Robotic-assisted stereotactic real-time navigation: initial clinical experience and feasibility for rectal cancer surgery

Stereotactic Navigation-Assisted Laparoscopic Resection of Challenging Low Pelvic Tumors: A Case Series

(1) Introduction: The laparoscopic approach to low pelvic tumors is challenging and hindered by suboptimal tumor visualization and dissection, with possible oncological failure. Stereotactic navigation provides real-time image guidance that may optimize safety, accuracy, and precision when dissecting challenging low pelvic tumors. (2) Methods: Preoperative CT images were acquired with eight skin-fixed fiducials and loaded into a navigation system. A patient tracker was mounted on the bed side. Patient-to-image paired point registration was performed, and an instrument tracker was mounted on a laparoscopic instrument and calibrated for instrument tracking. Surgical operations were performed with real-time stereotactic navigation assistance. (3) Results: Three patients underwent stereotactic navigation surgery. Fiducial registration errors were good to optimal (±1.9, ±3.4, and ±3.4 mm). Lesions were easily identified and targeted with real-time navigation. Surgeries were uneventful. Histopathology examinations identified one retro-rectal schwannoma, one lateral pelvic recurrence from rectal adenocarcinoma, and one advanced anal canal carcinoma. No navigation-related complications, readmissions, or postoperative mortalities were observed. (4) Conclusions: The application of laparoscopic stereotactic navigation surgery to complex low pelvic tumors is feasible and could impact oncological surgical quality by enabling tumor targeting and ensuring resection margins. Further wider series are needed to confirm stereotactic navigation's impact on challenging low pelvic tumors.

The influence of the da Vinci surgical robot on electromagnetic tracking in a clinical environment

Robot-assisted surgery is increasingly used in surgery for cancer. Reduced overview and loss of anatomical orientation are challenges that might be solved with image-guided surgical navigation using electromagnetic tracking (EMT). However, the robot's presence may distort the electromagnetic field, affecting EMT accuracy. The aim of this study was to evaluate the robot's influence on EMT accuracy. For this purpose, two different electromagnetic field generators were used inside a clinical surgical environment: a table top field generator (TTFG) and a planar field generator (PFG). The position and orientation of sensors within the electromagnetic field were measured using an accurate in-house developed 3D board. Baseline accuracy was measured without the robot, followed by stepwise introduction of potential distortion sources (robot and robotic instruments). The absolute accuracy was determined within the entire 3D board and in the clinical working volume. For the baseline setup, median errors in the entire tracking volume within the 3D board were 0.9 mm and 0.3° (TTFG), and 1.1 mm and 0.4° (PFG). Adding the robot and instruments did not affect the TTFG's position accuracy (p = 0.60), while the PFG's accuracies decreased to 1.5 mm and 0.7° (p < 0.001). For both field generators, when adding robot and instruments, accuracies inside the clinical working volume were higher compared to the entire tracking 3D board volume, 0.7 mm and 0.3° (TTFG), and 1.1 mm and 0.7° (PFG). Introduction of a surgical robot and robotic instruments shows limited distortion of the EMT field, allowing sufficient accuracy for surgical navigation in robotic procedures.

Indocyanine Green Fluorescence Guided Surgery in Colorectal Surgery

BACKGROUND

Indocyanine green (ICG) imaging has been increasingly used for intraoperative guidance in colorectal surgery over the past decade. The aim of this study was to review and organize, according to different type of use, all available literature on ICG guided colorectal surgery and highlight areas in need of further research and discuss future perspectives.

METHODS

PubMed, Scopus, and Google Scholar databases were searched systematically through November 2022 for all available studies on fluorescence-guided surgery in colorectal surgery.

RESULTS

Available studies described ICG use in colorectal surgery for perfusion assessment, ureteral and urethral assessment, lymphatic mapping, and hepatic and peritoneal metastases assessment. Although the level of evidence is low, results are promising, especially in the role of ICG in reducing anastomotic leaks.

