Thoracoscopic precision excision technique for small non-palpable lesions using radiofrequency identification lung marking system

Introduction

Background

Wedge resection is considered to be a safe and simple procedure. Wedge resection using a stapler is indicated when a tumor is located at the periphery of the lung parenchyma. However, there are some concerns about wedge resection, depending on the tumor location. It is challenging to perform a wedge resection with a stapler when a tumor is located on a deep, flat surface or close to the hilum (1).

Precision excision technique has been advocated to address the limitations of wedge resection. Perel’man described the electrocautery dissection technique for a lesion with a difficult anatomical location, which made wedge excision by a stapler challenging or impossible (2). Cooper et al. also showed that deep-seated lesions or nodules on the lung’s broad surface may be excised by coring them out of the parenchyma using an electric cautery (3). Due to the advancement of technology, improved energy devices have appeared in clinical practice, and Improved energy devices have made parenchymal dissection techniques more straightforward.

In the cases of small lung nodules, accurate identification of the tumor location is essential. While several marking methods have been established, Sato et al. recently developed a novel surgical marking system using near-field communication technology based on radio frequency identification (RFID) technology (4). Since the pitch of the sound changes according to the distance from the marker, which allows the tumor’s location to be identified, and the precision excision technique is used to decide an appropriate resection line in real time.

Rationale

While the use of RFID markers in thoracic surgery has been explored in prior studies, these primarily focus on the feasibility of RFID marking systems for lung tumor localization. However, existing literature lacks detailed procedural guidance on how RFID technology can be integrated into precision excision techniques, particularly for small, non-palpable nodules in challenging anatomical locations. This study not only outlines a step-by-step approach to RFID-guided precision excision but also addresses specific technical adjustments that enhance real-time tumor localization and resection margin accuracy. By providing these additional insights, this article aims to refine and expand the application of RFID technology in thoracic surgery.

Objective

This report presents the precision excision technique using RFID marker for small, non-palpable lung lesions. The surgical technique described in this paper is demonstrated through both a figure and a video. The figure illustrates the port placement and the use of energy devices during the precision excision, while the video provides a step-by-step guide to the entire procedure, including tumor localization, and excision with real-time monitoring. We present this article in accordance with the SUPER reporting checklist (available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-19/rc).

Preoperative preparations and requirements

Patient selection criteria and contraindications

This technique is suitable for patients with small, non-palpable lung lesions that are difficult to resect using conventional wedge resection techniques. There are no absolute contraindications or limitations when placing RFID marker. However, in cases with severe pulmonary emphysema, difficulties may arise with sealing air leaks after resection.

Surgical team composition

The surgical team typically includes one chief surgeon experienced in thoracoscopic procedures, an assistant surgeon, and two to three surgical nurses. The console surgeon, who performs most of the procedure, should have extensive experience in thoracoscopic lung resections, with at least 50 procedures performed using this technique to ensure proficiency. The assistant surgeon is responsible for handling instruments and providing exposure, while the nursing staff assists with equipment preparation and intraoperative management.

Chief surgeon’s experience and training

The chief surgeon should have a solid background in thoracoscopic lung resections, including specific training in minimally invasive techniques. Familiarity with RFID-guided precision excision is beneficial, though not mandatory. It is important that the surgeon has prior experience with thoracoscopic procedures and is comfortable with the use of advanced localization technologies. While there is no strict requirement for the number of procedures performed, surgeons should have gained proficiency in the core technical skills needed for accurate tumor localization, real-time monitoring, and margin determination to ensure optimal outcomes.

All procedures performed in this study were in accordance with the ethical standards of the Institutional Review Board of Yamagata University Hospital (IRB No. 2020-41 Dated: 2020.5.11) and with the Helsinki Declaration (as revised in 2013). Individual consent for this retrospective analysis was waived.

Step-by-step description

Imaging and pathway planning

The RFID marker localization procedure is generally performed on the day of surgery in the hybrid operating room under general anesthesia. In our institute, 3DCT imaging allows to create a bronchial pathway to place RFID marker at the target nodule’s location accurately. This pathway is used as a reference for the actual bronchoscopy procedure. Specifically, we first use DICOM CT images with 0.5–1 mm slices to create the pathway in the virtual bronchoscopy mode of the workstation SYNAPSE VINCENT (Fuji Film Medical Co., Ltd., Tokyo, Japan) (Video 1).

