Systematic Review and Meta‐Analysis on the Incidence of Level‐Specific Cervical Nodal Metastasis in Primary Parotid Malignancies

Objective In primary parotid gland malignancies, the incidence of level‐specific cervical lymph node metastasis in clinically node‐positive necks remains unclear. This study aimed to determine the incidence of level‐specific cervical node metastasis in clinically node‐negative (cN0) and node‐positive (cN+) patients who presented with primary parotid malignancies. Data Sources Electronic databases (MEDLINE, EMBASE, PubMed, Cochrane). Review Methods Random‐effects meta‐analysis was used to calculate pooled estimate incidence of level‐specific nodal metastasis for parotid malignancies with 95% confidence intervals (CIs). Subgroup analyses of cN0 and cN+ were performed. Results Thirteen publications consisting of 818 patients were included. The overall incidence of cervical nodal involvement in all neck dissections was 47% (95% CI, 31%‐63%). Among those who were cN+, the incidence of nodal positivity was 89% (95% CI, 75%‐98%). Those who were cN0 had an incidence of 32% (95% CI, 14%‐53%). In cN+ patients, the incidence of nodal metastasis was high at all levels (level I 33%, level II 73%, level III 48%, level IV 39%, and level V 37%). In cN0 patients, the incidence of nodal metastasis was highest at levels II (28%) and III (11%). Conclusion For primary parotid malignancies, the incidence of occult metastases was 32% compared to 89% in a clinically positive neck. It is recommended that individuals with a primary parotid malignancy requiring elective treatment of the neck have a selective neck dissection which involves levels II to III, with the inclusion of level IV based on clinical judgment. Those undergoing a therapeutic neck dissection should undergo a comprehensive neck dissection (levels I‐V).