Clinical aspects of sentinel node biopsy

Sentinel lymph node (SLN) biopsy requires validation by a backup axillary dissection in a defined series of cases before becoming standard practice, to establish individual and institutional success rates and the frequency of false negative results. At least 90% success in finding the SLN with no more than 5-10% false negative results is a reasonable goal for surgeons and institutions learning the technique. A combination of isotope and dye to map the SLN is probably superior to either method used alone, yet a wide variety of technical variations in the procedure have produced a striking similarity of results. Most breast cancer patients are suitable for SLN biopsy, and the large majority reported to date has had clinical stage T1-2N0 invasive breast cancers. SLN biopsy will play a growing role in patients having prophylactic mastectomy, and in those with 'high-risk' duct carcinoma in situ, microinvasive cancers, T3 disease, and neoadjuvant chemotherapy. SLN biopsy for the first time makes enhanced pathologic analysis of lymph nodes logistically feasible, at once allowing greater staging accuracy and less morbidity than standard methods. Retrospective data suggest that micrometastases identified in this way are prognostically significant, and prospective clinical trials now accruing promise a definitive answer to this issue

Lymphoscintigraphy and Ultrasound Guided Fine Needle Aspiration Cytology of Sentinel Lymph Nodes in Head and Neck Cancer Patients

Accurate staging of the regional lymph nodes is crucial for the appropriate management of patients with squamous cell carcinoma of the head and neck (HNSCC). However, the current diagnostic modalities have low accuracy for N0 neck, and even the most optimal procedure, ultrasound-guided fine needle aspiration cytology (USgFNAC), still has a sensitivity of only 42%-73%. In this study we evaluated whether the identification of the sentinel node might improve the selection of lymph nodes for USgFNAC. Twelve HNSCC patients received 3-4 peritumoral injections of 10-30 MBq 99mTc-labeled colloidal albumin, and the sentinel node was identified by dynamic scintigraphy and marked on the skin using a handheld probe, and/or by scintillation counting of the aspirates. After sentinel node identification USgFNAC was performed. Correct aspiration of the identified sentinel node(s) was confirmed by scintillation counting. In 11 out of 12 cases the sentinel node(s) could be visualized by dynamic planar imaging. In one case the sentinel node(s) were identified by scintillation counting only. In a number of patients different or supplementary lymph nodes were aspirated on the basis of sentinel node identification. These initial data strongly suggest that sentinel node identification might improve the staging of the neck by USgFNA