Detection and accurate quantification of treatment delivery errors is important in radiation therapy. This study aims to evaluate the accuracy of DVH based QA in quantifying delivery errors. Eighteen previously treated VMAT plans (prostate, H&N, and brain) were randomly chosen for this study. Conventional IMRT delivery QA was done with the ArcCHECK diode detector for error-free plans and plans ...

A novel approach for shape preserving contrast enhancement is presented in this paper. Contrast enhancement is achieved by means of a local histogram equalization algorithm which preserves the level-sets of the image. This basic property is violated by common local schemes, thereby introducing spurious objects and modifying the image information. The scheme is based on equalizing the histogram ...

A radiobiologically based 3D model of normal tissue has been developed in which complications are generated when 'irradiated'. The aim is to provide insight into the connection between dose-distribution characteristics, different organ architectures and complication rates beyond that obtainable with simple DVH-based analytical NTCP models. In this model the organ consists of a large number of f...

There are no records in Brazil for the culture of Pteridae family oysters, genus Pteria and Pinctada. The intermediate culture can be considered one of the critical stages during the oyster farming. The changes in life conditions from a semi-closed environment provided by the collector to the structures utilized for the growth represents a considerable stress factor to which the animals are sub...

Radiation quality indices (QI), tumor control probability (TCP), and normal tissue complication probability(NTCP) were evaluated for ideal single and double plane HDR interstitial implants. In the analysis, geometrically-optimized at volume (GOV) treatment plans were generated for different values of inter-source-spacing (ISS) within the catheter, inter-catheter-spacing (ICS), and inter-plane-s...

The purpose of the study was to investigate the potential of direct machine parameter optimization (DMPO) to achieve parotid sparing without compromising target coverage in IMRT of oropharyngeal cancer as compared to fluence modulation with subsequent leaf sequencing (IM) and forward planned 2-step arc therapy (IMAT). IMRT plans were generated for 10 oropharyngeal cancer patients using DMPO and...

Introduction: The high local control rates observed in patients with breast cancer who had been treated by modified radical mastectomy, chemotherapy and chest-wall irradiation using 120 kV X-rays (50 Gy in 25 fractions) motivated us to investigate their observed tumor control probability (TCP) and test a well-established radiobiological TCP model against our data. Mat...