Publications by authors named "Danny T M Chan"

Background: The optimal timing of initiating adjuvant temozolomide (TMZ) chemoradiotherapy after surgery in patients with glioblastoma is contentious. This study aimed to determine whether the timing of adjuvant treatment affects their overall survival (OS).

Methods: Consecutive adult patients with histologically-confirmed newly diagnosed glioblastoma treated with adjuvant TMZ chemoradiotherapy across all neurosurgical centers in Hong Kong between 2006 and 2020 were analyzed.

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Article Synopsis
  • Scientists are studying how gliomas, a type of brain tumor, change and can become resistant to treatments after they start with the tumor cells that are present when diagnosed.
  • They found that certain genetic features at diagnosis can predict how the tumor will behave later after treatment, like when it might become more aggressive or mutate.
  • They created a new tool called CELLO2 to help doctors understand these changes better and figure out which patients might need extra help based on their tumor's characteristics.
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Background: Deep brain stimulation (DBS) is an emerging and effective therapy for Parkinson's disease (PD). However, little is known about its utilization, surgical populations, centers, coverages, regional balance, and influential factors.

Materials And Methods: This large-scale multicenter cross-sectional study was conducted using a national census involving 74 Chinese centers.

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Objective: Despite benefits brought by recent neurosurgical robots, surgical safety and surgeon-robot collaboration remain significant challenges. In this article, we analyze and address these problems in the context of brain biopsy, by proposing a semi-autonomous system.

Methods: A robotic module is designed for the automation of all the brain biopsy procedures, and a biopsy cannula with tissue blocker is developed to avoid tissue excess and haemorrhage.

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Article Synopsis
  • * It involved 1,010 adult patients, finding a stable age standardized incidence rate (1.0 per 100,000) and a median overall survival of 10.6 months, with factors like performance score and treatment types impacting survival.
  • * Despite an increase in the use of temozolomide chemoradiotherapy from 39% to 63% of patients, this did not result in a significant improvement in median overall survival between 2006-2010 and 2015-2019.
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Introduction: In contrast to standard-of-care treatment of newly diagnosed glioblastoma, there is limited consensus on therapy upon disease progression. The role of resection for recurrent glioblastoma remains unclear. This study aimed to identify factors for overall survival (OS) and post-progression survival (PPS) as well as to validate an existing prediction model.

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Single-cell multi-omics can provide a unique perspective on tumor cellular heterogeneity. Most previous single-cell whole-genome RNA sequencing (scWGS-RNA-seq) methods demonstrate utility with intact cells from fresh samples. Among them, many are not applicable to frozen samples that cannot produce intact single-cell suspensions.

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Background:  The diagnostic accuracy of frameless stereotactic brain biopsy has been reported, but there is limited literature focusing on the reasons for nondiagnostic cases. In this study, we evaluate the diagnostic accuracy of frameless stereotactic brain biopsy, compare it with the current international standard, and review the field for improvement.

Methods:  This is a retrospective analysis of consecutive, prospectively collected frameless stereotactic brain biopsies from 2007 to 2020.

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Understanding the racial specificities of diseases-such as adult diffuse glioma, the most common primary malignant tumor of the central nervous system-is a critical step toward precision medicine. Here, we comprehensively review studies of gliomas in East Asian populations and other ancestry groups to clarify the racial differences in terms of epidemiology and genomic characteristics. Overall, we observed a lower glioma incidence in East Asians than in Whites; notably, patients with glioblastoma had significantly younger ages of onset and longer overall survival than the Whites.

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Objective: This study aims to identify independent factors associated with cervical spinal injuries in head-injured patients. The extent of injuries to other body parts was assessed by the Abbreviated Injury Scale (AIS) and was included in the analysis.

Methods: Consecutive head-injured patients admitted via the emergency department from January 1, 2014 to December 31, 2016 were retrospectively reviewed.

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Suprasellar germinomas can present with non-diagnostic, or even normal results on imaging. The spectrum of reported cases ranges from normal imaging, thickened pituitary stalks, to discrete tumour growths. This similar phenomenon is less commonly seen in the pineal region, or bifocal germinomas, and the literature is sparse with only a few case series or reports mentioning a similar presentation of signs and symptoms preceding radiological evidence of diagnosis.

