AbstractID: 9689 Title: Integrated Cone-Beam CT Imaging and Volumetric Guidance System for High-Precision
Radiotherapy of the Prostate
Advanced image-guidance techniques promise to revolutionize external beam radiation therapy of prostate cancer through dramatic improvement in
geometric precision and the possibility for novel dose escalation and fractionation techniques. A milestone critical to the adoption of image-guided
radiotherapy into the clinical setting is the streamlining and optimization of the image acquisition and feedback to the delivery system. With an x-ray
volume imaging system (flat-panel cone-beam CT) integrated with a medical linear accelerator combined with fast reconstruction and data transfer this
goal is being realized in our clinic using a pre-clinical research prototype. Building upon an existing protocol for image-guidance developed at our clinic
over the last 5 years using implanted fiducial markers and MV imaging with an EPID system, the new process provides significant enhancement through
the acquisition of a kV volumetric image following patient setup and immobilization. The imaging system is controlled by an “Acquisition Wizard” that
streamlines image capture and reconstruction. The volume reconstruction is automatically loaded by a commercial planning system for registration of soft
tissue anatomy with the planned treatment volume, making the power and flexibility of such tools available on-line. The subsequent registration yields a
3D estimate of the necessary correction for manual adjustment of the treatment couch and this shift is verified through on-line monitoring. The current
prototype achieves the functionality and timing constraints laid out in the design process.
This work is supported by NIH/NIA AG19381 and Elekta Oncology Systems Synergy RP Research Consortium