Table 2.

Dose-volume histogram (DVH) comparison for all five pelvic cancer groups and comparison between two synthetic computed tomography (sCT) versions ($\frac{\mathbf{sC}\mathbf{T}-\mathbf{C}\mathbf{T}}{\mathbf{C}{\mathbf{T}}_{\mathbf{r}\mathbf{e}\mathbf{f}}}$, mean relative difference (SD, standard deviation) [range]) including the planning target volume (PTV), rectum and bladder, gamma analysis, dose statistics ($\frac{\mathbf{sC}\mathbf{T}-\mathbf{C}\mathbf{T}}{\mathbf{C}\mathbf{T}}$, mean relative difference (SD)), gamma-index pass-rates (mean (SD) [range]), and Hounsfield unit (HU) similarity evaluation (mean (SD) [range]). V_X% indicates the volume, where the dose is higher than X% of the prescribed dose. For DVH comparison, the ${\mathrm{C}\mathrm{T}}_{\mathrm{r}\mathrm{e}\mathrm{f}}$ is either prescribed dose (for D_X%) or structure volume (for V_X%). For dose statistics per volume and PTV mean dose, values are relative to respective value obtained using CT. MAE: mean absolute error, ME: mean error.

	Pelvic lymph nodes (n = 15)	Rectal cancer (n = 15)	Gynecological cancer (n = 15)	Prostate cancer, post-operative (n = 15)	Prostate cancer, definitive (continuous HU, n = 15)	Prostate cancer, definitive (bulk HU, n = 15)
DVH comparison
PTV
Mean	0.0 (0.4) [−0.5 − 0.8]	0.1 (0.3) [−0.4 − 0.6]	−0.2 (0.4) [−1.0 − 0.3]	0.1 (0.3) [−0.4 − 0.6]	0.1 (0.2) [−0.2 − 0.4]	0.1 (0.2) [−0.5 − 0.3]
D2%	0.1 (0.5) [−0.6 − 1.2]	0.5 (0.6) [−0.7 − 2.0]	0.1 (0.4) [−0.7 − 0.7]	0.2 (0.6) [−0.4 − 2.0]	0.1 (0.2) [−0.3 − 0.4]	0.1 (0.2) [−0.6 − 0.4]
D50%	0.0 (0.4) [−0.6 − 0.8]	0.1 (0.3) [−0.3 − 0.5]	−0.2 (0.4) [−1.1 − 0.3]	0.0 (0.3) [−0.4 − 0.4]	0.1 (0.2) [−0.3 − 0.4]	0.1 (0.2) [−0.6 − 0.4]
D98%	−0.1 (0.3) [−0.9 − 0.5]	0.0 (0.4) [−1.0 − 0.4]	−0.2 (0.5) [−1.1 − 0.8]	0.0 (0.3) [−0.5 − 0.5]	0.1 (0.3) [−0.3 − 0.5]	0.1 (0.2) [−0.5 − 0.4]
Rectum
V95%	0.1 (0.3) [−0.3 − 0.5]		−0.2 (1.8) [−4.9 − 3.2]	0.1 (0.4) [−0.4 − 0.8]	0.1 (0.1) [−0.1 − 0.2]	0.1 (0.1) [−0.1 − 0.3]
V75%	0.0 (0.1) [−0.3 − 0.2]		−0.3 (0.6) [−1.7 − 0.5]	0.0 (0.2) [−0.2 − 0.4]	0.0 (0.1) [−0.1 − 0.1]	0.0 (0.1) [−0.1 − 0.1]
Bladder
V95%	−0.1 (0.3) [−0.6 − 0.7]	0.1 (0.5) [−0.6 − 1.2]	−0.1 (0.9) [−2.8 − 0.9]	−0.1 (0.2) [−0.3 − 0.3]	0.0 (0.2) [−0.7 − 0.3]	0.0 (0.2) [−0.7 − 0.2]
V75%	0.0 (0.2) [−0.2 − 0.5]	0.1 (0.2) [−0.2 − 0.6]	0.0 (0.2) [−0.2 − 0.3]	0.0 (0.1) [−0.1 − 0.1]	0.0 (0.1) [−0.3 − 0.2]	0.0 (0.1) [−0.4 − 0.1]
Gamma statistics (V10)
2%2mm	97.7 (0.7) [96.0 − 99.3]	96.2 (2.0) [91.3 − 97.8]	97.0 (1.5) [93.0 − 98.7]	98.0 (0.6) [96.7 − 98.8]	99.1 (0.5) [97.7 − 99.7]	98.9 (0.4) [97.8 − 99.6]
Dose statistics per volume
V10%	0.0 (0.2) [−0.5 − 0.2]	0.1 (0.3) [−0.5 − 0.5]	−0.1 (0.3) [−0.9 − 0.3]	−0.1 (0.2) [−0.4 − 0.2]	−0.1 (0.2) [−0.4 − 0.2]	−0.3 (0.2) [−0.6 − −0.1]
HU-similarity
MAE	49.1 (4.0) [42.8 − 54.3]	48.6 (2.8) [44.3 − 54.3]	47.7 (7.3) [37.1 − 67.5]	48.9 (3.6) [43.8 − 57.4]	47.4 (3.8) [42.6 − 54.2]	48.0 (5.7) [41.5 − 59.8]
ME	−4.6 (4.1) [−9.7 − 3.6]	−5.3 (4.6) [−14.1 − 2.2]	−6.6 (3.1) [−13.4 − −1.4]	−4.5 (3.4) [−9.9 − 1.1]	−5.7 (4.2) [−14.7 − 3.5]	7.2 (4.1) [−0.9 − 16.1]