Assessing the Efficiency and Consistency of Daily Image-guided Radiation Therapy in a Modern Radiotherapy Centre

Patients at Radiation Oncology Queensland Toowoomba are treated using the assistance of daily image-guided radiation therapy (IGRT). Each patient's daily setup is exposed to a number of variables. This study investigates the effect that these variables have on the total time taken to analyse field placement and the total time taken for treatment, as well accessing setup error across a variety of treatment types.

This is a retrospective study of 80 patients across a variety of treatment sites where daily IGRT was undertaken using kilovoltage and megavoltage orthogonal images. Variables investigated include the treatment type, the imaging modality used, and the setup error of each session. Statistical analysis was then performed on the data.

Patients being treated in the thoracic region had the greatest random setup error. The mean matching times were also longer for chest patients (197 seconds), whereas there were minimal differences in times regarding modality. Treatment times were longest for head and neck variables (399-405 seconds).

Pretreatment daily IGRT is beneficial to all patients and can be performed efficiently. Pelvic variables were the strongest performer, with fiducial markers providing the most consistent and rapid match times. Chest variables were the worst performer specifically regarding random setup error and match times indicating future work required on chest stabilization.