Publications from the Li Lab

Associate Professor of Neurosurgery and, by courtesy, of Neurology and of Otolaryngology-Head and Neck Surgery at the Stanford University Medical Center

Publications

  • Evaluating Shunt Survival Following Ventriculoperitoneal Shunting with and without Stereotactic Navigation in Previously Shunt-Naïve Patients. World neurosurgery Jin, M. C., Wu, A., Azad, T. D., Feng, A., Prolo, L. M., Veeravagu, A., Grant, G. A., Ratliff, J., Li, G. 2020

    View details for DOI 10.1016/j.wneu.2020.01.138

    View details for PubMedID 31996335

  • Functional Mapping for Glioma Surgery: A Propensity-matched Analysis of Outcomes and Cost. World neurosurgery Pendharkar, A. V., Rezaii, P. G., Ho, A. L., Sussman, E. S., Li, G., Desai, A. M. 2020

    Abstract

    To compare clinical outcomes and payments between glioma resections with and without functional mapping.The Thomas Reuters MarketScan national longitudinal database was used to identify patients undergoing resection of supratentorial primary malignant glioma with or without functional mapping between 2007-2016. Patients were stratified into mapped and unmapped (conventional) groups, and subsequently propensity-matched based on demographics, clinical comorbidities, and surgical characteristics (i.e., use of stereotactic navigation, microscope, intratumoral chemotherapy). Outcomes and charges were compared between matched groups using bivariate analyses.A total of 14,037 patients were identified, of which 796 (6.0%) received functional mapping. Propensity-matching (1:1) resulted in 796 mapped patients and 796 propensity-matched controls. Thirty-day postoperative rates of new-onset seizures, cerebral edema, hemorrhage, and neurological deficits were significantly lower for the functional mapping group (all p < 0.05). Functional mapping was also associated with shorter hospital length of stay (p = .0144), lower 30-day rates of emergency department visits (p = .0001) and fewer reoperations (p = .0068). Total costs of initial admission were not significantly different between groups.Intraoperative functional mapping during glioma resection was associated with decreased complications, reoperations, emergency department visits, and shorter lengths of stay. Furthermore, total charges of mapped resections were not significantly different from those of conventional resections. These findings support the utility of functional mapping for resection of supratentorial primary malignant gliomas.

    View details for DOI 10.1016/j.wneu.2020.01.197

    View details for PubMedID 32028000

  • Rindopepimut with Bevacizumab for Patients with Relapsed EGFRvIII-Expressing Glioblastoma (ReACT): Results of a Double-Blind Randomized Phase II Trial. Clinical cancer research : an official journal of the American Association for Cancer Research Reardon, D. A., Desjardins, A., Vredenburgh, J. J., O'Rourke, D. M., Tran, D. D., Fink, K. L., Nabors, L. B., Li, G., Bota, D. A., Lukas, R. V., Ashby, L. S., Duic, J. P., Mrugala, M. M., Cruickshank, S., Vitale, L., He, Y., Green, J. A., Yellin, M. J., Turner, C. D., Keler, T., Davis, T. A., Sampson, J. H. 2020

    Abstract

    Rindopepimut is a vaccine targeting the tumor-specific EGF driver mutation, EGFRvIII. The ReACT study investigated whether the addition of rindopepimut to standard bevacizumab improved outcome for patients with relapsed, EGFRvIII-positive glioblastoma.In this double-blind, randomized, phase II study (NCT01498328) conducted at 26 hospitals in the United States, bevacizumab-naïve patients with recurrent EGFRvIII-positive glioblastoma were randomized to receive rindopepimut or a control injection of keyhole limpet hemocyanin, each concurrent with bevacizumab. The primary endpoint was 6-month progression-free survival (PFS6) by central review with a one-sided significance of 0.2.Between May 2012 and 2014, 73 patients were randomized (36 rindopepimut, 37 control). Rindopepimut toxicity included transient, low-grade local reactions. As primary endpoint, PFS6 was 28% (10/36) for rindopepimut compared with 16% (6/37) for control (P = 0.12, one-sided). Secondary and exploratory endpoints also favored the rindopepimut group including a statistically significant survival advantage [HR, 0.53; 95% confidence interval (CI), 0.32-0.88; two-sided log-rank P = 0.01], a higher ORR [30% (9/30) vs. 18% (6/34; P = 0.38)], median duration of response [7.8 months (95% CI, 3.5-22.2) vs. 5.6 (95% CI, 3.7-7.4)], and ability to discontinue steroids for ≥6 months [33% (6/18) vs. 0% (0/19)]. Eighty percent of rindopepimut-treated patients achieved robust anti-EGFRvIII titers (≥1:12,800), which were associated with prolonged survival (HR = 0.17; 95% CI, 0.07-0.45; P < 0.0001).Our randomized trial supports the potential for targeted immunotherapy among patients with GBM, but the therapeutic benefit requires validation due to the small sample size and potential heterogeneity of bevacizumab response among recurrent patients with GBM.

