Background: Surgical treatment of head and neck squamous cell carcinoma (HNSCC) patients often results in complex defects, affecting functional structures. Frozen sections are valuable to guide resections and control for adequate margins; however, intraoperative assessment of bone remains challenging.
Objective: The objective of this study was to evaluate the clinical impact of an intraoperative cytological assessment of bone margins (ICAB) on resection status and patient outcome.
Methods: ICAB analysis (n = 267) was implemented in 102 patients during resection of HNSCC for a guided resection of affected bone. The cytological findings were compared with the final histological results of the corresponding bone margins, and the surgical consequences, R1 rates, and patient outcome of the ICAB intervention group were compared with an equal control group of 100 patients.
Results: ICAB revealed a sensitivity of 94.4 % [95 % confidence interval (CI) 81.3-99.3], specificity of 97.4 % (95 % CI 94.4-99.0), positive predictive value of 85.0 % (95 % CI 70.2-94.3), and negative predictive value of 99.1 % (95 % CI 96.9-99.9). Osseous R1 resections were reduced from 8 to 2.9 % (∆R1 = 5.1 %; p = 0.113), rendering a relative risk reduction (RRR) of 63.2 % with a number needed to treat (NNT) of 19.57. ICAB influenced final resection status, with a reduction of R1 resections from 17 to 7.8 % (∆R1 = 9.2 %; p = 0.026), with an RRR of 59.65 % and an NNT of 9.66. The ICAB intervention group revealed a higher disease-free survival [p(log-rank) = 0.045] and overall survival [p(log-rank) = 0.014] according to multivariable analysis.
Conclusion: ICAB, applied as a routine diagnostic tool to supplement frozen sections, can help to reduce R1 resections in order to improve patient outcome.