Radiation Medicine Commons^™

Fast Generation Of Lung Sbrt Plans With A Knowledge-Based Planning Model On Ring-Mounted Halcyon Linac, Justin Visak, Aaron Webster, Mark E. Bernard, Mahesh R. Kudrimoti, Marcus E. Randall, Ronald C. Mcgarry, Damodar Pokhrel

Radiation Medicine Faculty Publications

PURPOSE: To demonstrate fast treatment planning feasibility of stereotactic body radiation therapy (SBRT) for centrally located lung tumors on Halcyon Linac via a previously validated knowledge-based planning (KBP) model to support offline adaptive radiotherapy.

MATERIALS/METHODS: Twenty previously treated non-coplanar volumetric-modulated arc therapy (VMAT) lung SBRT plans (c-Truebeam) on SBRT-dedicated C-arm Truebeam Linac were selected. Patients received 50 Gy in five fractions. c-Truebeam plans were re-optimized for Halcyon manually (m-Halcyon) and with KBP model (k-Halcyon). Both m-Halcyon and k-Halcyon plans were normalized for identical or better target coverage than clinical c-Truebeam …

Predicting The Effect Of Indirect Cell Kill In The Treatment Of Multiple Brain Metastases Via Single-Isocenter/Multitarget Volumetric Modulated Arc Therapy Stereotactic Radiosurgery, Allison N. Palmiero, Denise Fabian, Marcus E. Randall, William St. Clair, Damodar Pokhrel

Radiation Medicine Faculty Publications

PURPOSE: Due to spatial uncertainty, patient setup errors are of major concern for radiosurgery of multiple brain metastases (m-bm) when using single-isocenter/multitarget (SIMT) volumetric modulated arc therapy (VMAT) techniques. However, recent clinical outcome studies show high rates of tumor local control for SIMT-VMAT. In addition to direct cell kill (DCK), another possible explanation includes the effects of indirect cell kill (ICK) via devascularization for a single dose of 15 Gy or more and by inducing a radiation immune intratumor response. This study quantifies the role of indirect cell death in dosimetric errors as a function of spatial patient setup uncertainty …

Computer Automation For Physics Chart Check Should Be Adopted In Clinic To Replace Manual Chart Checking For Radiotherapy, Edward L. Clouser, Quan Chen, Yi Rong

Radiation Medicine Faculty Publications

No abstract provided.

An Analytical Expression For R50% Dependent On Ptv Surface Area And Volume: A Cranial Srs Comparison, Dharmin D. Desai, Ellis Lee Johnson, Ivan L. Cordrey

Radiation Medicine Faculty Publications

The intermediate dose spill for a stereotactic radiosurgery (SRS) plan can be quantified with the metric R50%, defined as the 50% isodose cloud volume (V_IDC50%) divided by the volume of the planning target volume (PTV). By coupling sound physical principles with the basic definition of R50%, we derive an analytical expression for R50% for a spherical PTV. Our analytical expression depends on three quantities: the surface area of PTV (SA_PTV), the volume of PTV (V_PTV), and the distance of dose drop-off to 50% (Δr). The value of ∆r was obtained from a simple set …

A Novel And Clinically Useful Dynamic Conformal Arc (Dca)-Based Vmat Planning Technique For Lung Sbrt, Damodar Pokhrel, Justin Visak, Lana Sanford

Radiation Medicine Faculty Publications

PURPOSE: Volumetric modulated arc therapy (VMAT) is gaining popularity for stereotactic treatment of lung lesions for medically inoperable patients. Due to multiple beamlets in delivery of highly modulated VMAT plans, there are dose delivery uncertainties associated with small-field dosimetry error and interplay effects with small lesions. We describe and compare a clinically useful dynamic conformal arc (DCA)-based VMAT (d-VMAT) technique for lung SBRT using flattening filter free (FFF) beams to minimize these effects.

MATERIALS AND METHODS: Ten solitary early-stage I-II non-small-cell lung cancer (NSCLC) patients were treated with a single dose of 30 Gy using 3-6 non-coplanar VMAT arcs (clinical …