    View details for DOI 10.1158/1078-0432.CCR-18-1140

    View details for PubMedID 32034072

  • A Phase I/II Trial of 5-Fraction Stereotactic Radiosurgery with 5-mm Margins with Concurrent Temozolomide in Newly Diagnosed Glioblastoma: Primary Outcomes. Neuro-oncology Azoulay, M., Chang, S. D., Gibbs, I. C., Hancock, S. L., Pollom, E. L., Harsh, G. R., Adler, J. R., Harrahar, C., Li, G., Hayden Gephart, M., Nagpal, S., Thomas, R. P., Recht, L. D., Jacobs, L. R., Modlin, L. A., Wynne, J., Seiger, K., Fujimoto, D., Usoz, M., von Eyben, R., Choi, C. Y., Soltys, S. G. 2020

    Abstract

    We sought to determine the maximum tolerated dose (MTD) of 5-fraction stereotactic radiosurgery (SRS) with 5-mm margins delivered with concurrent temozolomide in newly diagnosed glioblastoma.We enrolled adult patients with newly diagnosed glioblastoma to 5 days of SRS in a 3+3 design on 4 escalating dose levels: 25, 30, 35, and 40 Gy. Dose limiting toxicity (DLT) was defined as CTCAE Grade 3-5 acute or late CNS toxicity, including adverse radiation effect (ARE), the imaging correlate of radiation necrosis.From 2010 to 2015, 30 patients were enrolled. The median age was 66 years (range 51-86 years). The median target volume was 60 cm3 (range 14.7-137.3 cm3). DLT occurred in 2 patients: one for post-treatment cerebral edema and progressive disease at 3 weeks (Grade 4, Dose 40 Gy); another patient died 1.5 weeks following SRS from post-operative complications (Grade 5, Dose 40 Gy). Late grade 1-2 ARE occurred in 8 patients at a median of 7.6 months (range 3.2-12.6 months). No grade 3-5 ARE occurred. With a median follow-up of 13.8 months (range 1.7-64.4 months), the median survival times were: PFS 8.2 months (95%CI 4.6-10.5), OS 14.8 months (95%CI 10.9-19.9), MGMT hypermethylated 19.9 months (95%CI 10.5-33.5) vs. 11.3 months (95%CI 8.9-17.6) for no/unknown hypermethylation (p=0.03), and 27.2 months (95%CI 11.2-48.3) if late ARE occurred vs. 11.7 months (95%CI 8.9-17.6) for no ARE (p=0.08).The per-protocol MTD of 5-fraction SRS with 5-mm margins with concurrent temozolomide was 40 Gy in 5 fractions. ARE was limited to grade 1-2 and did not statistically impact survival.

    View details for DOI 10.1093/neuonc/noaa019

    View details for PubMedID 32002547

  • Long-Term Update of Stereotactic Radiosurgery for Benign Spinal Tumors NEUROSURGERY Chin, A. L., Fujimoto, D., Kumar, K. A., Tupper, L., Mansour, S., Chang, S. D., Adler, J. R., Gibbs, I. C., Hancock, S. L., Dodd, R., Li, G., Gephart, M., Ratliff, J. K., Tse, V., Usoz, M., Sachdev, S., Soltys, S. G. 2019; 85 (5): 708–16
  • Prognostic Factors and Treatment Patterns in the Management of Giant Cell Glioblastoma WORLD NEUROSURGERY Jin, M. C., Wu, A., Xiang, M., Azad, T. D., Soltys, S. G., Li, G., Pollom, E. L. 2019; 128: E217–E224
  • Facial Nerve Paralysis Occurring 4 Days following Stereotactic Radiosurgery for a Vestibular Schwannoma. Asian journal of neurosurgery Chow, K. K., Ajlan, A., Ho, A. L., Li, G., Soltys, S. G. ; 14 (1): 262–65

    Abstract

    Stereotactic radiosurgery (SRS) is commonly used for the treatment of vestibular schwannomas given its high rate of tumor control and low rate of complications. Facial nerve palsy has been reported several months after treatment as a rare late complication of SRS. Here, we report a case of facial weakness occurring only 4 days after treatment and discuss potential etiology and management considerations.

    View details for PubMedID 30937049

    View details for PubMedCentralID PMC6417297

  • Osimertinib for EGFR-Mutant Lung Cancer with Brain Metastases: Results from a Single-Center Retrospective Study ONCOLOGIST Xie, L., Nagpal, S., Wakelee, H. A., Li, G., Soltys, S. G., Neal, J. W. 2019; 24 (6): 836–43
  • Adverse Radiation Effect and Disease Control in Patients Undergoing Stereotactic Radiosurgery and Immune Checkpoint Inhibitor Therapy for Brain Metastases WORLD NEUROSURGERY Koenig, J. L., Shi, S., Sborov, K., Gensheimer, M. F., Le, G., Nagpal, S., Chang, S. D., Gibbs, I. C., Soltys, S. G., Pollom, E. L. 2019; 126: E1399–E1411
  • Nodular Leptomeningeal Disease - A Distinct Pattern of Recurrence After Post-Resection Stereotactic Radiosurgery for Brain Metastases: A Multi-Institutional Study of Inter-Observer Reliability. International journal of radiation oncology, biology, physics Turner, B. E., Prabhu, R. S., Burri, S. H., Brown, P. D., Pollom, E. L., Milano, M. T., Weiss, S. E., Iv, M., Fischbein, N., Soliman, H., Lo, S. S., Chao, S. T., Cox, B. W., Murphy, J. D., Li, G., Gephart, M. H., Nagpal, S., Atalar, B., Azoulay, M., Thomas, R., Tillman, G., Durkee, B. Y., Shah, J. L., Soltys, S. G. 2019