CONCLUSIONS

ICG imaging is a safe and relatively cheap imaging modality in colorectal surgery, especially for perfusion assessment. Work is underway regarding its use in lymphatic mapping, ureter identification, and the assessment of intraperitoneal metastatic disease.

Robotic surgery for colorectal cancer

Background: Robotic surgical systems were created partly to solve several constraints of laparoscopic surgery and to offer technical advantages. With a substantial body of evidence demonstrating its efficacy in rectal cancer treatment, robotic surgery will soon become another conventional treatment. However, further investigations and randomized trials focusing on primary endpoints are necessary to establish some advantages of robot-assisted colon surgery.Current Concepts: Da Vinci Single-Site and SP platforms (Intuitive Surgical Inc.) were developed to overcome the shortcomings of single-port laparoscopic surgery. Despite the currently insufficient evidence, it seems that the SP platform addresses several limitations of single-port transabdominal or transanal surgery. Robotic transanal minimally invasive surgery and total mesorectal excision were developed to overcome conventional platforms’ limitations, using wristed instrumentation to enhance dexterity and ergonomics. Studies on the effectiveness and viability of this novel approach are ongoing. The near-infrared fluorescence technique, real-time stereotactic navigation technology, and other surgical data platforms based on artificial intelligence incorporated into the robotic system will play an important role in improving outcomes.Discussion and Conclusion: Robotic systems for advanced colorectal cancer offer technical advantages for complex and precise surgeries. If robotic surgery costs are reduced by expanding its indications and enhancing competition among different robotic platforms, it will provide clinical benefits to more patients and reduce social healthcare costs.

Direction of diagnosis and treatment improvement in colorectal cancer

Background: Cancer is a major public health problem and the leading cause of death in Korea since 2000. Colorectal cancer is the third leading cause of cancer-related death. Therefore, early detection through screening, surgical techniques improvement, anticancer drugs, adjuvant treatment, and medical resources advancement is important to reduce colorectal cancer-related mortality.Current Concepts: In Korea, the 5-year relative survival rate of patients with colorectal cancer is approximately mid-70%, which is superior to other developed countries, such as the United States, United Kingdom, and Japan, with 60% to 68% because of the well performed screening program and technical improvement. Efforts are underway to conduct active endoscopic treatment for early colorectal cancer and identify cases requiring surgery. Minimally invasive surgery has evolved beyond conventional applications into disease-specific methods, and the robotic system has an important role for evolvement. Performing metastatic colorectal cancer efforts is necessary to improve the survival rate through active surgical treatment and gene therapy.Discussion and Conclusion: Eventually, the role of the patient’s genetic information in diagnosing and treating colorectal cancer is expected to increase. In some cases, diagnosing colorectal cancer using a non-invasive method is already realized. Active surgical treatment based on personal characteristics contributes in improving the treatment outcomes for difficult-to-treat metastatic colorectal cancer. After the period of overall colorectal cancer treatment results improvement, we will undertake the precision treatment era.

Laparoscopic surgery for median arcuate ligament syndrome using real-time stereotactic navigation

INTRODUCTION

In median arcuate ligament syndrome (MALS), a hyperplastic MAL causes compression and stenosis of the celiac artery (CA). The treatment involves releasing the external pressure on this artery by dissecting the ligament. However, it is difficult to identify the artery because of its deep anatomical location. Stereotactic navigation provides real-time information regarding the surgical instrument's location on computed tomography (CT) images. We utilized this system to overcome the difficulty of anatomical identification.

