SPECT-CT topography of sentinel lymph nodes for radiotherapy of breast cancer
Purpose. To evaluate SPECT-CT topography of sentinel lymph nodes (SLNs) in patients with breast cancer and determine the role of this information for radiotherapy planning. SPECT-CT was performed in 268 patients with breast cancer. Date acquisition started 1-1.5 hours after intra- and/ or peritumoral injection of 150 MBq of <sup>99m</sup>Tc-radiocolloids. Finally, we compared topography of visualized SLNs with standard clinical volume designed for irradiation of regional lymph nodes. SPECT-CT visualized 572 SLNs. In most cases (72.4%) SPECT-CT detected 1-2 SLNs, in 27.6% cases SPECT-CT visualized 3 and more LNs with radiocolloid uptake. Despite high variability of SLNs topography, most of them were localized in the axilla region corresponded to axillary level I-II. Surprisingly, 14.9% LNs were detected in the lateral group of axillary LNs, which are usually not covered by standard LNs contours and often spared during LN dissection. SPECT-CT visualization of SLNs can be important for individual planning of surgical and radiotherapy treatment.