Radiotherapy-induced glioblastoma: distinct differences in overall survival, tumor location, pMGMT methylation and primary tumor epidemiology in Hong Kong chinese patients

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. Patients with RIGB were identified according to Cahan's criteria for radiation-induced tumors. A case-control analysis was performed to compare known prognostic factors for overall survival (OS) with an independent cohort of IDH-1 wildtype de novo glioblastomas treated with standard temozolomide chemoradiotherapy. Survival analysis was performed by Cox proportional hazards regression.

RESULTS

A total of 590 adult patients were diagnosed with glioblastoma. 19 patients (3%) had RIGB. The mean age of patients upon diagnosis was 48 years ± 15. The mean latency duration from radiotherapy to RIGB was 14 years ± 8. The mean total dose was 58Gy ± 10. One-third of patients (37%, 7/19) had nasopharyngeal cancer and a fifth (21%, 4/19) had primary intracranial germinoma. Compared to a cohort of 146 de novo glioblastoma patients, RIGB patients had a shorter median OS of 4.8 months versus 19.2 months (p-value: <.001). Over a third of RIGBs involved the cerebellum (37%, 7/19) and was higher than the control group (4%, 6/146; p-value: <.001). A fifth of RIGBs (21%, 3/19) were pMGMT methylated which was significantly fewer than the control group (49%, 71/146; p-value: .01). For RIGB patients (32%, 6/19) treated with re-irradiation, the one-year survival rate was 67% and only 8% for those without such treatment (p-value: .007).

CONCLUSION

The propensity for RIGBs to develop in the cerebellum and to be pMGMT unmethylated may contribute to their poorer prognosis. When possible re-irradiation may offer a survival benefit. Nasopharyngeal cancer and germinomas accounted for the majority of original malignancies reflecting their prevalence among Southern Chinese.

Patterns of care and survival of Chinese glioblastoma patients in the temozolomide era: a Hong Kong population-level analysis over a 14-year period

Background

The aim of this study is to address the paucity of epidemiological data regarding the characteristics, treatment patterns and survival outcomes of Chinese glioblastoma patients.

Methods

This was a population-level study of Hong Kong adult (>18 years) Chinese patients with newly diagnosed histologically confirmed glioblastoma between 2006 and 2019. The age standardized incidence rate (ASIR), patient-, tumor- treatment-related characteristics, overall survival (OS) as well as its predictors were determined.

Results

One thousand and ten patients with a median follow-up of 10.0 months were reviewed. The ASIR of glioblastoma was 1.0 per 100 000 population with no significant change during the study period. The mean age was 57 + 14 years. The median OS was 10.6 months (IQR: 5.2-18.4). Independent predictors for survival were: Karnofsky performance score >80 (adjusted OR: 0.8; 95% CI: 0.6-0.9), IDH-1 mutant (aOR: 0.7; 95% CI: 0.5-0.9) or MGMT methylated (aOR: 0.7; 95% CI: 0.5-0.8) glioblastomas, gross total resection (aOR: 0.8; 95% CI: 0.5-0.8) and temozolomide chemoradiotherapy (aOR 0.4; 95% CI: 0.3-0.6). Despite the significant increased administration of temozolomide chemoradiotherapy from 39% (127/326) of patients in 2006-2010 to 63% (227/356) in 2015-2019 (P-value < .001), median OS did not improve (2006-2010: 10.3 months vs 2015-2019: 11.8 months) (OR: 1.1; 95% CI: 0.9-1.3).

Conclusions

The incidence of glioblastoma in the Chinese general population is low. We charted the development of neuro-oncological care of glioblastoma patients in Hong Kong during the temozolomide era. Although there was an increased adoption of temozolomide chemoradiotherapy, a corresponding improvement in survival was not observed.

Repeat resection for recurrent glioblastoma in the temozolomide era: a real-world multi-centre study

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.

METHODS

This was a multi-centre retrospective study that reviewed consecutive adult patients from 2006 to 2019 that received a repeat resection for recurrent glioblastoma. The primary endpoint was PPS defined as from the date of second surgery until death.