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Background: Stereotactic brain biopsy is to perform the manual aspiration tissue biopsy using a cannula on a syringe under stereotactic guidance to provide histological confirmation. Excessive vacuum aspiration increases the risk of haemorrhage. Manual aspiration relies on the surgeon's experience while the minimum vacuum pressure is unknown.

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Introduction: Radiotherapy-induced glioblastomas (RIGB) are a well-known late and rare complication of brain irradiation. Yet the clinical, radiological and molecular characteristics of these tumors are not well characterized.

Methods: This was a retrospective multicentre study that analysed adult patients with newly diagnosed glioblastoma over a 10-year period.

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Background: The COVID-19 novel coronavirus is contagious, and the mortality is higher in the elderly population. Lockdown in different parts of the world has been imposed since January 2020. Chronic subdural haematoma (cSDH) has a unique natural history in which symptoms can be non-specific, and the onset is insidious.

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Adult medulloblastomas are clinically and molecularly understudied due to their rarity. We performed molecular grouping, targeted sequencing, and TERT promoter Sanger sequencing on a cohort of 99 adult medulloblastomas. SHH made up 50% of the cohort, whereas Group 3 (13%) was present in comparable proportion to WNT (19%) and Group 4 (18%).

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Aim: Cervical anterior spinal fusion (ASF) with corpectomy has risks of catastrophic acute complications such as airway obstruction requiring re-intubation. Our team has adopted a management plan for all cervical corpectomy patients to be admitted to the intensive care unit (ICU) after the operations for overnight observation. Some of these patients were kept intubated after the operations and transferred to the ICU.

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Metformin, an anti-hyperglycemic drug, has been known to have antitumor properties for around 15 years. Although there are a number of reports attributing the antitumor function of metformin to its impact on energy homeostasis and oxygen re-distribution in tumor microenvironment, detailed mechanisms remain largely unknown. In the past several years, there is an increasing number of publications indicating that metformin can affect various immunological components including lymphocytes, macrophages, cytokines and several key immunological molecules in both human and animal studies.

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Despite significant medical advances, glioblastoma multiforme (GBM) remains a formidable therapeutic challenge. Advent of targeted capture sequencing and patients-derived organoid cultures may hold the key to scientifically sound individualized treatment approaches. We report on our initial experience of using the combination of these two technologies to create a tailored approach of systemic therapies for a patient with GBM, which challenges the conventional treatment paradigm, as well as specifically highlighting the complexities of such an approach and the potential for a more favorable treatment outcome.

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Standard-of-care treatment of glioblastomas involves maximal safe resection and adjuvant temozolomide chemo-radiotherapy. Although extent of resection (EOR) is a well-known surgical predictor for overall survival most lesions cannot be completely resected. We hypothesize that in the event of incomplete resection, residual tumor volume (RTV) may be a more significant predictor than EOR.

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Treatment of arteriovenous malformations (AVM) located at the eloquent area has been a challenge. Awake brain mapping allows identification of a non-eloquent gyrus for intervention and can potentially facilitate resection with preservation of functions. An alternative treatment option is stereotactic radiosurgery (SRS).

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Background: 5-Aminolevulinic Acid (5-ALA) induced fluorescence is useful in guiding glioma resection. The extent of 5-ALA accumulation is beyond gadolinium contrast enhancement. Supratotal resection may be achieved, potentially granting patients with better survival.

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Objectives: MicroRNAs (miRNAs) are considered as the cellular regulators which post-transcriptionally modulate gene expression in diverse biological processes including cell development and immunity. In this study, we investigated functions of miR-181d in dendritic cells (DCs) maturation, and the underlying mechanisms were also explored.

Materials And Methods: Here we did the miRNA screening in human DCs in response to lipopolysaccharides (LPS) by quantitative real-time PCR (qRT-PCR).

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Chronic subdural haematoma (CSDH) is a common neurosurgical condition. Burr-hole for drainage is an effective treatment. However, recurrence can be up to 8-33% and is associated with morbidities and mortalities.

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