External validation of a prognostic model incorporating quantitative PET image features in esophageal cancer

Foley, Kieran, Whybra, Philip, Kalendralis, P, Larue, R, Berbee, M, Sosef, M, Parkinson, Craig, Staffurth, John, Crosby, Thomas, Roberts, S, Dekker, A, Wee, L and Spezi, Emiliano 2019. External validation of a prognostic model incorporating quantitative PET image features in esophageal cancer. Radiotherapy and Oncology 133 , pp. 205-212. 10.1016/j.radonc.2018.10.033 Item availability restricted.

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Abstract

Aim Enhanced prognostic models are required to improve risk stratification of patients with oesophageal cancer so treatment decisions can be optimised. The primary aim was to externally validate a published prognostic model incorporating PET image features. Transferability of the model was compared using only clinical variables. Methods This was a Transparent Reporting of a multivariate prediction model for Individual Prognosis Or Diagnosis (TRIPOD) type 3 study. The model was validated against patients treated with neoadjuvant chemoradiotherapy according to the Neoadjuvant chemoradiotherapy plus surgery versus surgery alone for oesophageal or junctional cancer (CROSS) trial regimen using pre- and post-harmonised image features. The Kaplan–Meier method with log-rank significance tests assessed risk strata discrimination. A Cox proportional hazards model assessed model calibration. Primary outcome was overall survival (OS). Results Between 2010 and 2015, 449 patients were included in the development (n = 302), internal validation (n = 101) and external validation (n = 46) cohorts. No statistically significant difference in OS between patient quartiles was demonstrated in prognostic models incorporating PET image features (X2 = 1.42, df = 3, p = 0.70) or exclusively clinical variables (age, disease stage and treatment; X2 = 1.19, df = 3, p = 0.75). The calibration slope β of both models was not significantly different from unity (p = 0.29 and 0.29, respectively). Risk groups defined using only clinical variables suggested differences in OS, although these were not statistically significant (X2 = 0.71, df = 2, p = 0.70). Conclusion The prognostic model did not enable significant discrimination between the validation risk groups, but a second model with exclusively clinical variables suggested some transferable prognostic ability. PET harmonisation did not significantly change the results of model validation.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Medicine Engineering
Publisher:	Elsevier
ISSN:	0167-8140
Date of First Compliant Deposit:	13 November 2018
Date of Acceptance:	25 October 2018
Last Modified:	03 Jun 2019 12:44
URI:	http://orca.cf.ac.uk/id/eprint/116688

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