Table 2.

Summary of Spearman correlations (r_s) comparing average absolute TLD error and complexity metric value for the subsamples described in this study (i.e. machine manufacturer, TPS, or delivery method).

	MU	MCS	EM	PI	PM	MI speed	MI accel.	MI total	LT/AL	Mean DR Var.	Mean GS Var.	Gap >10mm	Mean TG	MLC Inter- digitation	Mean MLC Speed Var.	Mean Gap Speed Var.
All Machines  rs N = 343 p	−0.025 0.645	0.031 0.570	−0.119 0.027	−0.082 0.130	−0.018 0.742	−0.024 0.655	−0.028 0.599	−0.007 0.899	−0.006 0.931	0.025 0.650	−0.006 0.917	−0.018 0.740	−0.080 0.141	−0.176 0.001*	−0.132 0.015	−0.134 0.013
Varian Machines  rs N = 304 p	−0.022 0.699	0.040 0.484	−0.107 0.063	−0.065 0.256	−0.011 0.853	−0.010 0.864	−0.011 0.853	0.008 0.896	0.002 0.976	0.039 0.500	0.008 0.890	0.015 0.798	−0.065 0.256	−0.174 0.002*	−0.120 0.036	−0.124 0.030
Elekta Machines  rs N = 39 p	−0.016 0.924	−0.303 0.061	−0.150 0.363	−0.071 0.668	0.016 0.922	−0.241 0.140	−0.223 0.173	−0.283 0.081	−0.095 0.636	−0.237 0.147	−0.227 0.165	−0.044 0.791	−0.075 0.649	0.002 0.991	−0.130 0.429	−0.174 0.289
Pinnacle TPS  rs N = 69 p	0.208 0.087	−0.103 0.397	0.233 0.054	0.188 0.122	0.158 0.196	0.018 0.883	0.022 0.855	0.020 0.872	−0.173 0.274	0.002 0.986	0.049 0.688	0.200 0.100	0.171 0.159	0.089 0.466	0.140 0.253	0.159 0.193
Eclipse TPS  rs N = 249 p	0.025 0.697	0.017 0.785	−0.093 0.142	−0.058 0.364	0.055 0.390	−0.080 0.208	−0.066 0.298	−0.070 0.269	−0.059 0.467	−0.063 0.322	−0.075 0.236	0.029 0.646	−0.022 0.730	−0.110 0.082	−0.131 0.039	−0.104 0.102
Varian + Eclipse  rs N = 248 p	0.024 0.708	0.019 0.768	−0.094 0.141	−0.058 0.362	0.056 0.382	−0.078 0.221	−0.065 0.306	−0.070 0.274	−0.054 0.509	−0.065 0.309	−0.076 0.236	0.028 0.659	−0.022 0.725	−0.114 0.073	−0.131 0.039	−0.106 0.096
Varian + Pinnacle  rs N = 45 p	0.143 0.349	0.116 0.447	0.235 0.121	0.200 0.187	0.080 0.603	0.149 0.327	0.124 0.417	0.127 0.405	0.327 0.110	0.103 0.499	0.192 0.207	0.144 0.344	0.124 0.417	−0.042 0.782	0.231 0.127	0.242 0.109
Elekta + Pinnacle  rs N = 24 p	0.296 0.160	−0.446 0.029	0.131 0.541	0.120 0.576	0.225 0.291	−0.295 0.161	−0.282 0.182	−0.314 0.135	−0.395 0.116	−0.311 0.139	−0.187 0.381	0.244 0.250	0.195 0.361	0.203 0.341	−0.144 0.502	−0.111 0.607
VMAT  rs N = 207 p	0.005 0.945	0.021 0.765	−0.077 0.272	−0.008 0.903	0.040 0.571	0.100 0.151	0.089 0.200	0.148 0.033	−0.006 0.931	0.122 0.079	0.119 0.086	0.176 0.011	−0.008 0.904	−0.140 0.044	−0.159 0.022	−0.177 0.011
DMLC  rs N = 93 p	−0.218 0.036	0.240 0.021	−0.188 0.071	−0.079 0.450	−0.088 0.402							−0.052 0.623	−0.179 0.086	−0.220 0.034	0.065 0.534	0.160 0.127
SMLC  rs N = 43 p	0.212 0.172	0.057 0.719	−0.003 0.987	0.119 0.446	0.097 0.535							0.067 0.670	0.111 0.480	−0.031 0.846

^*Correlation is significant at the 0.3% level (required for Bonferroni correction)

Note: DMLC = dynamic MLC, SMLC = static MLC, MU = monitor units, MCS = Modulation Complexity Score, EM = Edge Metric, PI = Plan Irregularity, PM = Plan Modulation, MI = Modulation Index, LT/AL = leaf travel per arc length, DR = dose rate, GS = gantry speed, TG = tongue and groove.