UvA - DARE ( Digital Academic Repository ) Radiotherapy for lung cancer

Purpose: Kilovoltage cone-beam computed tomography (CBCT) has been developed to provide accurate soft-tissue and bony setup information. We evaluated clinical CBCT setup data and compared CBCT measurements with electronic portal imaging device (EPID) images. Material and Methods: The setup error for CBCT scans at the treatment unit relative to the planning CT was measured for 62 patients (524 scans). For 19 of these patients (172 scans) also portal images were made. The mean, CBCT and the EPID. Also the differences between CBCT and EPID and the rotational setup error derived from the CBCT were evaluated.