Utility and reproducibility of 3-dimensional printed models in pre-operative planning of complex thoracic tumors

The application of three-dimensional custom-made prostheses in chest wall reconstruction after oncologic sternal resection

BACKGROUND AND OBJECTIVES

As one of the cutting-edge advances in the field of reconstruction, three-dimensional (3D) printing technology has been constantly being attempted to assist in the reconstruction of complicated large chest wall defects. However, there is little literature assessing the treatment outcomes of 3D printed prostheses for chest wall reconstruction. This study aimed to analyze the surgical outcomes of 3D custom-made prostheses for the reconstruction of oncologic sternal defects and to share our experience in the surgical management of these rare and complex cases.

METHODS

We summarized the clinical features of the sternal tumor in our center, described the surgical techniques of the application of 3D customized prosthesis for chest wall reconstruction, and analyzed the perioperative characteristics, complications, overall survival (OS), and recurrence-free survival of patients.

RESULTS

Thirty-two patients with the sternal tumor who underwent chest wall resection were identified, among which 13 patients used 3D custom-made titanium implants and 13 patients used titanium mesh for sternal reconstruction. 22 cases were malignant, and chondrosarcoma is the most common type. The mean age was 46.9 years, and 53% (17/32) of the patients were male. The average size of tumor was 6.4 cm, and the mean defect area was 76.4 cm2. 97% (31/32) patients received R0 resection. Complications were observed in 29% (9/32) of patients, of which wound infection (22%, 7/32) was the most common. The OS of the patients was 72% at 5 years.

CONCLUSION

We demonstrated that with careful preoperative assessment, 3D customized prostheses could be a viable alternative for complex sternal reconstruction.

Chest wall resections for sulcus superior tumors

Chemoradiotherapy followed by surgical resection (trimodality therapy) is a guideline recommended treatment for sulcus superior tumors (SST). By definition, SSTs invade the chest wall and therefore require en-bloc chest wall resection with the upper lung lobe or segments. The addition of a chest wall resection, potentially results in higher morbidity and mortality rates when compared to standard anatomical pulmonary resection. This, together with their anatomical location in the thoracic outlet, and varying grades of fibrosis and adhesions resulting from induction chemoradiotherapy in the operation field, make surgery challenging. Depending on the exact location of the tumor and extent to which it invades the surrounding structures, the preferred surgical approach may vary, e.g., anterior, posterolateral, hemi-clamshell, or combined approach; all with their own potential advantages and morbidities. Careful patient selection, adequate staging and discussion in a multidisciplinary tumor board in a center experienced in complex thoracic oncology leads to the best long-term survival outcomes with the least morbidity and mortality. Enhanced recovery guidelines are now available for thoracic surgery, promoting faster recovery and helping to minimize complications and morbidity, including infections and thoracotomy pain. Although minimally invasive surgery can enhance recovery and reduce chest wall morbidity, and is in widespread use in thoracic oncology, its use for SST has been limited. However, this is an evolving area and hybrid surgical approaches (including use of the robot) are being reported. Chest wall reconstruction is rarely necessary, but if so, the prosthetic materials are preferably radiolucent/non-scattering, rigid enough while still being somewhat flexible, and inert, providing structural support, allowing chest wall movement, and closing defects, while inciting a limited inflammatory response. New techniques such as 3D image reconstructions/volume rendering, 3D-printing, and virtual reality modules may help pre-operative planning and informed patient consent.

Preoperative Simulation of Ileal Pouch-Anal Anastomosis in Patients With Ulcerative Colitis Using a 3-Dimensional Printed Model

BACKGROUND

During restorative proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis-associated colorectal cancer or dysplasia, ileal pouch-anal handsewn anastomosis (IAA) is preferred to avoid the risk of cancer development in the remaining rectal mucosa. However, there is a risk of the ileal pouch not reaching the anus with this procedure. Here, we created deformable 3-dimensional (3D) models for simulation.

