Survey on reference dosimetry practice in Hokuriku region, Japan

This study aimed to obtain reference dosimetry practices for flattened photon and electron beams. A questionnaire survey on these practices was sent to 37 facilities that performed radiotherapy using these beams in Fukui, Ishikawa, Niigata and Toyama, Japan. The survey comprised equipment (dosemeters, water phantoms, thermometers, barometers and hygrometers) and procedures for reference dosimetry (water used as the phantoms, verification of chamber placement, periodic checks of ion recombination- and polarity-corrections, pre-irradiation and relative humidity monitoring). Responses were received from 19 institutions. In the 19 institutions, a reference-class dosemeter was used for the reference dosimetry. In 6 of the 19 institutions, a 10-year-old or older dosemeter was used. Any barometers, thermometers and hygrometers were not recalibrated. Dosimetry equipment necessitates regular maintenance. Moreover, it is necessary to have a backup dosimetry system in clinics to account for potential malfunctions or instances when the primary system is sent for calibration.