I. Santi, L. Fantini, K. Herrmann, Ch. Fuccio, T. Wendler, P. Caroli, P. Castelucci, A. K. Buck, M. Schwaiger, S. Fanti Freehand SPECT for sentinel lymph node biopsy: first clinical experience Proceedings of EANM 2010, Vienna, Austria, October 2010 (bib)
	Aim To evaluate freehand SPECT (FH) accuracy in the detection and localization of sentinel lymph-node (LN) in patients with breast cancer. Methods: 84 consecutive patients affected by invasive breast cancer cT1-cT2, already scheduled for surgery, underwent lymphatic mapping (standard procedure with intradermal administration of 60-80 MBq of Tc-99m nanocoll). Subsequently patients were scanned using a FH system (prototype of CSS300 by SurgicEye). The position and orientation of a gamma probe is acquired simultaneously with its read-out using an optical positioning system. After obtaining synchronized readings from a free hand scan containing the ROI, the information is used to reconstruct 3D images using ad hoc models. FH results (number and localization of the sentinel LN) were compared for reference with standard Planar Scintigraphy (PS) (lateral and diagonal views). Results: In all patients PS mapped at least one LN in the axilla, while FH managed to identify at least one LN in 83 out of 84 patients resulting in 99% sensitivity. Overall PS detected 142 LN, while FH identified 122/142 LN: on a LN basis, both sensitivity and accuracy resulted in 86%. In 15 patients FH detected fewer LN than PS: 20/142 false negative sentinel LN at FH. In 1 patient FH was able to detect 1 LN more than PS. False negative results (20 LN) were probably due to low tracer migration to sentinel LN, insufficient FH scanning time or too close LN that ended up merging. Conclusions: These preliminary data show that FH technology is able to localize sentinel LN in the axilla adding 3D information that could be potentially useful in the operating room. This could help surgeons for an easier image guided sentinel LN dissection.
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