[Distribution of metastatic affection in colorectal carcinoma using lymphatic mapping and radiation-navigated biopsy of the sentinel lymph node].

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 (U1a 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.