Bio

Bio


Navjot Chaudhary, MD, FRCSC, is a Clinical Associate Professor of Neurosurgery. She received her medical degree from McMaster University in Hamilton, Canada. Dr. Chaudhary completed her neurosurgery residency at the University of Western Ontario in London, Canada and fellowships in Spine Neurosurgery and Cyberknife Radiosurgery at Stanford University School of Medicine.

She works primarily in CyberKnife Neurosurgery at the Stanford Cancer Center, predominantly treating patients with brain and spine tumors, brain and spine arteriovenous malformations, and trigeminal neuralgia.

Her research interests include surgical outcomes. She has co-authored several papers relating to spine conditions, vascular malformations, and brain tumor management.

Clinical Focus


  • Neurosurgery
  • Spine
  • Tumors
  • Vascular Malformations
  • Trigeminal Neuralgia

Academic Appointments


Administrative Appointments


  • Clinical Assistant Professor, Stanford Healthcare (2015 - Present)

Professional Education


  • Medical Education:McMaster University Michael G DeGroote School of Medicine Registrar (2007) Canada
  • Residency:University of Western Ontario (2013) Canada
  • Fellowship:University of Western Ontario (2012) Canada
  • Internship:University of Western Ontario (2008) Canada
  • Board Certification: Neurosurgery, Royal College of Physicians and Surgeons of Canada

Publications

All Publications


  • Stereotactic radiosurgery in large intracranial meningiomas: a systematic review. World neurosurgery Fatima, N., Meola, A., Pollom, E., Chaudhary, N., Soltys, S., Chang, S. 2019

    Abstract

    Gross total resection (GTR) of large intracranial meningiomas (LIMs) can be challenging and cause significant morbidity and mortality. The aim of this systematic review is to determine the clinical effectiveness and safety of Stereotactic Radiosurgery (SRS) either as primary or adjuvant therapy for LIMs, with tumor ≥2.5 cm in maximum dimension (tumor volume ≥8.1 cm3). A total of 452 tumors in 496 patients [350 females (69.3%) and 146 males (30.6%)] with median age 60 years (48 to 65 years) were included. The median tumor volume at the time of diagnosis was 16.7 cm3 (10 to 53.3cm3). The tumors were typically located in the skull-base (77.2%), while only 14.6% were in the supratentorial space. The median follow-up after SRS was 54 months (18-90 months). 87.8% of patients were treated with single session gamma knife radiosurgery (SS GKS), while the remaining 12.1% patients received non-single session (non-SS) GKS. Of 452 LIMs assessed for clinical response, 45.1% showed improvement, and 15.7% deteriorated after SRS. Radiographic tumor control at last follow-up (2-7.5 years) ranged from 84% to 100%. Overall, radiation-induced toxicity occurred in 23% of patients; with the most common adverse effect being cranial nerve neuropathy (5.5%) and peritumoral edema (PTE) (5.3%). Sub-group analysis revealed that there is 2-fold higher likelihood of improvement in clinical symptoms in patients with non-SS GKS than SS GKS [OR: 2.47; 95% (1.38-4.44); p=0.002].SRS is safe and effective in the treatment of LIMs as primary or adjuvant treatment. Further prospective studies are required to validate our results.

    View details for DOI 10.1016/j.wneu.2019.06.064

    View details for PubMedID 31226450

  • Magnetic Particle Imaging in Neurosurgery WORLD NEUROSURGERY Meola, A., Rao, J., Chaudhary, N., Song, G., Zheng, X., Chang, S. D. 2019; 125: 261–70
  • "Magnetic Particle Imaging (MPI) in Neurosurgery". World neurosurgery Meola, A., Rao, J., Chaudhary, N., Song, G., Zheng, X., Chang, S. D. 2019

