New Technologies for Sentinel Lymph Node Detection

Abstract

The ‘standard of care' method for sentinel node mapping is the combination technique using radioisotope and blue dye although some centres use radioisotope or blue dye alone. Radioisotope usage requires licensing, has regulatory issues around handling and disposal of waste, and logistically may be unavailable or difficult to implement in some centres or less developed country. This has led to the development of alternative methods such as superparamagnetic iron oxide (SPIO), fluorescence techniques using indocyanine green (ICG) or fluorescein, computed tomography lymphography, and contrast-enhanced ultrasound scan (CEUS) using microbubbles. The newer techniques will potentially enable a more widespread adoption of this procedure; however, a common barrier for these techniques is the lack of standardisation and no randomised trials to evaluate their effectiveness against the current standard of care. Furthermore, many of these techniques are more costly and may become redundant in node-negative patients with small tumours if ongoing trials show that sentinel node biopsy offers no additional benefit to grey-scale axillary ultrasound. This review discusses the new techniques for sentinel node mapping that have emerged including their pros and cons.

Biopsy of sentinel lymph nodes after injection of methylene blue and lymphoscintigraphic guidance in 30 dogs with mast cell tumors

“…Other SLN mapping techniques without scintigraphy overcome the latter limitation. 23 However, scintigraphy is the gold standard method in human medicine, 55 and no comparative data on the feasibility and cost of different techniques have been reported in veterinary medicine. This diagnostic procedure has an additional cost, but clinicians must advise the owner about the high percentage of occult metastatic SLN, and that lymphadenectomy seems to have not only a staging purpose but also a therapeutic value.…”

Using Computed Tomography Lymphography for Mapping of Sentinel Lymph Nodes in Patients with Breast Cancer

“…[ 4 ] The Japanese guideline clearly states that “The combination of blue dye and RI showed slightly better identification rates than either method used alone; therefore, the combined method is standard.” [ 5 ] However, medical law stipulates that a license is required to use RI in Japan; therefore, the introduction of the RI method is not easy. Moreover, the gamma probe used in the RI method is very expensive, costing >€15,000, [ 6 ] which makes the introduction more difficult. Only 28% of Japanese private hospitals that perform breast cancer surgery have a gamma probe.…”

Evaluation of lymph node metastasis in a rabbit tumor model: correlations between contrast-enhanced ultrasound and pathologic findings

“…These modalities provide sufficient information for clinicians and surgeons to decide on a treatment method, but some have limitations for intraoperative use, such as a requirement to transfer the patient to an imaging facility and a relatively long preparation time. US has several advantages over alternative techniques such as positron emission tomography/ CT and lymphoscintigraphy, including the absence of radiation exposure or other harmful effects, easy accessibility, and lower costs [4,5].…”