PSMA-PET/MRI-Ultrasound Multimodal Fusion Navigation for Da Vinci Robot-Assisted Radical Prostatectomy: A Randomized Controlled Trial

Shanghai Jiao Tong University

Status: Not yet enrolling

Conditions: Prostate Cancer

Treatments: Procedure: experimental group (navigation-assisted RARP)

Study type: Interventional

Funder types: Other

Identifiers

NCT07272317

Y2025082 (Other Grant/Funding Number)

【2025】177

Details and patient eligibility

About

Radical prostatectomy faces the core dilemma of balancing functional preservation with tumor eradication. While nerve-sparing techniques improve urinary control, intraoperative tumor localization remains imprecise, resulting in positive surgical margin (PSM) rates of 11%-38% and elevated recurrence risk. Traditional preoperative 2D imaging fails to dynamically guide surgical boundaries. Although multimodal fusion studies (e.g., MRI or PSMA-PET/CT) attempt to address this, they struggle to achieve simultaneous precision in lesion identification and real-time spatial tracking. This study pioneers a PSMA-PET/MRI-ultrasound multimodal fusion navigation system for the Da Vinci surgical robot, leveraging three innovations: PSMA-PET/MRI dual-modality synergy for subclinical lesion detection at millimeter resolution; Non-rigid point-cloud registration algorithms to dynamically compensate for intraoperative prostate deformation, enabling 3D ultrasound-PET/MRI elastic fusion; Utilizing the telipro port of the Da Vinci surgical robot to achieve intraoperative picture-in-picture navigation, real-time localization of the tumor boundary, and precise resection as well as precise protection.This study aims to verify the safety and effectiveness of the world's first PSMA-PET/MRI-ultrasound multimodal fusion navigation system adapted for the Da Vinci surgical robot. This system is expected to reduce the positive margin rate to less than 10%, increase the rate of nerve preservation by 30%, shorten the postoperative urinary control recovery time to within 2 weeks, and establish a standard process for robotic surgery navigation. This will provide a new paradigm for precise surgical treatment of prostate cancer.

Full description

Prostate cancer, the second most prevalent malignancy in men globally, has long grappled with a core dilemma in radical surgery: balancing functional preservation against oncological efficacy. Although nerve-sparing techniques significantly improve postoperative urinary control and sexual function (with robotic surgery achieving >80% continence recovery rates), conventional approaches relying on intraoperative visual tumor boundary assessment result in positive surgical margin (PSM) rates of 11%- 38%, increasing biochemical recurrence risk exceeding 40% [1,2]. For locally advanced cases, sacrificing functional structures to ensure oncological radicality leads to postoperative erectile dysfunction rates up to 95% and urinary incontinence exceeding 50% [3].The essence of this conflict lies in: Extended resection reduces PSM rates but damages neurovascular bundles (NVBs) governing micturition and erectile function; Limited resection preserves function yet increases PSM risk due to residual microlesions-particularly in anatomically complex zones like the prostatic apex and anterior wall, where visual localization errors typically exceed 3 mm.

Preoperative imaging limitations exacerbate this: MRI offers high anatomical resolution (0.5 mm³) but cannot track intraoperative organ deformation; PSMA-PET/CT detects micrometastases with 98% sensitivity, yet spatial registration errors between metabolic/anatomical data exceed 2 mm [4]. Current multimodal fusion approaches are inadequate: MRI-based fusion misses early-stage lesions due to limited tumor contrast; PSMA-PET/CT fusion suffers from metabolic-anatomical misalignment.

Thus, a navigation system enabling simultaneous subclinical lesion detection and dynamic deformation compensation is imperative to resolve the function-versus-curability dilemma.

We have adopted the following approaches to complete the construction of the intraoperative navigation system: (1) On the PET/MRI before the operation, the prostate and the lesion were delineated: at least two nuclear medicine physicians independently reviewed the images and then provided a unified report; the external contour of the prostate and the three-dimensional lesion schematic diagram of the lesion were then delineated by a urologist; (2) On the intraoperative ultrasound, the prostate was delineated: the prostate image was captured in real time by BK ultrasound and then the external contour of the prostate was delineated by a urologist; (3) The multimodal fusion of the three-dimensional lesion delineated by BK ultrasound and PSMAPET/MRI was achieved through the MIM software built into the BK ultrasound; (4) The intraoperative resection was guided by the Da Vinci Tilepro functional module. So far, 6 cases have been successfully completed and compared with 6 T3a patients randomly selected from previous conventional surgeries. Currently, due to the small sample size, although the differences in the surgical margins have not reached a statistically significant difference, a trend of difference has been demonstrated. Due to the short follow-up period, the postoperative PSA and urination conditionshave not been included in the statistical cohort.

Enrollment: 98 estimated patients

Sex: Male

Ages: Under 90 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Target Population: Patients with clinical stage T3a, or T2 (with the lesion close to the surface of the prostate) scheduled for robot-assisted radical prostatectomy (RARP), who have been diagnosed with prostate cancer.

  • Age 50 - 80 years old;

    • Pathologically confirmed as prostate adenocarcinoma (Gleason score 6 - 10);

      • PSMA-PET/MRI indicates extracapsular invasion of the lesion; ④ Signed informed consent and committed to completing follow-up.

Exclusion criteria

• ① Metastasis (M1 stage) or lymph node metastasis (N1 stage);

  • Previous pelvic radiotherapy or endocrine therapy history;

    • Severe cardiopulmonary dysfunction (ASA grade ≥ III); ④ Mental illness or cognitive impairment that cannot cooperate with assessment; ⑤ Participating in other interventional clinical trials.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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98 participants in 2 patient groups

experimental group（navigation-assisted RARP）

Experimental group

Description:

The experimental group will use preoperative PSMA-PET/MRI and intraoperative ultrasound for multimodal fusion to construct a three-dimensional model and synchronize it in real time to the surgeon's control console through the Da Vinci surgical robot's Tilepro video integration module, and complete the anterior approach laparoscopic radical prostatectomy under this guidance.

Treatment:

Procedure: experimental group (navigation-assisted RARP)

Control group (traditional RARP)

No Intervention group

Description:

The control group will undergo the anterior approach laparoscopic radical prostatectomy in the conventional manner.