Sentinel Node Localization in Oral Cavity and Oropharynx Squamous Cell Cancer

Abstract

Objective: To evaluate the feasibility and predictive ability of the sentinel node localization technique for patients with squamous cell carcinoma of the oral cavity or oropharynx and clinically negative necks.Design: Prospective, efficacy study comparing the histopathologic status of the sentinel node with that of the remaining neck dissection specimen.Setting: Tertiary referral center.Patients: Patients with T1 or T2 disease and clinically negative necks were eligible for the study. Nine previously untreated patients with oral cavity or oropharyngeal squamous cell carcinoma were enrolled in the study.Interventions: Ulfiltered technetium Tc 99m sulfur colloid injections of the primary tumor and lymphoscintigraphy were performed on the day before surgery. Intraoperatively, the sentinel node(s) was localized with a gamma probe and removed after tumor resection and before neck dissection. Main Outcome Measures:The primary outcome was the negative predictive value of the histopathologic status of the sentinel node for predicting cervical metastases.Results: Sentinel nodes were identified in 9 previously untreated patients. In 5 patients, there were no positive nodes. In 4 patients, the sentinel nodes were the only histopathologically positive nodes. In previously untreated patients, the sentinel node technique had a negative predictive value of 100% for cervical metastasis.Conclusions: Our preliminary investigation shows that sentinel node localization is technically feasible in head and neck surgery and is predictive of cervical metastasis. The sentinel node technique has the potential to decrease the number of neck dissections performed in clinically negative necks, thus reducing the associated morbidity for patients in this group.

Sentinel Lymph Node Radiolocalization with 99mTc Filtered Tin Colloid in Clinically Node-Negative Squamous Cell Carcinomas of the Oral Cavity

“…The amount of 99m Tc filtered tin colloid radiotracer in this study was 5-6 mCi in contrast to that of other reports (1-2 mCi) (3, 4, 7-9). With its half-life of about 6 hr, 1-1.5 mCi of radiotracer remained in the tissue on the following morning, which is similar to several other reports.…”

Sentinel Lymph Node Biopsy in N0 Squamous Cell Carcinoma of the Oral Cavity and Oropharynx

“…[13][14][15] We found that 0.5 to 1.0 mCi in 0.5 to 1.0 mL effectively identified the SLN during lymphoscintigraphy and intraoperative gamma probing in all 20 patients. Our experience supports the theory of Taylor et al 17 that the use of small volumes of radioactive tracer increases the likelihood of capturing those lymphatics that drain the primary tumor. Larger injected volumes associated with higher tissue pressures would be expected to diffuse more widely, potentially involving other lymphatic channels unrelated to the primary tumor.…”

“…8,14,20 We did not attempt to use blue dye and had no difficulty in localizing the SLNs intraoperatively with the handheld gamma probe. Several authors 13,15 had no difficulty identifying the SLNs with the primary tumor in situ, but, as previously described, 17 we found significant benefit in removing the primary tumor before SLN localization to reduce the "shine through" effect of residual radioactivity. Even with removal of the primary tumor, there were instances in which there was still significant shine through, particularly when the SLN was close to the primary site.…”

Feasibility of Sentinel Lymph Node Radiolocalization in Neck Node-Negative Oral Squamous Cell Carcinoma Patients

“…Our experience confirmed the findings of others that SLN is very accurate in predicting nodal disease [3,[5][6][7][8][9]. Identification of SLN by LS and GP was found to be possible with this technique.…”