Table 1 Dosimetric evaluation of treatment plans
Case 1 | ||||
|---|---|---|---|---|
Cranial PTV 36 Gy, Dose from Reirradiation | ||||
X-ray | IMRT | Proton | ||
PTV covered by 65% IDL (23.4 Gy) | 91.0% | 95.8% | 99.1% | |
PTV covered by 90% IDL (32.4 Gy) | 82.1% | 86.1% | 96.1% | |
PTV covered by 95% IDL (34.2 Gy) | 64.2% | 76.8% | 94.8% | |
Minimum Dose to PTV | 3.2 Gy | 9.9 Gy | 0.9 Gy | |
Mean Dose to PTV | 32.9 Gy | 34.6 Gy | 36.0 Gy | |
Dose covering 95% of PTV | 9.8 Gy | 25.2 Gy | 34.0 Gy | |
Cumulative Dose to Optic Chiasm from Both Courses of Radiation | ||||
Prior RT | X-ray | IMRT | Proton | |
Mean dose | 41.0 Gy | 45.6 Gy | 51.0 Gy | 41.0 Gy |
Maximum point dose | 43.2 Gy | 47.9 Gy | 54.0 Gy | 43.9 Gy |
Case 2 | ||||
Cranial PTV 36 Gy, Dose from Reirradiation | ||||
X-ray | IMRT | Proton | ||
PTV covered by 65% IDL (23.4 Gy) | 92.9% | 96.9% | 99.9% | |
PTV covered by 90% IDL (32.4 Gy) | 88.5% | 87.9% | 98.1% | |
PTV covered by 95% IDL (34.2 Gy) | 85.7% | 76.6% | 96.1% | |
Minimum Dose to PTV | 3.6 Gy | 11.5 Gy | 6.5 Gy | |
Mean Dose to PTV | 33.9 Gy | 34.8 Gy | 35.8 Gy | |
Dose covering 95% of PTV | 12.8 Gy | 28.1 Gy | 34.7 Gy | |
Cumulative Dose to Brainstem from Both Courses of Radiation | ||||
Prior RT | X-ray | IMRT | Proton | |
Dose to 0.5 cc | 59.7 Gy | 64.4 Gy | 70.9 Gy | 61.2 Gy |
Dose to 1 cc | 57.8 Gy | 62.1 Gy | 68.6 Gy | 59.3 Gy |
Maximum point dose | 65.6 Gy | 71.2 Gy | 78.1 Gy | 71.2 Gy |