TABLE 2.
Clinical characteristics of HDMTX courses by methotrexate level measurement time periods.
| Total courses (n = 556) | First and second time periods (n = 340) | First and third time periods (n = 533) | Second and third time periods (n = 341) | ||
|---|---|---|---|---|---|
| Age at HDMTX infusion, median years (IQR) | 9.6 (4.4–37.7) | 6.6 (3.9–15.5) | 9.7 (4.4–37.7) | 6.6 (4.0–15.5) | |
| Sex, n (%) | Female | 240 (43.2) | 139 (40.9) | 228 (42.86) | 139 (40.8) |
| Male | 316 (56.8) | 201 (59.1) | 305 (57.2) | 202 (59.2) | |
| MTX dose, median mg/m2 (IQR) | 4834 (2849–4984) | 4921 (3008–4993) | 4833 (2845–4982) | 4921 (3008–4991) | |
| Baseline creatinine, median mg/dL (IQR) | 0.4 (0.3–0.6) | 0.4 (0.3–0.5) | 0.4 (0.3–0.6) | 0.3 (0.3–0.5) | |
| Baseline eGFR, mL/min/1.73m2 (IQR) | 132.7 (107.4–159.2) | 140.2 (110.1–165.6) | 132.6 (107.2–159.4) | 140.5 (111.9–165.2) | |
| Infusion length, n (%) | Long (24 h) | 461 (82.9) | 249 (73.2) | 442 (82.9) | 252 (73.9) |
| Short (4 h) | 95 (17.1) | 91 (26.8) | 91 (17.1) | 89 (26.1) | |
| AKI, n (%) | No AKI | 388 (69.8%) | 235 (69.1%) | 372 (69.8%) | 235 (68.9%) |
| Grade 1 | 127 (22.8%) | 79 (23.2%) | 124 (23.3%) | 78 (22.9%) | |
| Grade 2 | 36 (6.5%) | 24 (7.1%) | 32 (6.0%) | 26 (7.6%) | |
| Grade 3 | 5 (0.9%) | 2 (0.6%) | 5 (0.9%) | 2 (0.6%) | |
| DME n (%) | SD | 38 (6.8%) | 15 (4.4%) | 35 (6.6%) | 16 (4.7%) |
| μM | 215 (38.7%) | 130 (38.2%) | 204 (38.3%) | 133 (39.0%) | |
| Measurement time periods, n (%) | 1st and 2nd | 11 (2.0) | 11 (3.2) | 0 | 0 |
| 1st and 3rd | 204 (36.7) | 0 | 204 (38.3) | 0 | |
| 2nd and 3rd | 12 (2.2) | 0 | 0 | 12 (3.5) | |
| 1st, 2nd, and 3rd | 329 (59.2) | 329 (96.8) | 329 (61.7) | 329 (96.5) | |
| Site, n (%) | A | 285 (51.3) | 92 (27.1) | 278 (52.2) | 93 (27.3) |
| B | 271 (48.7) | 248 (72.9) | 255 (47.8) | 248 (72.7) | |
Abbreviations: AKI, acute kidney injury; DME, delayed MTX elimination; eGFR, estimated glomerular filtration rate; IQR, interquartile range; MTX, methotrexate; SD, standard deviation criterion; μM, micromolar criterion.