Radiation therapy for low- and high-risk perineural invasion in head and neck cutaneous squamous cell carcinoma: Clinical outcomes and patterns of failure

BackgroundPerineural invasion (PNI) in head and neck squamous cell carcinoma (HNSCC) portends poor prognosis. Extent of treatment of nerve pathways with varying degrees of PNI and patterns of failure following elective neural radiotherapy (RT) remain unclear. MethodsRetrospective review of HNSCC patients with high-risk (clinical/gross, large-nerve, extensive) or low-risk (microscopic/focal) PNI who underwent curative-intent treatment from 2010 to 2021. ResultsForty-four patients (mean follow-up 22 months; 59% high-risk, 41% low-risk PNI) were included. Recurrence following definitive treatment occurred in 31% high-risk and 17% low-risk PNI patients. Among high-risk patients, 69% underwent surgery with post-operative RT and 46% underwent elective neural RT. Local control (83% low-risk vs. 75% high-risk), disease-free, and overall survival did not differ between groups. ConclusionsHigh local control rates were achieved in high-risk PNI patients treated with adjuvant or primary RT, including treatment of both involved and uninvolved, communicating cranial nerves, with few failures in electively treated regions.

Automated summary

In this study, the treatment outcomes of high-risk and low-risk PNI patients with HNSCC were retrospectively reviewed. The results showed that recurrence occurred in 31% of high-risk patients and 17% of low-risk patients. High local control rates of 75% were achieved in high-risk patients who underwent surgery followed by RT or elective neural RT, indicating the efficacy of appropriate radiotherapy.