    Abstract

    For brain metastases, surgical resection with postoperative stereotactic radiosurgery (SRS) is an emerging standard of care. Postoperative cavity SRS is associated with a specific, under-recognized pattern of intracranial recurrence, herein termed nodular leptomeningeal disease (nLMD), which is distinct from classical leptomeningeal disease (cLMD). We hypothesized that there is poor consensus regarding the definition of LMD, and that a formal, self-guided training module will improve inter-rater reliability (IRR) and validity in diagnosing LMD.Twenty-two physicians at 16 institutions, including 15 physicians with central nervous system (CNS) expertise, completed a two-phase survey that included MRI imaging and treatment information for 30 patients. In the "pre-training" phase, physicians labeled cases using 3 patterns of recurrence commonly reported in prospective studies: local recurrence (LR), distant parenchymal recurrence (DR), and LMD. After a self-directed training module, participating physicians completed the "post-training" phase and relabeled the 30 cases using the 4 following labels: LR, DR, cLMD, nLMD.Inter-rater reliability (IRR) increased 34% after training (Fleiss' Kappa K=0.41 to K=0.55, p<0.001). IRR increased most among non-CNS specialists (+58%, p<0.001). Prior to training, IRR was lowest for LMD (K=0.33). After training, IRR increased across all recurrence subgroups and increased most for LMD (+67%). After training, ≥27% of cases initially labeled LR or DR were later recognized as nLMD.This study highlights the large degree of inconsistency among clinicians in recognizing nLMD. Our findings demonstrate that a brief self-guided training module distinguishing nLMD can significantly improve IRR across all patterns of recurrence, and particularly in nLMD. To optimize outcomes reporting, prospective trials in brain metastases should incorporate central imaging review and investigator training.

    View details for DOI 10.1016/j.ijrobp.2019.10.002

    View details for PubMedID 31605786

  • Targeted genomic CRISPR-Cas9 screen identifies MAP4K4 as essential for glioblastoma invasion. Scientific reports Prolo, L. M., Li, A., Owen, S. F., Parker, J. J., Foshay, K., Nitta, R. T., Morgens, D. W., Bolin, S., Wilson, C. M., Vega L, J. C., Luo, E. J., Nwagbo, G., Waziri, A., Li, G., Reimer, R. J., Bassik, M. C., Grant, G. A. 2019; 9 (1): 14020

    Abstract

    Among high-grade brain tumors, glioblastoma is particularly difficult to treat, in part due to its highly infiltrative nature which contributes to the malignant phenotype and high mortality in patients. In order to better understand the signaling pathways underlying glioblastoma invasion, we performed the first large-scale CRISPR-Cas9 loss of function screen specifically designed to identify genes that facilitate cell invasion. We tested 4,574 genes predicted to be involved in trafficking and motility. Using a transwell invasion assay, we discovered 33 genes essential for invasion. Of the 11 genes we selected for secondary testing using a wound healing assay, 6 demonstrated a significant decrease in migration. The strongest regulator of invasion was mitogen-activated protein kinase 4 (MAP4K4). Targeting of MAP4K4 with single guide RNAs or a MAP4K4 inhibitor reduced migration and invasion in vitro. This effect was consistent across three additional patient derived glioblastoma cell lines. Analysis of epithelial-mesenchymal transition markers in U138 cells with lack or inhibition of MAP4K4 demonstrated protein expression consistent with a non-invasive state. Importantly, MAP4K4 inhibition limited migration in a subset of human glioma organotypic slice cultures. Our results identify MAP4K4 as a novel potential therapeutic target to limit glioblastoma invasion.

    View details for DOI 10.1038/s41598-019-50160-w

    View details for PubMedID 31570734

  • Lumboperitoneal and Ventriculoperitoneal Shunting for Idiopathic Intracranial Hypertension Demonstrate Comparable Failure and Complication Rates. Neurosurgery Azad, T. D., Zhang, Y., Varshneya, K., Veeravagu, A., Ratliff, J. K., Li, G. 2019