METHOD

Six patients who underwent IAA without vessel ligation and 5 patients who underwent ileal pouch-anal canal double-stapled anastomosis (IACA) because the ileal pouch did not reach the anus were studied. A 3D printer was used to create deformable 3D models from the data obtained from computed tomography scans. The positional relationship among the mesenteric arteries, pubis, and coccyx were evaluated.

RESULT

The distance between the superior mesenteric artery root and the tip of the ileal artery was longer in the IAA group than that in the IACA group (IAA vs IACA: 26.2 ± 2.1 cm vs 20.9 ± 1.6cm). The distance from the tip of the ileal artery to the coccyx (IAA vs IACA: 6.7 ± 1.7 cm vs 12.1 ± 2.1 cm) and the distance from the tip of the ileal artery to the lower edge of the pubis (IAA vs IACA; 8.1 ± 1.3 cm vs 12.7 ± 2.4 cm) were longer in the IACA group than those in the IAA group.

CONCLUSIONS

We established a method for creating 3D deformable models of patients with ileal pouch-anal anastomosis. These 3D models may be useful for preoperative simulation.

CAD/CAM-assisted ablative surgery and intraoperative brachytherapy for pediatric skull-base sarcomas

BACKGROUND

Head and neck (H&N) sarcomas in children can poise numerous challenges to the surgical oncologist and require multidisciplinary input and meticulous surgical planning. The application of computer-assisted design/computer-assisted manufacturing (CAD/CAM) has been extensively examined in H&N reconstruction in adults, but its utility in ablative oncologic surgery in children warrants further examination. We present preliminary results utilizing CAD/CAM techniques to assist in planning tumor resections and the application of intra-operative radiation in children with skull-base sarcomas.

METHODS

A retrospective cohort review of all pediatric patients who presented to a tertiary care cancer center for surgical resection of a skull-base malignancy was performed between 1980 and 2021. All children under 18 years of age with diagnosis of a skull-base sarcoma as confirmed with imaging and pathology were analyzed.

RESULTS

A total of 21 children were identified but only four children with skull-base sarcomas had diagnostic imaging available in whom computer-assisted volumetric analyses were generated. In these cases, CAD/CAM was used to plan surgical approaches and intraoperative radiotherapy, significantly aiding in treatment for these complicated pediatric cases.

CONCLUSION

CAD/CAM planning for oncologic resection has huge potential. Here we have shown its utility in pre-operative surgical planning and for administration of intraoperative radiation therapy. Future studies are needed to examine its value in facilitating intraoperative surgical management and patient outcomes, as well as cost effectiveness.

Anatomic evaluation of Pancoast tumors using three-dimensional models for surgical strategy development

OBJECTIVE

Pancoast tumor resection planning requires precise interpretation of 2-dimensional images. We hypothesized that patient-specific 3-dimensional reconstructions, providing intuitive views of anatomy, would enable superior anatomic assessment.

METHODS

Cross-sectional images from 9 patients with representative Pancoast tumors, selected from an institutional database, were randomly assigned to presentation as 2-dimensional images, 3-dimensional virtual reconstruction, or 3-dimensional physical reconstruction. Thoracic surgeons (n = 15) completed questionnaires on the tumor extent and a zone-based algorithmic surgical approach for each patient. Responses were compared with surgical pathology, documented surgical approach, and the optimal "zone-specific" approach. A 5-point Likert scale assessed participants' opinions regarding data presentation and potential benefits of patient-specific 3-dimensional models.

