Table 1.
Selected median (range) dosimetric indices of the optimized plans
| Planning approach | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Dosimetric index | Carbon ion plans | Proton plans | |||||||
| uc LR | sc LR | mc LR | mc ROB | uc LR | mc LR | mc ROB | |||
| PTV V95% | 99.2 | 97.9 | 98.3 | 98.3 | 97.2 | 95.2 | 95.8 | ||
| [%] | (98.3-99.7) | (93.1-99.1) | (95.0-99.3) | (95.2-98.7) | (96.0-99.3) | (90.4-97.7) | (93.1-97.3) | ||
| CTV V95% | 100.0 | 99.7 | 99.8 | 99.7 | 99.5 | 98.8 | 99.2 | ||
| [%] | (99.9-100.0) | (97.3-100.0) | (98.5-100.0) | (98.8-100.0) | (99.2-99.8) | (95.5-99.6) | (97.8-100.0) | ||
| PTV HI | 5.9 | 7.8 | 7.7 | 7.8 | 11.2 | 13.9 | 12.5 | ||
| [p p] | (4.5-8.1) | (6.0-11.1) | (5.5-10.3) | (6.6-10.8) | (6.3-12.9) | (9.9-14.9) | (9.5-13.8) | ||
| CTV HI | 4.0 | 4.8 | 4.6 | 5.0 | 7.9 | 9.4 | 8.7 | ||
| [p p] | (3.4-5.0) | (3.6-8.2) | (3.7-7.7) | (4.5-7.3) | (5.1-9.3) | (7.0-12.5) | (6.3-9.9) | ||
| PTV CI | 0.85 | 0.87 | 0.87 | 0.86 | 0.78 | 0.79 | 0.78 | ||
| [−] | (0.81-0.91) | (0.80-0.91) | (0.82-0.91) | (0.82-0.89) | (0.70-0.88) | (0.71-0.87) | (0.71-0.84) | ||
| Dnear-max brainstem | n/a | 53.9 | 52.9 | 52.2 | n/a | 61.0 | 60.2 | ||
| [Gy(RBE) ] | (38.8-55.0) | (35.6-54.2) | (36.9-54.3) | (45.5-63.1) | (46.3-62.6) | ||||
| Dmax chiasm | n/a | 54.0 | 53.9 | 53.8 | n/a | 58.1 | 59.9 | ||
| [Gy(RBE) ] | (0.0-54.2) | (0.0-54.1) | (52.6-54.1) | (0.0-60.1) | (59.0-60.2) | ||||
| Dmax ips. optic nerve | n/a | 54.0 | 53.8 | 53.8 | n/a | 59.7 | 60.1 | ||
| [Gy(RBE) ] | (0.0-54.2) | (0.0-54.2) | (40.6-54.1) | (0.0-60.3) | (50.9-60.4) | ||||
| Dmax con. optic nerve | n/a | 42.9 | 43.3 | 39.2 | n/a | 51.2 | 42.5 | ||
| [Gy(RBE) ] | (0.0-54.2) | (0.0-54.2) | (0.0-53.9) | (0.0-60.5) | (0.0-59.8) | ||||
Abbreviations: CTV clinical target volume, PTV planning target volume, ips ipsilateral, con contralateral, LR lateral-opposed beam setup, ROB robust beam setup, uc unconstrained mode, sc single-field modulation, mc multiple-field modulation, pp percentage point, n/a not applicable.