Assessment of sentinel lymph node detection by radioisotope scan and methylene blue alone in operable oral cavity cancer to assess its accuracy for metastasis

Abstract

Background: Squamous cell carcinoma (SCC) is the most common malignancy affecting the oral cavity. It typically metastasizes into the regional cervical lymph nodes before spreading to distant organs.Methods: A prospective study on sentinel lymph node biopsy (SLNB) in early oral cancers using methylene blue dye and sentinel node localisation using pre-operative lymphoscintigraphy and intraoperative gamma probe in early oral cavity cancer.Results: Present study had a male to female ratio of 1.9:1, with (65.5%) male and (34.5%) female patients. Present study had a side distribution of disease more on left side with 138 patients (62.7%) and ratio of left to right was approximately 1.7:1. In present study most predominating gross morphological pattern of growth was ulcerative (35%) followed by ulcero-infilterative (25%). Buccal mucosa was the most common sub-site of origin of carcinoma in oral cavity, followed by tongue, with 83 (37.7%) and 64 (29.1%) patients. Identification rate of methylene blue dye was 91.7% (100 out of 109 patient). Identification rate of radionuclide tracer was 94.6% (105 out of 111 patient). In methylene blue dye group out of 103 metastatic sentinel lymph nodes, 9 metastatic sentinel lymph nodes were detected on IHC.Conclusions: With the above results it can be concluded the SLNB study is liable in detection of actual positive node and can avoid unnecessary neck dissections in patients with SCC with negative sentinel lymph node, as having very low risk of occult lymphatic metastases in the remaining lymphatic drainage.