The use of On-Board Imaging to plan and deliver palliative radiotherapy in a single cohesive patient appointment

To develop and assess a method of palliative radiotherapy utilising a kilovoltage imaging system incorporated with a linear accelerator. The conventionally separate procedures of simulation, planning and treatment were merged into a single appointment on a linear accelerator. The process was tested using a humanoid phantom and hypothetical treatment scenarios. A clinical investigation was then undertaken for patients requiring palliative radiotherapy. A total of 10 treatment sites were simulated, planned and treated using the online approach. Each step was timed for both the phantom and patient treatments and was compared with a simulation process involving a separate appointment on a conventional simulator. The contrast and resolution achievable with the linear accelerator-based imaging system was found to be comparable with a conventional simulator. Bony anatomy was plainly visible and suitable for target definition. The mean total treatment time for the humanoid phantom (n = 5) was 21.4 ± 0.9 (standard error) mins. The mean total treatment time for actual patients (n = 10) was 25.7 ± 1.6 mins (the mean simulation, planning and treatment times were 11.0 ± 0.5 mins, 14.5 ± 1.0 mins and 3.6 ± 0.2 mins, respectively). This study demonstrated that palliative radiotherapy treatments can be simulated, planned and treated in a single cohesive patient appointment, using an online approach that is technically comparable with the conventional simulation method. This approach has the potential to expedite palliative radiotherapy service delivery and reduce resource burdens by minimising the number of patient appointments and wait times between appointments.