Table 2.

Resulting P‐values of the student's t‐tests per volume threshold. In the second row, the number of patients after each volume threshold is given. None of the P‐values reach statistical significance.

Volume threshold	–	2 cm3	3 cm3	4 cm3	5 cm3	6 cm3	7 cm3
Number of patients (TTE — non‐TTE)	38–61	34–58	31–45	25–41	24–37	19–32	17–26
Age	0.315	0.514	0.696	0.604	0.614	0.643	0.149
Tumor volume at treatment	0.527	0.513	0.142	0.332	0.191	0.254	0.121
Dose to 99% of the tumor volume	0.152	0.145	0.094	0.126	0.204	0.202	0.301
Coverage	0.581	0.739	0.590	0.681	0.672	0.993	0.782
Selectivity	0.909	0.908	0.919	0.980	0.761	0.910	0.739
Gradient index	0.383	0.443	0.248	0.280	0.225	0.378	0.595
Paddick conformity index	0.961	0.989	0.954	0.932	0.774	0.740	0.757
Number of iso‐centers	0.792	0.645	0.786	0.499	0.687	0.768	0.819
Beam‐on time	0.548	0.630	0.550	0.853	0.504	0.611	0.990