The design and construction of a simulated linac control area (SLCA) for Radiation Therapy

Abstract

Purpose or Objective Knowledge and skills needed by radiation therapists (therapeutic radiographers) are wide ranging – combining care for patients with high level technical and medical skills. In the UK pre-registration training takes place in both university and clinical departments. But increasing pressures on clinical departments means training time is limited; extending training into simulated environments has been proven to be highly effective giving students more time to learn and develop, in a safe, non-clinical environment, using the same equipment, methods and discipline of the real clinic. This project aims to extend our simulation facilities to include a Linac control area, to complement students’ skills to safely and effectively ensure accurate and precise patient set-up and delivery of treatment. This paper describes the design and construction of such an area within our simulation centre. Materials and Methods Our aim was to create an SLCA with hardware and software components for patient selection, set-up, on-treatment image acquisition and registration and radiation delivery (with and without treatment interruptions). Using true-to-life components was as a high priority. The SLCA was designed around ARIA software, our Virtual Environment for RT (VERT) system, an indexed, flatbed motorised couch, a screened area to create a treatment bunker, a CCTV system, a real Linac function keypad with a specially designed MU counter/sound module, real controlled area/radiation on lighting panels and a simulated door interlock system. Results A schematic of the SLCA is shown in fig 1. All electronic components were built or assembled with documented specifications and design briefs. Screens create a ‘bunker’ so students set-up a patient in front of/using the VERT system and leave the room to the SLCA, as in a real bunker. The patient is visible all the time through the CCTV system. Patient and treatment plan can be selected on ARIA. CBCT acquisition and image registration is possible through the VERT system. The function keypad (from a decommissioned Elekta Linac) is interfaced to the MU counter and radiation-on light. MU are programmed into the counter and verified, before ‘beam-on’ is pressed, starting the MU counter, radiation-on sound (at realistic doserates) and radiation-on light. Conclusion All components have been designed and assembled; all work well as per design specification, enabling true-to-life patient set-up, patient selection and plan check, on-treatment CBCT verification and radiation-on effect with sound and light. The MU counter can be programmed with interruptions, so error scenarios can be simulated for training. The SLCA door interlock is being completed so simulated radiation cannot be initiated without a completed door interlock; and simulated radiation is interrupted when the door interlock is broken. Evaluation is on-going with clinical and university staff and UG/PG Radiation Therapy students.