Fig. 1

Overview of the acquired images. a Example of an anterior lymphoscintigram showing a clear sentinel node in the neck. b, c SPECT/CT imaging of the patient shown under a allowed placement of the hotspot in its anatomical context with the sentinel node being located in level V. The fused SPECT/CT images provided the surgeon with an anatomical roadmap for planning of the surgical procedure. d 2D mobile gamma camera image acquired in the operation room showing a sentinel node (SN) and the injection site (IS). e Zoom-in of the image shown in d. f A freehandSPECT scan was acquired and subsequently the gamma probe was navigated, in augmented reality, to the sentinel node as seen in the freehandSPECT scan