Initial experience with the EndoFusion 3D system for noninvasive intraoperative localization of pulmonary nodules

Introduction

The widespread implementation of low-dose computed tomography (LDCT) screening has substantially increased the detection rate of pulmonary nodules (1,2). Surgical resection remains the primary therapeutic strategy for such lesions, with video-assisted thoracic surgery (VATS) increasingly adopted as the preferred modality owing to its minimal invasiveness and facilitated recovery (3-5). Precise intraoperative localization is fundamental to successful VATS sublobar resection (6,7); however, conventional tactile localization poses significant challenges for small lesions or those lacking pleural indentations, necessitating alternative guidance strategies.

Among current approaches, preoperative computed tomography (CT)-guided percutaneous localization remains the most widely utilized technique in clinical practice (8), despite its inherent risks of pneumothorax, hemorrhage, and air embolism, along with the logistical challenges of coordinating between radiology and surgical teams (9,10). The rising adoption of anatomic segmentectomy for early-stage lesions has driven the parallel development and integration of three-dimensional computed tomography (3D-CT) reconstruction into surgical planning and nodules localization (11,12). Nevertheless, its intraoperative application remains constrained by the cognitive challenge of correlating virtual images with the surgical field—a process fundamentally dependent on the surgeon’s spatial reasoning and experiential acumen (13). Recently, electromagnetic navigation bronchoscopy (ENB) has emerged as an advanced technique for diagnostic biopsy and preoperative nodule localization (14,15); however, its integration into routine practice is constrained by limited device availability, technical complexity with a prolonged learning curve, and considerable patient financial burden (16). These constraints have therefore precipitated an urgent need for a dynamic, noninvasive, and streamlined intraoperative localization strategy that can be widely promoted in clinical practice.

Herein, we introduced the EndoFusion Image-Guided System, a novel platform that integrates preoperative 3D reconstructions with real-time intraoperative VATS imagery to facilitate the localization of peripheral pulmonary nodules. This study aims to evaluate the feasibility and safety of this technique and to summarize our initial clinical experience with its application. We present this article in accordance with the TREND reporting checklist (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0899/rc).

Methods

Study design

This single-center, retrospective study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments (17). This study was approved by the Institutional Review Board of The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, (approval No. 2025-95). The informed consent was waived for this retrospective observational study without additional interventions. Between September 2024 and August 2025, a total of 15 consecutive patients with radiologically confirmed peripheral pulmonary nodules who were scheduled for VATS resection at The First Affiliated Hospital of Nanchang University were enrolled. Inclusion criteria comprised: (I) presence of a solitary pulmonary nodule ≤2 cm in diameter and consolidation-to-tumor ratio (CTR) ≤0.5; (II) location in the outer third of the lung parenchyma; and (III) planned VATS wedge resection or segmentectomy. Exclusion criteria included: (I) severe pleural adhesions identified preoperatively; (II) inability to tolerate single-lung ventilation; and (III) presence of pleural indentation or retraction that could be easily identified.

Preoperative preparation and 3D reconstruction

All patients underwent preoperative thin-slice (1.0–1.5 mm) chest CT imaging within one month prior to surgery. The Digital Imaging and Communications in Medicine (DICOM) data were processed using FDIM-AQI software (Chongqing FDIM Technology Co., Ltd., China) to generate patient-specific three-dimensional reconstructions of the pulmonary parenchyma, vasculature, bronchial tree, and target nodule. These reconstructions provided critical anatomical guidance for surgical planning by delineating the spatial relationships between the nodule and adjacent segmental structures. All other preoperative preparations followed standard institutional protocols for conventional VATS procedures.

