BEBIG Ruthenium-106 ophthalmic plaques have been used for treatment of uveal melanoma, retinoblastoma, melanoma of the iris and other special applications for many years. The plaques consist of a thin film of Ru, a beta emitter, encapsulated in pure silver. The present work proposes a new mathematical eye model for ophthalmic brachytherapy dosimetry. This new model includes detailed description...

BACKGROUND To identify dose-volume parameters predictive for severity of acute esophagitis (CTC > grade 2) in locally-advanced non small-cell lung cancer (LA-NSCLC) patients treated with neoadjuvant concurrent hyperfractionated-accelerated chemoradiotherapy (HA-CRT) a retrospective analysis was performed. 88 patients were treated with HA-CRT followed by radical surgery. Predictive power of abso...

Background: External beam radiotherapy and brachytherapy plays a vital role in the management of cancer cervix.  High dose rate brachytherapy is being presently used worldwide for the brachytherapy applications. At present, 2-Dimensional linear array detectors   are the most common QA tool used for pretreatment patient specific quality assurance in external beam radiotherapy alon...

PURPOSE During intracavitary brachytherapy (ICBT) for cervical cancer, the choice of applicator system remains rather arbitrary. However, as the applicator geometry may play an important role in dose distribution, thereby improving the therapeutic ratio, this study was conducted to compare the Manchester-style and Fletcher-style applicator systems. MATERIAL AND METHODS After completion of EBR...

An experimental brachytherapy model has been developed to study acute and late normal tissue reactions as a tool to examine the effects of clinically relevant multifractionation schedules. Pig skin was used as a model since its morphology, structure, cell kinetics and radiation-induced responses are similar to human skin. Brachytherapy was performed using a microSelectron high dose rate (HDR) a...

HDR brachytherapy treatment planning often involves optimization methods to calculate the dwell times and dwell positions of the radioactive source along specified afterloading catheters. The purpose of this study is to compare the dose distribution obtained with geometric optimization (GO) and volume optimization (VO) combined with isodose reshaping. This is a retrospective study of 10 cervix ...

PURPOSE The goals of stereotactic radiosurgery (SRS) are the ablation of target tissue and sparing of critical normal tissue. We develop tools to aid in the selection of collimation and prescription (Rx) isodose line to optimize the dose gradient for single isocenter intracranial stereotactic radiosurgery (SRS) with GammaKnife 4C utilizing the updated physics data in GammaPlan v10.1. METHODS ...

In Gamma Knife forward treatment planning, normalization effect may be observed when multiple shots are used for treating large lesions. This effect can reduce the proportion of coverage of high-value isodose lines within targets. The aim of this study was to evaluate the performance of forward treatment planning techniques using the Leksell Gamma Knife for the normalization effect reduction. W...

We construct unramified central simple algebras representing 2-torsion classes in the Brauer group of a hyperelliptic curve, and show that every 2-torsion class can be constructed this way when the curve has a rational Weierstrass point or when the base field is C1. In general, we show that a large (but in general proper) subgroup of the 2torsion classes are given by the construction. Examples ...

In this brief note, we prove the following two Artin-Schreier curves are supersin-gular.