ICG/NIR TECHNIQUE IN LYMPH NODE MAPPING IN PATIENTS WITH COLORECTAL CANCER
Authors: Maliborska S. V. , Holotiuk V. V. , Partykevych Y. D. 
Published: July 2021

Most cancers in humans are epithelial in nature and such neoplasms metastasize via lymphatics; therefore, the lymphatic system plays a pivotal role in a significant number of malignancies. The hematologic behavior of metastatic cancer has been extensively studied, but little is known regarding lymphatic metastasis. Sentinel lymph node (SLN) is the first node to receive the drainage directly from a tumor. Detection and pathological examination of the SLN is an important oncological procedure that minimizes morbidity related to extensive nodal dissection. After many years of observation and research on its use in various malignancies SLN biopsy has become the standard surgical treatment in patients with malignant melanoma, breast and cervical cancers.

Today, the issue of diagnosing lymphogenous metastasis in patients with colorectal cancer remains relevant. Standardized methods for examining lymph nodes do not allow to reliably establish the presence of their metastatic lesions. For a more effective assessment, additional examinations are carried out to identify the sentinel lymph node and its precision study, in particular, one of the newest methods is mapping of sentinel lymph nodes using Indocyanine Green (ICG) using near infrared radiation (NIR). Along with the introduction of new technologies, such as the fluorescent dyes indocyanine green (ICG) and near-infrared fluorescence (NIR), and pathologic ultrastaging, Indocyanine green fluorescence-imaging (ICG-FI) has emerged as a potential tool for increasing the accuracy of staging of patients with primary colorectal cancer (CRC) through the detection of sentinel lymph nodes (SLNs).

Indocyanine green (ICG) is an inexpensive and safe non-specific fluorescent probe. SLN detection rate has increased and false-negative rate has decreased.Colorectal cancer is the third most common cancer in the Western hemisphere and the incidence increases with increasing age. Surgery is the only curative therapy for localized colorectal cancer and adjuvant chemotherapy is usually recommended for patients with lymph node metastases. Surgery, radiation therapy and chemotherapy are the key components of rectal cancer therapy.

Local recurrence greatly affects the treatment efficiency and the survival outcomes for patients with rectal cancer. Lateral pelvic lymph node (LPLN) metastasis (LPNM) is an important factor for local recurrence. Accurate staging TNM of colorectal cancer is essential for evaluating the prognosis and developing an optimal treatment strategy. The presence of metastatic lateral pelvic lymph nodes has been shown to portend a worse prognosis for patients with low rectal cancer. SLN biopsy should be used in this patients for evaluating the prognosis and developing an optimal treatment strategy. Only with all of the above diagnostic tools can accurate diagnosis according to TNM and the choice of the right treatment strategy. The article analyzes and summarizes the scientific literature data on the methods for determining the sentinel lymph node. The sensitivity and specificity of the sentinel lymph node detection using ICG/NIR has been demonstrated. The analysis of various techniques for introducing indocyanine green, the rate of SLN identification was carried out.