Publications by authors named "Chibuike Umeh"
Purpose: To develop and demonstrate a comprehensive method to directly measure radiation isocenter uncertainty and coincidence with the cone-beam computed tomography (kV-CBCT) imaging coordinate system that can be carried out within a typical quality assurance (QA) time slot.
Methods: An N-isopropylacrylamide (NIPAM) three-dimensional (3D) dosimeter for which dose is observed as increased electron density in kV-CBCT is irradiated at eight couch/gantry combinations which enter the dosimeter at unique orientations. One to three CBCTs are immediately acquired, radiation profile is detected per beam, and displacement from imaging isocenter is quantified.