MATERIALS AND SURGICAL TECHNIQUE

We present a case of aneurysm rupture caused by MALS, which was treated with laparoscopic MAL dissection with real-time stereotactic navigation. Surgery was performed in a hybrid operating room with three-dimensional C-arm CT (Artis Zeego, Siemens) and an installed Curve navigation system (BrainLab). Preoperative CT images were aligned with intraoperative C-arm CT-like images and the surgical instrument position was projected onto preoperative CT images. After the left gastric artery isolation, the fibrous tissue surrounding the left gastric artery was dissected toward the CA while confirming the location of the CA and aortic wall using the navigation system. The CA's diameter was dilated from 1.8 to 2.6 mm with intraoperative angiography.

DISCUSSION

This is the first report of laparoscopic MAL dissection using real-time stereotactic navigation. Although navigation setting was time-intensive, this system helped us understand the anatomical structures and in safely and precisely dissecting the MAL.

Fluorescence Imaging in Colorectal Surgery: An Updated Review and Future Trends

Fluorescence imaging in colorectal surgery is considered a novel predominantly intraoperative method of ensuring a greater surgical success. The use of fluorescence is linked to advanced tumor visualization and projection of its lymphatics, both vessels and nodes, which results in a higher chance of achieving a total excision. Additionally, iatrogenic complications prove to be reduced using fluorescence during the surgical excision. The combination of fluorescence and artificial intelligence to better facilitate oncological surgery will soon become an established approach in operating rooms worldwide.

Evaluation of the SYNAPSE VINCENT for lateral lymph node dissection in rectal cancer with robotic surgery: a preliminary report

Background

Even if 3D angiographic images of preoperative contrast-enhanced computed tomography (CT) are created, the coronal and axial sections can be unclear, and thus, it is difficult to achieve projection awareness similar to that of actual laparoscopic images. In recent years, the technology of analyzing and applying medical images has advanced, and surgical simulation and navigation have been widely used to improve the safety of surgical operations. It is important to understand pelvic anatomy in the area of rectal cancer, and use of the SYNAPSE VINCENT makes it possible to simulate the anatomy before surgery, which is very useful in educating surgeons and their assistants.

Materials and methods

An important objective in surgery is to understand the anatomy of the external/internal iliac arteries and lymph nodes in lateral lymph node dissection (LLD) for rectal cancer. In this study, we explored the accuracy and usefulness of SYNAPSE VINCENT images of pelvic anatomy (especially vascular anatomy) analyzed preoperatively in two cases of LLD for rectal cancer in our department.

Results

The patients were two men aged 73 and 57 years, respectively. Both patients underwent robotic abdominal perineal resection and LLD with neoadjuvant chemoradiotherapy. The operating times for LLD were 138 and 106 min, estimated blood loss was less than 10 mL and 20 mL, and the harvested lymph nodes were nos. 21 and 22, respectively. The SYNAPSE VINCENT could be used for simulation and navigation before and during surgery. For experienced surgeons, the system helped them carry out operations more accurately.

Conclusion

In the future, surgical support using virtual reality, augmented reality, and mixed reality based on medical images will be useful and is expected to improve the safety, accuracy, and efficiency of surgery, which is extremely useful for both young and skilled surgeons preparing for difficult operations.

Contemporary Management of Locally Advanced and Recurrent Rectal Cancer: Views from the PelvEx Collaborative

Pelvic exenteration is a complex operation performed for locally advanced and recurrent pelvic cancers. The goal of surgery is to achieve clear margins, therefore identifying adjacent or involved organs, bone, muscle, nerves and/or vascular structures that may need resection. While these extensive resections are potentially curative, they can be associated with substantial morbidity. Recently, there has been a move to centralize care to specialized units, as this facilitates better multidisciplinary care input. Advancements in pelvic oncology and surgical innovation have redefined the boundaries of pelvic exenterative surgery. Combined with improved neoadjuvant therapies, advances in diagnostics, and better reconstructive techniques have provided quicker recovery and better quality of life outcomes, with improved survival This article provides highlights of the current management of advanced pelvic cancers in terms of surgical strategy and potential future developments.