RESULTS

1032 glioblastoma patients were identified and 190 (18%) underwent resection for recurrence. Patients that had second surgery were more likely to be younger (<70 years) (adjusted OR: 0.3; 95% CI: 0.1-0.6), to have non-eloquent region tumours (aOR: 1.7; 95% CI: 1.1-2.6) and received temozolomide chemoradiotherapy (aOR: 0.2; 95% CI: 0.1-0.4). Resection for recurrent tumour was an independent predictor for OS (aOR: 1.5; 95% CI: 1.3-1.7) (mOS: 16.9 months versus 9.8 months). For patients that previously received temozolomide chemoradiotherapy and subsequent repeat resection (137, 13%), the median PPS was 9.0 months (IQR: 5.0-17.5). Independent PPS predictors for this group were a recurrent tumour volume of >50cc (aOR: 0.6; 95% CI: 0.4-0.9), local recurrence (aOR: 1.7; 95% CI: 1.1-3.3) and 5-ALA fluorescence-guided resection during second surgery (aOR: 1.7; 95% CI: 1.1-2.8). A National Institutes of Health Recurrent Glioblastoma Multiforme Scale score of 0 conferred an mPPS of 10.0 months, a score of 1-2, 9.0 months and a score of 3, 4.0 months (log-rank test, p-value < 0.05).

CONCLUSION

Surgery for recurrent glioblastoma can be beneficial in selected patients and carries an acceptable morbidity rate. The pattern of recurrence influenced PPS and the NIH Recurrent GBM Scale was a reliable prognostication tool.

scONE-seq: A single-cell multi-omics method enables simultaneous dissection of phenotype and genotype heterogeneity from frozen tumors

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. We have developed scONE-seq, a versatile scWGS-RNA-seq method that amplifies single-cell DNA and RNA without separating them from each other and hence is compatible with frozen biobanked samples. We benchmarked scONE-seq against existing methods using fresh and frozen samples to demonstrate its performance in various aspects. We identified a unique transcriptionally normal-like tumor clone by analyzing a 2-year frozen astrocytoma sample, demonstrating that performing single-cell multi-omics interrogation on biobanked tissue by scONE-seq could enable previously unidentified discoveries in tumor biology.

Multicentre study of hospitalised patients with sports- and recreational cycling-related traumatic brain injury in Hong Kong

INTRODUCTION

Cycling is associated with a greater risk of traumatic brain injury (TBI) than other recreational activities. This study aimed to investigate the epidemiology of sports-related TBI in Hong Kong and to examine predictors for recreational cycling-induced intracranial haemorrhage.

METHODS

This retrospective multicentre study included patients diagnosed with sports-related TBI in public hospitals in Hong Kong from 2015 to 2019. Computed tomography scans were reviewed by an independent assessor. The primary endpoint was traumatic intracranial haemorrhage. The secondary endpoint was an unfavourable Glasgow Outcome Scale (GOS) score at discharge from hospital.

RESULTS

In total, 720 patients were hospitalised with sports-related TBI. The most common sport was cycling (59.2%). The crude incidence of cycling-related TBI was 1.1 per 100 000 population. Cyclists were more likely to exhibit intracranial haemorrhage and an unfavourable GOS score, compared with patients who had TBI because of other sports. Although 47% of cyclists had intracranial haemorrhage, only 15% wore a helmet. In multivariate analysis, significant predictors for intracranial haemorrhage were age ≥60 years, antiplatelet medication, moderate or severe TBI, and skull fracture. Among 426 cyclists, 375 (88%) had mild TBI, and helmet wearing was protective against intracranial haemorrhage, regardless of age, antiplatelet medication intake, and mechanism of injury. Of 426 cyclists, 31 (7.3%) had unfavourable outcomes on discharge from hospital.

CONCLUSIONS

The incidence of sports-related TBI is low in Hong Kong. Although cycling-related head injuries carried greater risks of intracranial haemorrhage and unfavourable outcomes compared with other sports, most cyclists experienced good recovery. Helmet wearing among recreational cyclists with mild TBI was protective against intracranial haemorrhage and skull fracture.

Impact of metformin on immunological markers: Implication in its anti-tumor mechanism

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. These interesting results appear to be in line with emerging data that suggest associations between immune responses and energy homeostasis/oxygen re-distribution, which may explain effective impacts of metformin on immunotherapies against autoimmune diseases as well as cancers. This review article is to analyse and discuss recent development in the above areas with aim to justify metformin as a new adjuvant for immunotherapy against human cancers. We hope that our summary will help to optimize the application of metformin for various types of human cancers.

