Surgical outcomes of patients with neuroblastoma in a tertiary centre in Hong Kong: A 12-year experience

Introduction: Neuroblastoma has a heterogeneous clinical course. The prognosis varies widely depending on the age of diagnosis, extent of disease and tumour biology. However, the specific clinical outcome of this disease in Hong Kong has not been well characterised thus far. Complete tumour excision has been demonstrated to confer survival benefit on patients with advanced disease even if there is metastasis. Since year 2004, we have adopted a revised, more aggressive surgical approach in managing these patients. Here, we aim to review our experience in the management of this disease. Methods: A retrospective review was performed for the past 12 years to include all patients who presented with neuroblastoma in our institution. Data such as the survival, age at diagnosis, MYCN amplification status, the extent of tumour excision, and stage of the disease were recorded and analysed. Results: 37 patients were included in this study. Overall survival of our patients was 67.6%. Patients with Stage 1, 2 and 4S have 100% survival whereas stage 4 patients only have 41.4% survival. Since our revised surgical approach in 2004, patients who had been operated had a better survival. Survival of stage 4 patients with operation after 2004 was 57.1% whereas the survival of patients at the same stage before 2004 was only 30%. Age at diagnosis, completeness of tumour excision and stage of disease are also correlated with overall prognosis. Further, patients with the presence of MYCN gene amplification have apparently poorer survival but it is not statistically significant due to the small sample size. Conclusion: The management of patients with neuroblastoma remains a challenge. Advanced stage of disease, incomplete tumour excision and increased age at diagnosis were all associated with poor survival. We demonstrated a better survival for those who underwent a more aggressive surgical approach, though this is a technically demanding and time consuming procedure. Thus, the management of advanced neuroblastoma should be centralised in a centre with combined surgical, oncological and paediatric intensive care expertise.published_or_final_versio

Ultrasonic Evaluation of in-Plane and out-of-Plane Elastic Properties of Composite Materials

Evaluation of elastic properties of composite materials using ultrasound is important for the generation of output data for the design of composites. It is also extremely important as a nondestructive tool for quality evaluation of the composites after manufacturing. The problem was addressed in the seventies [1–3] when Markham [1] suggested using the time-delay through transmission technique with obliquely incident ultrasonic waves from water onto a composite plate. The full set of elastic constants was measured later by Kriz and Stinchcomb [4] on samples cut out in different directions from a composite plate. Recently several works have appeared where the set of elastic constants was measured by using Markham’s technique [5–7]

The Doctor as Fuduciaries: Do Doctors Have the Right Not to Treat

Composite structures are often desirable for their strength and weight characteristics. Since composites are not as well characterized mechanically as metallic or ceramic structures, much work has been performed to obtain that characterization and to develop methods of determining the mechanical properties of a composite nondestructively. Most of the work in the literature to date has been performed on nonenclosed structures on which several promising nondestructive evaluation (NDE) techniques have been used to predict the integrity of the composite.1,4 An increased use of composites in enclosed geometries has led to the desire to transfer and further develop the most promising NDE techniques used on nonenclosed geometries to enclosed geometries.5,6 As part of the further development of ultrasonic inspection techniques, a high-speed data-acquisition system has been assembled which digitizes an entire RF signal waveform at each point on a Kevlar-epoxy composite structure. The complete data set of ultrasonic A-scans is then available for analysis of particular features which might ordinarily have been overlooked when only the maximum amplitude is recorded from data in a preset gate. The system provides a three-dimensional view of the data in which either the XY, YZ, or XZ planes can be displayed using pseudo color or gray scale to indicate the maximum signal amplitude in a gate set under program control. Depth information can be displayed on the XY data plane, and various image display techniques can be implemented to enhance certain material or defect conditions