    Abstract

    Idiopathic intracranial hypertension results in increased intracranial pressure leading to headache and visual loss. This disease frequently requires surgical intervention through lumboperitoneal (LP) or ventriculoperitoneal (VP) shunting.To compare postoperative outcomes between LP and VP shunts, including failure and complication rates.A retrospective analysis was conducted using a national administrative database (MarketScan) to identify idiopathic intracranial hypertension (IIH) patients who underwent LP or VP shunting from 2007 to 2014. Multivariate logistic and Cox regressions were performed to compare rates of shunt failure and time to shunt failure between LP and VP shunts while controlling for demographics and comorbidities.The analytic cohort included 1082 IIH patients, 347 of whom underwent LP shunt placement at index hospitalization and 735 of whom underwent VP shunt placement. Rates of shunt failure were similar among patients with LP and VP shunt (34.6% vs 31.7%; P = .382). Among patients who experienced shunt failure, the mean number of shunt failures was 2.1 ± 1.6 and was similar between LP and VP cohorts. Ninety-day readmission rates, complication rates, and costs did not differ significantly between LP and VP shunts. Patients who experienced more than two shunt failures tended to have an earlier time to first shunt failure (hazard ratio 1.41; 95% confidence interval 1.08-1.85; P = .013).These findings suggest that LP and VP shunts may have comparable rates of shunt failure and complication. Regardless of shunt type, earlier time to first shunt failure may be associated with multiple shunt failures.

    View details for PubMedID 30937428

  • Non-Contrast T2-Weighted MR Sequences for Long Term Monitoring of Asymptomatic Convexity Meningiomas. World neurosurgery He, J. Q., Iv, M., Li, G., Zhang, M., Hayden-Gephart, M. 2019

    Abstract

    Gadolinium based contrast agents (GBCA) used to enhance MRs have been linked to tissue deposition, including in the brain. The management of indolent tumors such as meningiomas requires frequent MRs to monitor for interval growth. Given concern regarding GBCA deposition, we sought to determine if non-contrast MRs in patients with asymptomatic meningiomas were equivalent to GBCA-enhanced MRs in surveillance monitoring.This IRB-approved retrospective chart review included 106 MR sequences from 18 patients. Inclusion criteria were adult patients with asymptomatic meningiomas who received baseline contrast-enhanced and non-contrast axial MR imaging of the brain. Exclusion criteria included: 1) baseline or follow-up axial images were not available for review 2) baseline scan was obtained without contrast 3) diagnosis of meningioma was uncertain. Percent tumor growth was measured by comparing cross-sectional area at maximum tumor diameter from the earliest and most recent scans. For each patient, change in tumor size over time was compared using T1+contrast, T2, and T2 FLAIR sequences. These were compared to a qualitative consensus reading by a neurosurgeon and a neuroradiologist.Measured change of greater than 10% was taken to represent tumor growth. In 17 out of 18 patients, measurement of non-contrast studies (T2 and T2 FLAIR) matched consensus. For one patient, imaging on T2 suggested 11% growth while T2 FLAIR and overall consensus was stability.Our study provides evidence that non-contrasted MR images are equivalent to contrast-weighted MRs to follow change in tumor size over time in asymptomatic meningiomas.

    View details for DOI 10.1016/j.wneu.2019.11.051

    View details for PubMedID 31734418

  • Outcomes and costs following Ommaya placement with thrombocytopenia among US cancer patients. World neurosurgery Zhang, M., Zhang, Y., Zheng, E., Gephart, M. H., Veeravagu, A., Desai, A., Ratliff, J. K., Li, G. 2019

    Abstract

    Placement of Ommaya reservoirs for administration of intrathecal chemotherapy may be complicated by comorbid thrombocytopenia among patients with hematologic or leptomeningeal disease. Aggregated data on risks of Ommaya placement among thrombocytopenic patients is lacking. This study assesses complications, revision rates, and costs associated with Ommaya placement among patients with thrombocytopenia in a large population sample.Using a national administrative database, this retrospective study identifies a cohort of adult cancer patients who underwent Ommaya placement between 2007 and 2016. Preoperative thrombocytopenia was defined as diagnosis of secondary thrombocytopenia, bleeding event, procedure to control bleeding, or platelet transfusion, within 30 days prior to index admission. Univariate and multivariate analyses were performed to assess costs, 30-day complications, readmissions, and revisions among patients with and without preoperative thrombocytopenia.The analytic cohort included 1652 patients, of whom 29.3% met criteria for preoperative thrombocytopenia. In-hospital mortality rates were 7.7% among thrombocytopenic patients vs. 1.2% among non-thrombocytopenic patients (p < 0.001). Preoperative thrombocytopenia was associated with 14.5 times greater hazard of intracranial hemorrhage within 30 days following Ommaya placement, occurring in 25.6% vs. 2.0% of thrombocytopenic and non-thrombocytopenic patients, respectively (p < 0.014). Revision rates did not differ significantly between thrombocytopenic and non-thrombocytopenic patients. Thrombocytopenia was associated with longer length of stay (7.4 vs 13.9 days, p < 0.001) and additional

  • Casein kinase 2 inhibition sensitizes medulloblastoma to temozolomide. Oncogene Nitta, R. T., Bolin, S., Luo, E., Solow-Codero, D. E., Samghabadi, P., Purzner, T., Aujla, P. S., Nwagbo, G., Cho, Y. J., Li, G. 2019

