PET-enabled glove for molecular image-guided surgery
Objectives: Pre-surgical assessments are of limited benefit when the anatomy is likely to change as a result of interventional procedures. Non-imaging assessments (i.e., probes) are useful in high-contrast surgical cases (e.g., sentinel nodes), but are less useful in discriminating tumor from background tissues. We sought a technical solution capable of providing molecular images to surgeons in real-time, and with OR-friendly properties: low voltage, intuitive registration to features within the operative site, and single-use application. Methods: Compact PET detector assemblies were mounted on three fingers of an operator’s hand. Each PET detector assembly consists of two-dimensional arrays of Cerium-doped LuAG pillars (Crytur Inc., Czech Republic) mounted on quantum photodetectors (“silicon photomultipliers”) biased at approximately 35 volts. Electromagnetic position sensors are embedded in the PET detector assemblies, and read out with a motion tracking system (Northern Digital Incorporated, Waterloo, ON). Data is acquired with sampling analog-to-digital converters (National Instruments, Austin, TX), and displayed using a graphical user interface (GUI) based on the Georgetown Image Guided Surgery Toolkit, which shows PET findings superimposed on a representation of the surgeon’s fingers. Results: Simulations showed that small structures in the volume subtended by the fingers would be visualized with high contrast. Experimentally, the LuAG/APD PET detectors 511 keV photopeak showed no measurable effect due to the electromagnetic pulses from the motion tracker. Conclusions: We present a new paradigm for surgical visualization, consisting of finger-mounted PET detectors, in which a model of the surgeon’s own fingers with superimposed PET findings serves as an intuitive registration tool. The low component cost suggests that single-use application (i.e., as a disposable PET glove) is feasible.