RESULTS

Identification of tumor invasion of segmented neurovascular structures was more accurate with 3-dimensional physical reconstruction (2-dimensional 65.56%, 3-dimensional virtual reconstruction 58.52%, 3-dimensional physical reconstruction 87.50%, P < .001); there was no difference for unsegmented structures. Classification of assessed zonal invasion was better with 3-dimensional physical reconstruction (2-dimensional 67.41%, 3-dimensional virtual reconstruction 77.04%, 3-dimensional physical reconstruction 86.67%; P = .001). However, selected surgical approaches were often discordant from documented (2-dimensional 23.81%, 3-dimensional virtual reconstruction 42.86%, 3-dimensional physical reconstruction 45.24%, P = .084) and "zone-specific" approaches (2-dimensional 33.33%, 3-dimensional virtual reconstruction 42.86%, 3-dimensional physical reconstruction 45.24%, P = .501). All surgeons agreed that 3-dimensional virtual reconstruction and 3-dimensional physical reconstruction benefit surgical planning. Most surgeons (14/15) agreed that 3-dimensional virtual reconstruction and 3-dimensional physical reconstruction would facilitate patient and interdisciplinary communication. Finally, most surgeons (14/15) agreed that 3-dimensional virtual reconstruction and 3-dimensional physical reconstruction's benefits outweighed potential delays in care for model construction.

CONCLUSIONS

Although a consistent effect on surgical strategy was not identified, patient-specific 3-dimensional Pancoast tumor models provided accurate and user-friendly overviews of critical thoracic structures with perceived benefits for surgeons' clinical practices.

Application of 3-dimensional printing implants for bone tumors

Three-dimensional (3D) additive manufacturing has recently been used in various medical fields. Among them, orthopedic oncology is one that utilizes it most actively. Bone and tumor modeling for surgical planning, personalized surgical instrument fabrication, and implant fabrication are typical applications. The 3D-printed metal implants using titanium alloy powder have created a revolutionary change in bone reconstruction that can be customized to all body areas; however, bioprinting remains experimental and under active study. This review explores the practical applications of 3D printing in orthopedic oncology and presents a representative case. The 3D-printed implant can replace the conventional tumor prosthesis and auto/allobone graft, thereby personalizing bone reconstruction. Biologic bone reconstruction using biodegradable or bioprinted materials beyond metal may be possible in the future.

Standardizing evaluation of patient-specific 3D printed models in surgical planning: development of a cross-disciplinary survey tool for physician and trainee feedback

BACKGROUND

3D printed models are becoming increasingly popular in healthcare as visual and tactile tools to enhance understanding of anatomy and pathology in medical trainee education, provide procedural simulation training, and guide surgical procedures. Patient-specific 3D models are currently being used preoperatively for trainee medical education in planning surgical approaches and intraoperatively to guide decision-making in several specialties. Our study group utilized a modified Delphi process to create a standardized assessment for trainees using patient-specific 3D models as a tool in medical education during pre-surgical planning.

METHODS

A literature review was conducted to identify survey questions administered to clinicians in published surgical planning studies regarding the use of patient-specific 3D models. A core study team reviewed these questions, removed duplicates, categorized them, mapped them to overarching themes, and, where applicable, modified individual questions into a form generalizable across surgical specialties. The core study panel included a physician, physician-scientist, social scientist, engineer/medical student, and 3D printing lab manager. A modified Delphi process was then used to solicit feedback on the clarity and relevance of the individual questions from an expert panel consisting of 12 physicians from specialties including anesthesiology, emergency medicine, radiology, urology, otolaryngology, and obstetrics/gynecology. When the Radiological Society of North America (RSNA)/American College of Radiology (ACR) 3D Printing Registry Data Dictionary was released, additional survey questions were reviewed. A final cross-disciplinary survey of the utility of 3D printed models in surgical planning medical education was developed.

RESULTS

The literature review identified 100 questions previously published in surveys assessing patient-specific 3D models for surgical planning. Following the review, generalization, and mapping of survey questions from these studies, a list of 24 questions was generated for review by the expert study team. Five additional questions were identified in the RSNA/ACR 3D Printing Registry Data Dictionary and included for review. A final questionnaire consisting of 20 questions was developed.

