[Added value of SPECT/CT over planar imaging in improving sentinel node detection in breast cancer patients]

The aim of the study was to assess the diagnostic contribution of hybrid SPECT/CT lymphoscintigraphy compared to planar imaging for the correct identification of sentinel lymph nodes (SLN) in breast cancer (BC) patients.

73 planar and SPECT/CT lymphoscintigraphies were performed in 70 consecutive patients with BC (70 women, mean age 55.7±12.0 years, range 26-84) for pre-surgical SLNs research. Cohen'K was performed to evaluate the agreement between both techniques; their diagnostic capability was evaluated by the Student's t-test for paired data.

In 54/73 (73.9%) lymphoscintigraphies, SLNs were detected both on planar and SPECT/CT images. In 19/73 (26.1%) discordant cases, planar technique showed a higher number of SLNs in 4/19 lymphoscintigraphies, while SPECT/CT in 15/19. Radio-guided surgery confirmed SPECT/CT findings. Concordance between the two techniques was poor (K=-0.095). Overall, SPECT/CT detected 13 SLNs more than planar imaging (p=0.07). Furthermore, in 17/73 (23.2%) lymphoscintigraphies, SPECT/CT defined the exact SLNs anatomical localization, equivocal on planar images.

SPECT/CT demonstrated added value over planar imaging, providing more information for the best surgical approach. It is useful especially in patients with negative or doubt planar imaging.