    Abstract

    Magnetic particle imaging (MPI) is a novel radiation-free tomographic imaging method that provides a background-free, signal attenuation-free, direct quantification of the spatial distribution of superparamagnetic iron-oxide nanoparticles (SPIONs) with high temporal resolution (milliseconds), high spatial resolution (< 1 mm), and extreme sensitivity (mumol). The technique is based on non-linear magnetization of the SPIONs when exposed to an oscillating magnetic field. MPI was first described in 2001. Since then, the technique has been applied to experimental imaging of diseases affecting different organs in the human body. The aim of this paper is to review the potential applications of MPI in the field of neurosurgery. MPI has been used for the detection the loco-regional invasion of brain tumors, tracking and monitoring the viability of neural stem cells implanted for neuro-regenerative purposes, diagnosis of cerebral ischemia, and diagnosis and morpho-functional assessment of brain aneurysms. Currently, MPI is at a pre-clinical stage. In the future, human-sized MPI scanners, along with the optimal toxicity profile of SPIONs will allow diagnostic applications in neurosurgical diseases.

    View details for PubMedID 30738942

  • Long-term follow up data on difficult to treat intracranial arteriovenous malformations treated with the CyberKnife. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Gupta, R., Moore, J. M., Amorin, A., Appelboom, G., Chaudhary, N., Iyer, A., Steinberg, G. K., Chang, S. D., Soltys, S., Gibbs, I. 2018

    Abstract

    INTRODUCTION: The CyberKnife, a frameless, robotic, stereotactic device, has been developed to radiosurgically treat arteriovenous malformations (AVMs). While most AVMs are obliterated within two-to-three years, a subset remain recalcitrant; long-term data on these difficult to treat AVMs are limited in the neurosurgical literature.MATERIALS AND METHODS: A retrospective analysis of all patients who underwent CyberKnife treatment for intracranial AVMs at a single U.S. institution between 2002 and 2012, whose AVMs had failed to obliterate within 48 months or longer from the treatment start date, were eligible for inclusion.RESULTS: Eleven patients (9 AVMs; 7 males, 2 females) were followed for an average of 85.2 months (range 56.2-119.4). The median lesion size was 3.5 cm (range: 2.8-8.0 cm) and median Spetzler-Martin grade was 3 (range: 2-5). All AVMs were treated with one radiation dose (median prescribed dose was 18.0 Gy; median Dmax: 23.7 Gy). Six (66.7%) were obliterated in a median time of 84 months (range: 52-94 months), while 3 (33.3%) remained active after a median of 90.8 months (range 69.7-119.4). Transient, post-radiosurgery adverse radiation effects occurred in 5 (55.6%) cases. One (11.1%) patient had an acute hemorrhage from the AVM after radiosurgery. Four (44.4%) patients underwent repeat radiosurgery and/or embolization. Three of these lesions eventually obliterated, while 1 did not.CONCLUSION: The median time to obliteration was 84 months. Two-thirds of AVMs which persisted for over 4 years following initial radiosurgery treatment eventually obliterated. Transient post-radiosurgery adverse effects were common; delayed hemorrhages were rare in our case series.

    View details for PubMedID 30587419

  • Quantitative analysis of the safety and efficacy of microvascular decompression for patients with trigeminal neuralgia above and below 65 years of age. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Wallach, J., Ho, A. L., Kim, L. H., Chaudhuri, A. A., Chaudhary, N., Vaz-Guimaraes, F., Chang, S. D. 2018

    Abstract

    For medically-refractory trigeminal neuralgia (TN), microvascular decompression (MVD) is the first-line treatment, and has demonstrated the greatest efficacy and durability. However, due to potential surgical complications, a bias may exist against performing MVD in elderly patients. We sought to determine through a quantitative analysis whether MVD in the elderly is a safe and effective procedure for TN. We completed a Pubmed/SCOPUS literature search up to 12/2016 for eligible studies on MVD for TN. Only research articles with age stratification of results were included. In this quantitative analysis, we analyzed the data for the six articles identified in the literature comparing MVD for a group of patients ≥65 years with an elderly group <65 years. A total of 1483 were included. 455 patients were ≥65 years (mean 70.8 years, range 65-89 years) and 1028 patients were <65 years (mean 53.4 years, range 19-64 years). Composite mean follow-up time was 51.6 months for the elderly group, and 55.1 months for the young group. Following MVD, each group had 1 mortality (p = 0.43). There were 21 serious morbidities in the elderly group (4.62%) and 32 in the young group (3.11%) (p = 0.11). In addition, 15 patients (1.46%) in the elderly group and 24 patients (1.62%) in the young group experienced a cerebrospinal fluid leak (p = 0.23). TN recurrence rates 9.23% in the young group and 13.33% in the elderly group (p = 0.070). In conclusion, for properly-selected surgical candidates, MVD should not be ruled out on the basis of age ≥65 years.