Pattern of recurrence and factors associated with cerebrospinal fluid dissemination of glioblastoma in Chinese patients

Background:

Pattern of recurrence of glioblastoma (GBM) seems to have undergone some shifts from distant metastasis as a rarity to a higher proportion, including disease disseminated via cerebrospinal fluid (CSF) pathway. There is still no report on the pattern of recurrence for Chinese population. Here, we evaluated the pattern of recurrence of GBM in Chinese patients along with factors that could affect the distribution of recurrence.

Methods:

Medical records of GBM patients with definite recurrence were reviewed. Local recurrence was defined as tumor regrowth within the preoperative abnormal signals on magnetic resonance imaging (MRI) T2 sequence. New recurrence was a new lesion away from the preoperative T2 abnormalities. New recurrence in contact with CSF pathways was registered as new CSF dissemination. Progress-free survival (PFS) and survival after progress were compared using the Kaplan–Meier survival curves. Potential risk factors for new CSF dissemination were assessed using univariate models followed by multivariate analysis.

Results:

Thirty-six patients were proven to have recurrence; 22 local and 14 new recurrences. Among the 14 patients, 11 had new CSF dissemination. Median PFS for local, new parenchymal recurrence, and new CSF dissemination were 5.5 months, 9.9 months, and 12.1 months, whereas survival after progress were 6.1 months, 5.7 months, and 16.9 months, respectively. The ventricular entry during surgery and the completion of concomitant chemoradiotherapy were risk factors for new CSF dissemination. O⁶-methylguanine-DNA methyltransferase methylation was associated with the development of CSF dissemination.

Conclusion:

The majority of recurrence remained local (22/36, 61%). However, CSF dissemination was up to 30% (11/36). PFS for patients with CSF dissemination was the longest, and paradoxically survival after progress was the shortest. Ventricular entry should be avoided. Whole craniospinal MRI surveillance should be included for these patients.

Ictal high-frequency oscillations and hyperexcitability in refractory epilepsy

OBJECTIVE

High-frequency oscillations (HFOs, 80-500Hz) from intracranial electroencephalography (EEG) may represent a biomarker of epileptogenicity for epilepsy. We explored the relationship between ictal HFOs and hyperexcitability with a view to improving surgical outcome.

METHODS

We evaluated 262 patients with refractory epilepsy. Fifteen patients underwent electrode implantation, and surgical resection was performed in 12 patients using a semi-prospective design. Ictal intracranial EEGs were examined by continuous wavelet transform (CWT). Significant ictal HFOs were denoted by normalized wavelet power above the 50th percentile across all channels. Each patient underwent functional mapping with cortical electrical stimulation. Hyperexcitability was defined as the appearance of afterdischarges or clinical seizures after electrical stimulation (50Hz, biphasic, pulse width=0.5ms, 5s, 5mA).

RESULTS

Among the group of patients achieving Engel Class I/II outcome at 1+ year, the mean proportion of significant ictal HFOs among resected channels for any given patient was 69% (33.3-100%). The respective figures for conventional frequency ictal patterns (CFIPs), hyperexcitability, and radiological lesion were 68.3% (26.3-100%), 39.6% (0-100%), and 52.8% (0-100%). Statistical significance was only achieved with ictal HFOs when comparing patients with Engel Class I/II outcomes versus III/IV outcomes (12.6% vs. 4.2%, the number of channels as the denominator, p=0.005). Further analysis from all patients irrespective of the surgical outcome showed that ictal HFOs co-occurred with CFIP (p<0.001), hyperexcitability (p<0.001), and radiological lesion (p<0.001). The combination of ictal HFOs/hyperexcitability improved the sensitivity from 66.7% to 100%, and the specificity from 66.7% to 75% when compared with ictal HFOs or hyperexcitability alone.

CONCLUSIONS

We confirmed the utility of ictal HFOs in determining surgical outcome. Ictal HFOs are affiliated to cortical hyperexcitability, which may represent a pathological manifestation of epileptogenicity.

SIGNIFICANCE

Presurgical evaluation of refractory epilepsy may incorporate both ictal HFOs and cortical stimulation in determining epileptogenic foci.

