Prognostic value of pretreatment radiological MRI variables and dynamic contrast-enhanced MRI on radiotherapy treatment outcome in laryngeal and hypopharyngeal tumors

Abstract

Background: This study aimed to determine the prognostic value of radiological magnetic resonance imaging (MRI) variables and dynamic contrast enhanced (DCE)-MRI for local control (LC), disease control (DC), and overall survival (OS) in laryngeal and hypopharyngeal cancer patients after radiotherapy.

Methods: 320 patients treated with radiotherapy were retrospectively included. Pretreatment MRIs were evaluated for the following anatomical tumor characteristics: cartilage invasion, extralaryngeal spread, and involvement of the anterior commissure, pre-epiglottic space, and paralaryngeal space.Pretreatment DCE-MRI was available in 89 patients. The median and 95th percentile of the 60-second area under the contrast-distribution-curve (AUC60_median and AUC60_p95) were determined in the tumor volume.

Results: Univariable log-rank test determined that extralaryngeal spread, tumor volume and T-stage were prognostic for worse LC, DC, and OS. A low AUC60_p95 (<31.7 mmol·s/L) and thyroid cartilage invasion were prognostic for worse OS.In multivariable analysis, a Cox proportional hazard model showed that a AUC60_p95 ≥ 31.7 mmol·s/L was prognostic for better OS (HR=0.25, P<.001). Tumor volume was prognostic for DC (HR=3.42, P<.001) and OS (HR=3.27, P<.001). No anatomical MRI variables were significantly prognostic for LC, DC, or OS in multivariable analysis when corrected for confounders.

Conclusion: Low pretreatment AUC60_p95 is prognostic for a worse OS, suggesting that poor tumor perfusion leads to worse survival. Large tumor volume is also prognostic for worse DC and OS. Anatomical MRI parameters are not prognostic for any of the evaluated treatment outcomes when corrected for confounders like age, T-stage, N-stage, and tumor volume.

Keywords: Dynamic Contrast-Enhanced MRI; Head and neck cancer; Perfusion; Prognostic study; Tumor volume.

Fig. 1

Examples of two patients with low (A) and high (B) tumor perfusion. The AUC60 maps show the area under the contrast concentration curve for the first 60 s after contrast injection for each voxel. The concentration curves show the median and 95th percentile gadolinium concentration in the tumor over time. Patient A shows limited tumor perfusion with an AUC60_median of 7.1 mmol·s/L, while patient B shows a high perfusion with an AUC60_median of 26.6 mmol·s/L.

Fig. 2

Kaplan-Meier survival curves of local control, disease control and overall survival stratified according to the 95th percentile of the area under the concentration curve of the first 60 s (AUC60_p95) and tumor volume. The tables below show the number of at risk.