Sentinel lymph node biopsy has rapidly evolved into
the standard of care for node-negative melanoma. It
has been used at the Roswell Park Cancer Institute (RPCI) since 1993, and
through periodic reviews of results, several modifications have been made to
improve outcomes and contribute to the evolution of sentinel lymph node biopsy.
Michael S. Sabel, MD, and William G. Kraybill, MD, of RPCI’s department of
surgery, and colleagues, reported on the latest such review in a recent issue of
the journal, Surgery (128:556-563, 2000).
"Presently, there is great variation from hospital to
hospital in the technique of intraoperative sentinel lymph node mapping,"
said Dr. Sabel. "Several aspects of the technique have changed and evolved
since it was described initially in 1992. If sentinel lymph node biopsy is to be
the standard of care, these improvements in technique must be disseminated so
that it can be performed in a standardized manner," said Dr. Kraybill.
Nuclear Medicine and Pathology Improve Results
In the review, the charts of 182 patients with clinically
node-negative primary cutaneous melanoma, who had undergone sentinel lymph node
biopsy between January 1993 and December 1998 at RPCI, were reviewed and
assessed for the technique used to identify the sentinel lymph node, pathologic
evaluation, and use of the intraoperative frozen section. Results indicated
the accuracy of sentinel lymph node identification improved
from 91% to 100% with the combination of isosulfan blue dye and radiolabeled
colloid over isosulfan blue dye alone;
routine rather than selective lymphoscintigraphy identified
seven in-transit sentinel lymph nodes and increased detection of dual basin
drainage from 15% to 27%; and
identification of micrometastases in the sentinel lymph node
increased from 14% to 24% after discontinuing the frozen section analysis of the
sentinel lymph node in favor of processing tissue for permanent paraffin
sectioning with multiple hematoxylin and eosin levels and S-100 and HMB-45
"Through this careful review and strong collaboration with
colleagues in nuclear medicine and pathology, several areas have been identified
where sentinel lymph node biopsy may be improved," said Dr. Kraybill.
"We believe this approach is necessary if the benefits of the technique for
malignant melanoma are to be realized."