Spontaneous intracranial hypotension: improving recognition and treatment strategies in the local setting

We report a case of spontaneous intracranial hypotension with classic symptoms of orthostatic headache and acute presentation of subdural haematoma on computed tomographic scan. Conventional approach with conservative treatment was initially adopted. The patient's condition, however, deteriorated after 2 weeks, requiring surgical evacuation of the intracranial haemorrhage. We reviewed the clinical features of this disease and the correlated magnetic resonance imaging findings with the pathophysiological mechanisms, and described treatment strategies in the local setting. Subtle findings on initial computed tomographic scan are also reported which might improve pathology recognition. Spontaneous intracranial hypotension is not uncommonly encountered in Hong Kong, and physicians must adopt a high level of clinical suspicion to facilitate early diagnosis and appropriate management. In addition, novel therapeutic approaches may be required in those with recurrent symptoms or who are refractory to current treatment strategies.

Subthalamic nucleus deep brain stimulation for Parkinson's disease: evidence for effectiveness and limitations from 12 years' experience

OBJECTIVE

To present the result and experience of subthalamic nucleus deep brain stimulation for Parkinson's disease.

DESIGN

Case series.

SETTING

Prince of Wales Hospital, Hong Kong.

PATIENTS

A cohort of patients with Parkinson's disease received subthalamic nucleus deep brain stimulation from September 1998 to January 2010. Patient assessment data before and after the operation were collected prospectively.

RESULTS

Forty-one patients (21 male and 20 female) with Parkinson's disease underwent bilateral subthalamic nucleus deep brain stimulation and were followed up for a median interval of 12 months. For the whole group, the mean improvements of Unified Parkinson's Disease Rating Scale (UPDRS) parts II and III were 32.5% and 31.5%, respectively (P<0.001). Throughout the years, a multidisciplinary team was gradually built. The deep brain stimulation protocol evolved and was substantiated by updated patient selection criteria and outcome assessment, integrated imaging and neurophysiological targeting, refinement of surgical technique as well as the accumulation of experience in deep brain stimulation programming. Most of the structural improvement occurred before mid-2005. Patients receiving the operation before June 2005 (19 cases) and after (22 cases) were compared; the improvements in UPDRS part III were 13.2% and 55.2%, respectively (P<0.001). There were three operative complications (one lead migration, one cerebral haematoma, and one infection) in the group operated on before 2005. There was no operative mortality.

CONCLUSIONS

The functional state of Parkinson's disease patients with motor disabilities refractory to best medical treatment improved significantly after subthalamic nucleus deep brain stimulation. A dedicated multidisciplinary team building, refined protocol for patient selection and assessment, improvement of targeting methods, meticulous surgical technique, and experience in programming are the key factors contributing to the improved outcome.

A sequential comparison on the risk of haemorrhage with different sizes of biopsy needles for stereotactic brain biopsy

AIM

To compare the risk of postoperative haemorrhage with different sizes of brain biopsy needles.

PATIENTS AND METHOD

A cohort of patients using a 2.5-mm outer diameter side-cutting biopsy needle was compared to a subsequent cohort using a 1.8-mm needle of the same type. All data were collected prospectively. A CT scan was done within 12 h after surgery. Any visible haemorrhage at the operated site was documented.

RESULTS

From 2007 to 2013, 54 stereotactic brain biopsies (all frameless except for one frame-based) were performed. The 2.5-mm group comprised 29 procedures from 2007 to 2009. The 1.8-mm group comprised the subsequent 25 procedures. The diagnostic yields were 90 and 96% in the 2.5- and the 1.8-mm group, respectively (p = 0.615). Comparing the 2.5- and the 1.8-mm group, haemorrhage was significantly reduced: incidence (72 vs. 40%, p = 0.016); size of haemorrhage (mean 7.2 vs. 2.6 mm, p = 0.002); proportion of haemorrhage size >10 mm (34.5 vs. 4%, p = 0.006). Symptomatic haemorrhage rates were 3.4 and 0.0% in the 2.5- and the 1.8-mm group, respectively (p = 1.00).

CONCLUSION

The 1.8-mm outer diameter needle carried a lower risk of postoperative haemorrhage than the 2.5-mm one, without compromising the diagnostic yield.

Pseudoprogression of malignant glioma in Chinese patients receiving concomitant chemoradiotherapy

OBJECTIVES

To investigate the frequency of pseudoprogression of glioblastoma in Chinese patients receiving concomitant chemoradiotherapy and investigate its association with pseudoprogression and tumour molecular marker O(6)-methylguanine-DNA methyltransferase promoter methylation status.