    View details for PubMedID 29954647

  • Gold Nanoparticles for Brain tumor imaging: a Systematic Review FRONTIERS IN NEUROLOGY Meola, A., Rao, J., Chaudhary, N., Sharma, M., Chang, S. D. 2018; 9: 328

    Abstract

    Demarcation of malignant brain tumor boundaries is critical to achieve complete resection and to improve patient survival. Contrast-enhanced brain magnetic resonance imaging (MRI) is the gold standard for diagnosis and pre-surgical planning, despite limitations of gadolinium (Gd)-based contrast agents to depict tumor margins. Recently, solid metal-based nanoparticles (NPs) have shown potential as diagnostic probes for brain tumors. Gold nanoparticles (GNPs) emerged among those, because of their unique physical and chemical properties and biocompatibility. The aim of the present study is to review the application of GNPs for in vitro and in vivo brain tumor diagnosis.We performed a PubMed search of reports exploring the application of GNPs in the diagnosis of brain tumors in biological models including cells, animals, primates, and humans. The search words were "gold" AND "NP" AND "brain tumor." Two reviewers performed eligibility assessment independently in an unblinded standardized manner. The following data were extracted from each paper: first author, year of publication, animal/cellular model, GNP geometry, GNP size, GNP coating [i.e., polyethylene glycol (PEG) and Gd], blood-brain barrier (BBB) crossing aids, imaging modalities, and therapeutic agents conjugated to the GNPs.The PubMed search provided 100 items. A total of 16 studies, published between the 2011 and 2017, were included in our review. No studies on humans were found. Thirteen studies were conducted in vivo on rodent models. The most common shape was a nanosphere (12 studies). The size of GNPs ranged between 20 and 120 nm. In eight studies, the GNPs were covered in PEG. The BBB penetration was increased by surface molecules (nine studies) or by means of external energy sources (in two studies). The most commonly used imaging modalities were MRI (four studies), surface-enhanced Raman scattering (three studies), and fluorescent microscopy (three studies). In two studies, the GNPs were conjugated with therapeutic agents.Experimental studies demonstrated that GNPs might be versatile, persistent, and safe contrast agents for multimodality imaging, thus enhancing the tumor edges pre-, intra-, and post-operatively improving microscopic precision. The diagnostic GNPs might also be used for multiple therapeutic approaches, namely as "theranostic" NPs.

    View details for PubMedID 29867737

  • Magnetic resonance perfusion image features uncover an angiogenic subgroup of glioblastoma patients with poor survival and better response to antiangiogenic treatment. Neuro-oncology Liu, T. T., Achrol, A. S., Mitchell, L. A., Rodriguez, S. A., Feroze, A., Kim, C., Chaudhary, N., Gevaert, O., Stuart, J. M., Harsh, G. R., Chang, S. D., Rubin, D. L. 2016

    Abstract

    In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies.Quantitative image features characterizing subregions of tumors and the whole tumor were extracted from preoperative and pretherapy perfusion magnetic resonance (MR) images of 117 GBM patients in 2 independent cohorts. Unsupervised consensus clustering was performed to identify robust clusters of GBM in each cohort. Cox survival and gene set enrichment analyses were conducted to characterize the clinical significance and molecular pathway activities of the clusters. The differential treatment efficacy of antiangiogenic therapy between the clusters was evaluated.A subgroup of patients with elevated perfusion features was identified and was significantly associated with poor patient survival after accounting for other clinical covariates (P values <.01; hazard ratios > 3) consistently found in both cohorts. Angiogenesis and hypoxia pathways were enriched in this subgroup of patients, suggesting the potential efficacy of antiangiogenic therapy. Patients of the angiogenic subgroups pooled from both cohorts, who had chemotherapy information available, had significantly longer survival when treated with antiangiogenic therapy (log-rank P=.022).Our findings suggest that an angiogenic subtype of GBM patients may benefit from antiangiogenic therapy with improved overall survival.

