文摘
Purpose/Objective: Linac based stereotactic radiosurgery (SRS) may be performed with a wide range of flexibility, and overall treatment times vary substantially between institutions with respect to the number of arcs, isocenters, and couch rotations employed. At the present time protocols (RTOG 93-05) for SRS do not provide for a treatment delivery time requirement. However, variations in SRS treatment plans may not be biologically iso-effective when a great deal of time is required for intermittent treatment delivery with a large number of arcs, isocenters, and couch angles versus a continuous single isocenter treatment with a gamma knife. The intent of this research is to quantify the decreased toxicity of intermittent radiation exposures and permit the delivery of a biologically iso-effective dose.