Current and future role of three-dimensional modelling technology in rectal cancer surgery: A systematic review

BACKGROUND

Three-dimensional (3D) modelling technology translates the patient-specific anatomical information derived from two-dimensional radiological images into virtual or physical 3D models, which more closely resemble the complex environment encountered during surgery. It has been successfully applied to surgical planning and navigation, as well as surgical training and patient education in several surgical specialties, but its uptake lags behind in colorectal surgery. Rectal cancer surgery poses specific challenges due to the complex anatomy of the pelvis, which is difficult to comprehend and visualise.

AIM

To review the current and emerging applications of the 3D models, both virtual and physical, in rectal cancer surgery.

METHODS

Medline/PubMed, Embase and Scopus databases were searched using the keywords “rectal surgery”, “colorectal surgery”, “three-dimensional”, “3D”, “modelling”, “3D printing”, “surgical planning”, “surgical navigation”, “surgical education”, “patient education” to identify the eligible full-text studies published in English between 2001 and 2020. Reference list from each article was manually reviewed to identify additional relevant papers. The conference abstracts, animal and cadaveric studies and studies describing 3D pelvimetry or radiotherapy planning were excluded. Data were extracted from the retrieved manuscripts and summarised in a descriptive way. The manuscript was prepared and revised in accordance with PRISMA 2009 checklist.

RESULTS

Sixteen studies, including 9 feasibility studies, were included in the systematic review. The studies were classified into four categories: feasibility of the use of 3D modelling technology in rectal cancer surgery, preoperative planning and intraoperative navigation, surgical education and surgical device design. Thirteen studies used virtual models, one 3D printed model and 2 both types of models. The construction of virtual and physical models depicting the normal pelvic anatomy and rectal cancer, was shown to be feasible. Within the clinical context, 3D models were used to identify vascular anomalies, for surgical planning and navigation in lateral pelvic wall lymph node dissection and in management of recurrent rectal cancer. Both physical and virtual 3D models were found to be valuable in surgical education, with a preference for 3D printed models. The main limitations of the current technology identified in the studies were related to the restrictions of the segmentation process and the lack of 3D printing materials that could mimic the soft and deformable tissues.

CONCLUSION

3D modelling technology has potential to be utilised in multiple aspects of rectal cancer surgery, however, it is still at the experimental stage of application in this setting.

Robotic transanal total mesorectal excision: Is the future now?

Total mesorectal excision (TME) is the standard surgical treatment for the curative radical resection of rectal cancers. Minimally invasive TME has been gaining ground favored by the continuous technological advancements. New procedures, such as transanal TME (TaTME), have been introduced to overcome some technical limitations, especially in low rectal tumors, obese patients, and/or narrow pelvis. The earliest TaTME reports showed promising results when compared with the conventional laparoscopic TME. However, recent publications raised concerns regarding the high rates of anastomotic leaks or local recurrences observed in national series. Robotic TaTME (R-TaTME) has been proposed as a novel technique incorporating the potential benefits of a perineal dissection together with precise control of the distal margins, and also offers all those advantages provided by the robotic technology in terms of improved precision and dexterity. Encouraging short-term results have been reported for R-TaTME, but further studies are needed to assess the real role of the new technique in the long-term oncological or functional outcomes. The present review aims to provide a general overview of R-TaTME by analyzing the body of the available literature, with a special focus on the potential benefits, harms, and future perspectives for this novel approach.

Robotic Transanal Total Mesorectal Excision (RTaTME): State of the Art

Total mesorectal excision (TME) is the gold standard technique for the surgical management of rectal cancer. The transanal approach to the mesorectum was introduced to overcome the technical difficulties related to the distal rectal dissection. Since its inception, interest in transanal mesorectal excision has grown exponentially and it appears that the benefits are maximal in patients with mid-low rectal cancer where anatomical and pathological features represent the greatest challenges. Current evidence demonstrates that this approach is safe and feasible, with oncological and functional outcome comparable to conventional approaches, but with specific complications related to the technique. Robotics might potentially simplify the technical steps of distal rectal dissection, with a shorter learning curve compared to the laparoscopic transanal approach, but with higher costs. The objective of this review is to critically analyze the available literature concerning robotic transanal TME in order to define its role in the management of rectal cancer and to depict future perspectives in this field of research.

