Comparison of surveillance modalities in the surveillance of sinonasal squamous cell carcinoma recurrence: A multi-institutional study.

Background: Recurrence of sinonasal squamous cell carcinoma (SNSCC) follows an aggressive course, and early detection is paramount. This study identifies the parameters of different surveillance modalities.

Methods: We conducted a retrospective study of 105 SNSCC patients at three academic institutions from November 2009 to July 2024. Patient records were reviewed for demographics, tumor characteristics, endoscopy, CT, PET/CT, and MRI findings. Multivariable analyses were performed in RStudio.

Results: Mean time to recurrence was 12.1 months (SD 13.9 months). Patients with higher Charlson Comorbidity Index (p = 0.041), endoscopic surgical approach (p = 0.015), and suspicious surveillance findings (p = 0.029) had higher rates of recurrence. Endoscopy showed a sensitivity of 18.5% and specificity of 99.2%, with a positive predictive value (PPV) of 45.5% and negative predictive value (NPV) of 97.0%. CT had a sensitivity of 75.0% and specificity of 100.0%, with a PPV of 100.0% and NPV of 97.6%. PET/CT demonstrated a sensitivity of 95.2% and specificity of 90.8%, with a PPV of 64.5% and NPV of 97.6%. MRI showed a sensitivity of 72.4% and specificity of 97.1%, with a PPV of 65.6% and NPV of 97.9%. The median time from the last normal surveillance to recurrence was 2.07 months for endoscopy, 8.61 months for CT, 8.15 months for PET/CT, and 6.49 months for MRI.

Conclusions: The high specificity and NPV of endoscopy, alongside the high sensitivity of PET/CT, support a multimodal approach for surveillance. Given the mean onset of SNSCC recurrence at 12.1 months, surveillance beyond the National Comprehensive Cancer Network's asymptomatic 6-month guideline is warranted, and follow-up should be tailored to patient-specific risk factors.