Diffusion-weighted MRI versus PET/CT in evaluation of clinically N0 neck in patients with HNSCC. Systematic review and meta-analysis study

BackgroundEvaluation of a clinically N0 neck is essential in cases of head and neck squamous cell carcinoma (HNSCC) in order to determine whether the neck needs treatment or not.PurposeThe study was designed to compare the efficacy of DW-MRI with that of PET/CT scans in the preoperative evaluation of clinically N0 neck in cases of HNSCC.MethodsA systematic search was performed by the PubMed/MEDLINE to identify and select the relevant studies published within the last 20 years (up to 20/01/2014). Reported sensitivities, specificities, Positive Likelihood Ratio, Negative Likelihood Ratio and Diagnostic Odds Ratio were metaanalyzed. QUADAS criteria were used to evaluate the methodologic quality of the studies.ResultsSix studies met the inclusion criteria and were analyzed. Only one study evaluated DW-MRI whereas 5 studies evaluated PET/CT comprising a total sample size of 329 patients. Sensitivity was homogeneous across studies (P = 0.202), whereas specificity was heterogeneous across studies (P = 0.050). The overall sensitivity, specificity and accuracy rates of DW-MRI in evaluation of a clinically N0 neck were 100%, 71% and 85% respectively whereas PET/CT scans’ overall sensitivity, specificity and accuracy were 68%, 84% and 78% respectively.ConclusionsThe available evidence suggests that DWI is more sensitive than PET/CT in the preoperative evaluation of cN0 neck in patients with HNSCC. PET/CT exam has low sensitivity and a positive test would not help the clinician in the management of the patient with clinically N0 disease and therefore, it should not be routinely used in neck nodal status work-ups.