Medical Specialties Commons^™

A Measure Of Srs/Srt Plan Quality: Quantitative Limits For Intermediate Dose Spill (R50%) In Linac-Based Delivery, Dharmin D. Desai, Ivan L. Cordrey, Ellis L. Johnson

Radiation Medicine Faculty Publications

Stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) of multiple cranial targets using a single isocenter on conventional C-arm linear accelerators are rapidly developing clinical techniques. However, no universal guidelines for acceptable intermediate dose spill limits are currently available or widely accepted. In this work, we propose an intermediate dose spill guidance range for cranial SRS/SRT delivered on C-arm linacs with MLC collimation for single PTV plans and single isocenter multiple target plans with PTV volumes in the range 0.02–57.9 cm³. We quantify intermediate dose spill with the R50% metric (R50% = volume of 50% of prescription isodose cloud …

Feasibility Of Using Ring-Mounted Halcyon Linac For Single-Isocenter/Two-Lesion Lung Stereotactic Body Radiation Therapy, Damodar Pokhrel, Aaron Webster, Richard Mallory, Justin Visak, Mark E. Bernard, Ronald C. Mcgarry, Mahesh Kudrimoti

Radiation Medicine Faculty Publications

PURPOSE: To demonstrate the plan quality and delivery efficiency of volumetric-modulated arc therapy (VMAT) with the Halcyon Linac ring delivery system (RDS) in the treatment of single-isocenter/two-lesion lung stereotactic body radiation therapy (SBRT).

MATERIALS/METHODS: Sixteen previously treated non-coplanar VMAT single-isocenter/two-lesion lung SBRT plans delivered with SBRT-dedicated C-arm TrueBeam Linac were selected. Prescribed dose was 50 Gy to each lesion over five fractions with treatment delivery every other day and AcurosXB algorithm as the final dose calculation algorithm. TrueBeam single-isocenter plans were reoptimized for Halcyon Linac with coplanar geometry. Both TrueBeam and Halcyon plans were normalized for identical combined target coverage …