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.

PURPOSE: 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. METHODS AND MATERIALS: 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.
RESULTS: 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.
CONCLUSION: 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.