CONCLUSIONS

As 3D printed models become more common in medical education, the need for standardized assessment is increasingly essential. The standardized questionnaire developed in this study reflects the interests of a variety of stakeholders in patient-specific 3D models across disciplines.

Complex Bone Tumors of the Trunk-The Role of 3D Printing and Navigation in Tumor Orthopedics: A Case Series and Review of the Literature

The combination of 3D printing and navigation promises improvements in surgical procedures and outcomes for complex bone tumor resection of the trunk, but its features have rarely been described in the literature. Five patients with trunk tumors were surgically treated in our institution using a combination of 3D printing and navigation. The main process includes segmentation, virtual modeling and build preparation, as well as quality assessment. Tumor resection was performed with navigated instruments. Preoperative planning supported clear margin multiplanar resections with intraoperatively adaptable real-time visualization of navigated instruments. The follow-up ranged from 2–15 months with a good functional result. The present results and the review of the current literature reflect the trend and the diverse applications of 3D printing in the medical field. 3D printing at hospital sites is often not standardized, but regulatory aspects may serve as disincentives. However, 3D printing has an increasing impact on precision medicine, and we are convinced that our process represents a valuable contribution in the context of patient-centered individual care.

3D Printing Applications for Radiology: An Overview

Three-dimensional (3D) printing technologies are part of additive manufacturing processes and are used to manufacture a 3D physical model from a digital computer-aided design model as per the required shape and size. These technologies are now used for advanced radiology applications by providing all information through 3D physical model. It provides innovation in radiology for clinical applications, treatment planning, procedural simulation, medical and patient education. Radiological advancements have been made in diagnosis and communication through medical digital imaging techniques like computed tomography, magnetic resonance imaging. These images are converted into Digital Imaging and Communications in Medicine in Standard Triangulate Language file format, easily printable in 3D printing technologies. This 3D model provides in-depth information about pathologic and anatomic states. It is useful to create new opportunities related to patient care. This article discusses the potential of 3D printing technology in radiology. The steps involved in 3D printing for radiology are discussed diagrammatically, and finally identified 12 significant applications of 3D printing technology for radiology with a brief description. A radiologist can incorporate this technology to fulfil different challenges such as training, planning, guidelines, and better communications.

Application of 3D modeling and printing technology in accurate resection of complicated thoracic tumors

Background

To explore the application value of three-dimensional (3D) reconstruction and 3D printing in preoperative evaluation of precise resection of complicated thoracic tumors.

Methods

A retrospective analysis of 34 patients with complicated thoracic tumors who were treated by radical surgery from March 2016 to June 2019 was made. According to whether 3D reconstruction and 3D printing was used, the patients were divided into research group and control group. In the control group, preoperative evaluation was performed according to CT image data, and the operation plan was drawn up; in the research group, preoperative simulation and preoperative operation plan design were carried out according to 3D reconstruction and 3D printing technology. The operation time, change of operation approach, intraoperative blood loss, hospitalization time and postoperative complications were compared between the two groups. We also retrospectively reviewed additional 12 cases of unresectable complicated thoracic tumors. The above 34 patients who were treated by radical surgery were set as the resectable group. Three-dimensional reconstruction was performed for all cases. The tumor size, location, smoothness of tumor-vascular contact surface, close contact with adjacent organs were compared between these two groups.

Results

The 3D reconstruction and 3D printing model were successfully established. The indexes of operation time, change of incision approach and blood loss in the research group were lower than those in the control group (P<0.05). All the patients were followed up for 6 months, and there was no death, no tumor recurrence and metastasis in the two groups. In the unresectable group, the score of position and smoothness of tumor-vascular contact surface were significantly higher than that in the resectable group.

Conclusions

3D reconstruction and 3D printing can effectively help surgeons carry out accurate surgical treatment, reduce the operation time and bleeding, reduce the risk of surgery, and facilitate the postoperative rehabilitation of patients, which has the value of promotion and application.

