Three-dimensionally printed navigational template: a promising guiding approach for lung biopsy

Abstract

Background: Percutaneous transthoracic lung biopsy is customarily conducted under computed tomography (CT) guidance, which primarily depends on the conductors' experience and inevitably contributes to long procedural duration and radiation exposure. Novel technique facilitating lung biopsy is currently demanded.

Methods: Based on the reconstructed anatomical information of CT scans, a three-dimensionally printed navigational template was customized to guide fine-needle aspiration (FNA). The needle insertion site and angle could be indicated by the template after proper placement according to the reference landmarks. From June 2020 to August 2020, patients with peripheral indeterminate lung lesions ≥30 mm in diameter were enrolled in a pilot trial. Cases were considered successful when the virtual line indicated by the template in the first CT scan was pointing at the target, and the rate of success was recorded. The insertion deviation, procedural duration, radiation exposure, biopsy-related complications, and diagnostic yield were documented as well.

Results: A total of 20 patients consented to participate, and 2 withdrew. The remaining 18 participants consisting of 11 men and 7 women with a median age of 63 [inter-quartile range (IQR), 50-68] years and a median body mass index (BMI) of 23.5 (IQR, 20.8-25.8) kg/m2 received template-guided FNA. The median nodule size of the patients was 41.2 (IQR, 36.2-51.9) mm and 17 lesions were successfully targeted (success rate, 94.4%). One lesion was not reached through the designed trajectory due to an unpredictable alteration of the lesion's location resulting from pleural effusion. The median deviation between the actual position of the needle tip and the designed route was 9.4 (IQR, 6.8-11.7) mm. The median procedural duration was 10.7 (IQR, 9.7-11.8) min, and the median radiation exposure was 220.9 (IQR, 198.6-249.5) mGy×cm. No major biopsy-related complication was encountered. Definitive diagnosis of malignancy was reached in 13 of the 17 (76.5%) participants.

Conclusions: The feasibility and safety of navigational template-guided FNA were preliminarily validated in lung biopsy cohort. Nonetheless, patients with pleural effusion were not recommended to undergo FNA guided by such technique.

Trial registration: This study was registered with ClinicalTrials.gov (identifier: NCT03325907).

Keywords: Lung biopsy; computed tomography (CT); fine-needle aspiration (FNA); three-dimensional printing (3D printing).

Conflict of interest statement

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-22-172/coif). YW is a current employee of Lanhui Medical Technology Co., Ltd. The other authors have no conflicts of interest to declare.

2022 Translational Lung Cancer Research. All rights reserved.

Figures

Figure 1

Insertion route design and reconstruction of the CT images. The insertion route was designed by the referring pulmonologist based on the CT images (A). The whole thorax consisting of the target lesion (red part), insertion route (blue part), thoracic contour surface (purple part), and bony cage (grey part) was reconstructed and shown from the back (B) view. CT, computed tomography.

Figure 2

Navigational template design process. Prominent anatomical landmarks guiding accurate localization of the template were selected and horizontally projected (A). The navigational template was delineated according to the contour of the body surface encompassing the anatomical landmarks and insertion route (B). The overlapping part of the navigational template and projection parts of the anatomical landmarks were eliminated by means of a Boolean algorithm (C).

Figure 3

Template-guided biopsy procedure. After the placement of the template, the first CT scan was performed to evaluate the appropriateness of needle insertion, and an imaginary yellow line was drawn through the protrusion of the template (step 1). After the confirmation CT scan, sterilization and local anesthesia were subsequently administered. The biopsy needle was then inserted to the preset depth (step 2), and another CT scan was performed to calculate the insertion deviation (step 3), after which the core of the biopsy needle was drawn out and the needle was connected to a 50 mL syringe. The force inside the syringe created a vacuum, which allowed for the tumor cells to be suctioned out through the needle (step 4). CT, computed tomography; FNA, fine-needle aspiration.

Figure 4

Deviations of template-guided FNA. The deviations of template-guided FNA were demonstrated three-dimensionally (A). Positive values for CD, AD, or SD indicated that the biopsy needle deviated medially, anteriorly, or cranially, respectively. The deviations in each dimension were further compared (B). The horizontal line in each box indicates the median, while the top and bottom borders of each box indicate the 75th and 25th percentiles, respectively. The ends of the whiskers above and below each box indicate the minimum and maximum values. FNA, fine-needle aspiration; CD, coronal deviation; AD, axial deviation; SD, sagittal deviation.