† These authors contributed equally.
Introduction: Several studies suggest that there is an association between the metastatic nodal tumor volume and the clinical outcome in patients with solid cancers. However, despite the prognostic potential of nodal volume, a standardized method for estimating the nodal volumetric parameters is lacking. Herein, we conducted a systematic review of the published scientific literature towards investigating the prognostic value of nodal volume in the carcinomas of head and neck, taking into consideration the primary tumor site and the human papillomavirus (HPV) status. Methodological issues: For this purpose, the biomedical literature database PubMed/MEDLINE was searched for studies relevant to the relationship of nodal volume to the treatment outcome and survival in head and neck squamous cell carcinoma (HNSCC) patients. Collectively, based on stringent inclusion/exclusion criteria, 23 eligible studies were included in the present systematic review. Results: On the basis of our findings, nodal volume is suggested to be strongly associated with clinical outcomes in HNSCC patients. Of particular note, there is an indication that nodal volume is an independent factor for further risk stratification for recurrence-free survival in patients with squamous cell carcinoma of the pharynx (oropharynx and hypopharynx). Extranodal extension (ENE) and HPV status should be also taken into consideration in further studies.