Indocyanine green as an alternative to radioisotope in breast cancer sentinel node biopsy: a single centre experience during COVID19

Background: Multiple feasibility studies have confirmed high sensitivity of indocyanine green (ICG) fluorescence mapping for sentinel node detection in early breast cancer Due to relocation to a different hospital site without nuclear medicine facilities during the COVID19 pandemic, we adopted the ICG method in combination with blue dye and present our findings Materials and Methods: All consecutive patients undergoing sentinel node biopsy (SNB) for early breast cancer in NHS Tayside were included in a prospective audit of surgical and pathology findings All patients had a normal preoperative axillary ultrasound, including normal preoperative axillary ultrasound if neoadjuvant chemotherapy given, and had sentinel node biopsy injection of patent blue dye and ICG Approval was obtained from the local Caldicott guardian for collection and use of personal data Results: Data was available for 50 consecutive female patients in whom 52 cases were performed due to bilateral disease, with a mean age of 61 years (range 33-87), with 44 patients undergoing primary SNB, 6 patients having 4 node SNB post chemotherapy, and 2 having repeat SNB for failed SNB (n=1) and previous ipsilateral cancer SNB (n=1) In 4 cases neither blue dye nor ICG was present in the axilla and were converted to axillary node sample Of the 48 SNB cases in this series surgeons documented retrieval of 84 nodes in total, 67 with both ICG and blue dye, 15 nodes with ICG only and 2 nodes with blue dye only Of the 48 SNB cases 12 were node positive (25%) including 2 cases with micrometastases or isolated tumour cells only Histopathology showed in total 103 nodes retrieved with a mean nodal count of 2 1 per case (range 1-6), and in total 17 nodes were positive (16 5%) No patients contracted COVID19 during the peri-operative period Conclusions: SNB for breast cancer can be safely performed with ICG and blue dye with a short learning curve, as represented by node positivity and node retrieval rates comparable to previous multicentre studies of standard and/or ICG SNB This procedure has allowed us to continue high quality SNB during the COVID19 pandemic