Surgical approach to internal mammary sentinel node biopsy

Area of Science:

• Oncology
• Surgical Oncology
• Nuclear Medicine

Background:

• Internal mammary node (IMN) metastasis is a critical prognostic factor in breast cancer, comparable to axillary nodal involvement.
• Routine sampling of IMNs is not standard practice, potentially leading to understaging.

Purpose of the Study:

• To evaluate a simplified and reliable surgical technique for internal mammary sentinel node (IMSN) biopsy in breast cancer patients.
• To improve the accuracy of nodal staging in breast cancer by assessing IMN involvement.

Main Methods:

• A combined approach of simultaneous perilesional and intradermal radiocolloid injections was utilized.
• Internal mammary sentinel nodes (IMSNs) were confirmed preoperatively using lymphoscintigraphy and Carbon Nanoparticles Suspension Injection.
• Nodes were excised extrapleurally through the intercostal muscles, with confirmation via gamma probe and dye methods.

Main Results:

• Metastatic disease was found in the IMSNs of 23 out of 94 patients.
• Four patients had IMN metastases without axillary involvement, highlighting the importance of IMN sampling.
• The combined detection sensitivity for IMSN metastasis was 100%.

Conclusions:

• The described surgical approach is a reliable technique for IMSN biopsy.
• This method enhances nodal staging accuracy for breast cancer patients with potential IMN metastases.
• Improved staging can lead to more appropriate treatment decisions, including radiation to the internal mammary chain.