Lymphoscintigraphy (LS) in Oral Cavity Cancer (OCC) as a tool for a tailored surgical approach through selective and modified lymph-adenectomy: preliminary report

Aim: The purpose of the study was to assess the role of LS as a simple and widely accessible method with a favorable cost/benefit ratio in improving OCC staging and surgical appropriateness and implementing a tailored surgical approach to cervical lymph node dissection. The aim was to assess the lymphatic drainage in OCC through LS, in order to identify the percentage of patients with a lymphatic drainage beyond the compart- ments classically included in tumor surgery, and extend lymphadenecto- my to the side of abnormal lymphatic drainage evaluating the metastatic status of excised lymph nodes. Method: we enrolled 7 consecutive pa- tients (4 female, 3 male, median age 74±4.2 yo) affected by OCC sched- uled for surgery. The day before surgery all patients underwent LS with planar and SPECT/CT images acquisition comprising head and neck regions, after the administration of 99mTc-nanocoll (median 74±2.1 MBq) divided into injections (median 3±1) performed around the OCC, with lymph nodal drainage identification. Patients underwent tumor ecxision and lymphadenectomy of usual laterocervical compartment (de- pending on tumor localization) and radioguided surgery of additional sites of lymphatic drainage as shown by LS. Anatomo-pathological anal- ysis of tumor and lymph nodes was performed. Results: in 4 cases the tumor was in the tongue; in 1 case in the upper right dental arch and in 2 cases in the palate. Out of 7 patients, 3 (42%) showed laterocervical lymphatic drainage both ipsilateral and contralateral (LII, LIV and LIII respectively) to tumor. In 1 of these 3 cases (33%), metastasis was iden- tified in the contralateral cervical lymph nodes (LIII). In the remaining 4 cases the lymphatic drainage was only ipsilateral to tumor and lymph nodes metastases were observed in 2 cases (50%). Conclusions: Although the results of this study are limited and preliminary, it has been possible to observe that the lymphatic drainage from OCC can be abnor- mal, namely contralateral to tumor site in cervical region, in a non- negligible percentage of cases (42% overall), with possible cervical lymph nodes metastatic involvement (33% of cases and 14% overall). Therefore LS could be a useful tool to properly map the lymphatic drain- age from OCC, in order to perform a selective and modified lymphadenectomy (different from classical one) with potential benefits for patients in terms of more accurate cancer staging and better disease control, and for health service in terms of costs. Of course, our data should be increased in order to obtain more reliable and reproducible results.