Periodontal disease with treatment reduces subsequent cancer risks.

Aim: The aim of our study was to evaluate the relationship between routine treatment of periodontal disease (PD) and the subsequent risks for cancers in Taiwan.

Methods: Study participants were selected from the Taiwan National Health Insurance (NHI) system database. The PD with a routine treatment cohort contained 38 902 patients.

Calibration of EBT2 film by the PDD method with scanner non-uniformity correction.

The EBT2 film together with a flatbed scanner is a convenient dosimetry QA tool for verification of clinical radiotherapy treatments. However, it suffers from a relatively high degree of uncertainty and a tedious film calibration process for every new lot of films, including cutting the films into several small pieces, exposing with different doses, restoring them back and selecting the proper region of interest (ROI) for each piece for curve fitting. In this work, we present a percentage depth dose (PDD) method that can accurately calibrate the EBT2 film together with the scanner non-uniformity correction and provide an easy way to perform film dosimetry.

Scatter correction for 3D PET using beam stoppers combined with dual-energy window acquisition: a feasibility study.

Fully three-dimensional (3D) positron emission tomography (PET) can achieve high sensitivity of coincidence events, but the absence of inter-slice septa inevitably leads to increased scattered events. The scattered events can represent as much as 50% of the total detected events. In this research, we proposed a scatter correction method for 3D PET based on beam stoppers and dual-energy window acquisition.

Antisense thymidylate synthase electrogene transfer to increase uptake of radiolabeled iododeoxyuridine in a murine model.

Unlabelled: In vitro and in vivo experiments from our laboratory and others have suggested that the combination of thymidylate synthase (TS) inhibitor and radiolabeled iododeoxyuridine (IdUrd) is synergistic. Efficacy is limited by drug resistance, which is often mediated by TS overexpression. We designed an in vivo electrogene transfer (EGT) model for delivering antisense TS plasmid (ATS) into tumor to increase the subsequent efficacy of (131)I-IdUrd therapy.

Quality degradation in lossy wavelet image compression.

The objective of this study was to develop a method for measuring quality degradation in lossy wavelet image compression. Quality degradation is due to denoising and edge blurring effects that cause smoothness in the compressed image. The peak Moran z histogram ratio between the reconstructed and original images is used as an index for degradation after image compression.

A novel image quality index using Moran I statistics.

Measurement of image quality is very important for various applications such as image compression, restoration and enhancement. Conventional methods (e.g.

Determination of beam intensity in a single step for IMRT inverse planning.

In intensity modulated radiotherapy (IMRT), targets are treated by multiple beams at different orientations each with spatially-modulated beam intensities. This approach spreads the normal tissue dose to a greater volume and produces a higher dose conformation to the target. In general, inverse planning is used for IMRT treatment planning.

Comprehensive measurement for clinical dosimetry of tertiary multileaf collimator.

To initiate the use of a tertiary multileaf collimator (MLC) in the clinic, a set of dosimetry data for clinical use of the MLC, the secondary field size jaw and the MLC tracked by the jaw were measured. The dose calculation technique from the commissioned jaw field data was established. The dosimetry characteristics included absolute output (Dw), collimator scatter factor (Sc), total scatter factor (Scp), phantom scatter factor (Sp), percentage depth dose (PDD), tissue-maximum ratio (TMR), and peak scatter factor (PSF).