mid‐treatment nodal response in oropharyngeal squamous cell carcinoma

Prognostic potential of mid‐treatment nodal response in oropharyngeal squamous cell carcinoma:

Abstract

Background

We examine the prognostic implications of mid‐course nodal response in oropharyngeal cancer (OPX) to radiation therapy.

Methods

In 44 patients with node‐positive OPX undergoing concurrent chemoradiation, nodal volumes were measured on cone beam CTs from days 1, 10, 20, and 35. Nodal decrease (ND) was based on percent shrinkage from day 1.

Results

At a median follow‐up of 17 months, the 2‐year disease‐free survival (DFS), locoregional control (LRC), distant metastasis‐free survival (DMFS), and overall survival (OS) were 87%, 92%, 89%, and 92%, respectively. Patients with ND ≥43% at D20 had improved LRC (100% vs 78.4%, P = .03) compared to D20 ND <43%. On multivariate analysis, D20 ≥43% was independently prognostic for LRC (HR 1.17, P = .05).

Conclusion

Patients with low‐risk oropharynx cancer with ND of ≥43% by treatment day 20 had significantly improved LRC. The prognostic benefit of ND may assist in identifying candidates for treatment de‐escalation.