Purpose: To assess the impact of a diagnostic ladder including [(18)F]fluorodeoxyglucose positron emission tomography (PET) and lymphoscintigraphy guided sentinel node biopsy (LS/SNB) on neck treatment in patients with oral and oropharyngeal squamous cell carcinoma (OOSCC).
Patients and methods: Prospectively, 62 patients with resectable T1-3 OOSCC underwent computed tomography (CT) and PET. Patients without neck uptake in PET were defined as cN0 and were accrued for LS/SNB. Results were correlated with histopathology. The traditional guidelines according to CT findings were compared to the actual regimen and the outcome.
Results: Sensitivity, specificity, validity, and positive and negative predictive value of PET versus CT were 72% v 89%, 82% v 77%, 79% v 80.5%, 62% v 61.5%, and 88% v 94.5% (not significant). Thirty-eight PET negative patients underwent LS/SNB. Sentinel lymph nodes were found in all 38 patients. Five patients had positive nodes (PET false-negatives) and underwent neck dissection (ND). Fifty-one neck sides in 36 patients who were CT-negative would have been treated with selective ND according to the guidelines, and at least 45 neck sides would have had to undergo extensive ND because of positive CT findings (96 of 124 neck sides). In contrast, PET in combination with LS/SNB spared 59 neck sides, and 41 of 124 neck sides actually underwent ND as a result of PET staging, LS/SNB, and intraoperative decision. After a median follow-up of 35 months, two patients (both cN+ve and pN+ve) suffered from neck relapses.
Conclusion: Diagnostics using PET in combination with LS/SNB considerably reduced the number of extensive ND in OOSCC as compared to CT without locoregional hazard.