Original Article
Daily patient setup error in prostate image guided radiation therapy with fiducial-based kilovoltage onboard imaging and conebeam computed tomography Jason C. Ye1,2, Muhammad M. Qureshi1, Pauline Clancy1, Lauren N. Dise1, John Willins1, Ariel E. Hirsch1 1
Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA 02118, USA; 2Department of
Radiation Oncology, New York Presbyterian Hospital/Weill Cornell Medical Center, New York, NY 10065, USA Correspondence to: Jason C. Ye, MD. Department of Radiation Oncology, New York Presbyterian Hospital/Weill Cornell Medical Center, 525 East 68th St, New York, NY 10065, USA. Email: [email protected].
Background: This study examined the interfraction setup error in patients undergoing prostate radiotherapy using fiducial markers and on-board imaging. Methods: Patients (n=53) were aligned to the treatment isocenter by laser followed by orthogonal kilovoltage (kV) radiographs to visualize bony anatomy and implanted fiducial markers. The magnitude and direction of couch shifts for isocenter correction required was determined by image registration for bony anatomy and fiducial markers. Twice weekly, 25 of the 53 patients also underwent conebeam computed tomography (CBCT) to measure any residual error in patient positioning. Based on individual coordinate shifts from CBCT, a net three-dimensional (3D) residual shift magnitude vector R was calculated. Results: The average couch shifts were 0.26 and 0.40 cm in inferior direction and 0.25 and 0.33 cm in superior direction for alignments made with bony anatomy and fiducial markers, respectively (P
Daily patient setup error in prostate image guided radiation therapy with fiducial-based kilovoltage onboard imaging and conebeam computed tomography Jason C. Ye1,2, Muhammad M. Qureshi1, Pauline Clancy1, Lauren N. Dise1, John Willins1, Ariel E. Hirsch1 1
Department of Radiation Oncology, Boston Medical Center and Boston University School of Medicine, Boston, MA 02118, USA; 2Department of
Radiation Oncology, New York Presbyterian Hospital/Weill Cornell Medical Center, New York, NY 10065, USA Correspondence to: Jason C. Ye, MD. Department of Radiation Oncology, New York Presbyterian Hospital/Weill Cornell Medical Center, 525 East 68th St, New York, NY 10065, USA. Email: [email protected].
Background: This study examined the interfraction setup error in patients undergoing prostate radiotherapy using fiducial markers and on-board imaging. Methods: Patients (n=53) were aligned to the treatment isocenter by laser followed by orthogonal kilovoltage (kV) radiographs to visualize bony anatomy and implanted fiducial markers. The magnitude and direction of couch shifts for isocenter correction required was determined by image registration for bony anatomy and fiducial markers. Twice weekly, 25 of the 53 patients also underwent conebeam computed tomography (CBCT) to measure any residual error in patient positioning. Based on individual coordinate shifts from CBCT, a net three-dimensional (3D) residual shift magnitude vector R was calculated. Results: The average couch shifts were 0.26 and 0.40 cm in inferior direction and 0.25 and 0.33 cm in superior direction for alignments made with bony anatomy and fiducial markers, respectively (P
