Radar reflectors for marking of target lymph nodes in initially node-positive patients receiving neoadjuvant chemotherapy for breast cancer-a subgroup analysis of the prospective AXSANA (EUBREAST-03) trial.

BACKGROUND

Surgical staging procedures of the axilla in initially clinically node-positive (cN +) breast cancer patients receiving neoadjuvant chemotherapy (NACT) vary across countries. Different procedures such as axillary lymph node dissection, sentinel lymph node biopsy, target lymph node biopsy and targeted axillary dissection are currently in use. To date, data on radar reflectors as a non-wire and non-radioactive technique for marking target lymph nodes are limited. The present study aims at examining the detection rate, the rate of lost markers, and magnetic resonance imaging artifacts after TLN marking using a radar reflector before NACT in the largest available cohort of breast cancer patients enrolled in the international prospective AXSANA study.

METHODS

AXSANA (EUBREAST-03) is an international prospective cohort study including cN + patients managed with different surgical axillary staging techniques after NACT. Eligible patients have cT1-4c cN + breast cancer and receive neoadjuvant chemotherapy. Patients are followed up for 5 years. In the present subgroup analysis, only patients with a TLN marked by a radar reflector were included.

RESULTS

A TLN was marked by radar reflector insertion in 158 patients prior to NACT. Of these, 136 had final surgery results available at the time of analysis, and in 135 out of these 136 patients, localization of TLN was attempted. All radar markers were successfully removed. While lymphoid tissue corresponding to the TLN was identified in 132 patients (97.8%), no lymphoid tissue was detected on histopathology in three patients. It remains unclear whether the TLN was excised in these cases or not. In 1 out of 27 patients (3.7%) who underwent preoperative MRI, image assessment was compromised due to artifacts after radar marker placement.

CONCLUSION

To the best of our knowledge, this is the largest prospective series of patients receiving a radar reflector for the marking of a TLN prior to NACT for breast cancer. Our data demonstrate that radar reflectors are a reliable tool for marking target lymph nodes before neoadjuvant treatment.

TRIAL REGISTRATION NUMBER: NCT04373655 (date of registration May 4, 2020).