Table 1.
Descriptive statistics of patients with posterior fossa low-grade glioma who underwent surgery and had hearing-test results available (n = 115)
| Variables | Normal hearing | Hearing loss present | P value |
|---|---|---|---|
| Patients | 100 (86.9%) | 15 (13.0%) | |
| Median age at surgery, years (range) | 6.4 (0.6–16.8) | 6.8 (0.7–14.1) | |
| Median age at tumor diagnosis, years (range) | 6.1 (0.5–16.8) | 6.8 (0.7–14.1) | |
| Median age at hearing loss, years (range) | 7.0 (1.3–17.2) | ||
| Median time from tumor diagnosis to baseline testing of hearing loss, years (range) | 0.3 (0.01–7.2) | ||
| Median time from baseline hearing test to last follow-up hearing test, years* (range) | 8.6 (0.7–13.2) | ||
| Median severity of baseline hearing loss, CTCAE grade (range) | 4 (3–4) | ||
| Median severity of hearing loss at last follow-up, CTCAE grade (range) | 4 (1–4) | ||
| Sex | .1394 | ||
| Female | 47 (92.2%) | 4 (7.8%) | |
| Male | 53 (82.8%) | 11 (17.2%) | |
| Race | .0499 | ||
| Black | 17 (73.9%) | 6 (26.1%) | |
| White | 80 (90.9%) | 8 (9.1%) | |
| Multiple race | 3 (75.0%) | 1 (25.0%) | |
| Location of tumor | .9651 | ||
| Brainstem | 29 (87.9%) | 4 (12.1%) | |
| Cerebellum | 17 (89.5%) | 2 (10.5%) | |
| Cervicomedullary | 8 (88.9%) | 1 (11.1%) | |
| Midbrain extending to brainstem/cerebellum | 3 (100.0%) | ||
| Brainstem and cerebellum | 43 (84.3%) | 8 (15.7%) | |
| Extent of resection | .2920 | ||
| Biopsy | 22 (84.6%) | 4 (15.4%) | |
| GTR | 31 (96.9%) | 1 (3.1%) | |
| NTR | 8 (88.9%) | 1 (11.1%) | |
| STR | 38 (80.9%) | 9 (19.1%) | |
| Cyst aspiration | 1 (100.0%) | ||
| Posterior fossa syndrome | .3731 | ||
| No | 90 (88.2%) | 12 (11.8%) | |
| Yes | 10 (76.9%) | 3 (23.1%) | |
| Ventriculoperitoneal shunt | .8517 | ||
| No | 82 (87.2%) | 12 (12.8%) | |
| Yes | 18 (85.7%) | 3 (14.3%) | |
| Histology | .0836 | ||
| Diffuse astrocytoma | 7 (100.0%) | ||
| Pilocytic astrocytoma | 83 (89.3%) | 10 (10.8%) | |
| Low-grade astrocytoma | 2 (66.7%) | 1 (33.3%) | |
| Low-grade glioma (not otherwise specified) | 1 (100.0%) | ||
| Low-grade neuroepithelial | 1 (100.0%) | ||
| Ganglioglioma | 6 (60.0%) | 4 (40.0%) | |
| Grade | .5921 | ||
| Unknown | 4 (80.0%) | 1 (20.0%) | |
| 1 | 89 (86.4%) | 14 (13.6%) | |
| 2 | 7 (100.0%) | ||
| BRAF duplication | .8953 | ||
| No | 8 (88.9%) | 1 (11.1%) | |
| Yes | 21 (84.0%) | 4 (16.0%) | |
| NA | 71 (87.7%) | 10 (12.4%) | |
| BRAFv600E mutation | .1949 | ||
| No | 19 (79.2%) | 5 (20.8%) | |
| Yes | 3 (75.0%) | 1 (25.0%) | |
| NA | 78 (89.7%) | 9 (10.3%) |
*Hearing test at last follow-up available for 14 of the 15 patients with unilateral hearing loss; PF, posterior fossa; LGG, low-grade glioma; CTCAE, Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. (grade 1: threshold shift > 20 dB at 8 kHz in at least one ear; grade 2: threshold shift > 20 dB at 4 kHz and above in at least one ear; grade 3: hearing loss sufficient to indicate therapeutic intervention, including hearing aids, threshold shift > 20 dB at 3 kHz and above in at least one ear, and additional speech-language–related services indicated; grade 4: audiologic indication for cochlear implant and additional speech-language–related services indicated); GTR, gross total resection; NTR, near-total resection (at least 90% of the tumor resected); STR, subtotal resection; NA, not available.