Evaluation of nodal response after intra-arterial chemoradiation for node-positive head and neck cancer.

This retrospective study aimed to compare the accuracy of two nodal evaluation criteria using computed tomography after intra-arterial chemoradiation in node-positive head and neck squamous cell carcinomas. Computed tomography was used to evaluate radiographic nodal response 4-8 weeks after intra-arterial chemoradiation. We compared the accuracy of two different criteria: criterion 1 (radiographic complete response was recorded in the absence of focal abnormalities and if the maximum diameter of the metastatic node was less than 15 mm), and criterion 2 (radiographic complete response was recorded in the absence of focal abnormalities and if the minimum diameter of metastatic nodes was less than 7 mm in level II and if the minimum diameter of metastatic nodes in the rest of the neck was less than 6 mm). Positive predictive values were criterion 1: 69.2%, criterion 2: 47.8%; negative predictive values were criterion 1: 88.5%, criterion 2: 90.5%. Positive likelihood ratios were criterion 1: 7.50, criterion 2: 3.06. The difference between each criteria was statistically significant using McNemar's test (p = 0.0016). Computed tomography evaluation accuracy of nodal response after intra-arterial chemoradiation was comparable to recent reports, and it was feasible to perform salvage neck dissection by computed tomography evaluation for nodal response. We recommend using criterion 1 because of its simplicity and reliability.