Lymphoscintigraphy and radio-guided neck dissection in oral cavity squamous cell carcinoma

Purpose: The development of erratic distribution of cervical metastases from oral cavity squamous cell carcinoma (OSCC) bypassing the typical metastatic pattern can possibly challenge the role of the classic neck dissection. The purpose of this study was to assess the role of lymphoscintigraphy (LS) and radio-guided neck dissection as a simple and widely accessible method with a favorable cost/benefit ratio, able to improve the OSCC staging and possibly to tailor the surgical approach to cervical lymph node dissection. Methods: From June 2015 to December 2018, 16 patients (5 women, 11 men, median age 59.5±12.5 years) with cN0 (10) and cN+ (6) OSCC were enrolled. The day before surgery all patients underwent LS with acquisition of planar and SPECT (Single Photon Emission Computed Tomography)/CT images, after a peritumoral injection of 99mTc-Nanocoll® (median 74±1.2 MBq). Patients underwent tumor excision and a radioguided neck dissection, using a portable gamma camera. The sentinel lymph nodes (SLNs) were isolated and separately analyzed in 200-micron sections and pancytokeratin immunohistochemistry assessment, looking for micrometastases. reverse transcription polymerase chain reaction (qRT-PCR). Results: A homolateral lymphatic spread on LS was observed in all cases, whereas in 5 cases (31.3%) lymphatic drainage was contralateral to the OSCC site. In one cN0 patient, a skip micrometastasis has been identified in a SLN. Conclusion: The results of the present study may suggest a role of LS and radioguided neck dissection in detecting the real lymphatic spread of OSCC, in order to improve the oncological assessment and to tailor the neck dissection.