DESIGN

Case series with internal comparisons.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Patients with glioblastoma treated with concomitant chemoradiotherapy during April 2005 to June 2010 were reviewed. Magnetic resonance imaging brain scans, pre- and post-concomitant chemoradiotherapy and 3-monthly thereafter were reviewed by an independent neuroradiologist according to Macdonald's criteria. Relevant patient information (clinical condition, performance score, development of new neurological deficits, use of steroids, and survival) was retrieved. For each patient, O(6)-methylguanine-DNA methyltransferase methylation status was investigated with genomic DNA from formalin-fixed or paraffin-embedded sections of tumour tissues by methylation-specific polymerase chain reaction.

RESULTS

During the study period, 28 primary glioblastoma patients underwent concomitant chemoradiotherapy. The mean age of the patients was 48 (range, 16-71) years. Thirteen patients (13/28, 46%) developed early radiological progression of the tumour after completion of concomitant chemoradiotherapy, of whom five (39%) were subsequently found to have had pseudoprogression. Patients with pseudoprogression showed a trend towards longer survival (22 months in pseudoprogression vs 17 months in all others vs 11 months in those with genuine progression). Among the 27 patients tested for O(6)-methylguanine-DNA methyltransferase promoter status, 12 (44%) were methylated. Two (2/12, 17%) in the methylated group had pseudoprogression, while three (3/15, 20%) in the unmethylated group had pseudoprogression.

CONCLUSIONS

Nearly half of all patients (46%) developed early radiological progression (within 3 months of completing concomitant chemoradiotherapy). Moreover, about one in three of such patients had pseudoprogression. Pseudoprogression is an important clinical condition to be aware of to prevent premature termination of an effective treatment.

Loss of brain-enriched miR-124 microRNA enhances stem-like traits and invasiveness of glioma cells

miR-124 is a brain-enriched microRNA that plays a crucial role in neural development and has been shown to be down-regulated in glioma and medulloblastoma, suggesting its possible involvement in brain tumor progression. Here, we show that miR-124 is down-regulated in a panel of different grades of glioma tissues and in all of the human glioma cell lines we examined. By integrated bioinformatics analysis and experimental confirmation, we identified SNAI2, which is often up-regulated in glioma, as a direct functional target of miR-124. Because SNAI2 has been shown to regulate stem cell functions, we examined the roles of miR-124 and SNAI2 in glioma cell stem-like traits. The results showed that overexpression of miR-124 and knockdown of SNAI2 reduced neurosphere formation, CD133(+) cell subpopulation, and stem cell marker (BMI1, Nanog, and Nestin) expression, and these effects could be rescued by re-expression of SNAI2. Furthermore, enhanced miR-124 expression significantly inhibited glioma cell invasion in vitro. Finally, stable overexpression of miR-124 and knockdown of SNAI2 inhibited the tumorigenicity and invasion of glioma cells in vivo. These findings reveal, for the first time, that the tumor suppressor activity of miR-124 could be partly due to its inhibitory effects on glioma stem-like traits and invasiveness through SNAI2.

Intracranial electroencephalogram to evaluate refractory temporal and frontal lobe epilepsy

OBJECTIVE

We undertook a collaborative study in a multidisciplinary team to channel refractory epilepsy patients to test a hypothesis about placement of intracranial electroencephalography arrays.

DESIGN

This was a descriptive case series. Prospective non-invasive presurgical evaluations were based on clinical semiology, magnetic resonance imaging, video-electroencephalography findings and neuropsychological assessments. If the results were discordant, a hypothesis was generated using individualised combinations of positron emission tomography, single-photon emission computed tomography, functional magnetic resonance imaging and Wada tests. The indications for intracranial electroencephalography were: (a) focal magnetic resonance imaging, ictal/interictal scalp electroencephalography with variable results (group A); (b) multi-focal magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group B); (c) non-lesional magnetic resonance imaging, focal/multi-focal ictal scalp electroencephalography (group C). We evaluated whether the seizure-onset zones and eloquent areas were delineated, surgical outcomes (if operated on), and pathology results.

SETTING

A tertiary referral centre for neurology in Hong Kong.

PATIENTS

A total of 105 refractory epilepsy patients completed non-invasive presurgical evaluations over the period 2007 to 2009. Thirty-two patients were eligible for direct resective surgery, and another 25 patients had a testing hypothesis formulated. Of these 25 patients, 10 were eligible for intracranial electroencephalography based on technical/financial considerations.

