Distribution of Metastatic Affection in Colorectal Carcinoma Using Lymphatic Mapping and Radiation-Navigated Biopsy of the Sentinel Lymphonode

Overview

Aim:
The aim is to define distribution of the lymphonode metastatic affection in colorectal carcinoma and to evaluate a new methodology of lymphatic mapping and the sentinel lymphonode detection during colorectal carcinoma procedures in practice.

Used methods:
A method of peroperative lymphatic mapping using a Patentblue method in vivo. Rectoscopic peritumoral application of a radiocoloid in a two-day or a single-day protocol, scintigraphy, peroperative quants of radioactivity detection using a gamma probe. Radical or paliative tumor resection. Detection of the sentinel and non-sentinel nodes on a preparation ex vivo, divided according to levels. The metastatic affection distribution is assessed in three levels, marked U₁ – U₃, a S₁ – S₃. Histopathological examination of the nodes on series sections and, event. immunohistochemistry.

Results:
The methods were used in 66 patients. A total of 970 nodes have been examined, with an average of 14.6 nodes/patient. The metastases quantity decreases with distance from the tumor. The peritumoral levels (U₁ a S₁) record the highest rates of metastases. In our patient group, 92% of the metastases were recorded in the S₁ level, 4% in the S₂ level and 4 % in the S₃ level.

Conclusions:
The highest rate of metastases was recorded in the levels, closest to the tumor, therefore, in case of negative findings of sentinel nodes in the S₁ level, the nodes from this level may be closely examined (using the method of series sections and immunhistochemistry) and the staging be established more precisely.

Key words:
colorectal carcinoma – sentinel lymphonode – radiocoloid – lymphatic mapping