Deformation of the Pelvic Arteries Caused by Pneumoperitoneum and Postural Changes in an Animal Model

BACKGROUND/AIM

We investigated pelvic arterial deformation and shift due to intraoperative pneumoperitoneum and postural changes in an animal model.

MATERIALS AND METHODS

Computed tomography images of pigs were acquired in different body positions (supine, head down at 5° and 10°, right lateral recumbent at 5° and 15°) before and after insufflation. We used a free software (3D Slicer) for image analysis. After landmark registration using 10 markers inserted into the pelvis, pelvic arterial deformation and shift of seven arterial bifurcation points were evaluated. The distance moved was the target registration error (TRE) from the points registered in the supine position. Fiducial registration error (FRE) was measured using the 10 pelvic markers.

RESULTS

TRE average from postural changes ranged from 0.7 to 1.2 mm and was 1.4 mm due to pneumoperitoneum. TRE and FRE averages were 2.1 mm and 0.2 mm, respectively.

CONCLUSION

The pelvis was useful for registering anatomical landmarks.

The Emerging Role of Robotics in Pelvic Exenteration Surgery for Locally Advanced Rectal Cancer: A Narrative Review

Pelvic exenteration surgery for locally advanced rectal cancers is a complex and extensive multivisceral operation, which is associated with high perioperative morbidity and mortality rates. Significant technical challenges may arise due to inadequate access, visualisation, and characterisation of tissue planes and critical structures in the spatially constrained pelvis. Over the last two decades, robotic-assisted technologies have facilitated substantial advancements in the minimally invasive approach to total mesorectal excision (TME) for rectal cancers. Here, we review the emerging experience and evidence of robotic assistance in beyond TME multivisceral pelvic exenteration for locally advanced rectal cancers where heightened operative challenges and cumbersome ergonomics are likely to be encountered.

3D pelvimetry and biometric measurements: a surgical perspective for colorectal resections

PURPOSE

Male sex, high BMI, narrow pelvis, and bulky mesorectum were acknowledged as clinical variables correlated with a difficult pelvic dissection in colorectal surgery. This paper aimed at comparing pelvic biometric measurements in female and male patients and at providing a perspective on how pelvimetry segmentation may help in visualizing mesorectal distribution.

METHODS

A 3D software was used for segmentation of DICOM data of consecutive patients aged 60 years, who underwent elective abdominal CT scan. The following measurements were estimated: pelvic inlet, outlet, and depth; pubic tubercle height; distances from the promontory to the coccyx and to S3/S4; distance from S3/S4 to coccyx's tip; ischial spines distance; pelvic tilt; offset angle; pelvic inlet angle; angle between the inlet/sacral promontory/coccyx; angle between the promontory/coccyx/pelvic outlet; S3 angle; and pelvic inlet to pelvic depth ratio. The measurements were compared in males and females using statistical analyses.

RESULTS

Two-hundred patients (M/F 1:1) were analyzed. Out of 21 pelvimetry measurements, 19 of them documented a significant mean difference between groups. Specifically, female patients had a significantly wider pelvic inlet and outlet but a shorter pelvic depth, and promontory/sacral/coccyx distances, resulting in an augmented inlet/depth ratio when comparing with males (p < 0.0001). The sole exceptions were the straight conjugate (p = 0.06) and S3 angle (p = 0.17). 3D segmentation provided a perspective of the mesorectum distribution according to the pelvic shape.

CONCLUSION

Significant differences in the structure of pelvis exist in males and females. Surgeons must be aware of the pelvic shape when approaching the rectum.

