title: Revolutionizing (robot-assisted) laparoscopic gamma tracing using a drop-in gamma probe technology.
abstract: In complex (robot-assisted) laparoscopic radioguided surgery procedures, or when low activity lesions are located nearby a high activity background, the limited maneuverability of a laparoscopic gamma probe (LGP; 4 degrees of freedom (DOF)) may hinder lesion identification. We investigated a drop-in gamma probe (DIGP) technology to be inserted via a trocar, after which the laparoscopic surgical tool at hand can pick it up and maneuver it. Phantom experiments showed that distinguishing a low objective from a high background source (1:100 ratio) was only possible with the detector faced >90° from the high background source. Signal-low-objective-to-background ratios of 3.77, 2.01 and 1.84 were found for detector angles of 90°, 135° and 180°, respectively, whereas detector angles of 0° and 45° were unable to distinguish the sources. This underlines the critical role probe positioning plays. We then focused on engineering of the gripping part for optimal DIGP pick-up with a conventional laparoscopic forceps (4 DOF) or a robotic forceps (6 DOF). DIGPs with 0°, 45°, 90°, and 135° -grip orientations were designed, and their maneuverability- and scanning direction were evaluated and compared to a conventional LGP. The maneuverability- and scanning direction of the DIGP was found highest when using the robotic forceps, with the largest effective scanning direction range obtained with the 90° -grip design (0-180° versus 0-111°, 0-140°, and 37-180° for 0°, 45° and 135° -grip designs, respectively). For the laparoscopic forceps, the scan direction directly translated from the angle of the grip design with the advantage that the 135° -gripped DIGP could be faced backwards (not possible with the conventional LGP). In the ex vivo clinical setup, the surgeon rated DIGP pick-up most convenient for the 45°-grip design. Concluding, the DIGP technology was successfully introduced. Optimization of the grip design and grasping angle of the DIGP increased its utility for (robot-assisted) laparoscopic gamma tracing.
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center (LUMC) Leiden, The Netherlands.
authors.forename: Matthias N
authors.initials: MN
authors.lastname: van Oosterom
authors.affiliation: Eurorad S.A. Eckbolsheim, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Simon
authors.affiliation: Eurorad S.A. Eckbolsheim, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Mengus
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center (LUMC) Leiden, The Netherlands.
authors.forename: Mick M
authors.initials: MM
authors.lastname: Welling
authors.affiliation: Department of Urology, Antoni van Leeuwenhoek Hospital-Netherlands Cancer Institute (AVL-NKI) Amsterdam, The Netherlands.
authors.forename: Henk G
authors.initials: HG
authors.lastname: van der Poel
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center (LUMC)Leiden, The Netherlands; Department of Urology, Antoni van Leeuwenhoek Hospital-Netherlands Cancer Institute (AVL-NKI)Amsterdam, The Netherlands.
authors.forename: Nynke S
authors.initials: NS
authors.lastname: van den Berg
authors.affiliation: Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center (LUMC)Leiden, The Netherlands; Department of Urology, Antoni van Leeuwenhoek Hospital-Netherlands Cancer Institute (AVL-NKI)Amsterdam, The Netherlands.
authors.forename: Fijs Wb
authors.initials: FW
authors.lastname: van Leeuwen
keywords: Radioguided surgery; gamma probe; interventional molecular imaging; laparoscopic surgery; robot-assisted surgery; sentinel lymph node biopsy; urology