Defining the optimal surgeon experience for breast cancer sentinel lymph node biopsy: a model for implementation of new surgical techniques.

OBJECTIVE: To determine the optimal experience required to minimize the false-negative rate of sentinel lymph node (SLN) biopsy for breast cancer. SUMMARY BACKGROUND DATA: Before abandoning routine axillary dissection in favor of SLN biopsy for breast cancer, each surgeon and institution must document acceptable SLN identification and false-negative rates. Although some studies have examined the impact of individual surgeon experience on the SLN identification rate, minimal data exist to determine the optimal experience required to minimize the more crucial false-negative rate. METHODS: Analysis was performed of a large prospective multiinstitutional study involving 226 surgeons. SLN biopsy was performed using blue dye, radioactive colloid, or both. SLN biopsy was performed with completion axillary LN dissection in all patients. The impact of surgeon experience on the SLN identification and false-negative rates was examined. Logistic regression analysis was performed to evaluate independent factors in addition to surgeon experience associated with these outcomes. RESULTS: A total of 2,148 patients were enrolled in the study. Improvement in the SLN identification and false-negative rates was found after 20 cases had been performed. Multivariate analysis revealed that patient age, nonpalpable tumors, and injection of blue dye alone for SLN biopsy were independently associated with decreased SLN identification rates, whereas upper outer quadrant tumor location was the only factor associated with an increased false-negative rate. CONCLUSIONS: Surgeons should perform at least 20 SLN cases with acceptable results before abandoning routine axillary dissection. This study provides a model for surgeon training and experience that may be applicable to the implementation of other new surgical technologies.

Accuracy of sentinel lymph node biopsy for patients with T2 and T3 breast cancers.

Although numerous studies have demonstrated that sentinel lymph node (SLN) biopsy can accurately determine the axillary nodal status for early breast cancer some studies have suggested that SLN biopsy may be less reliable for tumors >2 cm in size. This analysis was performed to determine whether tumor size affects the accuracy of SLN biopsy. The University of Louisville Breast Cancer Sentinel Lymph Node Study is a prospective multi-institutional study involving 226 surgeons. The study was approved by the Institutional Review Board of each institution, and informed consent was obtained from all patients. Patients with clinical stage T1-2 N0 breast cancer were eligible for the study. Some patients with T3 tumors were included because they were clinically staged as T2 but on final pathology were found to have tumors >5 cm. This analysis includes 2148 patients who were enrolled from August 1997 through October 2000. All patients underwent SLN biopsy using a combination of radioactive colloid and blue dye injection followed by completion Level I/II axillary dissection. Statistical comparison was performed by chi-square analysis. The SLN identification rate, false negative rate, and overall accuracy of SLN biopsy were not significantly different among tumor stages T1, T2, and T3. We conclude that SLN biopsy is no less accurate for T2-3 breast cancers compared with T1 tumors.

Dermal injection of radioactive colloid is superior to peritumoral injection for breast cancer sentinel lymph node biopsy: results of a multiinstitutional study.

OBJECTIVE: To determine the optimal radioactive colloid injection technique for sentinel lymph node (SLN) biopsy for breast cancer. SUMMARY BACKGROUND DATA: The optimal radioactive colloid injection technique for breast cancer SLN biopsy has not yet been defined. Peritumoral injection of radioactive colloid has been used in most studies. Although dermal injection of radioactive colloid has been proposed, no published data exist to establish the false-negative rate associated with this technique. METHODS: The University of Louisville Breast Cancer Sentinel Lymph Node Study is a multiinstitutional study involving 229 surgeons. Patients with clinical stage T1-2, N0 breast cancer were eligible for the study. All patients underwent SLN biopsy, followed by level I/II axillary dissection. Peritumoral, subdermal, or dermal injection of radioactive colloid was performed at the discretion of the operating surgeon. Peritumoral injection of isosulfan blue dye was performed concomitantly in most patients. The SLN identification rates and false-negative rates were compared. The ratios of the transcutaneous and ex vivo radioactive SLN count to the final background count were calculated as a measure of the relative degree of radioactivity of the nodes. One-way analysis of variance and chi-square tests were used for statistical analysis. RESULTS: A total of 2,206 patients were enrolled. Peritumoral, subdermal, or dermal injection of radioactive colloid was performed in 1,074, 297, and 511 patients, respectively. Most of the patients (94%) who underwent radioactive colloid injection also received peritumoral blue dye injection. The SLN identification rate was improved by the use of dermal injection compared with subdermal or peritumoral injection of radioactive colloid. The false-negative rates were 9.5%, 7.8%, and 6.5% (not significant) for peritumoral, subdermal, and dermal injection techniques, respectively. The relative degree of radioactivity of the SLN was five- to sevenfold higher with the dermal injection technique compared with peritumoral injection. CONCLUSIONS: Dermal injection of radioactive colloid significantly improves the SLN identification rate compared with peritumoral or subdermal injection. The false-negative rate is also minimized by the use of dermal injection. Dermal injection also is associated with SLNs that are five- to sevenfold more radioactive than with peritumoral injection, which simplifies SLN localization and may shorten the learning curve.

Safety and efficacy of total thyroidectomy for differentiated thyroid carcinoma: a 20-year review.

Controversy continues to exist regarding the optimal extent of resection for differentiated thyroid carcinoma (DTC). Subtotal thyroidectomy has been advocated by some authors in expectation of lower complication rates, while others advocate total thyroidectomy to achieve better cure rates. To examine this issue, the medical records of 124 patients who underwent total thyroidectomy for DTC were retrospectively reviewed. Total thyroidectomy was the initial procedure in 115 patients, while nine patients had complete thyroidectomy following some type of subtotal resection. Concomitant procedures were performed in 47 patients. Ninety papillary, 20 mixed papillary-follicular variant, one Hürthle cell type, and 13 follicular carcinomas were performed. Tumors were bilateral or multicentric in 40 patients, with metastases present in one-third of patients at the same time of initial operation. Permanent hypoparathyroidism developed in two patients, and permanent ipsilateral recurrent laryngeal nerve palsy occurred in one patient, for an overall significant complication rate of 2.4 per cent. Tumor recurrence was noted at a mean of 19 months postoperatively in 14 patients. Ninety-six patients received adjuvant postoperative radioiodine therapy to ablate residual functioning thyroid tissue or suspected metastases. We conclude that total thyroidectomy as treatment for differentiated thyroid carcinoma carries a low rate of morbidity, treats occult contralateral disease, and should facilitate radioiodine scanning and ablation of residual functioning thyroid tissue or metastatic disease.