The EndoFusion system and localization procedure

The EndoFusion system (Chongqing FDIM Technology Co., Ltd., China) is a novel image-guidance platform comprising a computer workstation equipped with a dedicated video capture interface (Figure 1). The reconstructed 3D model was uploaded to the system preoperatively. Following general anesthesia and double-lumen intubation, patients were positioned in the lateral decubitus position. The video output from the standard thoracoscopic tower was connected to the system’s computer via standard video interfaces [high-definition multimedia interface (HDMI)/digital visual interface (DVI)/serial digital interface (SDI), with optional format conversion], enabling real-time capture of the intraoperative feed. The preoperative 3D reconstruction and virtual nodule location were overlaid onto the intraoperative video stream and displayed on the original surgical monitor in real time through a noninvasive “capture-processing-display” workflow. Minor positional adjustments were performed by the surgeon according to intraoperative anatomical landmarks to ensure correspondence between the projected localization and the actual operative field. No routine intraoperative re-registration was required after lung manipulation unless significant anatomical deviation or loss of registration accuracy was suspected. The system provided real-time virtual localization guidance throughout the dissection (Figure 2). All resections were performed by experienced thoracic surgeons. Registration time was defined as the interval from system initialization to completion of initial image-to-patient alignment.

Figure 1 Schematic illustration of noninvasive intraoperative virtual localization (EndoFusion). (A) Preoperative 3D reconstruction and intraoperative navigation rendering on the workstation; (B) Thoracoscopic video is captured from the endoscopic tower via standard outputs (HDMI/DVI/SDI; with optional format conversion) into the workstation for acquisition/time synchronization; 3D reconstruction and virtual localization are overlaid and the fused stream is sent back to the original OR monitor(s), enabling noninvasive integration without modifying the tower. (C) Intraoperative fused view on the main monitor with virtual localization guidance. 3D, three-dimensional; DVI, digital visual interface; HDMI, high-definition multimedia interface; OR, operating room; SDI, serial digital interface.

Figure 2 Intraoperative lung nodule localization using the EndoFusion system. (A,B) Preoperative CT images show the target pulmonary nodule (circled in red). (C) The 3D anatomical model is registered and fused with the actual lung surface. The target nodules are accurately projected and localized (yellow arrow) within the surgical field. (D) The final surgical specimen confirms the successful removal of the targeted nodules (marked by yellow arrow). 3D, three-dimensional; CT, computed tomography.

Data collection and outcome

Data for all consecutive patients were prospectively collected using a standardized case report form. Patient baseline characteristics included demographic information, nodule characteristics (size, location, CTR), and preoperative pulmonary function. Perioperative outcomes were defined as events occurring within 30 days after surgery and included intraoperative details (system setup time, registration time, total operative time, estimated blood loss) and postoperative variables (chest tube duration, postoperative complications, length of hospital stay). Perioperative complications were classified according to the Clavien-Dindo Classification System (18).

The primary outcomes were technical success and feasibility. Technical success was defined as successful system registration and nodule localization leading to accurate resection. Feasibility was assessed by the completion of the procedure without conversion to conventional manual palpation or alternative localization techniques. Secondary outcomes included safety (incidence of procedure-related complications) and pathological outcomes (R0 resection rate).

Statistical analysis

Statistical analyses were performed using IBM SPSS Statistics (version 23.0; IBM Corp.). Categorical data were presented as numbers and percentages, and continuous data as medians and ranges.

Results

Patient characteristics

A consecutive cohort of fifteen patients with radiologically confirmed peripheral pulmonary nodules scheduled for VATS resection was prospectively enrolled between September 2024 and August 2025. The cohort demonstrated a female predominance (80%, n=12) with a median age of 53 years [interquartile range (IQR), 42–59 years]. Most patients were non-smokers (93.3%), and two-thirds (66.7%) had no significant comorbidities. Only 1 patient (6.7%) had a history of prior pulmonary resection. Preoperative imaging revealed multiple nodules in 53.3% (n=8) of patients. A detailed summary of baseline characteristics is provided in Table 1.