Anesthesia and patient positioning

After inducing general anesthesia in the supine position with a single-lumen tube, a cone beam CT (CBCT) (ARTIS Zeego, Siemens Healthcare, Erlangen, Germany) scan is performed to identify the nodule’s location. In this situation, the anesthesiologist temporarily holds ventilation at maximum inspiratory pressure (approximately 10–20 cmH₂O) and allow the lungs to expand as much as possible. This technique helps to resolve atelectasis and makes ground-glass opacities and small nodules more visible. If the nodule’s location is identified on the CBCT, we mark the position of the nodule and overlay this marking onto the fluoroscopic image. The fluoroscopic image with the overlaid position of the nodule identified on the CBCT allows real-time verification of the positional relationship between the RFID marker delivery device and the nodule.

RFID marker placement

Using the route determined by the virtual bronchoscopy as a reference and the fluoroscopic image with the overlaid position of the nodule, we navigate the bronchoscope (BF-1T260 or BF-260; Olympus, Tokyo, Japan) to the target bronchial branch. Once the RFID marker delivery device is confirmed to be approximately near the tumor on the fluoroscopic image, another CBCT scan will be performed to verify the position. The RFID marker delivery device is inserted through the channel of the bronchoscope. Once the RFID marker delivery device has approximately reached the target location, a CBCT scan is performed to confirm its position. If the position is correct, the RFID marker is then placed. Then, the single-lumen tube is replaced with a double-lumen endotracheal tube, and the patient is positioned in the lateral decubitus position.

When selecting the bronchial route leading to the tumor, the route closest to the tumor is used; however, there is a possibility that the marker’s position may slightly deviate from the tumor’s exact location. Therefore, it is important to adjust the resection line accordingly.

Additionally, for dorsally located nodules, it can be difficult to identify them on CBCT images used to confirm marker placement due to atelectasis on the dorsal side.

Surgical procedure

Thoracoscopic surgery is performed through a multi or single-port approach. The receiver antenna is inserted through the main port and explores the surface of the lung (Figure 1). As the pitch of the sound changes according to the distance from the marker, we can identify the tumor location. In the RFID-guided precision excision, as shown in Figure 2, key stages include the dissection of lung parenchyma (Figure 2A), real-time monitoring of the RFID marker’s position (Figure 2B), and closure of the resection site using stapling devices (Figure 2C). The location with the highest pitch among the five sound levels is closest to the tumor. Then, the visceral pleura at that location is cauterized with an electric cautery to mark it.

Figure 1 Port settings in this case: the procedure was performed using four ports.

Figure 2 Key stages of RFID-guided precision excision technique. (A) Lung parenchyma is dissected using a bipolar sealing device. (B) The position of the RFID marker is monitored in real-time during the resection, and the resection line is adjusted to avoid approaching the tumor. (C) The defect was closed using stapling devices in this case. RFID, radio frequency identification.

After identification of the tumor, the lung parenchyma is excised in a round shape, securing safe surgical margins based on the marking. Conventional electrocauterization was used to outline the area corresponding to the tumor size on the pleura surface. The electrocautery was set to 30 W for minimal tissue coagulation, and the lung parenchyma was then gradually cut off. During resecting lung parenchyma using electrocauterization, counter-traction of the excised line is needed. Energy devices, ultrasonic coagulation, or bipolar devices are used for lung parenchyma according to the surgeons’ preference (Figure 2A). To avoid bronchopleural fistula and subsequent empyema, visible branches of the bronchus were ligated. Careful attention is required to avoid such severe complications.

While proceeding with the excision, a receiver antenna intermittently detects the RFID marker to ensure a sufficient surgical margin from the tumor. This point is an advantage of using RFID marking, as it allows for the real-time identification of the tumor’s location, enabling the surgeon to determine the resection line accordingly (Figure 2B). After the completion of this procedure, the parenchymal defect was closed by suturing, stapler, or combination of both methods. The bottom of the lung parenchyma may sometimes include the peripheral bronchovascular tree, and in such cases, the use of staples is common. When dissecting the bottom of the lung parenchyma with electrocautery or energy devices, it is crucial to carefully check for the presence of the peripheral bronchovascular tree before proceeding with the dissection.

