Successful Internal Mammary Visualization With Periareolar Injections of Tc-99m Antimony Sulfur Colloid in Sentinel Node Breast Lymphoscintigraphy

Surgical approach to internal mammary sentinel node biopsy

BACKGROUND

Internal mammary node (IMN) metastasis has a similar prognostic importance as axillary nodal involvement. However, sampling of IMN is not performed routinely.

AIMS

To evaluate a simplified method for internal mammary sentinel node (IMSN) biopsy of breast cancer patients.

METHODS

A combination of simultaneous perilesional and intradermal radiocolloid injections over the lesion was used. All IMSNs were confirmed by lymphoscintigraphy and Carbon Nanoparticles Suspension Injection preoperatively and excised extrapleurally through the intercostal muscles.

RESULTS

Twenty-three of the 94 patients were found to have metastatic disease in the IMSNs. Four of 65 patients had metastases in the IMNs but not in the axilla. All 23 patients with positive IMSN were upstaged and received radiation to the internal mammary chain. The time from separating the pectoral major muscle to touch the node was ranged 21-48 min. The detecting sensitivity combined with preoperative lymphoscintigraphy, intraoperative gamma probe detection, and intraoperative black dye methods for IMSN was 100%.

CONCLUSIONS

The approach used is a reliable surgical technique for removing IMSN. It can improve the nodal staging in breast cancer with IMN metastases.

Clinically node-negative breast cancer, internal mammary lymph nodes, and sentinel lymph node biopsy

We report 2 cases demonstrating that localization of internal mammary (IM) sentinel lymph nodes with lymphoscintigraphy using peritumoral injection of Tc-99m antimony sulfide colloid, followed by resection using minimal access surgery, can reveal nodal metastatic disease in patients with clinically node-negative breast cancer when axillary sentinel nodes are not affected by metastatic disease. When this is found, it changes staging and can affect prognosis and treatment. These cases confirm that the technique used is sampling true sentinel IM nodes, that is nodes that receive direct lymph flow from the breast cancer, and confirm the importance of sampling IM sentinel lymph nodes. Unless techniques are used that are specifically designed to identify IM node drainage from the breast cancer site itself, with subsequent directed surgical removal of sentinel IM nodes, some patients with breast cancer will not be staged correctly.