Learning curves for breast cancer sentinel lymph node mapping based on surgical volume analysis.

BACKGROUND: Implementation of new procedures, including lymphatic mapping for breast cancer, must be done and overseen by the medical community in a responsible way to ensure that the procedures are performed correctly. This study addresses the issues of adequacy of training and certification of surgeons performing lymphatic mapping. Ensuring quality in surgical care requires outcomes measures that are described in this study. STUDY DESIGN: Sixteen surgeons performed lymphatic mapping in 2,255 patients with breast cancer using a combination blue dye and Tc99m-labeled sulfur colloid to identify the sentinel lymph nodes (SLNs). All participants were trained in a 2-day CME-accredited course. The Cox learning curve model (total number of mapping failures/total number of mapping cases) for a consecutive series of lymphatic mapping cases is described. The relationship of the Surgical Volume Index, the cases performed in a 30-day period, to the failure rate for each surgeon was modeled as a logistic regression curve (y = e(a+bx)/[1 + e(a+bx)]). RESULTS: Surgeons performing less than three SLN biopsies per month had an average success rate of 86.23% +/- 8.30%. Surgeons performing three to six SLN biopsies per month had a success rate of 88.73% +/- 6.36%. Surgeons performing more than six SLN biopsies per month had a success rate of 97.81% +/- 0.44%. CONCLUSIONS: This experience defines a learning curve for lymphatic mapping in breast cancer patients. Data suggest that increased volumes lead to decreased failure rates. These data provide surgeons performing SLN biopsy with a new paradigm for assessing their skill and adequacy of training and describes the relationship between volume of cases performed and success rate of SLN detection.

The effects of postinjection massage on the sensitivity of lymphatic mapping in breast cancer.

BACKGROUND: The technique of lymphatic mapping and sentinel lymph node (SLN) biopsy is rapidly becoming the preferred method of staging the axilla of the breast cancer patient. This report describes the impact of postinjection massage on the sensitivity of this surgical technique. STUDY DESIGN: Lymphatic mapping at the H Lee Moffitt Cancer Center is performed using a combination of isosulfan blue dye and Tc99m labeled sulfur colloid. Data describing the rate of SLN identification and the node characteristics from 594 consecutive patients were calculated. Patients who received a 5-minute massage after injection of blue dye and radiocolloid were compared with a control group in which the patients did not receive a postinjection massage. RESULTS: When compared with controls, the proportion of patients who had their SLN identified using blue dye after massage increased from 73.0% to 88.3%, and the proportion of patients who had their SLN identified using radiocolloid after massage increased from 81.7% to 91.3%. The overall rate of SLN identification increased from 93.5% to 97.8%. The proportion of nodes that were stained blue among those removed increased from 73.4% to 79.7% after massage. CONCLUSIONS: As experience increases with this new procedure, the surgical technique of lymphatic mapping continues to evolve. The addition of a postinjection massage significantly improves the uptake of blue dye by SLNs and may also aid in the accumulation of radioactivity in the SLNs, further increasing the sensitivity of this procedure.

Clinical relevance of internal mammary node mapping as a guide to radiation therapy.

BACKGROUND: The surgical management of breast cancer has changed markedly with the development of lymphatic mapping and sentinel lymph node (SLN) biopsy. Lymphatic mapping technique varies with respect to injection method, mapping agent, and surgical technique. The decision to pursue the internal mammary nodes (IMN) is another source of controversy. METHODS: From April 1998 to November 2000, 1,470 patients underwent lymphatic mapping for breast cancer and were prospectively entered into the breast database. The combined technique method was used, consisting of both isosulfan blue dye and technetium-99 labeled sulfur colloid. Patients with inner quadrant lesions and suspicion for internal mammary metastasis had preoperative lymphoscintigraphy. Those with internal mammary radioactivity noted by either lymphoscintigraphy or gamma probe underwent removal of the internal mammary sentinel nodes. RESULTS: Thirty-six of the 1,470 (2.4%) patients mapped had at least 1 internal mammary lymph node removed. Inner quadrant lesions were present in 24 of the 36 (67%) IMN mapped patients. Of the 36 patients mapping to the IM area, 5 (14%) had at least 1 IM node positive. Two of the 5 (40%) had only IM metastasis, with 1 of these patients having 5 of 5 IMN positive and no disease detected in her axilla. A total of 2 of the 5 (40%) IM positive patients had more than 1 IMN positive. Twenty-eight of the 36 (78%) IM node harvested patients had preoperative lymphoscintigraphy, with 18 (64%) IMN appearing on imaging. Complications occurred in 3 of the 36 (8%) IMN mapped patients, without clinical significance. CONCLUSIONS: Mapping to the IMN basin with the finding of metastasis results in N3 disease by the current staging system. The consequence for these patients is radiation therapy to the IMN basin. It is significant to note that 14% (5 of 36) were upstaged as result of IMN detection and 40% (2 of 5) had multiple positive IMNs. Substantial disease was detected in these 5 patients necessitating additional radiation therapy while avoiding IM radiation and its attendant complications in 86% of patients mapping to the IM basin.

The role of selective sentinel lymph node dissection in breast cancer.

Axillary nodal status continues to be the most statistically significant predictor of survival for patients with breast cancer. Although still providing regional control of axillary disease, axillary dissection is more important as a staging and prognostic tool. Trials are currently underway to investigate the possibility of replacing the current standard treatment of breast cancer, axillary lymph node dissection, with the less invasive lymphatic mapping and sentinel lymph node biopsy. This issue and the technical aspects of sentinel lymph node mapping for breast cancer are discussed in detail in this article.

Utility of internal mammary lymph node removal when noted by intraoperative gamma probe detection.

BACKGROUND: Lymphatic mapping (LM) for breast cancer has made internal mammary node (IMN) detection practical and dependable. This study demonstrates the necessity of IMN removal when suggested by intraoperative radioguided surgery detection. METHODS: From April 1998 to July 2000, 1273 patients underwent LM for breast cancer. LM was performed using the combined dye and radiocolloid technique. Patients were scanned operatively with a gamma probe over the IMN area, and most underwent preoperative lymphoscintigraphy. Nodes were removed from patients in whom radioactivity was detected in the internal mammary area. RESULTS: Thirty of the 1273 (2.4%) patients mapped had at least one IMN removed. Twenty-two of 30 (73.3%) had inner quadrant lesions. Five of 30 (16.7%) patients had IMNs that were positive for metastatic disease. Three of these five had no metastatic spread to the axillary sentinel lymph node (SLN). One of thirty (3.3%) patients with IMN localization had neither hot nor blue nodes detected in an SLN procedure. CONCLUSIONS: Radioguided SLN detection should be attempted in the IMN basin with all tumors. If an IMN is identified, it should be removed. IMN biopsy is a feasible, low-risk procedure when directed by radioguided LM and provides a guide for radiotherapy for patients with positive IMNs.