Case presentation

Resection of left upper lobe small solid tumor (Video 1).

We performed precision excision technique on a 69-year-old woman with a history of treatment for pancreatic cancer, presenting a gradually increased 0.8 cm nodule in the left upper lobe on chest computed tomography (Figure 3). Since This nodule was located in a slightly deep from the pleural surface and was highly considered as a metastatic lung tumor, we decided to perform a resection using a precision excision technique.

Figure 3 Chest computed tomographic scan revealed a 0.8-cm nodule on the left S3 (red arrow).

This procedure was performed using a thoracoscopic approach. After RFID marked the target tumor using a CBCT, electrocauterization was used to outline the area corresponding to the tumor size on the pleura surface. After outlining the pleural surface, the lung parenchyma was gradually excited using a bipolar sealing device. Visible bronchus branches were ligated, and the lung parenchyma was excised roundly while securing sufficient surgical margins. An essential point of the precision excision technique is a vertical excision to ensure the deep margin. After removing the lung parenchyma, the incision was closed using sutures and staples in this case (Figure 2C). The surgery time was 116 minutes, and the blood loss was 10 cc.

She was discharged on postoperative day (POD) 2 without any postoperative complications.

Postoperative considerations and tasks

One of the most important tasks immediately after surgery is to ensure the retrieval of the RFID marker. After the excised specimen is removed from the body, it is essential to verify the tumor and its resection margins, as well as to use the receiver antenna to confirm audibly that the RFID marker is within the specimen. Finally, it is critical to retrieve the tag from the specimen.

Other aspects of postoperative management should follow standard procedures.

A chest tube will be placed through the incision site. After tumor resection, complete hemostasis was checked, and a sealing test showed no air leakage, proper lung expansion, and the absence of lung injury. The chest tube was removed 4 hours after surgery. Patients drank water 2 hours post-surgery and started a meal on the same day. Pain management was achieved through the administration of non-steroidal anti-inflammatory drugs three times daily, beginning on the day of surgery. After confirming no abnormal findings on blood test and lung expansion on chest X-ray, patients are discharged 1 or 2 days after chest tube removal.

Tips and pearls

• RFID marker placement for accurate localization: Proper placement of the RFID marker is crucial for determining an accurate resection line on the lung parenchyma. The tag should be positioned directly at the target nodule to ensure consistent localization throughout the procedure. This approach enables effective, real-time guidance of the excision line and minimizes deviations from the intended margin.
• Optimizing the angle of energy devices: When using an electric scalpel or other energy devices, careful management of the device’s angle relative to the lung surface is necessary. If the device is held at an angle that is too shallow, achieving an adequate deep surgical margin may be challenging. A near-vertical angle is therefore recommended to provide sufficient depth and precision in the excision.
• Periodic verification of tumor location: Periodic verification of the tumor’s location with the receiver antenna during the procedure is strongly recommended. By regularly checking the RFID signal, surgeons can adjust the resection line to maintain appropriate margins and ensure accurate alignment with the tumor’s actual position, thus reducing the risk of compromising the surgical margin.

Discussion

While wedge resection using a stapler is a safe and relatively easy technique among thoracic surgical procedures, it has some drawbacks depending on the tumor location. The precision excision technique has been reported by Perel’man et al. and Cooper et al. (2,3). Advanced energy devices could perform this procedure precisely without reducing the intraoperative and postoperative complications. We considered accurate tumor localization to be crucial to perform this method successfully. In addition to the precision excision technique, we applied an RFID marker localization procedure to identify small lung tumors.

Since 1992, various interventional techniques have been reported for marking small lung nodules, including micro coils, hook wires, dyes, contrast media, and fluorescence (5-11).

