The Hybrid SPECT/CT as an Additional Lymphatic Mapping Tool in Patients with Breast Cancer

Background Conventional lymphoscintigraphy does not always define the exact anatomic location of a sentinel node. The lymphatic drainage pattern may be unusual or may not be shown at all. The recently introduced hybrid SPECT/CT imaging could help overcome these difficulties. SPECT is a tomographic version of conventional lymphoscintigraphy and the images have better contrast and resolution. When fused with the anatomical details provided by CT into one image, a meaningful surgical ‘‘roadmap’’ can be created. So far, there is little literature on the use of hybrid SPECT/CT in lymphatic mapping in patients with breast cancer. The purpose of this review was to report on these publications, including our own experience, focusing on patient selection, SPECT/CT settings, anatomic localization, and the detection of additional sentinel nodes. Methods The majority of investigators did not formulate indications for additional SPECT/CT after conventional imaging but scanned all patients eligible for sentinel node biopsy. The SPECT/CT settings used in the studies of this review were mostly similar, but the methods used for conventional imaging were more variable. Results All studies demonstrated an improved anatomical localization by performing additional SPECT/CT; sentinel nodes outside the axilla or nodes close to the injection sit

Optical imaging as an expansion of nuclear medicine : Cerenkov-based luminescence vs fluorescence-based luminescence

Integration of optical imaging technologies can further strengthen the field of radioguided surgery. Rather than using two separate chemical entities to achieve this extension, hybrid imaging agents can be used that contain both radionuclear and optical properties. Two types of such hybrid imaging agents are available: (1) hybrid imaging agents generated by Cerenkov luminescence imaging (CLI) of ß-emitters and (2) hybrid imaging agents that contain both a radioactive moiety and a fluorescent dye. One major challenge clinicians are now facing is to determine the potential value of these approaches. With this tutorial review we intend to clarify the differences between the two approaches and highlight the clinical potential of hybrid imaging during image-guided surgery applications

Hybrid surgical guidance based on the integration of radionuclear and optical technologies

With the evolution of imaging technologies and tracers, the applications for nuclear molecular imaging are growing rapidly. For example, nuclear medicine is increasingly being used to guide surgical resections in complex anatomical locations. Here, a future workflow is envisioned that uses a combination of pre-operative diagnostics, navigation and intraoperative guidance. Radioguidance can provide means for pre-operative and intraoperative identification of “hot” lesions, forming the basis of a virtual data set that can be used for navigation. Luminescence guidance has shown great potential in the intraoperative setting by providing optical feedback, in some cases even in real time. Both of these techniques have distinct drawbacks, which include inaccuracy in areas that contain a background signal (radioactivity) or a limited degree of signal penetration (luminescence). We, and others, have reasoned that hybrid/multimodal approaches that integrate the use of these complementary modalities may help overcome their individual weaknesses. Ultimately, this will lead to advancement of the field of interventional molecular imaging/image-guided surgery. In this review, an overview of clinically applied hybrid surgical guidance technologies is given, whereby the focus is placed on tracers and hardware