Sentinel node biopsy

Krag et al. (Oct. 1 issue)1 present interesting data on the use of probe-guided resection of radioactive sentinel nodes in patients with breast cancer, but they conclude that “the procedure can be technically challenging, and the success rate varies according to the surgeon.” In our opinion, preoperative lymphoscintigraphy can facilitate surgical localization and excision of the sentinel node and increase the detection rate. Lymphoscintigraphy is a nuclear-medicine procedure that is easy to perform and, in conjunction with the intraoperative gamma probe, has been successfully used primarily in patients with malignant melanoma or breast cancer.2,3 The main advantage of this imaging technique is that it allows accurate preoperative localization of the sentinel node; after scintigraphic images have been obtained, a mark can be made on the skin that corresponds to the first lymph node detected by the gamma camera, thereby indicating precisely where the incision should be made. The use of the gamma probe during surgery then guides dissection, making the node biopsy easier and consistently successful. In most patients, the sentinel node is visible within 30 minutes after the injection, regardless of the size of the radiolabeled particles used, when they are injected subdermally.4 Lymphoscintigraphy is not time-consuming; anterior and lateral views, each obtained within five minutes, are sufficient to identify another 10 percent of sentinel nodes that might have not been detected with the use of a probe survey alone.5