These traditional localization methods for small lung nodules are effective under specific conditions, yet each has inherent limitations that RFID technology aims to address. Microcoil localization, often used for deep-seated nodules, provides robust marking for thoracic surgeries. However, complications such as coil migration, pneumothorax, and difficulty in tracking nodules intraoperatively remain concerns. Hook wire localization offers accurate marking but has a notable risk of dislodgment, pneumothorax, and potential patient discomfort due to the protruding wire. Dye marking with substances like methylene blue enables visible localization on the lung surface but is prone to diffusion, rendering it less practical for deeper or centrally located nodules. Contrast media and fluorescence have also been explored; while they offer improved visualization under imaging, their limitations include rapid washout and lack of durability throughout the surgery.

However, these techniques contained risks of severe complications, such as air embolism, pneumothorax, hemorrhage, high-grade fever, and anaphylaxis. Complication rates due to marking were from 1% to 38% (11-13). Furthermore, conventional localization technologies have a reported failure rate of approximately 5% (11,12).

RFID marking is a novel marking system to identify small pulmonary tumors. It was developed by Kojima et al. (14), Yutaka et al. (15,16), and Sato et al. (4). The system comprises RFID marker placed near the lesion preoperatively using a bronchoscope, a receiver antenna used in the operating field to detect the RFID marker, and a dedicated PC used outside the surgical field. The pitch of the sound changes depending on the distance between the RFID marker and the receiver antenna, with the pitch becoming higher as they get closer, changing in 1 mm increments. In recent years, developers of RFID marking systems have focused on reporting detailed marking methods, particularly concerning using this system in precision excision techniques (17). This paper focuses on reporting the actual surgical techniques used in lung resection.

Strengths and limitations

A precision excision technique could limit the excision of the tumor located on the hilar lesion or flat surface of the lung. Because the precision excision technique could reserve the lung structure without deformity, this procedure would be superior to wedge resection using a stapler. Recently, energy devices have become especially powerful in cauterizing blood vessels and achieving hemostasis. Ultrasonic coagulation cutting devices and bipolar sealing devices cater to larger vessels (18,19). Additionally, given that Japan’s national health insurance only covers up to six for wedge resection, this technique helps to reduce excess stapler costs borne by hospitals. This procedure benefits the medical economy of each country.

Precision excision technique and RFID marking have several limitations. First, the operation time would be longer if it takes a long time to mark the tumor. However, using a 3D image could support precise RFID marking of the tumor. As there is a slight potential risk of bleeding from large pulmonary vessels, meticulous surgical procedures are needed. Control of air leakage is the main point of this surgery. If the minute bronchial stumps are not sutured or ligated, it could result in postoperative bronchial fistulas and complicate the postoperative management.

Comparison with other surgical techniques and research

For the nodules located in the part where stapled partial resection is difficult, segmentectomy should be indicated as an option. However, segmentectomy typically involves dissecting and exposing the blood vessels and bronchi from the hilum to the periphery, leading to strong adhesions. In cases where repeated surgeries might be necessary, such as with metastatic lung tumors, manipulating the hilum during reoperation can be challenging. If it is difficult to dissect the hilum, there is a possibility that a pneumonectomy may be unavoidable. Precision excision technique allows for partial resection without exposing the hilar vessels and enables the removal of lesions relatively deep within the lung, making it a helpful method. This does not negate the utility of segmentectomy but rather should be considered as one of the surgical options available to the surgeon.

Furthermore, evidence has been gradually accumulating regarding limited resection surgeries in the field of lung cancer. Altorki et al., in the CALGB140503 study, reported no significant differences in disease-free survival, overall survival, or lung cancer-specific survival between lobectomy and both sublobar resection methods (segmentectomy and wedge resection). Additionally, although segmentectomy had more extended resection margins than wedge resection, there was no difference in the local recurrence rate (20).

Conclusions

Although more experience and follow-ups are required, Precision excision technique can be one of the surgical options for cases where stapled wedge resection is difficult. Additionally, precise resection can be achieved by combining this method with RFID marking.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the SUPER reporting checklist. Available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-19/rc

Peer Review File: Available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-19/prf

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jovs.amegroups.com/article/view/10.21037/jovs-24-19/coif). J.S. serves as an unpaid editorial board member of Journal of Visualized Surgery from September 2023 to August 2025. 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 are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the Institutional Review Board of Yamagata University Hospital (IRB No. 2020-41 Dated: 2020.5.11) and with the Helsinki Declaration (as revised in 2013). Individual consent for this retrospective analysis was waived.

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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