A review of kilovoltage radiotherapy treatment in the United Kingdom: quality control, radiation dosimetry, treatment equipment, and workload.

Abstract

Objectives: To survey kilovoltage (kV) radiotherapy in the United Kingdom, updating a 2016 study, focussing on radiotherapy physics, including equipment quality control (QC) and radiation dosimetry, with information on installed equipment and clinical activity.

Methods: All UK radiotherapy physics departments (n = 68) were invited to complete a comprehensive survey. An analysis of the installed equipment base, patient numbers, clinical activity, QC testing, and radiation dosimetry processes were undertaken.

Results: 91% of centres (n = 62) responded to the survey. kV radiotherapy was available in 70% of UK radiotherapy departments, with a wide variation in workload; 7-436 patients/centre annually. There has been an increase in centres using treatment calculation software rather than manual methods, up from 36% in 2016 to 50% currently. Only 50% of centres use an independent calculation check method. There was an increase in the use of the addendum to the UK dosimetry code of practice, enabling medium energy calibration in-air rather than at depth in phantom, citing "clinical relevance." Appropriate levels of QC testing were being conducted at UK centres, with Institute of Physics and Engineering in Medicine (IPEM) Report 81 cited as a primary source of guidance. Good consensus for the frequency and tolerance values used for QC was seen across UK centres.

Conclusions: A comprehensive review of consensus practice for QC and dosimetry in kV radiotherapy across the United Kingdom is presented, with supporting information on equipment installation and clinical use.

Advances in knowledge: Updated data are presented on kV radiotherapy treatment in the United Kingdom, with focus on physics aspects of QC and dosimetry.