Table 2.
Best estimates of Lyman–Kutcher–Burman (LKM) and log-logistic model parameters with 95% confidence interval (CI), log-likelihood (LL), Akaike's information criteria (AIC) and mean area under the ROC curve (AUROC)
| Organ at risk | Model | a (95% CI) | TD50 (95% CI) | γ50 (95% CI) | LL | AIC | Mean AUROC ± standard error |
|---|---|---|---|---|---|---|---|
| Inner ear | Log-logistic | 0.1 (0.1–0.6) | 53.6 (51.8–55.4) | 2.9 (2–3.8) | −74.4 | 154.8 | 0.86 ± 0.03 |
| LKM | 0.1 (0.1–0.6) | 53.7 (51.9–55.3) | 2.8 (2.1–3.7) | −74.2 | 154.3 | ||
| Cochlea | Log-logistic | 1.2 (0.1–3.6) | 56.0 (53.6–58.8) | 2.9 (1.8–4.3) | −36.1 | 78.1 | 0.81 ± 0.04 |
| LKM | 1.2 (0.1–3.6) | 56.0 (53.6–58.5) | 2.8 (1.9–4.2) | −35.8 | 77.5 | ||
| Internal auditory canal | Log-logistic | 0.1 (0.1–4.5) | 60.7 (56.8–65.0) | 1.9 (1–3) | −42.5 | 90.9 | 0.72 ± 0.05 |
| LKM | 0.1 (0.1–4.5) | 61.0 (56.8–65.0) | 1.9 (1.0–2.9) | −42.5 | 90.9 | ||
| Pituitary gland (adults) | Log-logistic | 6.4 (0.9–8.2) | 60.5 (59.1–62.0) | 5.2 (3.1–8.0) | −43.2 | 92.4 | 0.86 ± 0.04 |
| LKM | 6.4 (0.9–8.2) | 60.6 (59.1–62.0) | 4.9 (3.1–8.0) | −43.2 | 92.3 | ||
| Pituitary gland (children) | – | – | – | – | – | – | 0.59 ± 0.13 |
| – | – | – | – | – | – | ||
| Hypothalamus (children) | – | – | – | – | – | – | 0.65 ± 0.11 |
| – | – | – | – | – | – |
TD50 is the tolerance uniform dose delivered to the whole organ for 50% complication rate at a specific time; γ50, slope of the response curve at TD50.