The purpose of this paper is to present the dosimetry and mechanical accuracy of the first rotating gamma system (RGS) installed in North America for stereotactic radiosurgery. The data were obtained during the installation, acceptance test procedure, and commissioning of the unit. The RGS unit installed at UC Davis Cancer Center (RGSu) has modifications on the source and collimator bodies from...

PURPOSE Hypofractionated radiotherapy can reduce treatment durations and produce effects identical to those of conventionally fractionated radiotherapy for treating prostate cancer. Volumetric arc radiotherapy (VMAT) can decrease the treatment machine monitor units (MUs). Previous studies have shown that VMAT with multileaf collimator (MLC) rotation exhibits better target dose distribution. Thu...

Treatment of small animals with radiation has in general been limited to planar fields shaped with lead blocks, complicating spatial localization of dose and treatment of deep-seated targets. In order to advance laboratory radiotherapy toward what is accomplished in the clinic, we have constructed a variable aperture collimator for use in shaping the beam of microCT scanner. This unit can image...

To develop a second generation gamma-ray camera for industrial applications, various multiple-hole collimator designs that meet high-energy, high-intensity and far-eld imaging requirements have been studied. The collection of parallel holes each parallel to one another (parallel-hole, parallel collimator) is ineeective for imaging high energy far-eld sources, whereas a collimator with parallel ...

We summarize the formalism of collimator wakefields and their effect on beams that are near the center of the collimator gap, and apply the formalism to the TESLA, NLC, and CLIC collimation systems. Collimator Wakefield Calculations for ILC-TRC Report

UNLABELLED In SPECT using high-energy photon-emitting isotopes, such as (131)I, parallel-hole collimators with thick septa are required to limit septal penetration, at the cost of sensitivity and resolution. This study investigated a parallel-hole collimator with cone-shaped holes, which was designed to limit collimator penetration while preserving resolution and sensitivity. The objective was ...