarkers and KPS were not significant predictors of overall survival and stage at initial diagnosis was inversely associated with survival.

Conclusion

Stereotactic radiosurgery offers good local control and prolonged survival in selected patients. Age and number of lesions are strong predictors of overall survival.

Trigeminal neuralgia post-styloidectomy in Eagle syndrome: a case report

Introduction

Eagle syndrome is a condition characterized by an elongated (>3cm) styloid process with associated symptoms of recurrent facial or throat pain. In this report we present a case of Eagle syndrome exhibiting the typical findings of glossopharyngeal nerve involvement, as well as unusual involvement of the trigeminal nerve. Notably, this patient developed a classical trigeminal neuralgia post-styloidectomy.

Case presentation

A 68-year-old Caucasian woman presented with a 25-year history of dull pain along the right side of her throat, lateral neck, and jaw. Her symptoms were poorly controlled with medication until 15 years ago when she was diagnosed with Eagle syndrome, and underwent a manual fracture of her styloid process. This provided symptomatic relief until 5 years ago when the pain recurred and progressed. She underwent a styloidectomy via a lateral neck approach, which resolved the pain once again. However, 6 months ago a new onset of triggerable, electric shock-like facial pain began within the right V1 and V2 distributions.

Conclusions

Eagle syndrome is distressing to patients and often difficult to diagnose due to its wide variability in symptoms. It is easily confused with dental pain or temporomandibular joint disorder, leading to missed diagnoses and unnecessary procedures. Pain along the jaw and temple is an unusual but possible consequence of Eagle syndrome. An elongated styloid process should be considered a possible etiology of dull facial pain in the trigeminal distributions, in particular V3.

Implementation and preliminary clinical experience with the use of ceiling mounted mobile high field intraoperative magnetic resonance imaging between two operating rooms

OBJECTIVE

Intraoperative magnetic resonance imaging (ioMRI) provides immediate feedback and quality assurance enabling the neurosurgeon to improve the quality of a range of neurosurgical procedures. Implementation of ioMRI is a complex and costly process. We describe our preliminary 16 months experience with the integration of an IMRIS movable ceiling mounted high field (1.5 T) ioMRI setup with two operating rooms.

METHODS

Aspects of implementation of our ioMRI and our initial 16 months of clinical experience in 180 consecutive patients were reviewed.

RESULTS

The installation of a ceiling mounted movable ioMRI between two operating rooms was completed in April 2008 at Barnes-Jewish Hospital in St. Louis. Experience with 180 neurosurgical cases (M:F-100:80, age range 1-79 years, 71 gliomas, 57 pituitary adenomas, 9 metastases, 11 other tumor cases, 4 Chiari decompressions, 6 epilepsy resections and 22 other miscellaneous procedures) demonstrated that this device effectively provided high quality real-time intraoperative imaging. In 74 of all 180 cases (41%) and in 54% of glioma resections, the surgeon modified the procedure based upon the ioMRI. Ninety-three percent of ioMRI glioma cases achieved gross/near total resection compared to 65% of non ioMRI glioma cases in this time frame.

CONCLUSION

A movable high field strength ioMRI can be safely integrated between two neurosurgical operating rooms. This strategy leads to modification of the surgical procedure in a significant number of cases, particularly for glioma surgery. Long-term follow up is needed to evaluate the clinical and financial impact of this technology in the field of neurosurgery.

Combined surgical resection and stereotactic radiosurgery for treatment of cerebral metastases

BACKGROUND

Patients with limited intracranial metastatic disease traditionally have been treated with surgery followed by WBRT. However, there is growing concern for the debilitating cognitive effects after WBRT in long-term survivors. We present a series of patients treated with surgery followed by SRS, while reserving WBRT as a salvage therapy for disease progression.

METHODS

Medical records from 15 patients with 1 to 2 cerebral metastases who underwent both resection and SRS were reviewed. Outcome measures included overall survival, survival by RPA class, EOR, local tumor control, progression of intracranial disease, need for WBRT salvage therapy, and COD.

RESULTS

Fifteen patients with cerebral metastases were treated with the combined surgery-SRS paradigm. Eight of the 15 patients (53.3%) were designated RPA class 1, with 6 of 15 (40.0%) in class 2 and 1 of 15 (6.7%) in class 3. Gross total resection was achieved in 12 cases (80.0%). Overall median survival was 20.0 months, with values of 22.0 and 13.0 months for RPA classes 1 and 2, respectively. Local recurrence occurred in 16.7% of those patients with GTR. Six patients (40.0%) went on to receive WBRT at a median of 8.0 months from initial presentation. Twelve patients (80.0%) had died at the completion of the study, and the COD was CNS progression in 33.3%.

