Surgical guidance by freehand SPECT for sentinel lymph node biopsy in early stage breast cancer: A preliminary study

Sentinel lymph node biopsy (SLNB) is a standard for patients with early breast cancer. Using a gamma-detecting probe connected to an infrared camera, the Declipse freehand SPECT (FhSPECT) system (Surgiceye(®)) is able to detect and locate any radioactive source in 3D. The objective of this study was to evaluate the potential interest of FhSPECT imaging for real-time guidance SLNB in breast cancer.

A prospective single-center clinical study assessed sensitivity and usability of FhSPECT for SLN detection and surgical guidance in breast cancer patients. SLN detection rate with FhSPECT was compared with lymphoscintigraphy (LS) and colorimetric method. Durations of FhSPECT acquisitions and of the SLNB procedure were measured in order to evaluate the practicability of the device.

Between May and September 2014, 20 patients with early stage invasive breast cancer (cT0-2N0) underwent SLNB using FhSPECT and blue dye detection. Preoperative LS revealed 41 radioactive axillary SLNs (median=2 SLN per patient; range 0-4) in 20 patients. Preoperative FhSPECT detected 40 axillary SLNs (median=2; range: 1-4) in 20 patients. The corresponding sensitivity of FhSPECT was 97.5%. For 4 patients (20%), FhSPECT detected more axillary SLNs than LS. The colorimetric method identified only 24 axillary SLNs (2 patients had no blue dye injection on account of a history of allergy), leading to a sensitivity of 67% (24 blue SLNs/36 resected SLNs after blue dye injection). Median duration of FhSPECT acquisitions was 5minutes (range: 1-26min). Median duration of SLNB procedure was 11.5minutes (range: 3-55min). Duration of acquisitions analysis based on the number of use of the device showed decreasing values suggesting the existence of a short learning curve.

This study demonstrated that FhSPECT is feasible and facilitates SLN identification.