Robotic Total Mesorectal Excision for Rectal Cancer: Current Evidences and Future Perspectives

Despite the technical limitations of minimally invasive surgery, laparoscopic total mesorectal excision (LTME) for rectal cancer has short-term advantages over open surgery, but the pathological outcomes reported in randomized clinical trials are still in controversy. Minimally invasive robotic total mesorectal excision (RTME) has recently been gaining popularity as robotic surgical systems potentially provide greater benefits than LTME. Compared to LTME, RTME is associated with lower conversion rates and similar or better genitourinary functions, but its long-term oncological outcomes have not been established. Although the operating time of RTME is longer than that of LTME, RTME has a shorter learning curve, is more convenient for surgeons, and is better for sphincter-preserving operations than LTME. The robotic surgical system is a good technical tool for minimally invasive surgery for rectal cancer, especially in male patients with narrow deep pelvises. Robotic systems and robotic surgical techniques are still improving, and the contribution of RTME to the treatment of rectal cancer will continue to increase in the future.

Application of the da Vinci surgical robot system in presacral nerve sheath tumor treatment

The aim of the present study was to investigate the feasibility of da Vinci robotic surgery in the treatment of presacral tumors, and to observe its efficacy and safety. Between March 2016 and April 2019, 12 patients with presacral nerve sheath tumors underwent da Vinci robotic surgery, and the integrity of the tumor resection, surgical duration, pre- and postoperative visual analog scale (VAS) score, intra- and postoperative blood losses, postoperative bedtime, hospital stay and complications were observed. The tumor was completely removed in all 12 patients, the surgical duration ranged between 76 and 245 min (mean, 106.08 min) and the intraoperative blood loss was 76-145 ml (mean, 101.67 ml). The average preoperative VAS score of the patients was 3.25, and the average VAS score at 1 week, 1 month and 3 months post operation were 1.08, 0.42 and 0.08, respectively. All patients were out of bed on the second day after surgery, and the postoperative drainage was 10-50 ml (mean, 33.50 ml). The patients were hospitalized for 3-5 days (mean, 3.92 days). No complications occurred peri- or postoperatively, and wound pain was the main source of postoperative discomfort. In conclusion, the da Vinci robot can be applied to presacral nerve sheath tumors with high surgical safety, low-level bleeding, a rapid recovery and a short hospital stay, making it worthy of further study.

Robotic Surgical Approach to the Mesial Temporal Region: A Preliminary Three-Dimensional Cadaveric Study of Technical Feasibility

OBJECTIVE

Robotic surgical systems are used worldwide in various fields. In this study, we present the advantages and disadvantages of the most common robotic surgical system, the da Vinci Xi system, in the supracerebellar transtentorial approach to the mesial temporal region and discuss options for its integration into neurosurgery.

METHODS

Our study was conducted at the Advanced Simulation and Applied Endoscopic Surgery Training and Research Center and Anatomy Laboratory. Four formalin-fixed human cadaveric head specimens with red silicone dye injected into their arterial structures and blue silicone dye injected into their venous structures were used in the study. Dissections were performed in microscopic and robotic stages. All phases were photographed using a three-dimensional photographic technique.

RESULTS

The mesial temporal lobe could be accessed via the supracerebellar transtentorial route with the use of the robotic system. We show that the robotic system can be used in difficult approaches and narrow regions with a wider exposure and superior image quality than with the microscopic approach, improving the ergonomics for the surgeon. The shortcomings of robotic systems are examined and innovative solutions are offered.

CONCLUSIONS

This study shows the advantages and disadvantages of the robotic surgical approach to the mesial temporal region via the supracerebellar transtentorial route. Robotic surgical systems can play a major role in neurosurgical practices with the tools designed and the innovative solutions determined in this study. Nevertheless, further research and development of these systems and related instruments are necessary to ensure their wider implementation in neurosurgery.