CONCLUSIONS

Surgical resection combined with SRS is an effective treatment for selected patients with limited cerebral metastatic disease. Survival using this combined treatment was equivalent to or greater than that reported by other studies using surgery + WBRT or SRS + WBRT.

Safety and efficacy of subthalamic nucleus deep brain stimulation performed with limited intraoperative mapping for treatment of Parkinson's disease

OBJECTIVE

The aim of this study is to establish the safety and efficacy of bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) patients with disabling motor fluctuations performed with an expedient procedure with limited intraoperative mapping.

METHODS

Bilateral STN DBS systems were implanted in 110 PD patients. Targeting of STN was achieved with T2-weighted magnetic resonance imaging guidance and a stereotactic navigation system confirmed by limited electrophysiological mapping. The safety of the procedure was analyzed in all 110 patients. The efficacy of the procedure was assessed in the practically-defined off medication state in the 72 patients who underwent evaluations 3 to 12 months after electrode implantation.

RESULTS

Adverse effects were infrequent and transient with no incidence of death, hemiparesis, or seizure. In the 72 patients, STN DBS reduced total Unified Parkinson's Disease Rating Scale motor scores at the time of the follow-up evaluation by 47% from 43.4 +/- 16.1 with stimulators off to 22.8 +/- 11.6 with stimulators on (P < 0.001). The changes in Unified Parkinson's Disease Rating Scale motor subscores improved as follows: rest tremor, 74% (P < 0.001); rigidity, 58% (P < 0.001); bradykinesia, 37% (P < 0.001); pull test, 35% (P < 0.001); gait, 44% (P < 0.001); axial signs, 42% (P < 0.001); and speech, 13% (P = 0.002). The prescribed total daily levodopa-equivalent dose decreased 45 +/- 32%. We averaged 1.3 +/- 0.9 electrodes passes per lead implantation. The mean operating time from the mounting of the stereotactic frame to its removal was 5 hours 42 minutes (median, 5 h 25 min; standard deviation, 1 h 12 min).

CONCLUSION

This STN DBS surgical technique for PD is expedient with effective outcomes and low complication rates.

Gamma Knife Radiosurgery for Trigeminal Neuralgia: The Washington University Initial Experience

Seventy-three patients were evaluated for the changes in pain relief, numbness and paresthesias after Gamma Knife radiosurgery to a maximum dose of 76-87 Gy for trigeminal neuralgia. Patients experienced pain relief as follows: 59% attained complete pain relief without prior surgery (33% with prior surgery); 25% achieved > or = 50% pain reduction (28% with prior surgery); 11% of surgery patients obtained minor pain relief, and 16% of patients without surgery had no relief (28% with prior surgery). Level of pain decreased rapidly within 6 weeks after radiosurgery. Numbness/paresthesias developed slowly over the first 12-15 months. Bothersome levels were experienced by 15% of the patients without prior surgery (22% with prior surgery). Comparison of the occurrence of numbness/paresthesias, with respect to prior surgery, was not statistically significant. Only 2% of all patients had persistently bothersome side effects. In conclusion, radiosurgery is an effective treatment of trigeminal neuralgia, especially for those patients not having prior surgery.

Correlation of Severity of FDG-PET Hypometabolism and Interictal Regional Delta Slowing in Temporal Lobe Epilepsy

PURPOSE

We investigated the association of severity of hypometabolism detected by positron emission tomography (PET) with [(18)F]fluorodeoxyglucose (FDG) and persistence of interictal EEG focal slowing in patients with refractory temporal lobe epilepsy.

METHODS

Eighty temporal lobes of 40 consecutive patients with intractable temporal lobe epilepsy (mean age, 43.5 years) were studied. All patients underwent video-EEG monitoring, magnetic resonance imaging (MRI), and FDG-PET. Patients with either normal MRI or with unilateral mesial temporal sclerosis, but no other structural abnormality, were included. Interictal EEG delta slowing was graded as none, infrequent (one episode or less/hour), intermediate (more than one episode/hour), or continuous. PET hypometabolism was graded as none, mild, moderate, or severe.

RESULTS

The severity of temporal lobe hypometabolism with PET was significantly correlated with the amount of delta activity in the interictal EEG, independent of MRI findings (Spearman r = 0.46; p < 0.0005).

CONCLUSIONS

This observation suggests related underlying pathophysiologic mechanisms for metabolic and electrical dysfunction in temporal lobe epilepsy.

Stimulation of STN impairs aspects of cognitive control in PD

OBJECTIVE

To test the hypothesis that subthalamic nucleus (STN) stimulation in Parkinson disease (PD) patients affects working memory and response inhibition performance, particularly under conditions of high demand on cognitive control.

METHODS

To test this hypothesis, spatial working memory (spatial delayed response [SDR]) and response inhibition (Go-No-Go [GNG]) tasks requiring varying levels of cognitive control were administered to patients with PD with previously implanted bilateral STN stimulators (n = 24). Patients did not take PD medications overnight. Data were collected while bilateral stimulators were on and off, counterbalancing the order across subjects.