Characteristics of target pulmonary nodules

A total of 19 peripheral pulmonary nodules were resected in 15 patients. The median nodule size was 8.0 mm (IQR, 6.0–11.0 mm), with a median pleural depth of 3.0 mm (IQR, 1.0–7.0 mm). Based on the CTR, the majority of nodules (73.7%, n=14) were classified as CTR ≤0.25. Anatomically, nodules were distributed across all lung lobes, with the right upper lobe (RUL) and left upper lobe (LUL) each accounting for 31.6% (n=6), followed by the right middle lobe (RML) and right lower lobe (RLL) (15.8% each, n=3), and one nodule (5.3%) located in the left lower lobe (LLL). Radiologically, pure ground-glass nodules (pGGNs) constituted 68.4% (n=13) of the lesions. Pathological evaluation revealed a spectrum of diagnoses, including adenocarcinoma in situ (AIS) in 52.6% (n=10), minimally invasive adenocarcinoma (MIA) in 26.3% (n=5), invasive adenocarcinoma (IA) in 10.5% (n=2), and one case each (5.3%) of atypical adenomatous hyperplasia (AAH) and benign histology. A comprehensive summary of nodule characteristics is provided in Table 2.

Perioperative outcomes and safety

All 15 patients successfully underwent VATS resection without conversion to thoracotomy or lobectomy, comprising wedge resection (60.0%, n=9), combined wedge and segmentectomy (26.7%, n=4), and segmentectomy alone (13.3%, n=2). The median total operation time was 75.0 minutes (IQR, 60.0–110.0 minutes), with a median registration time of 128.0 seconds (IQR, 65.0–201.0 seconds). Intraoperative outcomes were favorable, with a median blood loss of 50.0 mL (IQR, 30.0–50.0 mL) and a median resection margin of 18.0 mm (IQR, 12.0–25.0 mm). No intraoperative complications occurred. Postoperatively, the median chest tube drainage on postoperative day 1 was 80.0 mL (IQR, 50.0–210.0 mL), with a median tube duration of 3 days (IQR, 2–3 days). Two patients (13.3%) experienced complications, including one case each of pneumothorax and impaired wound healing. The median hospital stay was 4 days (IQR, 3–4 days), with 1 patient (6.7%) readmitted within 30 days. A detailed summary of perioperative outcomes is provided in Table 3.

Discussion

In this preliminary study, we evaluated the feasibility and safety of the EndoFusion Image-Guided System for intraoperative localization of peripheral pulmonary nodules during VATS. Our findings demonstrate that this novel platform enables accurate real-time guidance without additional invasive procedures, achieving a 100% technical success rate and favorable perioperative outcomes. These results suggest that image fusion-assisted localization may serve as a promising adjunct to VATS sublobar resection, particularly for peripheral, small, ground-glass-predominant lesions.

Over the past decades, strategies for pulmonary nodule localization have shifted from invasive preoperative interventions to integrated intraoperative guidance (6). Conventional CT-guided percutaneous localization, though widely used, requires an additional invasive procedure outside the operating room and carries risks such as pneumothorax, pulmonary hemorrhage, and marker displacement (11). Moreover, the extra procedural step increases patient anxiety, radiation exposure, and workflow inefficiencies (12). In contrast, intraoperative navigation systems like EndoFusion provide real-time localization without needle puncture, reduce perioperative risk, streamline surgical workflow, and minimize patient burden—representing a meaningful refinement over traditional preoperative methods (19,20).

Recent high-quality evidence has strengthened the rationale for non-invasive intraoperative localization. In a randomized clinical trial involving 440 patients, Jiang et al. demonstrated that a real-time, CT-based non-invasive technique was non-inferior to CT-guided percutaneous localization for successful sublobar resection (98.1% vs. 98.6%), yet completely avoided puncture-related complications such as pneumothorax, minor hemorrhage, puncture-site pain, and marker misplacement (19). These findings highlight that accurate nodule targeting can be achieved without tissue puncture and that non-invasive strategies markedly improve patient safety. However, Jiang’s method presented the reconstructed CT information and the thoracoscopic view as separate visual modalities, requiring surgeons to mentally integrate static 3D anatomy with a dynamic operative field. The EndoFusion system advances this concept by directly fusing patient-specific 3D reconstructions with real-time VATS imaging, enabling intuitive, in-field visualization of lesion location and resection margins. Our results not only align with the safety benefits reported by Jiang et al. but also demonstrate that true intraoperative image fusion improves surgical precision and facilitates intuitive, real-time lesion localization