RESULTS

All 10 patients (group A=2, group B=4, group C=4) had their epileptogenic zones defined. Six patients underwent functional mapping, all of whom had their eloquent areas defined. Seven of the 10 patients underwent resective surgery; four of them achieved Engel class I/II outcomes. The dichotomised outcomes were 100% (group A), 50% (group B), and 33% (group C) achieving Engel class I/II. Two patients had asymptomatic subdural haematoma. There was no intracranial infection or operative mortality. In five (71%) of seven of the patients, a histological diagnosis was established.

CONCLUSION

Proper deployment of intracranial electroencephalography is useful in the presurgical evaluation of patients with refractory epilepsy. This modality of management is potentially of benefit for patients with refractory epilepsy, but is underutilised locally.

Association of molecular marker O(6)Methylguanine DNA methyltransferase and concomitant chemoradiotherapy with survival in Southern Chinese glioblastoma patients

OBJECTIVES

(1) To compare the survival of concomitant chemotherapy and radiotherapy with radiotherapy alone in Chinese patients with primary glioblastoma. (2) To determine the methylation status of O(6)Methylguanine DNA methyltransferase in Chinese primary glioblastoma, and to assess the prognostic value of O(6)Methylguanine DNA methyltransferase methylation status in such patients.

DESIGN

Retrospective correlative analysis.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Patients diagnosed with histologically proven primary glioblastoma in the period of March 2005 to June 2007 were recruited. Genomic DNA was isolated from formalin-fixed and paraffin-embedded sections of glioblastoma tissues. Methylation-specific polymerase chain reaction for O(6)Methylguanine DNA methyltransferase was performed. Patients' information at presentation was collected (age, performance status, steroid use, extent of resection, complications, radiotherapy data, use of chemotherapy). Primary outcome was measured by overall survival while secondary outcome was measured by progression-free survival. Overall and progression-free survivals were estimated by the Kaplan-Meier technique. Outcomes were assessed for groups with and without concomitant chemoradiotherapy and for groups with and without O(6)Methylguanine DNA methyltransferase methylation.

RESULTS

A total of 35 glioblastoma patients were recruited; 27 were male and 8 female. Their mean age was 50 years. In all, 17 received concomitant chemoradiotherapy, and 18 received radiotherapy only. Their median overall survival was 12 (range, 7-17) months and the median progression-free survival was 5 (range, 3-6) months. In the radiotherapy alone group, the median progression-free survival and overall survival was 4 (range, 3-5) months and 6 (range, 2-10) months, respectively. In the concomitant radiochemotherapy group, the median progression-free survival and overall survival was 6 (range, 2-10) months and 13 (range, 8-18) months, respectively. Fifteen (43%) of the tumour samples showed methylation of O(6)Methylguanine DNA methyltransferase. There was a trend towards overall longer survival in the group with methylated tumours compared to those with unmethylated tumours; respective values for median survival (ranges) were 17 (13-21) versus 10 (6-14) months (P=0.105).

CONCLUSIONS

Our single-centre results indicated that Chinese glioblastoma patients who had received concomitant chemoradiotherapy showed a trend towards longer overall survival compared to those receiving radiotherapy alone. Approximately 43% of our Chinese glioblastoma samples showed methylation of O(6)Methylguanine DNA methyltransferase. O(6)Methylguanine DNA methyltransferase methylation may be a significant prognostic factor in Chinese glioblastoma patients.

The use of diffusion tensor tractography to measure the distance between the anterior tip of the Meyer loop and the temporal pole in a cohort from Southern China

Object

Anterior temporal lobe resection plus amygdalohippocampectomy can cause damage to the anterior portion of the optic radiation, also known as the Meyer loop, resulting in homonymous superior quadrantanopia. Magnetic resonance diffusion tensor tractography (DTT) of the Meyer loop can help in surgical planning. In this study, the distance of the anterior tip of the Meyer loop to the temporal lobe pole (ML-TP) in the Southern Chinese population was assessed.

Methods

The authors studied 16 Southern Chinese individuals (8 men and 8 women; mean age 45.6 years, range 21–60 years). Diffusion tensor images were obtained with a 3-T MR imaging system using a single-shot spin echo echo planar imaging sequence. Two trained operators, one neurosurgeon (Operator A) and one radiologist (Operator B), carried out the DTT analysis with software iPlan (BrainLAB) and FiberTrak (Philips).