RESULTS

On the SDR task, STN stimulation decreased patients' working memory performance under a high but not low memory load condition (effect of stimulator condition on high load only and condition x load interaction, p < 0.05). On the GNG task, STN stimulation reduced discriminability on a high but not medium inhibition condition (effect of stimulator condition on high inhibition level only, p = 0.05; condition x inhibition level interaction, p = 0.07).

CONCLUSION

STN stimulation reduces working memory and response inhibition performance under conditions of greater challenge to cognitive control despite significant improvement of motor function.

Cortical and subcortical blood flow effects of subthalamic nucleus stimulation in PD

OBJECTIVE

To assess whether subthalamic nuclei (STN) stimulation's primary mechanism of action is to drive or inhibit output neurons.

METHODS

Cerebral blood flow responses to STN stimulation were measured using PET in 13 patients with Parkinson disease. Patients were scanned with stimulators off and on (six scans each condition). Clinical ratings, EMG, and videotaping of movements were obtained at each scan. Scans with observable tremor or movement were eliminated from analysis. Brain regions where STN stimulation significantly altered blood flow were identified.

RESULTS

STN stimulation increased blood flow in midbrain (including STN), globus pallidus, and thalamus, primarily on the left side, but reduced blood flow bilaterally in frontal, parietal, and temporal cortex.

CONCLUSIONS

These data suggest that STN stimulation increases firing of STN output neurons, which increases inhibition of thalamocortical projections, ultimately decreasing blood flow in cortical targets. STN stimulation appears to drive, rather than inhibit, STN output neurons.

Wada testing reveals frontal lateralization for the memorization of words and faces

Neuroimaging studies have suggested that specific regions of the frontal and medial temporal cortex are engaged during memory formation. Further, there is specialization across these regions such that verbal materials appear to preferentially engage the left regions while nonverbal materials primarily engage the right regions. An open question, however, has been to what extent frontal regions contribute to successful memory formation. The present study investigates this question using a reversible lesion technique known as the Wada test. Patients memorized words and unfamiliar faces while portions of their left and right hemispheres were temporarily anesthetized with sodium amytal. Subsequent memory tests revealed that faces were remembered better than words following left-hemisphere anesthesia, whereas words were remembered better than faces following right-hemisphere anesthesia. Importantly, inspection of the circulation affected by the amytal further suggests that these memory impairments did not result from direct anesthetization of the medial temporal regions. Taken in the context of the imaging findings, these results suggest that frontal regions may also contribute to memory formation in normal performance.

Rapid optical imaging of whisker responses in the rat barrel cortex

Videomicroscopy was used to image 'intrinsic' responses over the rat barrel cortex through a closed cranial window during controlled whisker stimulation. With a Macintosh IIfx running Image 1.49 VDM, video frames from a CCD camera were captured and averaged before, during and after whisker stimulation. The technique presented here is a functional imaging modality--using conventional videomicroscopic equipment, a small computer, and public domain NIH Image software--with a temporal resolution of 33 ms. Images can be obtained directly from the CCD camera or recorded to videotape for post hoc analysis. Pixel by pixel comparison of prestimulation images to images obtained during stimulation revealed changes in the reflectance characteristics of cortex and vessels overlying the barrel field. Imaged responses superimposed on barrel histology to map intrinsic signal matched barrels of the stimulated whiskers in every case. Video imaging of the rat barrel cortex provides a useful method for rapid targeting for other experimental protocols and has potential for analyzing localized responses to physiologic stimuli in vivo.

LCBF changes in rat somatosensory cortex during whisker stimulation monitored by dynamic H2 clearance

We evaluated increases in local cerebral blood flow (LCBF) localized to single activated cortical columns by H2 clearance methods. The rat whisker-barrel cortex is a model for cortical function and neural processing in active explorative behaviors. Up to four 30-40 microns Pt wire electrodes were inserted in or near the rat whisker-barrel cortex. Electrode positions were mapped by postmortem histology. H2 was generated electrochemically by constant current from one electrode and detected by one or more other electrodes 300-500 microns away. Changes in LCBF produced inverse changes in PH2. Shifts during steady H2 generation were calibrated against standard H2 inhalation clearance curves at rest and during inhalation of 7.5% CO2 for 1 min for quantitative estimates of LCBF. Contralateral whisker stimulation at 3 Hz, 1 min duration and delivered every 2 min produced the largest increases in LCBF. LCBF responses were detected in approximately 1 s. Stimulation of single whiskers produced the largest responses when an electrode was in the corresponding barrel. These results indicate that increased neural activity in a single cortical column produces blood flow responses primarily in that column.