    View details for DOI 10.1093/neuonc/now270

    View details for PubMedID 28007759

  • Evidence for use of Teriparatide in Spinal Fusion Surgery in Osteoporotic Patients. World neurosurgery Chaudhary, N., Lee, J. S., Wu, J. Y., Tharin, S. 2016

    Abstract

    Osteoporosis is defined as a bone mineral density (BMD) less than 2.5 standard deviations below the mean BMD at peak bone mass, or the presence of a fragility fracture. In the setting of osteoporosis, early hardware loosening is thought to cause decreased spinal fusion rates. The two mainstays of osteoporosis treatment are bisphosphonates and Teriparatide. Teriparatide, a form of synthetic parathyroid hormone (PTH), is an anabolic agent that increases osteoblast activity and, thereby, bone mass. Preclinical studies in animal models show that Teriparatide increases spinal fusion rates. Early clinical studies show that teriparatide both increases spinal fusion rates and decreases hardware loosening in the setting of postmenopausal osteoporosis. Ongoing additional trials will help formulate preoperative screening recommendations, determine the optimal duration of pre- and post-operative Teriparatide treatment, and investigate its utility in men.

    View details for DOI 10.1016/j.wneu.2016.11.135

    View details for PubMedID 27923758

  • Stereotactic radiosurgery for metastasis to the craniovertebral junction preserves spine stability and offers symptomatic relief JOURNAL OF NEUROSURGERY-SPINE Azad, T. D., Esparza, R., Chaudhary, N., Chang, S. D. 2016; 24 (2): 241-247
  • Magnetic resonance perfusion image features uncover an angiogenic subgroup of glioblastoma patients with poor survival and better response to antiangiogenic treatment. Neuro-Oncology Liu, T. T., Achrol, A. S., Mitchell, L. A., Rodriguez, S. A., Feroze, A., Iv, M., Kim, C., Chaudhary, N., Gevaert, O., Stuart, J. M., Harsh, G. R., Chang, S. D., Rubin, D. L. 2016

    Abstract

    In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies.Quantitative image features characterizing subregions of tumors and the whole tumor were extracted from preoperative and pretherapy perfusion magnetic resonance (MR) images of 117 GBM patients in 2 independent cohorts. Unsupervised consensus clustering was performed to identify robust clusters of GBM in each cohort. Cox survival and gene set enrichment analyses were conducted to characterize the clinical significance and molecular pathway activities of the clusters. The differential treatment efficacy of antiangiogenic therapy between the clusters was evaluated.A subgroup of patients with elevated perfusion features was identified and was significantly associated with poor patient survival after accounting for other clinical covariates (P values <.01; hazard ratios > 3) consistently found in both cohorts. Angiogenesis and hypoxia pathways were enriched in this subgroup of patients, suggesting the potential efficacy of antiangiogenic therapy. Patients of the angiogenic subgroups pooled from both cohorts, who had chemotherapy information available, had significantly longer survival when treated with antiangiogenic therapy (log-rank P=.022).Our findings suggest that an angiogenic subtype of GBM patients may benefit from antiangiogenic therapy with improved overall survival.

