Table 1. Patient and Treatment Characteristics.
| Characteristic | All patients (n = 25) | |
|---|---|---|
| n (%) | ||
| Age (yr) | Median (range) | 45 (23–61) |
| <45 | 10 (40) | |
| ≥45 | 15 (60) | |
| Sex | Male | 11 (44) |
| Female | 14 (56) | |
| Initial histology | WHO II glioma | 2 (8) |
| WHO III glioma | 6 (24) | |
| GBM | 17 (68) | |
| Initial RT dose (Gy) | Median (range) | 60 (54–70) |
| Initial CTx | No | 7 (28) |
| Yes | 18 (72) | |
| KPS at recurrence | Median (range) | 90 (60–100) |
| Eloquent area involvement at recurrence | No | 13 (52) |
| Yes | 12 (48) | |
| Extent of surgery at recurrence | Gross total | 15 (58) |
| Subtotal | 10 (42) | |
| MGMT status at recurrence | Unmethylated | 9 (36) |
| Methylated | 16 (64) | |
| IDH mutation at recurrence | Present | 8 (32) |
| Absent | 14 (56) | |
| Unknown | 3 (12) | |
| Tumor volume at recurrence (mL)* | Median (range) | 32 (4–90) |
| <50 | 15 (60) | |
| ≥50 | 10 (40) | |
| GTV of HFReRT (mL) | Median (range) | 97 (21–261) |
| <100 | 14 (56) | |
| ≥100 | 11 (44) | |
| CTV of HFReRT (mL) | Median (range) | 270 (101–1353) |
| CTx after HFReRT | No | 12 (48) |
| Yes, sequential | 13 (52) | |
| Cumulative dose of RT (Gy) | Median (range) | 105 (95.4–115) |
| <100 | 2 (8) | |
| ≥100 | 23 (92) | |
| Interval between RT (month) | Median (range) | 29 (12–72) |
| <30 | 13 (52) | |
| ≥30 | 12 (48) | |
WHO, World Health Organization; GBM, glioblastoma; RT, radiotherapy; KPS, Karnofsky performance score; MGMT, O6-methylguanine-DNA-methyltransferase; IDH, isocitrate dehydrogenase; GTV, gross tumor volume; CTV, clinical target volume; HFReRT, hypofractionated re-irradiation; CTx, chemotherapy.
*Classified using a tumor volume cut-off value of 50 mL at recurrence, according to the National Institutes of Health recurrent GBM scale.