    Abstract

    Medulloblastoma (MB) is the most common malignant pediatric brain tumor. Since surviving patients experience severe neurocognitive disabilities, better and more effective treatments are needed to enhance their quality of life. Casein kinase 2 (CK2) is known to regulate cell growth and survival in multiple cancers; however, the role of CK2 in MB is currently being studied. In this study, we verified the importance of CK2 in MB tumorigenesis and discovered that inhibition of CK2 using the small molecule inhibitor, CX-4945, can sensitize MB cells to a well-known and tolerated chemotherapeutic, temozolomide (TMZ). To study the role of CK2 in MB we modulated CK2 expression in multiple MB cells. Exogenous expression of CK2 enhanced cell growth and tumor growth in mice, while depletion or inhibition of CK2 expression decreased MB tumorigenesis. Treatment with CX-4945 reduced MB growth and increased apoptosis. We conducted a high-throughput screen where 4000 small molecule compounds were analyzed to identify compounds that increased the anti-tumorigenic properties of CX-4945. TMZ was found to work synergistically with CX-4945 to decrease cell survival and increase apoptosis in MB cells. O-6-methylguanine-DNA methyltransferase (MGMT) activity is directly correlated to TMZ sensitivity. We found that loss of CK2 activity reduced β-catenin expression, a known MGMT regulator, which in turn led to a decrease in MGMT expression and an increased sensitivity to TMZ. Our findings show that CK2 is important for MB maintenance and that treatment with CX-4945 can sensitize MB cells to TMZ treatment.

    View details for DOI 10.1038/s41388-019-0927-y

    View details for PubMedID 31406250

  • Correction: Casein kinase 2 inhibition sensitizes medulloblastoma to temozolomide. Oncogene Nitta, R. T., Bolin, S., Luo, E., Solow-Cordero, D. E., Samghabadi, P., Purzner, T., Aujla, P. S., Nwagbo, G., Cho, Y. J., Li, G. 2019

    Abstract

    The original version of this Article contained an error in the spelling of the author David Solow-Cordero, which was incorrectly given as David Solow-Codero. This has now been corrected in both the PDF and HTML versions of the Article.

    View details for DOI 10.1038/s41388-019-1077-y

    View details for PubMedID 31659253

  • Stereotactic Radiosurgery for Pediatric and Adult Intracranial and Spinal Ependymomas. Stereotactic and functional neurosurgery Shi, S., Jin, M. C., Koenig, J., Gibbs, I. C., Soltys, S. G., Chang, S. D., Li, G., Hayden Gephart, M., Hiniker, S. M., Pollom, E. L. 2019: 1–6

    Abstract

    We report efficacy and toxicity outcomes with stereotactic radiosurgery (SRS) for intracranial and spinal ependymoma.We analyzed adult and pediatric patients with newly diagnosed or recurrent intracranial or spinal ependymoma lesions treated with SRS at our institution. Following SRS, local failure (LF) was defined as failure within or adjacent to the SRS target volume, while distant failure (DF) was defined as failure outside of the SRS target volume. Time to LF and DF was analyzed using competing risk analysis with death as a competing risk.Overall survival (OS) was calculated from the date of first SRS to the date of death or censored at the date of last follow-up using the Kaplan-Meier method.Twenty-one patients underwent SRS to 40 intracranial (n = 30) or spinal (n = 10) ependymoma lesions between 2007 and 2018, most commonly with 18 or 20 Gy in 1 fraction. Median follow-up for all patients after first SRS treatment was 54 months (range 2-157). The 1-year, 2-year, and 5-year rates of survival among patients with initial intracranial ependymoma were 86, 74, and 52%, respectively. The 2-year cumulative incidences of LF and DF after SRS among intracranial ependymoma patients were 25% (95% CI 11-43) and 42% (95% CI 22-60), respectively. No spinal ependymoma patient experienced LF, DF, or death within 2 years of SRS. Three patients had adverse radiation effects.SRS is a viable treatment option for intracranial and spinal ependymoma with excellent local control and acceptable toxicity.

    View details for DOI 10.1159/000502653

    View details for PubMedID 31590165

  • Stereotactic radiosurgery for resected brain metastases: single-institutional experience of over 500 cavities. International journal of radiation oncology, biology, physics Shi, S., Sandhu, N., Jin, M. C., Wang, E., Jaoude, J. A., Schofield, K., Zhang, C., Liu, E., Gibbs, I. C., Hancock, S. L., Chang, S. D., Li, G., Hayden-Gephart, M., Adler, J. R., Soltys, S. G., Pollom, E. L. 2019

