Navigation of a robot-integrated fluorescence laparoscope in preoperative SPECT/CT and intraoperative freehand SPECT imaging data: a phantom study

Abstract

Robot-assisted laparoscopic surgery is becoming an established technique for prostatectomy and is increasingly being explored for other types of cancer. Linking intraoperative imaging techniques, such as fluorescence guidance, with the three-dimensional insights provided by preoperative imaging remains a challenge. Navigation technologies may provide a solution, especially when directly linked to both the robotic setup and the fluorescence laparoscope. We evaluated the feasibility of such a setup. Preoperative single-photon emission computed tomography/X-ray computed tomography (SPECT/CT) or intraoperative freehand SPECT (fhSPECT) scans were used to navigate an optically tracked robot-integrated fluorescence laparoscope via an augmented reality overlay in the laparoscopic video feed. The navigation accuracy was evaluated in soft tissue phantoms, followed by studies in a human-like torso phantom. Navigation accuracies found for SPECT/CT-based navigation were 2.25 mm (coronal) and 2.08 mm (sagittal). For fhSPECT-based navigation, these were 1.92 mm (coronal) and 2.83 mm (sagittal). All errors remained below the <1-cm detection limit for fluorescence imaging, allowing refinement of the navigation process using fluorescence findings. The phantom experiments performed suggest that SPECT-based navigation of the robot-integrated fluorescence laparoscope is feasible and may aid fluorescence-guided surgery procedures.

Navigating surgical fluorescence cameras using near-infrared optical tracking

“…In this study we have investigated possible solutions to solve the interference issues found during the navigation of clinical (1) the spectral overlap between the ICG emission light and the NIR OTS light, (2) the OTS light intensity, (3) the OTS duty cycle, (4) the OTS frequency, (5) the fluorescence camera recording frequency, and (6) the camera sensitivity. As we have also observed during our previous studies, 4,5,8 this combination of features means that the severity of interference varied between the type of fluorescence camera used. More specifically, the observed interference with the OTS vicra completely obstructed fluorescence imaging with the PDE camera while its influence on the imaging output of the VITOM camera was only minor.…”

“…A surgical fluorescence phantom was fabricated for the experiments. This setup consisted of a previously described, siliconebased phantom 8 with two fluorescent beads incorporated (see Appendix B). In addition, surgically excised human tissue was used.…”

“…The effective ICG concentration in the beads was therefore 60 μg∕mL, which roughly presents a clinically relevant and detectable ICG concentration. 8…”

“…Initial studies, using a near-infrared (NIR) optical tracking system (OTS) and tracking fiducials placed on both the fluorescence camera and the patient, helped to demonstrate the potential of this navigated fluorescence camera concept in a variety of settings. 4,5,7,8 Unfortunately, in some of the open surgical procedures, the OTS caused an interfering flickering signal that prevented fluorescence imaging (see Figs. 1-3).…”

Recent advances in nuclear and hybrid detection modalities for image-guided surgery

“…Next to the use of fully integrated hybrid detection modalities, hybrid surgical navigation concepts have been used to successfully integrate nuclear guidance (i.e. SPECT/CT or fhSPECT) with fluorescence guidance in vivo [175,[179][180][181]. In this approach, the surgical targets (e.g.…”