Table 2.

Evaluation of a class solution for prostate IMRT. Percentage volumes associated with target coverage (median [range] or means [SD]): comparison of the clinical plan (CP) and class solutions T1, T2 and Tfinal.

Metric	CP	T1	T2	Tfinal	RM-ANOVA (P value)
[CTV] % covered by TD	99.80 (94.50–100.0)	99.53***,††† (92.81–100.0)	99.81 (46.08–100.0)	99.81 (88.50–100.0)	<0.001
[PTV] % covered by TD	97.02 (90.35–99.96)	96.36***,† (83.19–99.86)	97.99††† (40.43–99.98)	96.87* (76.04–99.92)	<0.0001
[PTV] % covered by 95% TD	99.94 (95.33–100.0)	99.93** (96.34–100.0)	99.97†† (71.82–100.0)	99.93 (98.28–100.0)	0.0045
[PTV] % covered by 107% TD	0.004 (0–1.31)	0.000*** (0.000–0.010)	0.019*,††† (0.000–0.261)	0.000*** (0.000–0.012)	<0.0001
[PTV] % covered by 105% TD	1.65 (0.00–15.67)	2.20††† (1.15–3.61)	2.79*,††† (0.000–11.24)	0.23*** (0.02–0.70)	<0.0001
[PTV] Mean dose (Gy)	83.03 (82.44–83.82)	83.16*,††† (82.13–83.61)	83.15††† (79.31–83.89)	82.80*** (81.86–83.14)	<0.0001
[PTV] Homogeneity index [81.0 Gy]	0.066 (0.038–0.251)	0.071***,††† (0.042–0.203)	0.065 (0.032–0.228)	0.061* (0.035–0.110)	<0.0001
[PTV] Conformation number [76.95 Gy]	0.685 (0.578–0.782)	0.636***,††† (0.551–0.778)	0.689††† (0.582–0.884)	0.697*** (0.602–1.000)	<0.0001
Volume (cc) covered by TD outside PTV	16.83 (6.30)	18.72††† (5.41)	16.93††† (6.51)	13.64*** (3.71)	<0.0001

^*Compared to CP, P < 0.05.

^**P < 0.01.

^***P < 0.0001.

^†Compared to Tfinal, P < 0.05.

^††P < 0.01.

^†††P < 0.0001.

Homogeneity index = [dose covering 1% of PTV − dose covering 99% of PTV] (Gy)/prescribed dose (Gy). The prescribed dose was 81 Gy.

Conformation number = [PTV volume (cc) covered by specified dose (95% in Gy)]²/[total volume covered by 95% dose (Gy) × total volume of PTV (cc)].