1. Physics and Imaging in Radiation Oncology
Radiotherapy reference dose audit in the United Kingdom by the National Physical Laboratory: 20years of consistency and improvements 
Russell A.S. Thomas, Matthew A. Bolt, Graham Bass, Rebecca Nutbrown, Tao Chen, Andrew Nisbet, Catharine H. Clark 
Physics and Imaging in Radiation Oncology 
Volume 3, Pages (July 2017)
DOI: /j.phro
Copyright © 2017 The Authors Terms and Conditions

2. Fig. 1
Measured beam output ratios separated into the eight individual regional audit groups. Mean value for each beam type in each group is indicated by a horizontal line (−).
Physics and Imaging in Radiation Oncology 2017 3, 21-27DOI: ( /j.phro )
Copyright © 2017 The Authors Terms and Conditions

3. Fig. 2
Plot of MV (a) and MeV (b) output results in order of completion. The standard deviation of the previous 20 audits (after removing three known erroneous MeV results) is shown by the dashed line. Bars indicate the standard uncertainty as given in the NPL report of the audit produced for the department.
Physics and Imaging in Radiation Oncology 2017 3, 21-27DOI: ( /j.phro )
Copyright © 2017 The Authors Terms and Conditions