LOS ANGELES - Lymphoscintigraphy has been used for several years to map sentinel lymph nodes for the detection of intra- and extra-axillary breast metastases. However, the uneven success rate associated with the technique has led some doctors to rely on gamma probes for sentinel node detection. The latter method, known as radiodetection, has proved more reliable for the detection of sentinel nodes, leading many surgeons to embrace the technology.
Moreover, the first lymph node radiodetected by a surgeon may not be the only sentinel node. Some patients may have as many as four, according to research presented by Dr. Chantal Curtet at the 2002 Society of Nuclear Medicine meeting this week.
"By definition, the sentinel lymph node is the first lymph node receiving lymphatic drainage from a primary cancer site," Curtet said. "Thus, surgeons search for and remove the first lymph node that they radiodetect."
Curtet, representing a team from the Cancer Center North Hospital in Nantes, France, presented compelling evidence that surgeons should search for and remove not only one sentinel lymph node but also sometimes two or more sentinel nodes.
Her group conducted an analysis of 464 sentinel lymph nodes removed from 230 patients with infiltrative breast cancer. Two injections of Tc-99m sulfur colloid were used as a tracer for the procedure and were injected into patients 20 hours before surgery.
Preoperative radiodetection was performed using a Novelec gamma probe with a bismuth germanate oxide (BGO) scintillator on background axilla, sentinel lymph nodes, and lymphadenectomy. In addition, all nodes underwent histological analysis with sections at 500µ intervals.
The researchers radiodetected two or more sentinel lymph nodes in approximately 68% of the patients. In examining patients who had two or three identified sentinel lymph nodes, they discovered metastases in 44%, with 10% and 21% of the cancer findings occurring in the second and third sentinel lymph nodes, respectively.
"In our patient groups with multiple sentinel lymph nodes, 19 had metastases not radiodetected in the first or second sentinel lymph node, and these patients would not have had lymphadenectomy if only one sentinel lymph node was removed. For 13 of them no more activity was found," Curtet said.
In addition to having surgeons search for more than one sentinel lymph node to detect metastases, Curtet recommended that facilities institute a rigorous histopathological procedure to ensure optimal detection of metastases and micrometastases.
By Jonathan S. Batchelor
AuntMinnie.com staff writer
June 17, 2002
Related Reading
Scintimammography catches chemoresistance in breast cancer patients, June 13, 2002
Copyright © 2002 AuntMinnie.com
