PURPOSE: To evaluate the utility of relatively low-dose megavoltage computed tomography (MVCT) images from a clinical helical tomotherapy system for setup verification purposes. METHODS AND MATERIALS: Cross-sectional kilovolt computed tomography (kVCT) images were obtained for treatment planning purposes on a diagnostic third-generation CT scanner, followed by MVCT images from a helical tomotherapy system in 8 pet dogs with spontaneously occurring tumors. The kVCT and MVCT images were aligned for setup verification purposes, allowing repositioning before treatment delivery. RESULTS: Tumors are readily visualized on the MVCT images. At a dose of 2-3 cGy, the MVCT images are of sufficient quality for verification of treatment setup, but soft-tissue contrast is inferior to that with conventional kVCT. The MV and kVCT images were successfully aligned. When necessary, patients undergoing helical tomotherapy were repositioned before treatment. CONCLUSIONS: Megavoltage CT image quality is sufficient for tumor identification and three-dimensional setup verification in dogs with spontaneous tumors. The MVCT images can be aligned with the planning kVCT to ensure proper patient registration before treatment. Image alignment was successful in these canine patients, despite no skin markings defining patient positioning between the two scans. MVCT images facilitate setup verification, and their tomographic nature offers improvements over conventional portal imaging.
PURPOSE: To evaluate the utility of relatively low-dose megavoltage computed tomography (MVCT) images from a clinical helical tomotherapy system for setup verification purposes. METHODS AND MATERIALS: Cross-sectional kilovolt computed tomography (kVCT) images were obtained for treatment planning purposes on a diagnostic third-generation CT scanner, followed by MVCT images from a helical tomotherapy system in 8 pet dogs with spontaneously occurring tumors. The kVCT and MVCT images were aligned for setup verification purposes, allowing repositioning before treatment delivery. RESULTS:Tumors are readily visualized on the MVCT images. At a dose of 2-3 cGy, the MVCT images are of sufficient quality for verification of treatment setup, but soft-tissue contrast is inferior to that with conventional kVCT. The MV and kVCT images were successfully aligned. When necessary, patients undergoing helical tomotherapy were repositioned before treatment. CONCLUSIONS: Megavoltage CT image quality is sufficient for tumor identification and three-dimensional setup verification in dogs with spontaneous tumors. The MVCT images can be aligned with the planning kVCT to ensure proper patient registration before treatment. Image alignment was successful in these caninepatients, despite no skin markings defining patient positioning between the two scans. MVCT images facilitate setup verification, and their tomographic nature offers improvements over conventional portal imaging.
Authors: Jessica A Lawrence; Lisa J Forrest; Michelle M Turek; Paul E Miller; T Rockwell Mackie; Hazim A Jaradat; David M Vail; Richard R Dubielzig; Richard Chappell; Minesh P Mehta Journal: Vet Radiol Ultrasound Date: 2010 Sep-Oct Impact factor: 1.363
Authors: Deshan Yang; Summer R Chaudhari; S Murty Goddu; David Pratt; Divya Khullar; Joseph O Deasy; Issam El Naqa Journal: Med Phys Date: 2009-02 Impact factor: 4.071
Authors: Lyndsay N Kubicek; Songwon Seo; Richard J Chappell; Robert Jeraj; Lisa J Forrest Journal: Vet Radiol Ultrasound Date: 2012-06-25 Impact factor: 1.363