Appropriate case selection is essential for fully leveraging the advantages of this system. In our study, the majority of resected lesions were small, subcentimeter, and ground-glass-predominant nodules, which are known to be difficult to palpate or visualize during minimally invasive surgery. These lesions generally lack pleural indentation and therefore benefit significantly from the surface-based guidance offered by EndoFusion. Notably, our cohort also included patients with multiple synchronous pulmonary nodules, a scenario that traditionally poses substantial challenges for conventional localization approaches (21). Preoperative percutaneous localization of multiple lesions not only increases procedural risk but also adds complexity when nodules lie in different lung segments or lobes (13). EndoFusion effectively overcomes these limitations by enabling simultaneous and noninvasive intraoperative localization of all target nodules once fusion registration is completed. This capability proved advantageous for both multiple lesions within the same lobe and nodules distributed across different lobes, allowing surgeons to switch between target sites effortlessly without additional waiting time or repeated localization procedures. This feature significantly streamlined the operative process and reduced the cumulative trauma and risk associated with multi-lesion management.

A key advantage of this technique is its reproducibility and short learning curve. Following completion and upload of the preoperative 3D reconstruction to the EndoFusion system, the platform captures the thoracoscopic video feed in real-time and performs surface-based registration by aligning the pleural contours with the reconstructed model. Once registration is established, the fused overlay remains stable throughout the operation, providing continuous intraoperative guidance without the need for repeated adjustments. This reliability enables surgeons of varying experience levels, including junior surgeons and residents, to accurately localize nodules and define safe resection margins. By integrating volumetric anatomical information directly into the surgical field, the method reduces reliance on mental correlation of preoperative images, minimizes inter-operator variability, and facilitates broader clinical adoption.

This study has several limitations. First, it is a single-center, retrospective observational study with a relatively small sample size, which may limit the generalizability of the findings. Second, although intraoperative localization and subsequent resection were successfully achieved in all cases, the study lacked standardized quantitative metrics to objectively evaluate localization accuracy, such as localization error, resection margin accuracy, and pathological correlation. Therefore, the precise accuracy and reproducibility of the system require further validation in future prospective studies. In addition, the current cohort mainly included small peripheral and ground-glass predominant nodules, which represent the clinical scenarios in which adjunctive localization is most commonly required. The applicability of the EndoFusion system to deeper lesions or anatomically complex resections remains to be further evaluated in future studies. . Finally, the study did not include a direct comparative group, such as CT-guided percutaneous localization or conventional preoperative 3D reconstruction alone, preventing robust evaluation of relative advantages in terms of operative time, learning curve, or patient outcomes. Future prospective, multicenter studies with larger cohorts and comparative designs are warranted to further validate the safety, efficacy, and clinical utility of this approach.

Conclusions

This study demonstrates the feasibility and safety of the EndoFusion system for intraoperative localization during VATS. The system enables needle-free, real-time guidance and may facilitate localization of small ground-glass nodules and multiple lesions. Further prospective studies are warranted to define its clinical value in minimally invasive thoracic surgery.

Acknowledgments

The authors would like to thank the Department of Thoracic Surgery at The First Affiliated Hospital of Nanchang University for their support throughout this study. During the preparation of this work, the authors used ChatGPT (OpenAI) in order to improve the language and readability of the manuscript. After using this tool/service, the authors reviewed and edited the content as needed and take full responsibility for the content of the published article.

Footnote

Reporting Checklist: The authors have completed the TREND reporting checklist. Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0899/rc

Data Sharing Statement: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0899/dss

Peer Review File: Available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0899/prf

Funding: This study was partially supported by the Science and Technology Program of the Provincial Health Commission (No. 202210406).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-2026-0899/coif). Q.L.H. is a current employee of Chongqing FDIM Technology Co., Ltd. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. This study was approved by the Institutional Review Board of The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, (approval No. 2025-95). The informed consent was waived for this retrospective observational study without additional interventions.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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