    Abstract

    Post-operative stereotactic radiosurgery (SRS) has less detrimental impact on cognition and quality of life compared to whole brain radiotherapy (WBRT) and is increasingly used for resected brain metastases (BMs). Post-operative SRS techniques are not standardized, and there is a concern for a different pattern of failure following post-operative SRS compared to WBRT. We aim to study the efficacy, toxicity, and failure pattern of post-operative SRS.We retrospectively reviewed outcomes of patients with resected BMs treated with post-operative SRS between 2007 and 2018. Overall survival (OS) and cumulative incidences of local failure (LF), overall distant intracranial failure [distant parenchymal failure (DPF), nodular leptomeningeal disease (nLMD), classical leptomeningeal disease (cLMD)], and adverse radiation effect (ARE) were reported. Neurological death was determined for patients with leptomeningeal disease (LMD).A total of 442 patients with 501 resected BMs were treated over 475 total SRS courses. Median clinical follow-up and OS after SRS were 10.1 months [interquartile range (IQR) 3.6-20.7 months] and 13.9 months [95% confidence interval (CI) 11.8-15.2 months], respectively. At 12 months, event rates were 7% (95% CI 5%-10%) for LF, 9% (95% CI 7%-12%) for ARE, 44% (95% CI 40%-49%) for overall distant intracranial failure, 37% (95% CI 33%-42%) for DPF and 13% (95% CI 10%-17%) for LMD. The overall incidence of LMD was 15.8% (53% cLMD, 46% nLMD). cLMD was associated with shorter survival than nLMD (2.0 versus 11.2 months, p<0.01) and a higher proportion of neurological death (67% versus 41%, p=0.02). A total of 15% of patients ultimately received WBRT.We report the largest clinical experience of post-operative SRS for resected BMs, showing excellent local control and low toxicity. Intracranial failure was predominantly distant, with a rising incidence of LMD.

    View details for DOI 10.1016/j.ijrobp.2019.11.022

    View details for PubMedID 31785338

  • Topical vancomycin surgical prophylaxis in pediatric open craniotomies: an institutional experience JOURNAL OF NEUROSURGERY-PEDIATRICS Ho, A. L., Cannon, J. D., Mohole, J., Pendharkar, A., Sussman, E. S., Li, G., Edwards, M. B., Cheshier, S. H., Grant, G. A. 2018; 22 (6): 710–15
  • Publisher Correction: Notch1 regulates the initiation of metastasis and self-renewal of Group 3 medulloblastoma. Nature communications Kahn, S. A., Wang, X., Nitta, R. T., Gholamin, S., Theruvath, J., Hutter, G., Azad, T. D., Wadi, L., Bolin, S., Ramaswamy, V., Esparza, R., Liu, K., Edwards, M., Swartling, F. J., Sahoo, D., Li, G., Wechsler-Reya, R. J., Reimand, J., Cho, Y., Taylor, M. D., Weissman, I. L., Mitra, S. S., Cheshier, S. H. 2018; 9 (1): 4651

    Abstract

    The original version of this Article omitted Suzana A. Kahn, Siddhartha S. Mitra & Samuel H. Cheshier as jointly supervising authors. This has now been corrected in both the PDF and HTML versions of the Article.

    View details for PubMedID 30389946

  • TREATMENT WITH THE CASEIN KINASE 2 INHIBITOR, CX-4945, SENSITIZES MEDULLOBLASTOMA TO TEMOZOLOMIDE Nitta, R., Li, G. OXFORD UNIV PRESS INC. 2018: 52–53
  • How Intraoperative Tools and Techniques Have Changed the Approach to Brain Tumor Surgery. Current oncology reports Fatemi, P., Zhang, M., Miller, K. J., Robe, P., Li, G. 2018; 20 (11): 89

    Abstract

    PURPOSE OF REVIEW: Surgical treatment of brain tumors remains an integral part of a comprehensive treatment plan. Here, we review technological advances that have enhanced what surgeons are capable of doing within and outside the traditional operating room.RECENT FINDINGS: Extent of surgical resection has improved with the use of MRI and fluorescent dyes intraoperatively. Neurological injury during brain tumor surgery has decreased with appropriate use of neurophysiological monitoring. New operative scopes have enhanced ability of surgeons to visualize tissues during dissection. Laser interstitial therapy and radiation treatment have made possible the treatment of previously considered non-operable brain tumors in addition to replacing or serving as adjunct to surgical treatment of brain tumors. Surgery remains an important pillar in treatment of most brain tumors. Ongoing technological advances have augmented extent of what is possible in this realm.

    View details for PubMedID 30259202

  • Developmental phosphoproteomics identifies the kinase CK2 as a driver of Hedgehog signaling and a therapeutic target in medulloblastoma. Science signaling Purzner, T., Purzner, J., Buckstaff, T., Cozza, G., Gholamin, S., Rusert, J. M., Hartl, T. A., Sanders, J., Conley, N., Ge, X., Langan, M., Ramaswamy, V., Ellis, L., Litzenburger, U., Bolin, S., Theruvath, J., Nitta, R., Qi, L., Li, X., Li, G., Taylor, M. D., Wechsler-Reya, R. J., Pinna, L. A., Cho, Y., Fuller, M. T., Elias, J. E., Scott, M. P. 2018; 11 (547)

