Interest of SPECT/CT in Detection of Sentinel Lymph Node in Breast Cancer

Abstract

Aim: Assess the role of hybrid modality SPECT/CT versus planar scintigraphy in sentinel lymph node (SLN) identification in patients with breast cancer. Methods: Planar scintigraphy and hybrid modality SPECT/CT were performed in 23 women with breast cancer (mean age 59.5 years with range 25 -82 years) with invasive breast cancer (T0, T1 and T2), without clinical evidence of axillary lymph node metastases (N0) and no remote metastases (M0), radiocolloid was injected in four subareolar sites. Planar and SPECT/CT images were separately interpreted. Results: SLNs were detected on lymphoscintigraphy in all patients (100%), taking into consideration both techniques (planar and SPECT-CT images). Planar images identified 45 SLNs in 23 women, with a mean of 1.95 per patient, whereas 56 SLNs were detected on SPECT/CT, increasing this mean to 2.43 per patient. Drainage to internal mammary lymph nodes was seen in 4 patients (17.39%). However, two foci of uptake were identified on planar image as hot SLN in two patients (8.69%); while they have been found as a false positive non-nodal site of uptake on SPECT/CT. Conclusion: SPECT/CT is more focused than planar scintigraphy in the detection of SLN in patients with breast cancer. It detects some lymph nodes not visible on planar images, excludes false positive uptake and exactly locates axillary and non-axillary SLNs.