A survey and analysis of radiotherapy linear accelerator quality control in the United Kingdom, for c-arm and ring gantry systems and associated patient specific quality control.

OBJECTIVES

To conduct a survey of radiotherapy linear accelerator quality control (QC) across the United Kingdom (UK) on behalf of the Institute of Physics and Engineering in Medicine (IPEM) Radiotherapy Special Interest Group and Interdepartmental Dosimetry Audit (IDA) Sub-committee. To update results from a similar survey published in 2012 and compare to the latest guidance from IPEM Report 81 (2018). There have been significant developments of equipment and clinical practice since the previous survey and IPEM publication, requiring an updated review and benchmark of QC practice.

METHODS

All UK radiotherapy centres were invited to complete a comprehensive survey of their local QC practice, with questions on c-arm gantry, ring-gantry, linac ancillary equipment, and patient-specific QC.

RESULTS

63% (n = 43/68) of the UK radiotherapy centres responded. IPEM Report 81 was used to inform QC practice in 91% of centres. For the majority of tests studied centres were meeting or exceeding the recommendations of this report. Standard output was still performed weekly in 26% of centres compared to monthly recommendation in Report 81. Comprehensive tables of frequency and tolerances of QC tests were collated for c-arm and ring gantry linacs and ancillary equipment.

CONCLUSIONS

A comprehensive review of consensus practice for linac QC radiotherapy across the UK is presented. Findings include the main stated reasons QC is undertaken is to "demonstrate safe use." On efficiency, it was found that about half of centres state they undertake "the right amount of QC." Half also state review of their QC process is "required."

ADVANCES IN KNOWLEDGE

Updated data are presented on current practice for linac QC in the UK.