Post-RT CT results as a predictive model for the necessity of planned post-RT neck dissection in patients with cervical metastatic disease from squamous cell carcinoma.

Abstract

To establish whether the extent of neck disease on postradiation therapy (RT) computed tomography (CT) can predict the likelihood of positive neck nodes and, thereby, the necessity of planned post-RT neck dissection. Ninety-five patients who underwent post-RT neck dissection within 2 months for squamous cell carcinoma of the head and neck were eligible. Of the 95 patients, 37 (32.7%) of 113 hemineck specimens were pathologically positive. On post-RT CT imaging studies, the number and size of lymph nodes >1 cm were recorded. Internal focal defects and the likelihood of extracapsular spread were graded. If lymph nodes on post-RT CT were < or = 15 mm, free of significant internal focal low-attenuation or calcification, and without imaging evidence of extracapsular spread, the surgical hemineck specimen was positive in 1 (3.4%) of the 29 hemineck specimens. A focal low-attenuation defect (p = 0.0078) and evidence of extracapsular spread (p = 0.0721) seen in the residual nodal mass on CT were independent predictors of a positive surgical specimen by multivariate analysis. CT findings on post-RT neck studies can help predict the likelihood of residual disease and, thereby, the necessity of planned post-RT neck dissection.