Virtual reality tumor navigated robotic radical prostatectomy by using three-dimensional reconstructed multiparametric prostate MRI and 68Ga-PSMA PET/CT images: A useful tool to guide the robotic surgery?

Abstract

Objectives: To evaluate the use and benefits of tumor navigation during performing robotic assisted radical prostatectomy (RARP).

Patients and methods: Borders of the visible tumor(s) was/were and surrounding structures marked on multiparametric prostate magnetic resonance imaging (mpMRI) and ⁶⁸Ga-labeled prostate-specific membrane antigen ligand using positron emission computed tomography (Ga68 PSMA-PET/CT). Three dimensional (3D) reconstruction of the images were done that were transferred to virtual reality (VR) headsets and Da Vinci surgical robot via TilePro. Images were used as a guide during RARP procedures in five cases. Indocyanine green (ICG) guided pelvic lymph node dissection (n = 2) and Martini Klinik Neurosafe technique (n = 2) were also applied.

Results: Mean patient age was 60.6 ± 3.7 years (range, 56-66). All VR models were finalized with the agreement of radiologist, urologist, nuclear physician, and engineer. Surgeon examined images before the surgery. All VR models were found very useful particularly in pT3 diseases. Pathological stages included pT2N0 (n = 1), pT3aN0 (n = 1), pT3aN1 (n = 2), and pT3bN1 (n = 1). Positive surgical margins (SMs) occurred in two patients with extensive disease (pT3aN1 and pT3bN1) and tumor occupied 30% and 50% of the prostate volumes. Mean estimated blood loss was 150 ± 86.6 cc (range, 100-300). Mean follow-up was 3.4 ± 1.7 months (range, 2-6). No complication occurred during perioperative (0-30 days) and postoperative (30-90 days) periods in any patient.

Conclusions: 3D reconstructed VR models by using mpMRI and Ga68 PSMA-PET/CT images can be accurately prepared and effectively applied during RARP that might be a useful tool for tumor navigation. Images show prostate tumors and anatomy and might be a guide for the console surgeon. This is promising new technology that needs further study and validation.

Keywords: 3D reconstruction; augmented reality; radical prostatectomy; robotic; training; virtual reality.

Figure 1

A, mpMRI image. Axial T2‐weighted space sequence shows a 3.5 cm PI‐RADS 5 lesion in the left posterior peripheral zone at the level of midgland‐basis. There is suspicion of left seminal vesicle and NVB involvement. Borders of the lesion which was pathologically known to be adenocarcinoma was drawn. B, Ga68 PSMA‐PET/CT: PSMA uptakes were seen in left lateral‐medial sides of mid‐gland and left medial side of apex with 3.21 SUVmax. C, 3D reconstructed image of the prostate. Left up (yx axis): appearance from the top, left down (zx axis): appearance from front, right down (zy axis): appearance from right, right up (xyz axis, perspective). Green: tumor on MRI, yellow: peripheral zone, purple: anterior‐transition zone, red: bladder. D, 3D reconstructed image of the prostate (maximized perspective, xyz axis). Green: tumor on MRI, yellow: peripheral zone, purple: anterior‐transition zone, red: bladder. Tumor involving almost the entire left half of the prostate gland with obvious extraprostatic extension is visible (green). E, 3D reconstructed image of the prostate with tumor on Ga68 PSMA‐PET/CT overlap in addition to mpMRI (maximized perspective, xyz axis). Orange: 68Ga‐PSMA uptake area, Green: tumor on MRI, yellow: peripheral zone, purple: anterior‐transition zone, red: bladder. F, Real time use of 3D reconstructed image of the prostate during RARP and intraoperative surgical appearance. Due to the possible involvement of left seminal vesicle and NVB by the tumor that also appears in the 3D images, console surgeon did not preserve left NVB and did a careful dissection at the level of left seminal vesicle. G, ICG guided pelvic LN dissection (left side). Please note ICG(+) LN that was excised and sent for intraoperative pathological frozen evaluation that was reported as metastatic. H, Postoperative pathology mapping of the prostate