Table 2.
Prior studies examining SRS for brainstem metastases
| Study | Treatment modality | Patients, n | Mean age, y | Median tumor volume, mL | Median prescribed SRS Dose, Gy | Median survival, mo | Local tumor control, % | Factors associated With shorter survival | Complication rate |
|---|---|---|---|---|---|---|---|---|---|
| Huang et al. [8] |
Gamma Knife |
26 |
56 |
1.1 |
16 |
9 |
95 |
Presence of active extracranial disease |
27% |
| Shuto et al. [13] |
Gamma Knife |
25 |
57.1 |
2.1 (mean) |
13 (mean) |
4.9 |
77 |
N/A |
8% |
| Fuentes et al. [6] |
Gamma Knife |
28 |
57.7 |
2.1 (mean) |
19.6 (mean) |
12 |
92 |
N/A |
0% |
| Yen et al. [14] |
Gamma Knife |
53 |
57.3 |
2.8 (mean) |
17.6 (mean) |
11 |
87 |
Presence of extracranial disease |
0% |
| Hussain et al. [9] |
Gamma Knife |
22 |
60 (median) |
0.9 |
16 |
8.5 |
100 |
N/A |
5% |
| Kased et al. [10] |
Gamma Knife |
42 |
55 (median) |
0.26 |
16 |
9 |
85 |
Multiple metastases, melanoma primary |
10% |
| Lorenzoni et al. [15] |
Gamma Knife |
25 |
54 |
0.6 (mean) |
20 (mean) |
11.1 |
95 |
KPS <80, uncontrolled primary tumor, radiotherapy, SRS < 18 Gy |
0% |
| Koyfman et al. [11] |
Gamma Knife |
43 |
59 (median) |
0.37 |
15 |
5.8 |
85 |
Lower KPS, larger tumor volume, SIR, GPA |
12% |
| Hatiboglu et al. [7] |
Linac-based SRT/SRS |
60 |
61 (median) |
1 |
15 |
4.2 |
76 |
Tumor volume ≥4 mL, male sex |
20% |
| Lin et al. [12] |
Linac-based SRT/SRS |
45 |
59.9 |
0.4 |
14 |
11.6 |
91 |
Lower KPS |
4% |
| Present Study | Linac-based SRT/SRS | 36 | 61 | 0.94 | 17 | 3 | 93 | Lower GPA, lower prescription dose, fewer fractions | 8% |