Curative-Intent Radiotherapy for Squamous Cell Carcinoma of the Head and Neck in Sri Lanka: The Impact of Radiotherapy Technique on Survival.

AIMS: We conducted a retrospective analysis of patients with squamous cell carcinoma of the head and neck (SCCHN) treated with curative-intent radiotherapy at the National Cancer Institute of Sri Lanka to determine the impact of the treatment technique on disease-free survival (DFS). MATERIALS AND METHODS: SCCHN patients treated with radical radiotherapy or adjuvant postoperative radiotherapy from 2016 to 2017 were included in the study. Data on the following variables were collected by reviewing clinical and radiotherapy treatment records: age, gender, tumour site, stage, time to delivery of radiotherapy, use of neoadjuvant chemotherapy, use of concurrent radiosensitising chemotherapy and treatment technique. DFS, defined as the time to death, tumour recurrence or loss to follow-up, was the primary end point and outcomes were compared between patients treated with intensity-modulated radiotherapy (IMRT) in linear accelerators and those treated with conventional radiotherapy in cobalt teletherapy units. Univariate and multivariate analyses were carried out on known prognostic variables. RESULTS: In total, 408 patients were included in the study, with 138 (34%) being treated with IMRT in the linear accelerator. More than 75% of patients were of stage III or IV at diagnosis. The 2-year DFS of the whole cohort was 25% (95% confidence interval 21-30%). Patients treated with IMRT in the linear accelerator had a superior DFS in comparison with those treated with conventional radiotherapy in the cobalt teletherapy units (P < 0.001, hazard ratio 0.64, 95% confidence interval 0.5-0.82). Higher stage, cobalt treatment and use of neoadjuvant chemotherapy were adversely associated with DFS on multivariate analysis. CONCLUSION: A large proportion of patients with SCCHN treated with curative-intent radiotherapy in Sri Lanka had locally advanced disease and DFS was superior in patients treated with IMRT in the linear accelerator.

Fabrication of Al-TiO2 Thin Film Electrode by Spray Pyrolysis Technique for Urea Sensing.

A simple cost effective Al-TiO2 thin film electrode was fabricated for urea sensing. Urea is the key end product of nitrogen metabolism in humans. Increased level of urea leads to loss of kidney function. Thus determination of urea is important in analysis of kidney diseases. Al-TiO2 thin films were deposited with different concentration of Al by Spray pyrolysis technique. The X-ray diffraction (XRD) pattern reveals the anatase phase of the Al-TiO2 thin films with tetragonal structure. A shift is observed in the XRD peak position compared to as prepared TiO2 thin film indicates the incorporation of Al ions into Ti ions. The UV-Vis spectroscopy study shows that the absorption increases and the absorption peak shifts towards the visible region for Al-TiO2 thin films compared with that of the as prepared TiO2 thin film. The optical band gap values changes with the change in the Al concentration in TiO2 thin films. The electrochemical analysis for optimized Al-TiO2 thin film electrode was carried out by cyclic voltammetry (CV) method. CV studies of Al-TiO2 thin film electrode show the good stability and linearity which is essential to fabricate biosensor. The sensor response to urea is linear with correlation coefficient of 0.944 and the sensitivity is 3.17 µA mM-1 cm-2.