Surgeon Injected Technetium-99m for Sentinel Lymph Node Biopsies in Breast Cancer-Outcomes in a Regional Hospital

The most common technique for sentinel node localisation is technetium-99m (Tc-99m) injection. Tc-99m is typically administered in a nuclear medicine department, causing logistical challenges in regional hospitals. This study compares outcomes of surgeon-administered Tc-99m injection with the nuclear medicine injection technique.

Retrospective review was conducted of patients undergoing sentinel lymph node biopsy for breast cancer at Tauranga Hospital between July 2021 and July 2023. Prior to July 2022, patients travelled to a tertiary hospital for their Tc-99m injection. From July 2022, the surgical team administered the injection. Patients were excluded if neoadjuvant therapy received, axillary dissection performed due to lymph node metastases on frozen section, or if insufficient information was recorded. Radioactivity signal was assessed before commencing the operation, with patent blue dye injected if no signal detected. Outcomes included blue dye requirement and number of nodes harvested.

Eighty-five patients were included in the nuclear medicine injected group and 97 in the surgeon injected group. All patients in the surgeon injected group received Tc-99m. Despite referral for the nuclear medicine procedure, 21% of patients did not receive Tc-99m in the nuclear medicine injected group. Blue dye use was significantly lower in the surgeon injected group (17.5% vs. 36.0%, p = 0.004). Mean number of nodes harvested did not differ significantly (3.24 vs. 3.77, p = 0.076). The localisation rate using Tc-99m alone in the surgeon injected group was 93%, which was within the range quoted in the literature.

Preoperative surgeon-administered Tc-99m injection improved accessibility and significantly reduced the need for blue dye without compromising sentinel node localisation or lymph node yield.