Pharmacists and their effectiveness in ensuring the appropriateness of the chronic medication regimens of geriatric inpatients.

Objective: Geriatric patients are prescribed multiple medications by multiple physicians, leaving them at an increased risk for adverse events. The Beers criteria for determining inappropriately prescribed medications have been applied to elderly patients in various geriatric settings. Using the 1997 Beers criteria, we planned to determine if the Acute Care for Elders (ACE) team pharmacist improved the medication regimens of geriatric inpatients.

Simulation of Compton camera imaging with a specific purpose Monte Carlo code.

A specific purpose Monte Carlo model that treats the physical processes of image formation in Compton cameras is presented. Features of the model include: detailed Compton scattering physics, including incoherent scattering functions and Doppler broadening; multiple scattering; and peak detector response functions. Calculation efficiency is enhanced by making every history result in a partial success through the extensive use of pathway sampling variance reduction techniques.

A comparison of different intensity modulation treatment techniques for tangential breast irradiation.

Purpose: Several intensity modulation (IM) treatment techniques for tangential breast irradiation were evaluated in terms of dose uniformity in the treated breast volume, contralateral breast dose, and treatment irradiation time.

Methods And Materials: Contralateral breast dose was measured via TLD chips, and the dose uniformity was calculated on two anthropomorphic phantoms. IM was applied to all beams or to the lateral-medial (LM) beam only.

Modulation transfer function for a large-area amorphous silicon image receptor.

The modulation transfer function (MTF) of an amorphous silicon (aSi) sensor array was measured using proper sampling techniques to determine the edge spread function (ESF). The detector under study was a 10 cm2 area detector (EG&G Heimann, RTM128) consisting of 128 x 128 aSi photodiodes arranged in a square array. Two independent methods for calculating the presampling MTF were implemented, based on finely sampling the ESF measurements produced using 40 kV x-rays from a Faxitron microfocal spot x-ray tube.

Benchmark test cases for evaluation of computer-based methods for detection of setup errors: realistic digitally reconstructed electronic portal images with known setup errors.

Purpose: The purpose of this investigation was to develop methods and software for computing realistic digitally reconstructed electronic portal images with known setup errors for use as benchmark test cases for evaluation and intercomparison of computer-based methods for image matching and detecting setup errors in electronic portal images.

Methods And Materials: An existing software tool for computing digitally reconstructed radiographs was modified to compute simulated megavoltage images. An interface was added to allow the user to specify which setup parameter(s) will contain computer-induced random and systematic errors in a reference beam created during virtual simulation.

Core-based portal image registration for automatic radiotherapy treatment verification.

Purpose: Portal imaging is the most important quality assurance procedure for monitoring the reproducibility of setup geometry in radiation therapy. The role of portal imaging has become even more critical in recent years due to the migration of three-dimensional (3D) treatment planning technology, including high-precision conformal therapy, from the research setting to routine clinical practice. Unfortunately, traditional methods for acquiring and interpreting portal images suffer from a number of deficiencies that contribute to the well-documented observation that many setup errors go undetected, and some persist for a clinically significant portion of the prescribed dose.