New Surgical Approaches in the Treatment of Non-Small Cell Lung Cancer

Surgery for non-small cell lung cancer has undergone repeated innovations over time. Although medical thoracoscopy has been available for centuries, it was not incorporated into the standard approach until the 1990s, when successful video-assisted thoracoscopic surgery (VATS) techniques were widely reported. Progressive efforts to offer minimally invasive approaches while maintaining oncologic surgical quality led to the development of robotic-assisted thoracic surgery and uniportal VATS, which offer improved pain control, shorter hospital stays, and more patients able to receive adjuvant therapy. Innovations in interventional bronchoscopy, localization methods, and 3D printing have improved the safety, efficacy, and precision of surgery.

Simultaneous Two-Dimensional and Three-Dimensional Simulation of Thoracoscopic Sleeve Lobectomy: A Quick Understanding of Pitfalls

Thoracoscopic sleeve lobectomy is challenging, considering the technical difficulty in controlling the needle angle and thread through the port. However, effective simulation of the procedure remains to be established. Here, we describe our first experience with thoracoscopic sleeve lobectomy simulation using a three-dimensional printed thoracic model and a handmade rolled sponge. Owing to the transparent structure, we could simultaneously confirm the suturing technique through the monitor (two-dimensional) and direct vision (three-dimensional). We are certain that our realistic and easily repeatable simulation will assist in developing better technique and conduct feasible thoracoscopic sleeve lobectomy.

Implementation of 3D printed superior mesenteric vascular models for surgical planning and/or navigation in right colectomy with extended D3 mesenterectomy: comparison of virtual and physical models to the anatomy found at surgery

BACKGROUND

Three-dimensional (3D) printing technology has recently been well approved as an emerging technology in various fields of medical education and practice; e.g., there are numerous studies evaluating 3D printouts of solid organs. Complex surgery such as extended mesenterectomy imposes a need to analyze also the accuracy of 3D printouts of more mobile and complex structures like the diversity of vascular arborization within the central mesentery. The objective of this study was to evaluate the linear dimensional anatomy landmark differences of the superior mesenteric artery and vein between (1) 3D virtual models, (2) 3D printouts, and (3) peroperative measurements.

METHODS

The study included 22 patients from the ongoing prospective multicenter trial "Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic MDCT Angiography," with preoperative CT and peroperative measurements. The patients were operated in Norway between January 2016 and 2017. Their CT datasets underwent 3D volume rendering and segmentation, and the virtual 3D model produced was then exported for stereolithography 3D printing.

RESULTS

Four parameters were measured: distance between the origins of the ileocolic and the middle colic artery, distance between the termination of the gastrocolic trunk and the ileocolic vein, and the calibers of the middle colic and ileocolic arteries. The inter-arterial distance has proven a strong correlation between all the three modalities implied (Pearson's coefficient 0.968, 0.956, 0.779, respectively), while inter-venous distances showed a weak correlation between peroperative measurements and both virtual and physical models.

CONCLUSION

This study showed acceptable dimensional inter-arterial correlations between 3D printed models, 3D virtual models and authentic soft tissue anatomy of the central mesenteric vessels, and weaker inter-venous correlations between all the models, reflecting the highly variable nature of veins in situ.

Three-Dimensional Printed Pediatric Airway Model Improves Novice Learners' Flexible Bronchoscopy Skills With Minimal Direct Teaching From Faculty

INTRODUCTION

Training in pediatric flexible bronchoscopy (FB) is predominantly completed on patients. Early trainees are less accurate and slower than experienced bronchoscopists. This report describes the development of a three-dimensional printed airway model and describes how the model was used to teach learners basic FB skills.

