Table 2 Characteristics of treated metastases and radiotherapy
|  | SRS (n fraction = 1) | HFSRT (n fraction = 3 or 6) | p value |
|---|---|---|---|
n metastases (total = 193) | 52 (27%) | 141 (73%) |  |
|  |  | 3 fractions n = 106 / 6 fractions n = 35 |  |
Follow up (mean (sd)) | mean: 359Â days (315) | mean: 230Â days (206) | 0.001 |
Treatment schedules | 1x18Gy (n = 5) | 6x5Gy (n = 3) |  |
1x20Gy (n = 34) | 6x6Gy (n = 32) |  | |
1x22Gy (n = 12) | 3x9Gy (n = 8) |  | |
1x25Gy (n = 1) | 3x10Gy (n = 97) |  | |
|  | 3x11Gy (n = 1) |  | |
Dose per fraction | Mean: 20.38 (1.34) Median: 20 | Mean: 8.94 (1.77) Median: 10 | < 0.001 |
GTV volume | Mean: 173.70 (183.78) Median: 125 | Mean: 1820.40 (2622.22) Median: 699 | < 0.001 |
PTV volume | Mean: 565.37 (407.64) Median: 474.5 | Mean: 4118.31 (7895.40) Median: 1752 | 0,001 |
Homogeneity Index | Mean: 0.22 (0.07) Median: 0.22 | Mean: 0.22 (0.08) Median; 0.21 | 0.057 |
Conformity Index | Mean: 1.02 (0.28) Median: 1.04 | Mean: 1.01 (0.18) Median: 1.04 | 0.894 |
Coverage index | Mean: 0.96 (0.06) Median: 0.99 | Mean: 0.94 (0.12) Median: 0.97 | 0.034 |
Gradient index 50 | Median: 5.71 | Median: 4.39 | < 0.001 |
Isodose of prescription (median) | 80% [58–96] | 80% [75–91] | 0.334 |
Histology | |||
 Melanoma (n = 137) | 38 | 99 | 0.833 |
 Renal cancer (n = 56) | 14 | 42 |  |
Localization | |||
 Supra tentorial (n = 165) | 45 | 120 | 0.98 |
 Infra tentorial (n = 28) | 7 | 21 |  |
Time from planning IRM to Irradiation (median) | 26 days [5–82] | 17 days [3–69] | < 0.001 |