Table 2.
Univariate analysis of OS and PFS in all patients pre- and post-GKRS
| Characteristics | Number of patients (%) | Median PFS (95% CI) p-value | Median OS (95% CI) p-value |
|---|---|---|---|
| Sex | 0.458 | 0.425 | |
| Female | 58(54.2) | 7.0(1.4-12.6) | 21.0(8.5-33.5) |
| Male | 49(65.8) | 6.0(2.6-9.4) | 14.0(9.8-18.1) |
| Pathological grade | 0.018 | 0.000 | |
| LGG | 39(36.4) | 13.0(1.1-24.9) | 49.0(22.7-75.3) |
| HGG | 68(63.6) | 5.5(3.4-7.6) | 11.0(6.6-15.4) |
| Adjuvant treatment after first surgery | 0.808 | 0.877 | |
| Chemoradiotherapy | 51(47.7) | 6.5(3.9-9.1) | 11.0(5.3-16.7) |
| EBRT | 25(23.4) | 12.0(1.4-22.6) | 17.0(0.7-33.3) |
| TMZ | 5(4.7) | 5.5(4.4-6.6) | 18.0(11.6-24.4) |
| GKRS | 10(9.3) | 8.0(0.0-22.7) | 33.5(18.1-48.8) |
| None | 16(15.0) | 5.0(0.0-24.6) | 12.5(3.3-21.7) |
| Age at GKRS procedure | 0.938 | 0.804 | |
| ≥50 years | 58 (54.2) | 8.0(5.2-10.8) | 18.0(11.1-24.9) |
| <50 years | 49(45.8) | 6.5(0.1-12.9) | 13.2(4.0-22.4) |
| Recurrence time interval | 0.034 | 0.012 | |
| ≥15 months | 54(50.5) | 12.0(6.1-17.9) | 23.0(8.7-37.2) |
| <15 months | 53(49.5) | 5.0(3.5-6.7) | 14.0(8.0-20.0) |
| Surgery for recurrence | 0.013 | 0.002 | |
| Yes | 27(25.2) | 17.5(0.0-43.8) | 52.0(2.9-101.1) |
| No | 80(74.8) | 5.5(3.6-7.4) | 14.0(7.7-20.8) |
| KPS | 0.004 | 0.000 | |
| ≥80 | 48(44.9) | 14.0(6.1-21.9) | 40.0(16.1-63.9) |
| <80 | 59(55.1) | 4.5(3.7-5.3) | 10.0(7.9-12.1) |
| Number of targets | 0.130 | 0.008 | |
| Single | 45(42.1) | 12.0(4.8-19.2) | 24.0(3.7-44.3) |
| Multiple | 62(57.9) | 5.0(2.2-7.8) | 11.0(6.6-15.4) |
| Total volume of target | 0.624 | 0.544 | |
| ≥18.5 cm3 | 51(47.7) | 7.0(4.0-10.0) | 14.3(5.7-22.9) |
| <18.5 cm3 | 49(52.3) | 7.0(0.7-13.3) | 21.0(9.7-32.3) |
| Maximum dose | 0.255 | 0.122 | |
| ≥24.5 Gy | 53(49.5) | 13.0(6.9-19.1) | 22.0(15.0-29.0) |
| <24.5 Gy | 54(50.5) | 4.5(3.5-6.5) | 12.0(7.7-16.3) |
| Marginal dose | 0.300 | 0.165 | |
| ≥12.5 Gy | 54(50.5) | 12.0(5.9-18.1) | 22.0(14.0-30.0) |
| <12.5 Gy | 53(49.5) | 5.0(2.7-7.3) | 12.0(8.2-16.7) |
| Two or more GKRS | 0.031 | 0.001 | |
| Yes | 36(33.6) | 13.0(9.0-17.0) | 33.5(1.8-65.2) |
| No | 71(66.4) | 5.0(2.9-7.1) | 10.5(7.7-13.3) |
| Target location | 0.000 | 0.000 | |
| In or adjacent field | 63(58.9) | 13.0(8.1-18.0) | 26.0(18.9-33.1) |
| Out of field | 44(41.1) | 4.0(2.3-5.7) | 8.0(4.8-11.2) |
| Site of recurrence | |||
| 0.889 | 0.629 | ||
| Frontal | 52(48.6) | 7.0(4.2-9.8) | 21.0(14.4-27.6) |
| Others | 55(51.4) | 8.0(0.0-17.5) | 11.0(6.1-15.9) |
| 0.496 | 0.299 | ||
| Temporal | 40(37.4) | 8.0(0.0-18.0) | 9.0(2.9-15.1) |
| Others | 67(62.6) | 6.5(4.0-9.0) | 21.0(13.5-28.5) |
| 0.416 | 0.687 | ||
| Occipital | 10(9.3) | 14.0(0.0-33.3) | 11.0(7.2-14.8) |
| Others | 97(90.7) | 6.5(3.8-9.2) | 18.0(10.9-25.1) |
| 0.804 | 0.390 | ||
| Parietal | 15(14.1) | 12.5(3.0-22.0) | 18.5(0.0-48.2) |
| Others | 92(85.9) | 7.0(4.0-10.0) | 17.0(9.8-24.2) |
| 0.000 | 0.000 | ||
| Brainstem | 3(2.8) | 1.5(0.7-2.3) | 3.0(1.4-4.6) |
| Others | 104(97.2) | 8.0(3.2-12.8) | 18.0(11.1-24.9) |
| 0.032 | 0.000 | ||
| Encephalocoele | 14(13.1) | 2.0(0.0-5.5) | 8.0(4.6-11.4) |
| Others | 93(86.9) | 8.0(2.9-13.1) | 21.0(13.2-28.8) |
| Left or right side of the brain | 0.001 | 0.007 | |
| Left | 40(37.4) | 7.0(0.0-17.9) | 14.3(7.0-21.0) |
| Right | 44(41.1) | 12.0(6.4-17.6) | 39.0(15.0-63.0) |
| Bilateral | 23(21.5) | 4.5(1.6-7.4) | 10.5(7.3-13.6) |
| Bevacizumab used after recurrence | 0.360 | 0.633 | |
| Yes | 14(13.1) | 8.0(2.7-13.3) | 10.0(0.0-23.9) |
| No | 93(86.9) | 7.0(2.9-11.0) | 18.0(9.4-26.6) |
Abbreviations: LGG Low-grade glioma, HGG High-grade glioma, WHO World health organization, EBRT External beam radiotherapy, TMZ Temozolomide, GKRS Gamma knife radiosurgery, KPS Karnofsky performance status, Target location In relation to the previously irradiated tumor volume