3-D Conformal Volumetric Alignment of Savi® Applicator Using Cone Beam Imaging Technique

We report a novel technique to confirm volumetric alignment of the SAVI® (Strut-Adjusted Volume Implant) applicator by utilizing fiducial markers embedded within the struts of the applicator. The technique compares Treatment Planning Cone Beam Images with daily, pre-treatment Cone Beam CT (CBCT) images obtained using the imaging option on a linear accelerator. The accelerator vault is also used for delivering High Dose Rate radiation treatment using Ir-192 source in a Nucletron after-loader immediately following matching of CBCT images. This allows for rapid verification of the correct position of SAVI Catheters without having to move patient when delivering HDR therapy.