    Abstract

    A major limitation of targeted cancer therapy is the rapid emergence of drug resistance, which often arises through mutations at or downstream of the drug target or through intrinsic resistance of subpopulations of tumor cells. Medulloblastoma (MB), the most common pediatric brain tumor, is no exception, and MBs that are driven by sonic hedgehog (SHH) signaling are particularly aggressive and drug-resistant. To find new drug targets and therapeutics for MB that may be less susceptible to common resistance mechanisms, we used a developmental phosphoproteomics approach in murine granule neuron precursors (GNPs), the developmental cell of origin of MB. The protein kinase CK2 emerged as a driver of hundreds of phosphorylation events during the proliferative, MB-like stage of GNP growth, including the phosphorylation of three of the eight proteins commonly amplified in MB. CK2 was critical to the stabilization and activity of the transcription factor GLI2, a late downstream effector in SHH signaling. CK2 inhibitors decreased the viability of primary SHH-type MB patient cells in culture and blocked the growth of murine MB tumors that were resistant to currently available Hh inhibitors, thereby extending the survival of tumor-bearing mice. Because of structural interactions, one CK2 inhibitor (CX-4945) inhibited both wild-type and mutant CK2, indicating that this drug may avoid at least one common mode of acquired resistance. These findings suggest that CK2 inhibitors may be effective for treating patients with MB and show how phosphoproteomics may be used to gain insight into developmental biology and pathology.

    View details for PubMedID 30206138

  • Casein kinase 2 is a major regulator of medulloblastoma growth Nitta, R., Bolin, S., Nwagbo, G., Purzner, T., Kahn, S., Cho, Y., Li, G. AMER ASSOC CANCER RESEARCH. 2018
  • In Reply: The Use of Vancomycin Powder for Surgical Prophylaxis Following Craniotomy NEUROSURGERY Ho, A. L., Li, G. H. 2018; 82 (2): E71

    View details for DOI 10.1093/neuros/nyx537

    View details for Web of Science ID 000424225800017

    View details for PubMedID 29149292

  • Topical vancomycin surgical prophylaxis in pediatric open craniotomies: an institutional experience. Journal of neurosurgery. Pediatrics Ho, A. L., Cannon, J. G., Mohole, J., Pendharkar, A. V., Sussman, E. S., Li, G., Edwards, M. S., Cheshier, S. H., Grant, G. A. 2018: 1–6

    Abstract

    OBJECTIVE Topical antimicrobial compounds are safe and can reduce cost and complications associated with surgical site infections (SSIs). Topical vancomycin has been an effective tool for reducing SSIs following routine neurosurgical procedures in the spine and following adult craniotomies. However, widespread adoption within the pediatric neurosurgical community has not yet occurred, and there are no studies to report on the safety and efficacy of this intervention. The authors present the first institution-wide study of topical vancomycin following open craniotomy in the pediatric population. METHODS In this retrospective study the authors reviewed all open craniotomies performed over a period from 05/2014 to 12/2016 for topical vancomycin use, SSIs, and clinical variables associated with SSI. Topical vancomycin was utilized as an infection prophylaxis and was applied as a liquid solution following replacement of a bone flap or after dural closure when no bone flap was reapplied. RESULTS Overall, 466 consecutive open craniotomies were completed between 05/2014 and 12/2016, of which 43% utilized topical vancomycin. There was a 1.5% SSI rate in the nontopical cohort versus 0% in the topical vancomycin cohort (p = 0.045). The number needed to treat was 66. There were no significant differences in risk factors for SSI between cohorts. There were no complications associated with topical vancomycin use. CONCLUSIONS Routine topical vancomycin administration during closure of open craniotomies can be a safe and effective tool for reducing SSIs in the pediatric neurosurgical population.

    View details for PubMedID 30141749

  • Multiple Extradural Spinal Meningiomas in a Patient with Acquired Immunodeficiency Syndrome: Case Report and Literature Review. World neurosurgery Ghanchi, H., Hariri, O. R., Takayanagi, A., Li, G. 2018

    View details for PubMedID 29966786

  • Osimertinib for EGFR-Mutant Lung Cancer with Brain Metastases: Results from a Single-Center Retrospective Study. The oncologist Xie, L., Nagpal, S., Wakelee, H. A., Li, G., Soltys, S. G., Neal, J. W. 2018

    Abstract

    Osimertinib is a third-generation tyrosine kinase inhibitor, initially approved for epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) with T790M acquired resistance, and now approved in the first-line setting. However, data supporting the use of osimertinib in untreated brain metastases are limited, although it has established central nervous system (CNS) activity. Our study compares the clinical outcomes of patients experiencing progressing brain metastases treated with cranial irradiation and osimertinib with those treated with osimertinib alone.Forty patients who were treated with osimertinib at the Stanford Cancer Center from November 2015 to December 2016 were identified by searching an electronic medical record database. Eleven patients had progressing brain metastases and did not receive radiation (group A), 9 patients had progressing brain metastases and received radiation when starting osimertinib (group B), and 20 patients had stable brain metastases at the time of initiating osimertinib (group C). Patient and disease characteristics, radiographic responses, and survival outcomes were evaluated retrospectively for the three groups.The CNS response rate was 32.3%. Median time to treatment failure (TTF), overall progression-free survival (PFS), and overall survival (OS) were 10.0 months (95% confidence interval [CI], 4.5-11.8), 8.8 months (95% CI, 6.2-12.1), and 16.2 months, respectively. Median TTF was 15.1 months for group A (95% CI, 1.7-28.5), 7.7 months for group B (95% CI, 0-15.5), and 10.7 months for group C (95% CI, 9.0-12.5). The median PFS was 8.8 months for group A (95% CI, 4.3-13.4), not reached for group B, and 8.4 months for group C (95% CI, 5.6-11.1). The median OS was not reached for group A and C, and was 16.2 months for group B. There was no apparent difference in TTF, PFS, or OS between the three groups.Receiving radiation prior to starting osimertinib for patients with progressing brain metastases did not prolong TTF, PFS, or OS in our series. To minimize the risks of radiation-related toxicity, delaying radiation could be considered for some patients with EGFR-mutant NSCLC with brain metastases who initially respond to osimertinib in the second-line setting.Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor recently approved for the first-line treatment of EGFR-mutant non-small cell lung cancer. Although it appears to have central nervous system (CNS) activity, most clinical trials have excluded patients with untreated, progressing brain metastases. This study included patients with stable and progressing CNS metastases treated with osimertinib and found no apparent differences in median time to treatment failure, time to progression, and overall survival in patients who received osimertinib alone compared with those who received osimertinib and radiosurgery. This may support a clinician's decision to defer radiation for selected patients with untreated brain metastases who are candidates for osimertinib therapy.

