Publishing Title: Evaluation of the Systematic Accuracy of Cutting Edge Technology for Stereotactic Radiosurgery

Treatment Session title: Physics 1 - Innovative Planning and Delivery

StrategiesDate/Time: 2014-09-16 13:00

Location: Room D-1Monitor number: 3

Ning WenDepartment of Radiation Oncology

Henry Ford Health System2799 W. Grand Blvd

Detroit, MI48202

The Edge system at Henry Ford

E: 6XFFF, 10XFFF2.5XFFF, HD120MLC

MV DetectoraS1200, 43x43 cm2

Calypso

PerfectPitch® 6D Couch

OSMS x 3

IR camera

Calypso x 3

EDGE E2E Phantom (Prototype) Outer cube dimensions: 15 x 15 x 15 cm3,

density 0.45 g/cm3

Trackable using– kV, MV radiographic imaging (16x 5mm diameter

BB’s made of ceramics Al2O3)– CBCT (densities: 0.25, 0.45, 1.05 and 1.42 g/cm3)– Calypso (Beacon® transponders are not

removable)– OSMS

Interchangable inner cubes (7 x 7 x 7 cm3)– Single film plane for all 3 orthogonal isocenter

planes, density=1.05 g/cm3

– Two orthogonal film planes, density=1.05 g/cm3

– 5 mm diameter tungsten BB in center (W-L test)

Mechanical accuracy < 5/100 mm

Image Courtesy from Varian

Winston Lotz Test ResultsGantry Rotation Gantry-Collimator-Couch Rotation

 Central

BB56.5 mm

BB65 mm

BB92 mm

BB

Mean 0.30 0.44 0.52 0.47

Std 0.08 0.19 0.13 0.15Max 0.44 0.71 0.84 0.65Min 0.17 0.14 0.43 0.25

 Central

BB56.5 mm

BB65 mm

BB92 mm

BB

Mean 0.56 0.51 0.62 0.63

Std 0.24 0.24 0.43 0.35Max 0.84 0.80 1.18 1.18Min 0.16 0.20 0.05 0.20

Multiple Targets Single Isocenter Test

Auto + Manual Auto

Summary

Coincidence of isocenters of the imaging systems and Linac is within 1 mm.

The localization accuracy of the Edge platform can achieve submillimeter level.

The targeting accuracy for multiple lesions with shared isocenter is promising. However lesion size and the distance from the isocenter should be evaluated before planning.

Other factors (CT, MR, imaging fusion, contour, tumor motion) should be considered in the SRS/SBRT treatment.