Sentinel node biopsy using indocyanine green in oral/oropharyngeal cancer

Abstract

Backgrounds: Radioactive tracer-based detection has been proposed as a standard procedure in identifying sentinel nodes for cN0 oral/oropharyngeal carcinoma. However, access to radioactive isotopes may be limited in some surgical centers, and there is potential risk of the radioactive tracers to the operators. This study was designed to evaluate the feasibility of near-infrared fluorescence imaging with indocyanine green combined with blue dye mapping in sentinel node biopsy for cN0 oral/oropharyngeal carcinoma. Methods: Twenty-six cases of previously untreated oral/oropharyngeal carcinoma staged cT1-2N0M0 were enrolled in this study. One milliliter of indocyanine green (5 mg/ml) and 1.5 ml of methylene blue (1 mg/ml) were injected sequentially around the primary tumor in a four-quadrant pattern before skin incision. After elevation of the platysma flap and posterior retraction of the sternocleidomastoid muscle, fluorescence images were taken with a near-infrared detector, with special attention paid to any blue-dyed lymph nodes. Lymph nodes identified first with fluorescent hot spots with or without blue dye were defined as sentinel nodes, and they were harvested and sent for pathologic study. Results: Sentinel nodes were successfully harvested in all 26 cases. The number of sentinel nodes (SNs) per case varied from 1 to 9, with an average of 3.4. Routine pathology demonstrated occult metastasis exclusively in SNs in four cases (15.4 %). No tracer-associated side effects occurred in this series. Conclusions: Near-infrared imaging using indocyanine green combined with methylene blue mapping is a feasible and reliable new method for SN biopsy in cN0 oral/oropharyngeal carcinoma.

Surgical margins in oral cavity squamous cell carcinoma: Current practices and future directions

“…Indocyanine green (ICG) has been utilized for fluorescent guidance in sentinel lymph node dissections of OSCC patients by injection of the agent at the primary site . However, ICG does not show effective tissue specificity at the primary site to be useful as a tool for intraoperative margin delineation …”

Contrast-enhanced ultrasound mapping of sentinel lymph nodes in oral tongue cancer—a pilot study

“…Safety, reliability and high IR were observed in preliminary studies of NIF used for SLN identification in head and neck cancers. 22 Christensen et al 23 reported pre-operative NIF detection of the SLNs in all of their 30 patients with oral cancer and intraoperative IR of 97% (66/68 nodes). In total, these newly introduced means of lymphatic imaging possess prominent advantages over the traditional radiocolloid technique; still, these advanced technologies unfortunately are not too widely accessible.…”

Feasibility of sentinel lymph node detection by near-infrared endoscopy in squamous cell carcinoma of the oral cavity: a pilot study

“…NIR fluorescence imaging has demonstrated promising results in detecting SLN(s) in cervical cancer and melanoma patients [14,15]. There are a few studies for head and neck cancer with open systems positioned outside the surgical field [16][17][18][19]. The authors confirmed an identification rate of 97-100%, with an average of 3 SLN in each patient, without micro-metastases in non-SLN(s).…”

“…The costs of ICG is much lower than for a radiotracer. Besides this, the fluorescence imaging system is less expensive than a radiation detection probe [18]. Image acquisition can be performed mono-institutional by the treating surgeon.…”