Radiobiological model-based bio-anatomical quality assurance in intensity-modulated radiation therapy for prostate cancer.

A bio-anatomical quality assurance (QA) method employing tumor control probability (TCP) and normal tissue complication probability (NTCP) is described that can integrate radiobiological effects into intensity-modulated radiation therapy (IMRT). We evaluated the variations in the radiobiological effects caused by random errors (r-errors) and systematic errors (s-errors) by evaluating TCP and NTCP in two groups: patients with an intact prostate (G(intact)) and those who have undergone prostatectomy (G(tectomy)). The r-errors were generated using an isocenter shift of ±1 mm to simulate a misaligned patient set-up.

Calculation of patient effective dose and scattered dose for dental mobile fluoroscopic equipment: application of the Monte Carlo simulation.

The objective of this study was to evaluate the patient effective dose and scattered dose from recently developed dental mobile equipment in Korea. The MCNPX 2.6 (Los Alamos National Laboratory, USA) was used in a Monte Carlo simulation to calculate both the effective and scattered doses.

Dose area product measurement for diagnostic reference levels and analysis of patient dose in dental radiography.

In this study, diagnostic reference levels (DRLs) were suggested and patient doses were analysed through the dose-area product value in dental radiography. In intraoral radiography, at three sites, i.e.

Dose evaluation of selective collimation effect in cephalography by measurement and Monte Carlo simulation.

Recently, simulations based on the Monte Carlo code have been increasingly applied for physics phenomena, patient dose and quality assurance of radiation systems. The objective of this study was to use Monte Carlo simulation and measurement to verify dose and dose reduction in cephalography. The collimator was constructed with 3-mm thick lead plate, and attached to the tube head to remove regions of disinterest in the radiation field.

The characteristics of dental X-ray fluoroscopic equipment 'DreamRay 60F'.

This study examined the characteristics of the dental X-ray fluoroscopic equipment, 'DreamRay 60F', which was recently developed in Korea. The output linearity, output reproducibility, half-value layer (HVL), leakage radiation and scattered radiation were measured using an ionisation chamber. The surface dose equivalent rate and estimated dose equivalent of the operator were also calculated.

The development of a guidance level for patient dose for CT examinations in Korea.

The primary goal of this study was to analyse the state of patient doses in the field of computed tomography (CT) examinations in the Republic of Korea. All survey data including the CT applications and patient dose details were obtained from general hospitals registered in the Korean Hospital Association. The systematic analysis of the patient dose survey gives target values of the weighted computed tomography dose index (CTDI(w)) and the dose-length product (DLP).

Suppressed production of pro-inflammatory cytokines by LPS-activated macrophages after treatment with Toxoplasma gondii lysate.

During Toxoplasma gondii infection, macrophages, dendritic cells, and neutrophils are important sources of pro-inflammatory cytokines from the host. To counteract the pro-inflammatory activities, T. gondii is known to have several mechanisms inducing down-regulation of the host immunity.

The development of a diagnostic reference level on patient dose for CT examination in Korea.

The purpose of this research is to develop a diagnostic reference level for computed tomography (CT) suitable for Korean medical purposes. The direction of CT application and details on patient dose were investigated by survey, and the dose measurement is targeted in general hospitals registered with the Korean Hospital Association. The dose measurement was done with head and body phantom, and an accurate dosimeter was utilised in medical institutions that participated in the survey.

Patient dose measurements in diagnostic radiology procedures in Korea.

This study is the first nationwide investigation aimed at estimating the patient dose for radiographic examinations in Korea including gastrointestinal studies, computed tomography and mammography. The survey data from 161 hospitals and the dose data from 32 hospitals were analysed. The third quartile entrance surface dose, dose area product (DAP), weighted CT dose index (CTDIw) and mean glandular dose (MGD) were reported.

Involvement of MAPK activation in chemokine or COX-2 productions by Toxoplasma gondii.

This experiment focused on MAPK activation in host cell invasion and replication of T. gondii, as well as the expression of CC chemokines, MCP-1 and MIP-1 alpha , and enzyme, COX-2/prostaglandin E2 (PGE2) in infected cells via western blot, [3H]-uracil incorporation assay, ELISA and RT-PCR. The phosphorylation of ERK1/2 and p38 in infected HeLa cells was detected at 1 hr and/or 6 hr postinfection (PI).