Results

For the 32 temporal lobes, the intraclass correlation coefficient (ICC) of the 2 operators' results using iPlan was 0.96, while that of Operator A using iPlan and Operator B using FiberTrak was 0.75. The ICC of Operator B using iPlan and FiberTrak was 0.81. The ML-TP distance of normal lobes (30 lobes [2 lobes that previously underwent surgery were excluded]) was 36.3 ± 5.5 mm (range 26.6–48.9 mm), 36.3 ± 5.3 mm (range 26.8–48.2 mm), and 35.9 ± 6.4 mm (range 20.8–48.4 mm) for Operator A using iPlan, Operator B using iPlan, and Operator B using FiberTrak, respectively (p > 0.05).

Conclusions

The 2 operators reached good agreement on ML-TP distance measurement using DTT. The DDT results can be more software dependent than operator dependent. The measurement with FiberTrak demonstrated larger range and standard deviation than measurement with iPlan.

Meteorological factors and aneurysmal subarachnoid haemorrhage in Hong Kong

OBJECTIVE

To evaluate the influence of meteorological factors on the onset of aneurysmal subarachnoid haemorrhage in Hong Kong.

DESIGN

Retrospective review of prospectively collected data.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

A total of 135 consecutive patients with acute aneurysmal subarachnoid haemorrhage presenting to the hospital within 48 hours after ictus from October 2002 to October 2006.

MAIN OUTCOME MEASURES

Occurrence of aneurysmal subarachnoid haemorrhage in relation to daily changes in atmospheric pressure, temperature, and humidity.

RESULTS

The peak incidence of aneurysmal subarachnoid haemorrhage occurred in winter (December to February), especially January. The mean (+/-standard deviation) daily atmospheric pressure change was significantly higher on days with aneurysmal subarachnoid haemorrhage onset as opposed to days without (1.75+/-1.47 hPa vs 1.48+/-1.28 hPa; P=0.032).

CONCLUSIONS

A seasonal variation and relationship to atmospheric pressure change in aneurysmal subarachnoid haemorrhage was noted in the current study carried out in Hong Kong. The mechanism linking atmospheric pressure change and aneurysmal rupture remained to be explored.

Temozolomide in the treatment of recurrent malignant glioma in Chinese patients

OBJECTIVE

To determine the anti-tumour efficacy and safety profile of temozolomide in local Chinese patients with recurrent malignant glioma. DESIGN. Open-label trial.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Twenty-two patients had been enrolled in the study since 2001. Patients had to show unequivocal evidence of tumour recurrence or progression on gadolinium-enhanced magnetic resonance imaging after failing conventional radiotherapy and surgery for initial disease. Histology reviewed by a neuropathologist was required to show anaplastic glioma (anaplastic astrocytoma, anaplastic oligodendroglioma, or mixed anaplastic oligoastrocytoma) or glioblastoma multiforme.

INTERVENTIONS

Patients were treated with temozolomide (200 mg/m(2) per day for the first 5 days of a 28-day cycle for four cycles) and monitored clinically every month and radiologically (gadolinium magnetic resonance imaging) at 6 months.

MAIN OUTCOME MEASURES

Six-month progression-free survival and objective response rate.

RESULTS

Twenty-two patients with recurrent malignant glioma were recruited between January 2001 and July 2004. Progression-free survival at 6 months was 54.5%. The mean progression-free survival for all patients was 7.2 months. The objective response rate, determined by gadolinium magnetic resonance imaging, was 9% for patients demonstrating a complete or partial response and a further 45% for patients demonstrating stable disease. Temozolomide was well tolerated orally with minimal adverse events. CONCLUSION. Preliminary results showed that temozolomide had an acceptable safety profile and anti-tumour activity in recurrent malignant glioma in local Chinese population. The results were comparable with those of western studies.

Tissue plasminogen activator expression in meningiomas and glioblastomas

OBJECTIVES

Enzyme-linked immunosorbent assay (ELISA) and Western blotting techniques were used to investigate and compare the expression of tissue plasminogen activator (tPA) in benign (meningioma) and malignant (glioblastoma) human brain tumours.

METHODS

A total of 22 tumour samples comprising 11 meningiomas and 11 glioblastomas with adjacent peritumoural tissue were analysed.

