Sentinel Lymph Node Biopsy



Reza Rahbar, Carlos Rodriguez-Galindo, John G. Meara, Edward R. Smith and Antonio R. Perez-Atayde (eds.)Pediatric Head and Neck Tumors2014A-Z Guide to Presentation and Multimodality Management10.1007/978-1-4614-8755-5_6
© Springer Science+Business Media New York 2014


6. Sentinel Lymph Node Biopsy



Christopher Weldon 


(1)
Department of Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA

 



 

Christopher Weldon



Abstract

The utilization of sentinel lymph node biopsies in children is tumor specific and patient dependent. The technique is straightforward with little morbidity, and the means to perform this technique are neither expensive, nor labor intensive. Furthermore, the information gleaned can define the extent of disease, the scope of treatment, and its utilization will only increase in the decades to come.


Keywords
Sentinel lymph node biopsyPediatricOncologyHead and neckTechnique



Introduction


The role of a sentinel lymph node biopsy (SLNB) in the management of head and neck tumors is dependent on two factors: (1) the propensity for the known malignancy to spread to and through the lymphatic system from local to regional lymph node basins, especially in the absence of enlarged or suspected pathologic lymph nodes (LN) by physical exam and/or radiographic studies, and (2) the need to confirm that the tumor in question has spread to the most proximal, ‘upstream’ lymph node draining basin for staging information and determination of the best therapeutic option . The technique of SLNB has been employed in a variety of malignancies since its inception almost 4 decades ago with a great deal of success. It is now a vital component of staging tumors as varied as melanoma [1], breast cancer [2], and certain sarcomas [3], in addition to squamous cell head and neck tumors [4]. In children’s cancers, prospective, randomized, controlled trials documenting its utility and prognostic success are lacking. However, if results on the same cancers afflicting adults are extrapolated to children and if we review the data available for its utility in children is reviewed, then specific pediatric applications can be identified.


Key Points






  • SLNB is a safe and effective operative technique performed in the outpatient setting that is utilized to document the presence of occult lymph node metastases from specific head and neck malignancies (melanoma; various sarcomas [rhabdomyosarcoma, epithelioid sarcoma, synovial cell sarcoma]) afflicting children .


  • The technique relies upon both preoperative (via lymphatic mapping by lymphoscintigraphy utilizing technetium 99m sulfur colloid) and intraoperative detection (via administration of blue dye [isosulfan blue] by visual documentation of a discolored lymph node and/or detection of the radiolabelled tracer (technetium 99m sulfur colloid) by using a handheld gamma probe of the occult, first ‘upstream’ lymph node(s) with subsequent removal for pathological evaluation. One or several lymph nodes can be harvested and sent for pathologic determination depending on intraoperative results.


Objectives


An in depth review of the specific cancers and specific data tracing its utility as a technique is beyond the scope of this work . However, pediatric tumors in which this technique demonstrated utility in the accurate staging and management include melanoma [5], other melanocytic lesions [6], rhabdo- and some nonrhabdomyomatous soft-tissue sarcomas (epithelioid, synovial cell, clear cell, alveolar soft part, fibrosarcoma), and breast cancer [7].


Presentation


Patients will present in a variety of ways at diagnosis, and the symptoms will be related to the specific tumor type, in addition to the size and location of the tumor or organ of origin, especially when one considers the anatomic area that houses the tumor with resultant functional loss. Furthermore, for the dermatological-based cancers (melanoma), there is often no presenting symptom save the presence of the skin lesion and possible changes in the size, border, color, thickness, or general appearance of the lesion. The patient will generally require an initial history and physical exam documenting any loss of function, in addition to the anatomical boundaries and characteristics of the involved mass or lesion. A dedicated evaluation of all possible draining lymph node basins should be undertaken both at the initial evaluation and all subsequent visits. These investigations will begin with a physical exam, but they will also include radiographic (ultrasound [US], computed tomograms [CT], or magnetic resonance [MR]) and nuclear medicine (positron emission scanning [PET]) studies. Though it would be common to assume that cervical lymph node chains are the only likely lymphatic metastatic sites of head and neck lesions (especially melanomas), this may not always be the case. Hence, it is imperative that preoperative lymphatic mapping be performed to determine the precise draining basin(s), especially for those lesions or masses at the base of the neck. The axillae, inguinal regions, and intrathoracic locations have been known to provide drainage for some melanomas discovered in the head and neck .


Diagnosis and Evaluation



Physical Examination




Dec 28, 2016 | Posted by in PEDIATRICS | Comments Off on Sentinel Lymph Node Biopsy
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