Study on intraoperative localization of sentinel lymph nodes using freehand SPECT in breast cancer patients

The diagnostic and therapeutic approach to axillary lymph nodes is considered indispensable in the treatment of breast cancer patients.

To investigate the effectiveness of 3D freehand SPECT (fhSPECT) in sentinel lymph node (SLN) mapping in breast cancer, compared with the use of a conventional gamma probe.

We retrospectively compared the fhSPECT lymph node mapping modality, with gamma probe detection in early-stage, clinically node-negative breast cancer patients, with biopsy-confirmed malignancy. The two techniques were compared based on the average number of LNs excised per axilla. The duration of SLN mapping was also compared between the two groups. The performance of the two methods on obese and post-systemic therapy patients was evaluated. FhSPECT was used in 150 cases, while the gamma probe was employed in 50 cases.

FhSPECT detected at least 3 nodes in 83.3% of the patients vs. 72.0% with the γ-probe (p = 0.107). The mean number of SLNs excised per axilla was 3.66 using the γ-probe and 4.18 with fhSPECT (p = 0.03). The average surgical time was 39 ±7 min with the γ-probe and 37.54 ±17 min with fhSPECT (p = 0.228). Sentinel lymph node biopsy (SLNB) mean surgical time evolved from 40.2 ±20.77 min to 32.35 ±10.46 min (p = 0.033). In obese patients, a reduction in surgical times was noted from 45.5 ±3.09 min to 44.04 ±20.9 (p = 0.27), in addition to a significant increase in average LN detection in the fhSPECT group (4.26 ±1.44) compared to the γ-probe group (3.2 ±1.65) (p = 0.043).

The use of the fhSPECT modality is effective and safe, and, when compared to the γ-probe, has significant advantages in SLN mapping.