    View details for DOI 10.1093/neuonc/now270

  • Stereotactic radiosurgery for metastasis to the craniovertebral junction preserves spine stability and offers symptomatic relief. Journal of neurosurgery. Spine Azad, T. D., Esparza, R., Chaudhary, N., Chang, S. D. 2015: 1-7

    Abstract

    OBJECT Metastatic disease to the craniovertebral junction (CVJ) is rare but presents unique management challenges. To date, studies on using stereotactic radiosurgery (SRS) for CVJ metastases have been limited to case reports and small case series. The aim of this analysis was to evaluate the utility of SRS in the management of these secondary lesions. METHODS Clinical and radiological information from the charts of 25 patients with metastatic disease of the CVJ who were treated with SRS between 2005 and 2013 at the Stanford CyberKnife Center were retrospectively reviewed. RESULTS Seven male and 18 female patients with a median age of 58 years (range 34-94 years) were identified. The most common primary tumors were breast cancer (n = 5) and non-small cell lung cancer (n = 5), and the most frequent symptom was neck pain (n = 17). The average tumor volume treated was 15.9 cm(3) (range 0.16-54.1 cm(3)), with a mean marginal radiation dose of 20.3 Gy (range 15-25.5 Gy). The median follow-up was 18 months (range 1-81 months), though 1 patient was lost to follow-up. SRS provided radiographic tumor stability in over 80% of patients, offered pain alleviation in nearly two-thirds of patients, and produced no serious complications. Moreover, SRS preserved spinal stability in all but 1 patient, in whom pre-SRS stability was established. There was no evidence of radiation toxicity in the patient population. Median survival was 28 months (range 2-81 months), with survival of 13.3% at 5 years. CONCLUSIONS In the absence of unstable pathological fracture and spinal cord compression, metastatic tumors of the CVJ can be safely and effectively treated with SRS. This treatment option offers palliative pain relief and can halt tumor progression with only a low risk of complications or spinal instability.

    View details for PubMedID 26516666

  • A Modified Retromaxillary Approach to the Infratemporal Fossa: Three Case Studies JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY Woodford, R., Chaudhary, N., Wolf, A., Lownie, S., Armstrong, J. E. 2015; 73 (4): 769-780

    Abstract

    The infratemporal fossa (ITF) is an anatomically complex region with multiple neural and vascular structures entering and exiting through foramina in the skull base. The main obstacles to approaching the ITF are the zygomatic arch, the parotid gland, the facial nerve, and the ascending ramus AND condylar head of the mandible. Different surgical approaches to the ITF exist and the best approach should provide optimal visibility, minimal impairment of temporomandibular joint function, and preservation of motor and sensory nerve integrity. This report describes a modified Obwegeser retromaxillary approach to access lesions within the ITF. A multidisciplinary team was involved, which included an oral and maxillofacial surgery team, a neurosurgery team, and an otolaryngology team. Three patients with large skull base lesions, including an aneurysmal bone cyst, a giant cell tumor of the bone, and an invasive melanoma, underwent resection using this approach and were followed postoperatively. Excellent exposure of the floor of the middle cranial fossa and ITF was achieved with this approach. Functional status remained unchanged with respect to mastication, speech, swallowing, and cosmesis. Given the severity of the patients' conditions and extent of involvement of the skull base, outcomes were favorable, with minimal morbidity. This experience suggests that this approach provides safe access to an anatomically complex region and lessens challenges associated with more conventional approaches.

    View details for DOI 10.1016/j.joms.2014.10.025

    View details for Web of Science ID 000351240100034

    View details for PubMedID 25631866

  • Familial syndromes associated with intracranial tumours: a review CHILDS NERVOUS SYSTEM Ranger, A. M., Patel, Y. K., Chaudhary, N., Anantha, R. V. 2014; 30 (1): 47-64

    Abstract

    Most cancers of the central nervous system (CNS) occur sporadically in the absence of any known underlying familial disorder or multi-systemic syndrome. Several syndromes are associated with CNS malignancies, however, and their recognition has significant implications for patient management and prognosis. Patients with syndrome-associated CNS malignancies often have multiple tumours (either confined to one region or distributed throughout the body), with similar or different histology.This review examines syndromes that are strongly associated with CNS cancers: the phakomatosis syndromes, familial syndromes such as Li-Fraumeni and familial polyposis syndromes and dyschondroplasia.

    View details for DOI 10.1007/s00381-013-2309-z

    View details for Web of Science ID 000329624100006

    View details for PubMedID 24193148