XR-Assisted PET/CT Navigation for Cervical Lymph Node Dissection in Lung Cancer

Application of Extended Reality (XR)-Assisted PET/CT Fusion Navigation in Supraclavicular-to-Cervical Lymph Node Dissection for Lung Cancer

This single-arm, prospective feasibility study evaluates an Extended Reality (XR) headset-based preoperative surgical planning workflow that fuses 18F-FDG PET metabolic hotspots with CT anatomy on the OpVerse platform, in patients with non-small cell lung cancer (NSCLC) and supraclavicular or cervical lymph node metastasis (N3 disease) requiring lymph node dissection. Ten participants will undergo standard preoperative contrast-enhanced CT and whole-body PET. Synapse 3D software is used to segment key anatomic structures (clavicle, sternocleidomastoid, internal jugular vein, subclavian vessels, brachial plexus) and to project PET SUV hotspots onto the high-resolution CT model, yielding a patient-specific digital twin of functional tumor boundaries and at-risk neurovascular structures.

Immediately prior to skin incision, the operating surgeon dons an XR head-mounted display (HoloLens via OpVerse) and registers the digital twin to the patient's neck using stable bony landmarks (clavicular head, sternal notch, mastoid). The surgeon plans the optimal incision and initial dissection trajectory, avoiding superficial veins and projecting the location of deep PET-positive nodes. The XR device is then removed, and the planned cervical or supraclavicular lymph node dissection is performed using standard surgical technique without further intraoperative XR guidance.

The primary endpoint is a composite of safety and feasibility: absence of Grade ≥2 (Clavien-Dindo) phrenic nerve, brachial plexus, chyle leak, Horner syndrome, or major vascular injury through 30 days postoperatively, together with successful XR registration and incision planning. Secondary endpoints include incision planning accuracy, PET hotspot clearance rate, target registration error, operative time, estimated blood loss, and lymph node yield.

Background and Rationale NSCLC with supraclavicular or cervical lymph node metastasis (N3 disease) was historically considered unresectable. With the advance of multimodal therapy, complete lymph node dissection in selected patients has been shown to improve locoregional control. However, the supraclavicular fossa - frequently described as 'Pandora's Box' - is anatomically narrow and dense, with metastatic nodes often abutting the subclavian vessels, internal jugular vein, phrenic nerve, and brachial plexus. Conventional surgery relies heavily on the surgeon's tactile experience and 2D mental reconstruction of preoperative CT, increasing the risk of inadvertent neurovascular injury and incomplete clearance of post-treatment fibrotic versus active disease.

Intervention This study integrates two complementary technologies. (1) Multimodal image fusion using Fujifilm Synapse 3D maps PET SUV hotspots representing biologically active tumor onto a high-resolution CT anatomical model, producing a patient-specific digital twin. The fused model is exported to a static 3D format (OBJ/STL) and imported into the OpVerse XR platform - an offline data-conversion workflow with no real-time API coupling between the two systems, ensuring system stability and software compatibility. (2) Preoperative XR planning: in the operating room after general anesthesia and head/neck positioning, the surgeon wears an XR head-mounted display (HoloLens) and performs surface registration using stable bony landmarks. The 'see-through' overlay enables the surgeon to identify subcutaneous tumor hotspots and superficial venous anatomy, and to mark the optimal skin incision and initial dissection trajectory before any cut is made. The XR headset is then removed; lymph node dissection proceeds using standard sterile technique. Therefore the device functions purely as a preoperative visual aid (Non-Significant Risk), without entry into the sterile operative field.

Lymph node dissection definition En bloc systematic resection of the fibrofatty tissue containing metastatic nodes within the defined cervical or supraclavicular region, to achieve oncologic clearance and provide adequate tissue for pathologic staging and next-generation sequencing.

Statistical analysis All analyses are performed using SPSS. Continuous variables (operative time, blood loss, lymph node count) are summarized as mean ± SD or median; categorical variables (complications, registration success) as frequency and percentage. Successful completion rate of the XR-assisted workflow is reported with 95% confidence intervals. As a single-arm feasibility trial, no formal hypothesis testing is planned.

Preliminary data The investigators have completed a prior pilot trial (REC 202502149RINB, 2025) of XR-assisted lung nodule localization in 20 patients undergoing thoracoscopic sublobar resection, achieving 6-7 mm mean target registration error and 19/20 successful localizations without major complications. Because the supraclavicular region is more rigidly tethered to the bony skeleton and less affected by respiratory motion, registration accuracy in the present study is expected to be ≤5 mm.

Inclusion Criteria:

• Age 18 to 80 years.
• Confirmed or highly suspected lung cancer with supraclavicular or cervical lymph node metastasis requiring lymph node dissection.
• Willing to undergo preoperative PET/CT imaging.
• Able to provide written informed consent.

Exclusion Criteria:

• Prior high-dose radiation therapy to the neck causing severe distortion of cervical anatomy.
• Inability to undergo imaging studies, or known allergy to iodinated contrast media.
• Vulnerable populations as defined by local IRB regulations (e.g., pregnant women, prisoners, individuals lacking decisional capacity).