Table 3.
Therapies administered and the development of radiation necrosis.
| Treatment characteristic | Any RN diagnosis (N = 7) | No RN diagnosis (N = 19) | Total (N = 26) | P value |
|---|---|---|---|---|
| Prior radiation therapy | ||||
| WBRT | 0 (0.0%) | 2 (10.5%) | 2 (7.7%) | 1.00a |
| SRS/SRT | 1 (14.3%) | 0 (0.0%) | 1 (3.8%) | 0.26b |
| Initial SRS/SRT dose (Gy) | 0.71a | |||
| Mean (SD) | 20.6 (1.5) | 20.4 (2.7) | 20.4 (2.4) | |
| Median | 20.0 | 20.0 | 20.0 | |
| Range | (18.0-22.0) | (14.0-27.0) | (14.0-27.0) | |
| Fractions | 1.00b | |||
| SRS (1) | 7 (100.0%) | 18 (94.7%) | 25 (96.2%) | |
| SRT (3) | 0 (0.0%) | 1 (5.3%) | 1 (3.8%) | |
| Met target dosimetric goal | (N = 6) | (N = 10) | (N = 16) | |
| V12 (<10 ccs) or V14(<7 ccs) | 5 | 9 | 14 | 0.70c |
| Total number of courses administered | 0.85a | |||
| Mean (SD) | 2.1 (1.8) | 1.7 (0.7) | 1.8 (1.1) | |
| Median | 2.0 | 2.0 | 2.0 | |
| Range | (1.0-6.0) | (1.0-3.0) | (1.0-6.0) | |
| Systemic therapy prior to radiation | 6 (86%) | 18 (95%) | 24 (92%) | 0.47a |
| Cytotoxic chemotherapy | 3 (43%) | 8 (42%) | 11 (42%) | 1.00a |
| Immunotherapy | 5 (71%) | 17 (90%) | 22 (85%) | 0.29a |
| Targeted therapy | 3 (43%) | 8 (42%) | 11 (42%) | 1.00a |
| Cumulative cytotoxic chemo exposure prior to first radiation (days) | (N = 1) | (N = 3) | (N = 4) | 0.18d |
| Mean (SD) | 122.0 | 98.3 (29.1) | 104.3 (26.6) | |
| Median (IQR) | 122 (122, 122) | 111 (65, 119) | 115 (88, 121) | |
| Range | 122.0, 122.0 | 65.0, 119.0 | 65.0, 122.0 | |
| Cumulative cytotoxic chemo exposure prior to RN (days) | (N = 2) | |||
| Mean (SD) | 148.5 (37.5) | |||
| Median (IQR) | 149 (122, 175) | |||
| Range | 122.0, 175.0 | |||
| Cumulative immunotherapy exposure prior to first radiation (days) | (N = 4) | (N = 13) | (N = 17) | 0.73d |
| Mean (SD) | 130.0 (74.9) | 164.8 (124.8) | 156.6 (113.9) | |
| Median (IQR) | 128 (66, 195) | 120 (63, 245) | 120 (63, 203) | |
| Range | 61.0, 203.0 | 42.0, 378.0 | 42.0, 378.0 | |
| Cumulative immunotherapy exposure prior to RN (days) | (N = 5) | |||
| Mean (SD) | 317.0 (275.3) | |||
| Median (IQR) | 203 (196, 351) | |||
| Range | 61.0, 774.0 | |||
| Cumulative targeted therapy exposure prior to first radiation (days) | (N = 1) | (N = 3) | (N = 4) | 0.18d |
| Mean (SD) | 232.0 | 59.0 (16.1) | 102.3 (87.5) | |
| Median (IQR) | 232 (232, 232) | 61 (42, 74) | 68 (52, 153) | |
| Range | 232.0, 232.0 | 42.0, 74.0 | 42.0, 232.0 | |
| Cumulative targeted therapy exposure prior to RN (days) | (N = 3) | |||
| Mean (SD) | 210.0 (30.6) | |||
| Median (IQR) | 223 (175, 232) | |||
| Range | 175.0, 232.0 | |||
| Number prior systemic treatments | 1.00b | |||
| Mean (SD) | 3.3 (1.6) | 3.9 (2.6) | 3.8 (2.3) | |
| Median | 3.0 | 3.0 | 3.0 | |
| Range | (1.0-6.0) | (1.0-10.0) | (1.0-10.0) | |
| Surgery prior to radiation | 4 (57%) | 5 (26%) | 9 (35%) | 0.19a |
| Surgery to radiation (days) | 0.54b | |||
| Mean (SD) | 44.3 (19.8) | 33.4 (25.5) | 38.2 (22.5) | |
| Median | 49.0 | 23.0 | 30.0 | |
| Range | (18.0-61.0) | (15.0-78.0) | (15.0-78.0) |
Abbreviations: IQR, interquartile range; RN, radiation necrosis; SD, standard deviation; SRS, stereotactic radiosurgery; SRT, Stereotactic Radiotherapy; WBRT, whole brain radiation therapy.
a
Fisher exact.
b
Wilcoxon.
c
Chi-square.
d
Kruskal-Wallis.