Population exposure-response model of 131I in patients with benign thyroid disease

xlomafota13 shared this article with you from Inoreader Population exposure-response model of <sup>131</sup>I in patients with benign thyroid disease Via radioactive iodine Eur J Pharm Sci. 2021 Oct 1;165:105942. doi: 10.1016/j.ejps.2021.105942. Epub 2021 Jul 14. ABSTRACT PURPOSE: The study aimed to explore the relationship of different exposure measures with 131I therapy response in patients with benign thyroid disease, estimate the variability in the response, investigate possible covariates, and discuss dosing implications of the results. METHODS: A population exposure-response analysis was performed using nonlinear mixed-effects m odelling. Data from 95 adult patients with benign thyroid disease were analysed. Evaluated exposure parameters were: administered radioactivity dose (Aa) [MBq], total absorbed dose (ABD) [Gy], maximum of absorbed dose-rate (MXR) [Gy/h] and biologically effective dose (BED) [Gy]. The response was modelled as ordered categorical data: hyper-, eu- and hypothyroidism. The final model performance was evaluated by a visual predictive check. RESULTS: The probability of the outcome following 131I therapy was best described by a proportional-odds model, including the log-linear model of 131I effect and the exponential model of the response-time relationship. All exposure measures were statistically significant with p<0.001, with BED and ABD being statistically better than the other two. Nevertheless, as BED resulted in the lowest AIC value, it was included in the final model. Accordingly, BED value of 289.7 Gy is associated with 80% probability of successful tr eatment outcome 12 months after 131I application in patients with median thyroid volume (32.28 mL). The target thyroid volume was a statistically significant covariate. The visual predictive check of the final model showed good model performance. CONCLUSION: Our results imply that BED formalism could aid in therapy individualisation. The larger thyroid volume is associated with a lower probability of a successful outcome. PMID:34273482 | DOI:10.1016/j.ejps.2021.105942 View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.