RESULTS

The mean tPA content of meningiomas was approximately half that of glioblastomas (55.40 (S.D. 34.58) versus 106.98 (S.D. 43.82) ng/ml, p=0.006). Comparing tPA quantity in tumour and peritumoural tissue, there was a significant difference for meningiomas (55.40 (S.D. 34.58) versus 28.35 (S.D. 22.55) ng/ml, p=0.05), but no difference for glioblastomas (106.98 (S.D. 43.82) versus 84.23 (S.D. 57.39) ng/ml, p=0.32). Comparing tumour with normal brain tissue, there was no difference for meningiomas (55.40 (S.D. 34.58) versus 33.08 (S.D. 21.55) ng/ml, p=0.22), but a significant difference for glioblastomas (106.98 (S.D. 43.82) versus 33.08 (S.D. 21.55) ng/ml, p=0.004). Western blotting showed that in the meningioma group, the molecular weight pattern was constant with a dominant well-defined band at 41kD. Peritumoural tissue demonstrated two bands, with the stronger band at 41kD and a slightly weaker band at 71kD. In the glioblastoma group, there was more heterogeneity, with a dominant 41kD band found in all tumour and peritumoural samples, together with additional bands at 34, 58 and 66kD.

CONCLUSION

These results indicate that (1) tPA is present in larger quantities in glioblastoma compared to meningioma and normal brain, (2) tPA quantity is not significantly different in the peritumoural tissue adjacent to glioblastoma but is significantly less for meningioma, and (3) tPA is expressed in more heterogenous forms in glioblastoma. This present study therefore suggests that the expression of tPA in a brain tumour may be an additional prognostic factor in terms of its malignant and invasive potential.

Spinal shock in spontaneous cervical spinal epidural haematoma

A young man presented with quadriparesis and spinal shock because of a spontaneous cervical spinal epidural haematoma was reported. Immediate MRI diagnosis followed by emergency decompression with six hours of presentation resulted in complete recovery.

How useful is glucose detection in diagnosing cerebrospinal fluid leak? The rational use of CT and Beta-2 transferrin assay in detection of cerebrospinal fluid fistula

BACKGROUND

This report describes the sensitivity and specificity of glucose detection using Glucostix test strips and computed tomography (CT) of the skull base for confirming cerebrospinal fluid (CSF) fistulae in patients with persistent rhinorrhoea or otorrhoea, and comparing them with the beta-2 transferrin assay as the gold standard for CSF detection.

METHODS

Fluid samples from the nose were collected from 18 patients with suspected CSF fistulae. The samples were assayed for beta-2 transferrin using the Western blotting and immunostaining technique. CT (5mm axial slice) of the skull base was performed for evidence of skull base fracture. The glucose levels and Glucostix results were compared.

RESULTS

Out of the 18 samples, 15 were positive for beta-2 transferrin adn the leaks were validated surgically in 10 patients. Give leaks healed spontaneously with conservative management. Glucostix tests produced three false positive results from blood and nasal mucus contaminated fluid. Glucostix failed to detect another three CSF leaks resulting from false negative tests because of low CSF glucose levels. The Glucostix glucose test was nonspecific and insensitive compared with the beta-2 transferrin assay. CT failed to detect three of the 15 beta-2 transferrin-positive leaks but there were no false positive results. CT produced six negative results, of which three were false negatives.

CONCLUSIONS

Glucose detection using Glucostix test strips is not recommended as a confirmatory test due to its lack of specificity and sensitivity. In the presence of a skull bas fracture on CT and a clinical CSF leak, there is no need for a further confirmatory test. In cases where a confirmatory test is needed, the beta-2 transferrin assay is the test of choice because of its high sensitivity and specificity.

The use of stereotactic navigation guidance in minimally invasive transnasal nasopharyngectomy: a comparison with the conventional open transfacial approach

The purpose of this paper is to study the efficacy of applying stereotactic navigation guidance to nasopharyngectomy via a minimally invasive transnasal approach as compared with the conventional open transfacial approaches. The nasopharynx is the centre of the anterior skull base, which is remote from the surface of the facial skeleton. It is well known that there are several surgical approaches for access to resect tumours from the nasopharynx. However, the open techniques have been associated with much morbidity and only provide access to, and identification of, the ipsilateral internal carotid artery that forms the lateral boundary and resection limit of the nasopharynx. The coupling of stereotactic navigation guidance and a minimally invasive transnasal approach for nasopharyngectomy allows the surgeon to identify and protect the internal carotid artery bilaterally at the nasopharynx. This technique reduces operating time and morbidity to a minimum and yet is oncologically sound for resecting nasopharyngeal lesions. We compare 15 patients who underwent the stereotactic navigation guidance approach with 20 patients who received a conventional open transfacial approach.