A DROP-IN beta probe for robot-assisted 68Ga-PSMA radioguided surgery: first ex vivo technology evaluation using prostate cancer specimens

• Published in: EJNMMI research Vol. 10; no. 1; pp. 92 - 10
• Main Authors: Collamati, Francesco, van Oosterom, Matthias N., De Simoni, Micol, Faccini, Riccardo, Fischetti, Marta, Mancini Terracciano, Carlo, Mirabelli, Riccardo, Moretti, Roberto, Heuvel, Judith olde, Solfaroli Camillocci, Elena, van Beurden, Florian, van der Poel, Henk G., Valdes Olmos, Renato A., van Leeuwen, Pim J., van Leeuwen, Fijs W. B., Morganti, Silvio
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 06.08.2020; Springer Nature B.V; SpringerOpen
• Subjects: Beta particle detection; Beta particles; Beta rays; Cardiac Imaging; Computer simulation; Feasibility studies; Housing; Imaging; In vivo methods and tests; Isotopes; Lymphatic system; Medicine; Medicine & Public Health; Nodes; Nuclear Medicine; Oncology; Optimization; Original Research; Orthopedics; PET; Prostate cancer; Prototypes; PSMA; Radioguided surgery; Radiology; Robot-assisted surgery; Robotic surgery; Robots; Sensors; Surgery; Technology assessment; Tracers; Tumors; Radioguided surgery; PSMA; Beta particle detection; Robot-assisted surgery; Prostate cancer; PET
• ISSN: 2191-219X; 2191-219X
• DOI: 10.1186/s13550-020-00682-6

Background Recently, a flexible DROP-IN gamma-probe was introduced for robot-assisted radioguided surgery, using traditional low-energy SPECT-isotopes. In parallel, a novel approach to achieve sensitive radioguidance using beta-emitting PET isotopes has been proposed. Integration of these two concepts would allow to exploit the use of PET tracers during robot-assisted tumor-receptor-targeted. In this study, we have engineered and validated the performance of a novel DROP-IN beta particle (DROP-IN β ) detector. Methods Seven prostate cancer patients with PSMA-PET positive tumors received an additional intraoperative injection of ~ 70 MBq 68 Ga-PSMA-11, followed by robot-assisted prostatectomy and extended pelvic lymph node dissection. The surgical specimens from these procedures were used to validate the performance of our DROP-IN β probe prototype, which merged a scintillating detector with a housing optimized for a 12-mm trocar and prograsp instruments. Results After optimization of the detector and probe housing via Monte Carlo simulations, the resulting DROP-IN β probe prototype was tested in a robotic setting. In the ex vivo setting, the probe—positioned by the robot—was able to identify 68 Ga-PSMA-11 containing hot-spots in the surgical specimens: signal-to-background (S/B) was > 5 when pathology confirmed that the tumor was located < 1 mm below the specimen surface. 68 Ga-PSMA-11 containing (and PET positive) lymph nodes, as found in two patients, were also confirmed with the DROP-IN β probe (S/B > 3). The rotational freedom of the DROP-IN design and the ability to manipulate the probe with the prograsp tool allowed the surgeon to perform autonomous beta-tracing. Conclusions This study demonstrates the feasibility of beta-radioguided surgery in a robotic context by means of a DROP-IN β detector. When translated to an in vivo setting in the future, this technique could provide a valuable tool in detecting tumor remnants on the prostate surface and in confirmation of PSMA-PET positive lymph nodes.