First Live-Experience Session with PET/CT Specimen Imager: A Pilot Analysis in Prostate Cancer and Neuroendocrine Tumor

Abstract

Objective: to evaluate the feasibility of the intra-operative application of a specimen PET/CT imager in a clinical setting. Materials and methods: this is a pilot analysis performed in three patients who received an intra-operative administration of 68Ga-PSMA-11 (n = 2) and 68Ga-DOTA-TOC (n = 1), respectively. Patients were administrated with PET radiopharmaceuticals to perform radio-guided surgery with a beta-probe detector during radical prostatectomy for prostate cancer (PCa) and salvage lymphadenectomy for recurrent neuroendocrine tumor (NET) of the ileum, respectively. All procedures have been performed within two ongoing clinical trials in our Institute (NCT05596851 and NCT05448157). Pathologic assessment with immunohistochemistry (PSMA-staining and SSA immunoreactivity) was considered as standard of truth. Specimen images were compared with baseline PET/CT images and histopathological analysis. Results: Patients received 1 MBq/Kg of 68Ga-PSMA-11 (PCa) or 1.2 MBq/Kg of 68Ga-DOTA-TOC (NET) prior to surgery. Specimens were collected, positioned in the dedicated specimen container, and scanned to obtain high-resolution PET/CT images. In all cases, a perfect match was observed between the findings detected by the specimen imager and histopathology. Overall, the PET spatial resolution was sensibly higher for the specimen images compared to the baseline whole-body PET/CT images. Furthermore, the use of the PET/CT specimen imager did not significantly interfere with any procedures, and the overall length of the surgery was not affected using the PET/CT specimen imager. Finally, the radiation exposure of the operating theater staff was lower than 40 µSv per procedure (range 26–40 μSv). Conclusion: the image acquisition of specimens obtained by patients who received intra-surgery injections of 68Ga-PSMA-11 and 68Ga-DOTA-TOC was feasible and reliable also in a live-experience session and has been easily adapted to surgery daily practice. The high sensitivity, together with the evaluation of intra-lesion tumor heterogeneity, were the most relevant results since the data derived from specimen PET/CT imaging matched perfectly with the histopathological analysis.

Innovations in dedicated PET instrumentation: from the operating room to specimen imaging

“…A 3D rendered image, which users can rotate, is also provided. Reproduced from Muraglia et al (2023). CC BY 4.0. mapping of 18 F-FDG through ultra-fine PET/CT scans.…”

“…Until recently, there had not been a PET imager specifically tailored for specimen imaging. Addressing this gap, Muraglia et al (2023) have pioneered the introduction of the AURA10® PET/CT imager, manufactured by Xeos Medical NV (Ghent, Belgium). This innovative equipment is purposefully crafted for intraoperative specimen PET imaging, signifying a pivotal shift in the approach to surgical specimen evaluation (figure 12).…”

“…This efficient setup ensures that imaging results are swiftly available, Included in this figure are macroscopic images of the surgical specimens (B), (F) and (J), high-resolution PET/CT scans of these specimens (C, G, and K), and a histopathological evaluation, where an immunohistochemical analysis using PSMA staining was executed (D and H). Reproduced from Muraglia et al (2023). CC BY 4.0.…”

“…Furthermore, the system's 3D viewing capability plays a pivotal role in pinpointing malignant cells within the specimen with remarkable accuracy. Muraglia et al (2023) explored the practicality of using the Aura 10 specimen PET/CT imager intra-operatively in a clinical environment. They conducted an initial study involving three patients.…”

Prostate-specific membrane antigen (PSMA) radioguided surgery in prostate cancer: An overview of current application and future perspectives

“…PET/ CT specimen imagers have been developed for a molecularbased evaluation of surgical margins and first live experiences were promising. The first analysis of this novel imaging approach in patients undergoing RALP with extended lymphadenectomy in PCa proved that the extremely high resolution of these images could offer a deeper understanding of the biodistribution of PSMA in prostate cancer lesions and might improve surgeon's confidence in ensuring complete removal of the primary tumour when prostate's margin involvement is assessed [24]. According to preliminary data [24], PET/CT specimen imagers hold high sensitivity, and cancer lesions smaller than 1 mm might be detected.…”