Development of RTS-200S 2D automatic scanning dose measuring water phantom for radiotherapy

Objective: To develop a 2D automatic scanning water phantom, being applicable for acceptance tests of radiotherapy equipment and quick measurements of clinical physical parameters for radiotherapy beams and suitable for use in radiotherapy departments and provincial monitoring institutions. Methods: Two chambers were used as a scanning detector and a beam monitor, respectively. Modern automatic techniques were adopted in the scanning system so as to realize rapid and accurate measurement for medical linear accelerator, X-knife and Co-60 therapy beams. The precision of scanning position was less than ±0.1 mm by means of computer-controlled stepper motors. Results: RTS-200S enabled user to acquire data of beam profiles, depth dose curve. RTP software program integrated data collection, analysis, output and storage. The measuring results were in agreement with those measured by Varian company. Conclusion: The RTS-200S water phantom and electronic control are excellent in both accuracy and reliability for measuring beam speciality of radiotherapy units