Imaging defined rapid recurrence is an independent risk factor for worse overall survival

Abstract

We appreciate the interest of Iqbal et al in our work. We also appreciate the opportunity to respond. Histologic evaluation is the only method to confirm malignancy—imaging, physical examination, and elevated tumor markers are by contrast surrogates. Although many practitioners champion a certain surrogate as superior to the others, computed tomorgraphy (CT) imaging, magnetic resonance (MR) imaging (de Bondt), positron emission tomography (PET/CT) (Acrin), and physical exam all have limitations. Yet despite these limitations imaging is powerful. At our practice it is not routine to histologically confirm every separate area of malignancy identified by imaging. A patient with multiple positive neck nodes is not recommended separate biopsies of each node. In situations of nuance additional biopsies are pursued, but in a majority of cases this is not necessary. We agree with Iqbal et al regarding the clinical dilemma this presents in the setting of early postoperative imaging. We also agree that the associated worse prognosis reported suggests that this phenomenon is real—however, we differ in the interpretation. Figure 3 was specifically included in the manuscript to address the concern that the worse prognosis of rapid recurrence was captured by histologic extracapsular extension (ECS)—there is a significant overall survival (OS) difference between the patients with histologic ECS with or without rapid recurrence. This is further demonstrated numerically in the multivariable analyses presented in Tables 3 and 4—imaging defined rapid recurrence is an independent risk factor for worse OS in head and neck cancer patients. We agree with Iqbal et al that diagnostic imaging involvement is essential and our workflow has changed as a consequence of this work. It is our current practice to obtain a diagnostic neck CT immediately prior to CT simulation in patients with histologic ECS. By contrast CT simulation data sets of patients without ECS but with unanticipated concerning imaging findings are reviewed by neuroradiology on an as needed basis.