Radio-isotope occult lesion localization (ROLL) techniques to identify the clipped node for targeted axillary dissection (TAD) in breast cancer.

BACKGROUND

Breast cancer patients having neoadjuvant systemic therapy (NAST) who have a positive (clipped) lymph node (CN) at presentation must have that CN removed to assess pathologic response at later surgery. Multiple techniques for localizing the CN have been described. We describe a novel ROLL-based approach.

METHODS

Consecutive patients between 2018 and 2021, having NAST with biopsy proven positive lymph node(s), had a clip placed into the most abnormal node(s). At later surgery sentinel node and occult lesion localization (SNOLL) was performed with peritumoral radio-isotope (99m Tc-Nanoscan) injected under ultrasound guidance. Planar and single photon emission computed tomography (SPECT-CT) images were used to identify sentinel nodes (SN) and the CN. If the CN was not a SN, then additional 99m Tc-Nanoscan was injected directly into the CN using ultrasound (ROLL). TAD was performed using a gamma probe and intra-operative specimen radiographs to confirm excision of the CN.

RESULTS

Thirty-eight patients underwent TAD. 20/38 CNs were SNs on SPECT-CT. 17/38 CN were localized separately. 1/38 CN was not a SN and could not be identified on ultrasound. The remaining 37/38 (97.4%) of the CNs were removed intra-operatively. Pathological complete response in the axilla was identified in 18/38 cases. The CN was the only positive node in 10/20 cases. In 18/20 cases the CN contained the largest tumour deposit.

CONCLUSION

Combining SNOLL and ROLL techniques to identify the SNs and, if separate, the CN for TAD is very reliable and logistically robust, especially for units already performing peritumoral lymphoscintigraphy.