Intensity-modulated radiation therapy (IMRT) quality assurance (QA) is often performed using a 2D device and compares measured and computed fluence maps to determine if a field passes or fails certain dose and position criteria. The effects of a measured deviation to the 3D patient spatial dosimetry and dose volume histogram (DVH) are largely unknown because they cannot be analyzed using commer...

Patients with chronic bronchial asthma show a depressed ventilatory response to hypoxia (DVH), but the underlying mechanism remains unclear. We tested whether DVH existed in ovalbumin (Ova)-treated guinea pigs, an established animal model of asthma. Twelve guinea pigs were exposed to Ova (1% in saline) or saline aerosol (control) for 5 min, 5 days/wk, for 2 wk. After completing aerosol exposure...

The purpose of this study was to evaluate different homogeneity indices for IMRT of head and neck cancers and to suggest the best representative homogeneity index for quantitative measure of dose homogeneity. In this study 3 different homogeneity indices were evaluated for 22 head and neck cancer patients receiving dynamic IMRT treatments on Clinac-DHX linear accelerator with 6 MV photon beam. ...

Intensity-modulated radiation therapy (IMRT) provides the protection of the normal organs and a precise treatment plan through its optimization process. However, the final dose-volume histogram (DVH) obtained by this technique differs from the optimal DVH, owing to optimization convergence errors. Herein, intermediate dose calculation was applied to IMRT plans during the optimization process to...

Current inverse treatment planning methods that optimize both catheter positions and dwell times in prostate HDR brachytherapy use surrogate linear or quadratic objective functions that have no direct interpretation in terms of dose-volume histogram (DVH) criteria, do not result in an optimum or have long solution times. We decrease the solution time of the existing linear and quadratic dose-ba...

Management of mild dyskaryosis remains controversial. In this study, we compared the cost-effectiveness of active versus conservative colposcopic management of women presenting with mild dyskaryosis in two different hospital settings. All women presenting in 2001 with a mild dyskaryotic smear and requiring colposcopy were studied in two different clinical settings (70 women at Darent Valley Hos...

PURPOSE To propose a method of intensity-modulated radiotherapy (IMRT) planning that generates achievable dose-volume histogram (DVH) objectives using a database containing geometric and dosimetric information of previous patients. METHODS AND MATERIALS The overlap volume histogram (OVH) is used to compare the spatial relationships between the organs at risk and targets of a new patient with ...

Sulfate-reducing bacteria (SRB) are anaerobic that form biofilm and induce corrosion on various material surfaces. The quorum sensing (QS) system employs acyl homoserine lactone (AHL)-type QS molecules primarily govern formation. Studies SRB have reported the presence of AHL, but no AHL synthase been annotated in so far. In this computational study, we used a combination data mining, multiple s...

PURPOSE The aim of this report is dosimetric evaluation for an intraoperative fusion computed tomography (CT) as a superior predictor of 1-month CT based dosimetry in comparison to transrectal ultrasound (TRUS) in permanent interstitial prostate brachytherapy. MATERIAL AND METHODS Data of 65 patients treated with seed implantation were analyzed. All procedures has been performed with patients...

The purpose was to study correlations amongst IMRT DVH evaluation points and how their relaxation impacts the overall plan. 100 head-and-neck cancer cases, using the Eclipse treatment planning system with the same protocol, are statisti-cally analyzed for PTV, brainstem, and spinal cord. To measure variations amongst the plans, we use (i) interquartile range (IQR) of volume as a function of dos...