Evaluation of stereotactic radiosurgery conformity indices for 170 target volumes in patients with brain metastases.

A database of clinically approved stereotactic radiosurgery treatment plans was created. One hundred and seventy targets in the database were then retrospectively evaluated using conformity indices suggested by RTOG, SALT-Lomax and Paddick. Relationships between the three alternative conformity indices were determined.

Experimental validation of the Eclipse AAA algorithm.

The present study evaluates the performance of a newly released photon-beam dose calculation algorithm that is incorporated into an established treatment planning system (TPS). We compared the analytical anisotropic algorithm (AAA) factory-commissioned with "golden beam data" for Varian linear accelerators with measurements performed at two institutions using 6-MV and 15-MV beams. The TG-53 evaluation regions and criteria were used to evaluate profiles measured in a water phantom for a wide variety of clinically relevant beam geometries.

The clinical implementation of a method for calculating the output factor and per cent depth dose for an electron beam.

A modified sector-integration method has been developed that predicts electron beam output factor at any point on the beam central axis, for a given source to surface distance (SSD), as a function of the geometry of the irradiated field. The main concept of this method is that with the arbitrary field shape divided into small sectors, the individual contributions from each sector can be calculated based on the sector radius, using a dataset consisting of circular inserts of standard radii. A computer program was developed based on this algorithm.

Dosimetric characteristics of wedged fields.

The beam characteristics of the wedged fields in the nonwedged planes (planes normal to the wedged planes) were studied for 6 MV and 15 MV x-ray beams. A method was proposed for determining the maximum field length of a wedged field that can be used in the nonwedged plane without introducing undesirable alterations in the dose distributions of these fields. The method requires very few measurements.

Hidden-part suppression on three-dimensional plots.

The conceptual and mathematical description of a method to draw a three-dimensional histographic surface in oblique projection, with the drawing of hidden parts suppressed, is given.