A national audit of current cardiac device policies from radiotherapy centres across the UK.

AIMS: The number of patients with cardiac implantable electronic devices (permanent pacemakers and implantable cardioverter defibrillators) undergoing radiotherapy treatment is increasing. The aims of this audit were to establish current UK practice regarding the management of patients with implanted cardiac devices undergoing radiotherapy and to compare this practice with current 'gold standard' evidence-based guidelines. MATERIALS AND METHODS: All UK radiotherapy departments were contacted and asked to provide their current cardiac implantable electronic device policy or to indicate if there was no current policy. A proforma was created to analyse these policies and to compare with current best practice. RESULTS: In total, 47/67 (70%) radiotherapy departments responded and 45 departmental policies were submitted; 31/45 (69%) policies defined the radiotherapy tolerance dose to permanent pacemakers and 14/45 (31%) defined the monitoring procedure for patients in line with current best practice. Only 5/45 (11%) policies defined the radiotherapy tolerance dose to implantable cardioverter defibrillators and 12/45 (27%) defined the monitoring procedure in line with current best practice. CONCLUSION: Most UK cardiac device policies do not reflect current best evidence. Policies are based on research carried out in 1994 by the American Association of Physicists in Medicine. This evidence does not account for advances in cardiac implantable electronic device technology. Further research is urgently needed to establish the effect of radiotherapy on these devices.

Basic materials physics of transparent conducting oxides.

Materials displaying the remarkable combination of high electrical conductivity and optical transparency already from the basis of many important technological applications, including flat panel displays, solar energy capture and other opto-electronic devices. Here we present the basic materials physics of these important materials centred on the nature of the doping process to generate n-type conductivity in transparent conducting oxides, the associated transition to the metallic (conducting) state and the detailed properties of the degenerate itinerant electron gas. The aim is to fully understand the origins of the basic performance limits of known materials and to set the scene for new or improved materials which will breach those limits for new-generation transparent conducting materials, either oxides, or beyond oxides.

A comparison of the techniques of secondary ion mass spectrometry and resonance ionization mass spectrometry for the analysis of potentially toxic element accumulation in neural tissue.

A comparison is made of the techniques of secondary ion mass spectrometry (SIMS) and resonance ionization mass spectrometry (RIMS) for the detection of the neuro-toxic element aluminium in cortical tissue. Experiments were performed using a reflectron-type time-of-flight mass spectrometer (TOFMS) in conjunction with an Ar+ source for target sputtering and a pulsed tuneable dye laser system for resonance ionization. It is shown how isobaric interference of species such as CNH and C2H3 in the case of aluminium greatly affect the quantitative accuracy and the detection limit of aluminium in biological samples when analysed using SIMS. In contrast the use of RIMS virtually eliminates this problem, so allowing easier quantification and much lower detection limits to be achieved. Detection limits of approximately 3 ppm for aluminium in brain tissue homogenates were achieved using RIMS, with a spatial resolution of less than 100 microns.