Sentinel node biopsy in N0 squamous cell carcinoma of the oral cavity and oropharynx in patients previously treated with surgery or radiation therapy: a pilot study.

OBJECTIVES To assess the feasibility of sentinel lymph node (SLN) localization and to determine the predictive value of SLN biopsy for occult neck metastases in patients previously treated with surgery or radiation therapy and with N0 squamous cell carcinoma of the oral cavity or oropharynx. DESIGN Prospective case series. SETTING Tertiary academic hospital. PATIENTS Eleven patients with T1 to T4 N0 squamous cell carcinoma of the oral cavity or oropharynx. INTERVENTIONS Patients underwent preoperative peritumoral injection of technetium Tc 99m sulfur colloid followed by dynamic lymphoscintigraphy and operative localization of the SLN(s) with the use of a handheld gamma probe. MAIN OUTCOME MEASURES The presence or absence of metastatic disease in N0 squamous cell carcinoma of the oral cavity and oropharynx in patients previously treated with surgery or radiation therapy as identified by SLN biopsy findings. RESULTS In each of the 11 patients, 1 to 3 SLNs were identified by lymphoscintigraphy. All SLNs identified by lymphoscintigraphy were successfully identified and removed with the use of an intraoperative gamma probe. In 10 of the 11 patients, the biopsy findings from the SLN(s) accurately predicted the presence or absence of occult neck metastasis. There was 1 instance of a negative SLN with a positive neck dissection. The overall negative predictive value of the study was 91%. No aberrant lymphatic drainage patterns were observed in this study. CONCLUSION In patients previously treated with surgery or radiation therapy, SLN biopsy was as effective as in previously untreated patients according to published reports and warrants inclusion of this patient group into larger studies.