Dermal Injection of Radioactive Colloid Is Superior to Peritumoral Injection for Breast Cancer Sentinel Lymph Node Biopsy: Results of a Multiinstitutional Study

Abstract

ObjectiveTo determine the optimal radioactive colloid injection technique for sentinel lymph node (SLN) biopsy for breast cancer. Summary Background DataThe 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. MethodsThe 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 chisquare tests were used for statistical analysis. ResultsA 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. ConclusionsDermal 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.

Sentinel lymph node mapping of breast cancer via intradermal administration of Lymphoseek

“…The intradermal method [4,5,14] is extremely convenient, is less stressful for the patient, generates higher SLN uptake, and produces less scatter from the injection site. Given the propensity for many surgeons to use an intradermal approach, we conducted this study to ensure that Lymphoseek was compatible with this technique.…”

“…Each patient received a single injection (0.1 ml) of either Lymphoseek (1 nmole) or filtered [ 99m Tc]sulfur colloid above the lesion using an intradermal technique [4,5]. The administration site was massaged for several minutes.…”

Current Status of Sentinel Lymph Node Mapping and Biopsy: Facts and Controversies

“…All three techniques have been shown to be reliable in experienced hands. The dermal technique has been shown by McMasters et al [31] to identify the SLN in the axilla with increased frequency: 98% SLN identification rate compared with 90% for a peritumoral parenchymal technique. No difference in false negatives was observed, and the dermal technique results in significantly higher counts in the SLN.…”

“…No difference in false negatives was observed, and the dermal technique results in significantly higher counts in the SLN. The dermal technique compares favorably with the peritumoral injection for concordance and false negatives as well as offering many advantages [31]. The subareolar technique has recently been championed by Kern and Klimberg and offers many of the advantages of the dermal injection: it is easy, it avoids the need for image-guided injection, and it increases the distance from the tumor to the SLN, thus eliminating shine through from upper outer quadrant lesions.…”

Sentinel lymph node biopsy in breast cancer: the node to recovery

“…Since then, many investigators have reported equally good results with the intradermal, subdermal or subareolar routes of injection, and a comparably low rate of false-negative procedures. 16,17 It appears from these studies that most of the breast tissue and its overlying skin drains to the same few axillary SLNs regardless of injection site. Intradermal and subdermal injections are given as a single dose into the breast skin directly over the tumour or just cephalad to a previous biopsy scar.…”