Evaluation of Downtime of Linear Accelerators Installed at Radiotherapy Departments in the Czech Republic

Abstract

The National Radiation Protection Institute (NRPI) performed the study evaluating linear accelerator (linac) unscheduled downtime and other parameters related to linac failure (e.g. treatment cancellations, patients transferred to other linac, patients treated with modified dose fractionation) at radiotherapy departments in the Czech Republic. Thirteen radiotherapy departments with at least one linac (out of 21 departments in the Czech Republic) voluntarily participated in the study covering 29 out of 47 linacs. Downtime was evaluated for a one year period from July of 2016 to June of 2017. The methodology was as follows: NRPI designed the data entry form which was sent electronically to medical physicists at participating radiotherapy departments. Data related to linac failures were filled in. The completed forms were evaluated by NRPI. Unscheduled downtime was defined as time when linac cannot be operated during operating hours. Unscheduled downtime per linac per year ranged from 4 to 222 h (mean = 73 h, median = 61 h). Downtime percentage calculated as a ratio of downtime and total sum of operating hours per year ranged from 0.2 to 7.6% (mean = 2.8%, median = 2.2%). The number of treatment cancellations per linac per year ranged from 0 to 661. Unified methodology enabled objective comparison of linac downtime at particular radiotherapy departments in the Czech Republic. The study confirmed usefulness of having minimally two matched linacs at a department. The results of this study could help radiotherapy departments negotiate better service contract (e.g. agreement on maximum guaranteed downtime).