METHODS

Postgraduate year two (PGY2) pediatric residents completing a 1-month pediatric pulmonology rotation with minimal previous exposure to FB were randomized into a simulation trainee group (n = 18) or a control resident group (n = 9). The simulation group received four 15-minute practice sessions (3 self-directed, 1 with feedback). Participants completed a bronchoscopy assessment on the model at prestudy, poststudy, and delayed (at least 2 months after the rotation) time points. Outcomes were identification of markers located in the six lung areas and completion time.

RESULTS

There was no difference in prestudy scores between groups. In the poststudy assessment, the simulation participants correctly identified more lung area markers (median = 6 vs 1.5, P < 0.001) and were faster (median = 102 vs 600 seconds, P < 0.001). In the delayed assessment, correct marker identification trended toward improvement in the simulation group compared with controls (median = 4 vs 2, P = 0.077).

CONCLUSIONS

With 1 hour of practice time, requiring 15 minutes of direct teaching, novice resident bronchoscopists are able to more accurately identify and visualize the five lung lobes and lingula via FB and are able to do so in less time than control residents. This anatomically accurate model could be used to train basic FB skills at a low cost compared with other models.

Multidisciplinary Assessment of Planning and Resection of Complex Bone Tumor Using Patient-Specific 3D Model

Oncological interventions in thoracic cavity have some important problems such as choice of correct operative approaches depending on the tumor, size, extension, and location. In sarcoma surgery, wide resection should be aimed for the curative surgery. Purpose of this study was to evaluate pre-operative planning of patient-specific thoracic cavity model made by multidisciplinary surgeon team for complex tumor mass for oncological procedures. Patient's scans showed a large mass encroaching on the mediastinum and heart, with erosion of the adjacent ribs and vertebral column. Individual model of this case with thoracic tumor was reconstructed from the DICOM file of the CT data. Surgical team including six interdisciplinary surgeons explained their surgical experience of the use of 3D life-size individual model for guiding surgical treatment. Before patients consented to surgery, each surgeon explained the surgical procedure and perioperative risks to her. A questionnaire was applied to 10 surgical residents to evaluate the 3D model's perception. 3D model scans were useful in determining the site of the lesion, the exact size, extension, attachment to the surrounding structures such as lung, aorta, vertebral column, or vascular involvement, the number of involved ribs, whether the diaphragm was involved also in which order surgeons in the team enter the surgery. 3D model's perception was detected statistical significance as < 0.05. Viewing thoracic cavity with tumor model was more efficient than CT imaging. This case was surgically difficult as it included vital structures such as the mediastinal vessels, aorta, ribs, sternum, and vertebral bodies. A difficult pathology for which 3D model has already been explored to assist anatomic visualization was mediastinal osteosarcoma of the chest wall, diaphragm, and the vertebral column. The study helped to establish safe surgical line wherever the healthy tissue was retained and enabled osteotomy of the affected spinal corpus vertically with posterior-anterior direction by preserving the spinal cord and the spinal nerves above and distal the tumor. 3D tumor model helps to transfer complex anatomical information to surgeons, provide guidance in the pre-operative planning stage, for intra-operative navigation and for surgical collaboration purposes. Total radical excision of the bone tumor and reconstructions of remaining structures using life-size model was the key for successful treatment and better outcomes. The recent explosion in popularity of 3D printing is a testament to the promise of this technology and its profound utility in orthopedic oncological surgery.

Preoperative planning and tracheal stent design in thoracic surgery: a primer for the 2017 Radiological Society of North America (RSNA) hands-on course in 3D printing

In this work, we provide specific clinical examples to demonstrate basic practical techniques involved in image segmentation, computer-aided design, and 3D printing. A step-by-step approach using United States Food and Drug Administration cleared software is provided to enhance surgical intervention in a patient with a complex superior sulcus tumor. Furthermore, patient-specific device creation is demonstrated using dedicated computer-aided design software. Relevant anatomy for these tasks is obtained from CT Digital Imaging and Communications in Medicine images, leading to the generation of 3D printable files and delivery of these files to a 3D printer.