Vision-based tracking system for augmented reality to localize recurrent laryngeal nerve during robotic thyroid surgery

We adopted a vision-based tracking system for augmented reality (AR), and evaluated whether it helped surgeons to localize the recurrent laryngeal nerve (RLN) during robotic thyroid surgery. We constructed an AR image of the trachea, common carotid artery, and RLN using CT images. During surgery, an AR image of the trachea and common carotid artery were overlaid on the physical structures after they were exposed. The vision-based tracking system was activated so that the AR image of the RLN followed the camera movement. After identifying the RLN, the distance between the AR image of the RLN and the actual RLN was measured. Eleven RLNs (9 right, 4 left) were tested. The mean distance between the RLN AR image and the actual RLN was 1.9 ± 1.5 mm (range 0.5 to 3.7). RLN localization using AR and vision-based tracking system was successfully applied during robotic thyroidectomy. There were no cases of RLN palsy. This technique may allow surgeons to identify hidden anatomical structures during robotic surgery.

Stereotactic Navigation for Rectal Surgery: Comparison of 3-Dimensional C-Arm-Based Registration to Paired-Point Registration

BACKGROUND

Stereotactic navigation enables surgeons to use the preoperative CT or MRI images as a real-time "navigation map." Although stereotactic navigation has been established in neurosurgery and orthopedic surgery, whether this technology is applicable to GI tract surgery remains challenging because of tissue deformation and organ motion. A critical component of this technology is the registration that links the patient's actual body to the preoperative imaging data.

OBJECTIVE

The objective was to assess the applicability of stereotactic navigation in rectal surgery, focusing on the registration method.

DESIGN

This study was based on a prospective case series.

SETTING

The study was conducted in a single university hospital.

PATIENTS

Four patients who underwent laparoscopic rectal surgery were included.

INTERVENTIONS

Paired-point registration was performed for 2 cases, whereas 3-dimensional C-arm-based registration was performed for the other 2 cases. In addition, 3-dimensional C-arm-based registration was performed twice during the operation.

MAIN OUTCOME MEASURE

Navigation accuracy was evaluated by measuring target registration error at 8 anatomical landmarks.

RESULTS

Target registration error of the 3-dimensional C-arm-based registration group was significantly smaller than that of the paired-point registration group (median, 19.5 mm vs 54.1 mm; p < 0.001). In particular, the error of Z-axis (cranial-to-caudal direction) was significantly smaller in 3-dimensional C-arm-based registration (median, 12.4 mm vs 48.8 mm; p < 0.001). In one case in the 3-dimensional C-arm-based registration group, target registration error of the second registration became significantly smaller than that of the first registration (p = 0.008).

LIMITATIONS

This was an observational study with small sample size.

CONCLUSION

Three-dimensional C-arm-based registration could be performed with the patient in a lithotomy position with head down and lateral tilt without being affected by positional changes. Three-dimensional C-arm-based registration resulted in significantly higher navigation accuracy than paired-point registration, and its accuracy could be further improved by intraoperative re-registration.

Accurate surgical navigation with real-time tumor tracking in cancer surgery

In the past decades, image-guided surgery has evolved rapidly. In procedures with a relatively fixed target area, like neurosurgery and orthopedics, this has led to improved patient outcomes. In cancer surgery, intraoperative guidance could be of great benefit to secure radical resection margins since residual disease is associated with local recurrence and poor survival. However, most tumor lesions are mobile with a constantly changing position. Here, we present an innovative technique for real-time tumor tracking in cancer surgery. In this study, we evaluated the feasibility of real-time tumor tracking during rectal cancer surgery. The application of real-time tumor tracking using an intraoperative navigation system is feasible and safe with a high median target registration accuracy of 3 mm. This technique allows oncological surgeons to obtain real-time accurate information on tumor location, as well as critical anatomical information. This study demonstrates that real-time tumor tracking is feasible and could potentially decrease positive resection margins and improve patient outcome.