    View details for PubMedID 30126856

  • First-in-human intraoperative near-infrared fluorescence imaging of glioblastoma using cetuximab-IRDye800. Journal of neuro-oncology Miller, S. E., Tummers, W. S., Teraphongphom, N., van den Berg, N. S., Hasan, A., Ertsey, R. D., Nagpal, S., Recht, L. D., Plowey, E. D., Vogel, H., Harsh, G. R., Grant, G. A., Li, G. H., Rosenthal, E. L. 2018

    Abstract

    Maximizing extent of surgical resection with the least morbidity remains critical for survival in glioblastoma patients, and we hypothesize that it can be improved by enhancements in intraoperative tumor detection. In a clinical study, we determined if therapeutic antibodies could be repurposed for intraoperative imaging during resection.Fluorescently labeled cetuximab-IRDye800 was systemically administered to three patients 2 days prior to surgery. Near-infrared fluorescence imaging of tumor and histologically negative peri-tumoral tissue was performed intraoperatively and ex vivo. Fluorescence was measured as mean fluorescence intensity (MFI), and tumor-to-background ratios (TBRs) were calculated by comparing MFIs of tumor and histologically uninvolved tissue.The mean TBR was significantly higher in tumor tissue of contrast-enhancing (CE) tumors on preoperative imaging (4.0 ± 0.5) compared to non-CE tumors (1.2 ± 0.3; p = 0.02). The TBR was higher at a 100 mg dose than at 50 mg (4.3 vs. 3.6). The smallest detectable tumor volume in a closed-field setting was 70 mg with 50 mg of dye and 10 mg with 100 mg. On sections of paraffin embedded tissues, fluorescence positively correlated with histological evidence of tumor. Sensitivity and specificity of tumor fluorescence for viable tumor detection was calculated and fluorescence was found to be highly sensitive (73.0% for 50 mg dose, 98.2% for 100 mg dose) and specific (66.3% for 50 mg dose, 69.8% for 100 mg dose) for viable tumor tissue in CE tumors while normal peri-tumoral tissue showed minimal fluorescence.This first-in-human study demonstrates the feasibility and safety of antibody based imaging for CE glioblastomas.

    View details for PubMedID 29623552

  • Notch1 regulates the initiation of metastasis and self-renewal of Group 3 medulloblastoma. Nature communications Kahn, S. A., Wang, X., Nitta, R. T., Gholamin, S., Theruvath, J., Hutter, G., Azad, T. D., Wadi, L., Bolin, S., Ramaswamy, V., Esparza, R., Liu, K. W., Edwards, M., Swartling, F. J., Sahoo, D., Li, G., Wechsler-Reya, R. J., Reimand, J., Cho, Y. J., Taylor, M. D., Weissman, I. L., Mitra, S. S., Cheshier, S. H. 2018; 9 (1): 4121

    Abstract

    Medulloblastoma is the most common malignant brain tumor of childhood. Group 3 medulloblastoma, the most aggressive molecular subtype, frequently disseminates through the leptomeningeal cerebral spinal fluid (CSF) spaces in the brain and spinal cord. The mechanism of dissemination through the CSF remains poorly understood, and the molecular pathways involved in medulloblastoma metastasis and self-renewal are largely unknown. Here we show that NOTCH1 signaling pathway regulates both the initiation of metastasis and the self-renewal of medulloblastoma. We identify a mechanism in which NOTCH1 activates BMI1 through the activation of TWIST1. NOTCH1 expression and activity are directly related to medulloblastoma metastasis and decreased survival rate of tumor-bearing mice. Finally, medulloblastoma-bearing mice intrathecally treated with anti-NRR1, a NOTCH1 blocking antibody, present lower frequency of spinal metastasis and higher survival rate. These findings identify NOTCH1 as a pivotal driver of Group 3 medulloblastoma metastasis and self-renewal, supporting the development of therapies targeting this pathway.

    View details for PubMedID 30297829