Cancer Research Lab

Adding single photon emission computed tomography with computed tomography (SPECT/CT) imaging to lymphoscintigraphy improves sentinel node identification in overweight patients with breast cancer, according to a report by Israeli researchers in the February issue of Journal of Nuclear Medicine.

“We think SPECT/CT, as a minimally invasive procedure for sentinel nodes status, is a useful tool in correct staging and, as a consequence, in accurate therapeutic planning,” Dr. Hedva Lerman from Tel-Aviv Sourasky Medical Center, Tel-Aviv, said.

Dr. Lerman and associates investigated whether the improved spatial resolution of SPECT and the better image quality achieved with the use of CT data for attenuation correction would improve the diagnostic accuracy of sentinel node mapping in general and specifically in overweight patients with breast cancer.

Lymphoscintigraphy identified 317 hot nodes (and 20 false-positive nodes) in 200 of the 220 study patients, the authors report, and SPECT/CT detected 402 hot nodes in 200 patients.

Both SPECT and attenuation correction contributed to the better identification of hot nodes by SPECT/CT than by planar imaging, the investigators say. In particular, the superiority of SPECT/CT over planar imaging appeared to be enhanced in overweight and obese patients.

At surgery, metastatic involvement of sentinel nodes was found in 6 of 19 patients for whom lymphoscintigraphy results were negative, the researchers note.

“We use SPECT/CT fused imaging for the identification of sentinel nodes as a routine procedure after planar acquisition,” Dr. Lerman concluded. “We have found SPECT/CT to be superior to planar imaging alone in identification of more nodes in more patients, more draining basins, precise anatomical localization of the nodes, and avoiding false positives.”