112. The role of the secondary standard dosimetry laboratory in the quality assurance in radiotherapy in poland

Abstract

In Poland, in 1937, a special measurement unit was established in the Radium Institute (former name of the Institute of Oncology). The continuation of this unit is the SSDL, which was established in 1966 at the Medical Physics Department (MPD) of the Institute of Oncology. In 1988, the Laboratory was approved as a member of the IAEA/WHO SSDL network, and is periodically audited by the IAEA. The SSDL plays an important role in maintaining proper dosimetry standards in radiotherapy in Poland. The main activities of the SSDL are: - Collecting data concerning the intrastructure of radiotherapy in Poland. This activity started in 1993 and is continued on the yearly basis. - Calibration of dosimeters at the national level; it started as early as 1937. The SSDL calibrates over 20 ionisation chambers each year. The Co-60 exposure calibration factors are established, and then the air-kerma and the absorbed dose calibration factors are calculated. The system linearity and energy characteristics are determined in the orthovoltage range. In 2002 the measurement facility for calibrating the mammography dosimeters was set-up. - External quality audits of dosimetry in radiotherapy centres in Poland. During the period 1991–2001, 151 audits, based on TLD dose inter-comparisons were performed in reference conditions. The deviations above 3.5% (detined as acceptance level) were observed in 18 cases (nearly 12%). Since 2002 the audits in more complex, non standard conditions started. - Preparation of protocols and recommendations on dosimetry in radiotherapy. The QC recommendations for Co-60 units and accelerators were issued (brachytherapy has been taken care of by the Centre of Oncology in Cracow). The QC- recommendations for simulators and CT-scanners are in preparation. Training of physicists and radiotherapists (including the participants from other East European countries) in order to adhere to the increasing complexity of modern radiotherapy procedures. Trainings are performed individually or in a form of courses. This activity follows the recommendations of the Euroatom Directive 97/43 on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure.