Image guided surgery: New technology for surgery of soft tissue and bone sarcomas

Fluorescence guidance improves the accuracy of radiological imaging-guided surgical navigation

BACKGROUND

Imaging-based navigation technologies require static referencing between the target anatomy and the optical sensors. Imaging-based navigation is therefore well suited to operations involving bony anatomy; however, these technologies have not translated to soft-tissue surgery. We sought to determine if fluorescence imaging complement conventional, radiological imaging-based navigation to guide the dissection of soft-tissue phantom tumors.

METHODS

Using a human tissue-simulating model, we created tumor phantoms with physiologically accurate optical density and contrast concentrations. Phantoms were dissected using all possible combinations of computed tomography (CT), magnetic resonance, and fluorescence imaging; controls were included. The data were margin accuracy, margin status, tumor spatial alignment, and dissection duration.

RESULTS

Margin accuracy was higher for combined navigation modalities compared to individual navigation modalities, and accuracy was highest with combined CT and fluorescence navigation (p = 0.045). Margin status improved with combined CT and fluorescence imaging.

CONCLUSIONS

At present, imaging-based navigation has limited application in guiding soft-tissue tumor operations due to its inability to compensate for positional changes during surgery. This study indicates that fluorescence guidance enhances the accuracy of imaging-based navigation and may be best viewed as a synergistic technology, rather than a competing one.

Real and Simulated Microgravity: Focus on Mammalian Extracellular Matrix

The lack of gravitational loading is a pivotal risk factor during space flights. Biomedical studies indicate that because of the prolonged effect of microgravity, humans experience bone mass loss, muscle atrophy, cardiovascular insufficiency, and sensory motor coordination disorders. These findings demonstrate the essential role of gravity in human health quality. The physiological and pathophysiological mechanisms of an acute response to microgravity at various levels (molecular, cellular, tissue, and physiological) and subsequent adaptation are intensively studied. Under the permanent gravity of the Earth, multicellular organisms have developed a multi-component tissue mechanosensitive system which includes cellular (nucleo- and cytoskeleton) and extracellular (extracellular matrix, ECM) “mechanosensory” elements. These compartments are coordinated due to specialized integrin-based protein complexes, forming a distinctive mechanosensitive unit. Under the lack of continuous gravitational loading, this unit becomes a substrate for adaptation processes, acting as a gravisensitive unit. Since the space flight conditions limit large-scale research in space, simulation models on Earth are of particular importance for elucidating the mechanisms that provide a response to microgravity. This review describes current state of art concerning mammalian ECM as a gravisensitive unit component under real and simulated microgravity and discusses the directions of further research in this field.

Progresses in Fluorescence Imaging Guidance for Bone and Soft Tissue Sarcoma Surgery

R0 surgical resection is the preferred treatment for bone and soft tissue sarcoma. However, there is still a lack of precise technology that can visualize bone and soft tissue sarcoma during surgery to assist the surgeon in judging the tumor surgical boundary. Fluorescence imaging technology has been used in the diagnosis of cancer. It is a simple and essentially safe technique that takes no additional time during the operation. Intraoperative fluorescence imaging has potential application prospects in assisting the surgeons in judging the tumor boundary and improving the accuracy of surgical resection. This review mainly starts with clinical studies, animal experimentation, and newly designed probes of intraoperative fluorescence imaging of bone and soft tissue sarcoma, to appraise the application prospects of fluorescence imaging technology in bone and soft tissue sarcoma.

Surgical navigation for challenging recurrent or pretreated intra-abdominal and pelvic soft tissue sarcomas

BACKGROUND

This study assessed whether electromagnetic navigation can be of added value during resection of recurrent or post-therapy intra-abdominal/pelvic soft tissue sarcomas (STS) in challenging locations.

MATERIALS AND METHODS

Patients were included in a prospective navigation study. A pre-operatively 3D roadmap was made and tracked using electromagnetic reference markers. During the operation, an electromagnetic pointer was used for the localization of the tumor/critical anatomical structures. The primary endpoint was feasibility, secondary outcomes were safety and usability.

RESULTS

Nine patients with a total of 12 tumors were included, 7 patients with locally recurrent sarcoma. Three patients received neoadjuvant radiotherapy and three other patients received neoadjuvant systemic treatment. The median tumor size was 4.6 cm (2.4-10.4). The majority of distances from tumor to critical anatomical structures was <0.5 cm. The tumors were localized using the navigation system without technical or safety issues. Despite the challenging nature of these resections, 89% were R0 resections, with a median blood loss of 100 ml (20-1050) and one incident of vascular damage. Based on the survey, surgeons stated navigation resulted in shorter surgery time and made the resections easier.

CONCLUSION

Electromagnetic navigation facilitates resections of challenging lower intra-abdominal/pelvic STS and might be of added value.

Innovative Surgical Planning in Resecting Soft Tissue Sarcoma of the Foot Using Augmented Reality With a Smartphone

Augmented or hybrid reality is a display technology that combines the real world with the virtual world; it permits digital images of preoperative planning information to be combined with the surgeon's view of the real world. Augmented reality (AR) can increase the surgeon's intraoperative vision by providing virtual transparency of the real patient and has been applied to a wide spectrum of orthopedic procedures, such as tumor resection, fracture fixation, arthroscopy, and component's alignment in total joint arthroplasty. We present a case of a male patient who presented with pain in the medial aspect of his left foot after he underwent an incomplete mass excision elsewhere where it turned out to be synovial sarcoma. Because the mass was small, impalpable, and deeply positioned beneath both the plantar and the medial plantar aponeuroses, it was impossible to preoperatively decide a plan for resection. We opted to use the aid of AR in the form of an application using the camera of a smartphone. We were able to excise the tumor with negative surgical margins. On 12-month follow-up, the patient is in complete remission and has optimal mobility and functionality of his foot. In conclusion, AR holds great potential for use in the future of orthopedic surgical oncology. We emphasize using it via a handheld device that we found to be optimal for planning resection of the small and relatively fixed tumor. Based on our literature review, this is the first case describing the surgical planning in resecting an impalpable synovial sarcoma of the foot using AR technology.

A case-control study of computer navigation assisted resection of primary sacral chordoma above sacrum 3 level

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This is a retrospective case-control study.

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The computer navigation aided technology can make more cases achieve safe surgical margin.

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The clear bone resection margins were achieved in all cases in navigation group.

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The application of computer navigation doesn’t increase the operation time and intraoperative blood loss.

Background

The operation of sacral chordoma resection is difficult especial in the tumor above sacrum 3 level and the local recurrence rate was high. The purpose of this study is to analyze the effect of computer navigation aided technology in primary sacral chordoma resection above sacrum 3 level through a case-control study, which including perioperative safety, surgical margin, postoperative recurrence and function results.

Methods

This is a retrospective case-control study. The clinical data of 25 patients received initial computer-assisted resection of sacral chordoma above the level of sacrum 3 from 2009 to 2016 were analyzed; the patients underwent non-navigation assisted resection of tumor above the level of sacrum 3 in the same period were matched and 25 patients were selected randomly. There was no significant difference between these two groups in gender (P = 0.370), age (P = 0.554), tumor transverse diameter (P = 0.836). The average maximum diameter of tumor in navigation group was significant bigger than that in non-navigation group (P = 0.005). The intraoperative safety results, surgical margin, postoperative complications, recurrence rate and function were compared between these groups.

Results

There was no significant difference between navigation and non-navigation group in operative time (P = 0.105) and intraoperative blood loss (P = 0.537). There were 18 wide resections, 4 marginal resections and 3 intracapsular resections in navigation group; there were 6 wide resections, 12 marginal resections and 7 intracapsular resections in non-navigation group; the surgical margins of two groups were significant different (P = 0.003). There were 5 cases (20%) and 6 cases (24%) with wound complication in navigation group and non-navigation group (P = 0.733). The average follow-up was 49.6 (16–102) months in navigation group and 51.3 (12–110) months in non-navigation group. Three cases (12%) showed recurrence in navigation group and six cases showed recurrence (24%) in non-navigation group. The surgical margin was significantly related with tumor recurrence (P = 0.000). The average MSTS score was 27.3 (19–30) and 26.5 (20–29) in navigation group and non-navigation group (P = 0.374).

Conclusion

The computer navigation aided technology can improve the accuracy of primary sacral chordoma resection, and make more cases achieve safe surgical margin. Compared with the traditional operation, the application of computer navigation in the larger tumor resection does not increase the operation time and intraoperative blood loss, which shows good safety.

Surgical Innovation in Sarcoma Surgery

The field of orthopaedic oncology relies on innovative techniques to resect and reconstruct a bone or soft tissue tumour. This article reviews some of the most recent and important innovations in the field, including biological and implant reconstructions, together with computer-assisted surgery. It also looks at innovations in other fields of oncology to assess the impact and change that has been required by surgeons; topics including surgical margins, preoperative radiotherapy and future advances are discussed.

Computer Navigation-aided Resection of Sacral Chordomas

BACKGROUND

Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas.

METHODS

Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old (range: 35-84 years old). Tumors were located above the level of the S3 neural foramen in 23 patients and below the level of the S3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months (range: 18-84 months).

RESULTS

Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 mm. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 (7.7%) exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 (range: 19-30).

CONCLUSIONS

Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

A portable surgical navigation device to display resection planes for bone tumor surgery

INTRODUCTION

Surgical navigation has been used in musculoskeletal tumor surgical procedures to improve the precision of tumor resection. Despite the favorable attributes of navigation-assisted surgery, conventional systems do not display the resection margin in real time, and preoperative manual input is required. In addition, navigation systems are often expensive and complex, and this has limited their widespread use. In this study, we propose an augmented reality surgical navigation system that uses a tablet personal computer with no external tracking system.

MATERIAL AND METHODS

We realized a real-time safety margin display based on three-dimensional dilation. The resection plane induced by the safety margin is updated in real time according to the direction of sawing. The minimum separation between the saw and the resection plane is also calculated and displayed. The surgeon can resect bone tumors accurately by referring to the resection plane and the minimum separation updated in real time.

RESULTS

The effectiveness of the system was demonstrated with experiments on pig pelvises. When the desired resection margin was 10 mm, the measured resection margin was 9.85 ± 1.02 mm.

CONCLUSIONS

The proposed method exhibits sufficient accuracy and convenience for use in bone tumor resection. It also has favorable practical applicability due to its low cost and portability.

Near infrared fluorescence imaging for early detection, monitoring and improved intervention of diseases involving the joint

Joints consist of different tissues, such as bone, cartilage and synovium, which are at risk for multiple diseases. The current imaging modalities, such as magnetic resonance imaging, Doppler ultrasound, X-ray, computed tomography and arthroscopy, lack the ability to detect disease activity before the onset of anatomical and significant irreversible damage. Optical in vivo imaging has recently been introduced as a novel imaging tool to study the joint and has the potential to image all kinds of biological processes. This tool is already exploited in (pre)clinical studies of rheumatoid arthritis, osteoarthritis and cancer. The technique uses fluorescent dyes conjugated to targeting moieties that recognize biomarkers of the disease. This review will focus on these new imaging techniques and especially where Near Infrared (NIR) fluorescence imaging has been used to visualize diseases of the joint. NIR fluorescent imaging is a promising technique which will soon complement established radiological, ultrasound and MRI imaging in the clinical management of patients with respect to early disease detection, monitoring and improved intervention.

How intraoperative navigation is changing musculoskeletal tumor surgery

Computer-assisted orthopedic surgery (CAOS) was introduced, developed, and implemented in musculoskeletal tumor surgery recently to enhance surgical precision in resecting malignant and benign tumors. The origins of computer-assisted surgery were in other subspecialties including maxillofacial surgery, spine surgery, and arthroplasty. Early studies have shown that CAOS can also be used safely for bone tumor resection surgery. Additional technological improvements may allow use of CAOS in soft tissue tumor surgery. It has the potential to improve surgical precision and accuracy, but more study is needed to evaluate clinical efficacy and long term results.

Impact of navigated-control assistance on performance, workload and situation awareness of experienced surgeons performing a simulated mastoidectomy

BACKGROUND

Navigated control (NC) is an advanced image-guided navigation system that provides an additional control function to enhance patient safety. It automatically stops the surgical instrument if it comes close to critical anatomical structures that need to be protected during surgery. The purpose of this study was to explore the human performance consequences of computer-based navigated control assistance.

METHODS

Seven experienced surgeons conducted a simulated mastoidectomy manually and with support of the NC system. The impact on surgical performance, workload and situation awareness was analysed.

RESULTS

NC support led to a better quality of surgical outcome and a lower level of physiological effort during surgery. Cost effects were reflected in reduced time efficiency and an increased subjectively experienced workload.

CONCLUSION

The results demonstrate the potential of NC support in terms of lower workload and enhanced patient safety. Cost effects might be reduced by remodelling the control function.

Comparison of Surface Area across the Allograft-Host Junction Site Using Conventional and Navigated Osteotomy Technique

Bulk allograft reconstruction plays an important role in limb-salvage surgery; however, non-union has been reported in up to 27% of cases. The purpose of this study is to quantify average surface contact areas across simulated intraoperative osteotomies using both free-hand and computer-assisted navigation techniques. Pressure-sensitive paper was positioned between two cut ends of a validated composite sawbone and compression was applied using an eight-hole large fragment dynamic compression plate. Thirty-two samples were analyzed for surface area contact to determine osteotomy congruity. Mean contact area using the free-hand osteotomy technique was equal to 0.21 square inches. Compared with a control of 0.69 square inches, average contact area was found to be 30.5% of optimal surface contact. Mean contact area using computer-assisted navigation was equal to 0.33 square inches. Compared with a control of 0.76 square inches, average contact area was found to be 43.7% of optimal surface contact. Limited contact achieved using standard techniques may play a role in the high rate of observed non-union, and an increase in contact area using computer-assisted navigation may improve rates of bone healing. The development of an oncology software package and navigation hardware may serve an important role in decreasing non-union rates in limb salvage surgery.

Potential use of computer navigation in the treatment of primary benign and malignant tumors in children

The treatment of benign and malignant primary bone tumors has progressed over time from relatively simple practice to complex resection and reconstruction techniques. Recently, computer-assisted orthopaedic surgery (CAOS) has been used to assist surgeons to enhance surgical precision in order to achieve these goals. Initially, software developed for CT-based spinal applications was used to perform simple intraoperative point localization. With advances in technique and software design, oncology surgeons have now performed joint sparing complex multiplanar osteotomies using combined CT and MRI image data with precision and accuracy. The purpose of this paper is to provide a review of the clinical progress to date, the different types of navigation available, methods for error management, and limitations of CAOS in the treatment of pediatric benign and malignant primary bone tumors.

Irregular osteotomy in limb salvage for juxta-articular osteosarcoma under computer-assisted navigation

BACKGROUND

Joint-preserving limb salvage surgery has been expected to have good functional outcomes. However, it is still a unsolved problem to perform a joint preserving resection for patients with juxta-articular osteosarcoma invading epiphyseal line. We determined whether irregular osteotomy under image-guided navigation make joint-saving resection possible for juxta-articular osteosarcoma while adhering oncological principles.

METHODS

We performed joint-preserving limb salvage surgeries on six patients with juxta-articular osteosarcoma of the long bone. Three lesions located in humerus, two in tibia and one in femur. Two tumors extend to and four beyond the epiphyseal line. CT and MRI data fusion images were applied for intraoperative navigation. Planned irregular osteotomy under image-guided navigation was employed for obtaining clear surgical margin while maximizing host tissue preservation. All tumors were en bloc removed and intercalary defect were reconstructed by allograft in one and combination of allograft with vascularized fibula graft in five patients. All specimens were examined for resection margin. Patients were followed up for average of 17.5 months for evaluating of functional and oncology outcomes.

RESULT

Entire joint were preserved in three patients and part of joint were saved in another three patients. Clear surgical margin was obtained in all specimens with a minimum of 6-mm distance between tumor and osteotomy line. No patient experienced a local recurrence. One patient developed lung metastasis and had no evidence of disease at the most recent follow-up. All allografts but one healed during the study period. The MSTS average score was 88.8% at final follow-up.

CONCLUSIONS

With careful patient selection, the irregular osteotomy under navigation guidance was proved to be an effective and safe technique for precise tumor resection in joint preserving limb salvage procedures for treating patients with juxta-articular osteosarcomas.

Automation in surgery: the impact of navigated-control assistance on performance, workload, situation awareness, and acquisition of surgical skills

OBJECTIVE

Human performance consequences of a new technology of image-guided navigation (IGN) support for surgeons are investigated.

BACKGROUND

Navigated control (NC) represents an advancement of IGN technology. In contrast to currently available pointer-based systems, it represents a higher degree of automation that supports processes not only of information analysis and integration but also of intraoperative decision making.

METHOD

In the first experiment, 14 surgical novices performed a simulated mastoidectomy with and without NC support. Effects of provision of the system were analyzed with respect to different measures of surgical performance and outcome, workload, and situation awareness. In the second experiment, 21 advanced medical students were trained to perform a mastoidectomy by practicing it either with or without NC support. It was investigated to what extent the provision of the system during practice would affect the acquisition of surgical skills.

RESULTS

The results reveal that NC support can reduce both the risk of intraoperative injuries and complications as well as the physiological effort of surgeons. "Cost effects" compared to a conventional (i.e., not supported) surgery emerged with respect to the time needed for the surgery, increased subjective workload, reduced spare capacity, and a reduced level of situation awareness. However, no significant effects on processes of skill acquisition were found.

CONCLUSION

NC systems can contribute to improved patient safety. Most of the cost effects seem to be related not to the basic principle of NC but to its current technological implementation.

APPLICATION

The results have consequences for the design and clinical use of automated navigation support.

Computer-assisted resection and reconstruction of pelvic tumor sarcoma

Pelvic sarcoma is associated with a relatively poor prognosis, due to the difficulty in obtaining an adequate surgical margin given the complex pelvic anatomy. Magnetic resonance imaging and computerized tomography allow valuable surgical resection planning, but intraoperative localization remains hazardous. Surgical navigation systems could be of great benefit in surgical oncology, especially in difficult tumor location; however, no commercial surgical oncology software is currently available. A customized navigation software was developed and used to perform a synovial sarcoma resection and allograft reconstruction. The software permitted preoperative planning with defined target planes and intraoperative navigation with a free-hand saw blade. The allograft was cut according to the same planes. Histological examination revealed tumor-free resection margins. Allograft fitting to the pelvis of the patient was excellent and allowed stable osteosynthesis. We believe this to be the first case of combined computer-assisted tumor resection and reconstruction with an allograft.

MRI-guided navigation surgery with temporary implantable bone markers in limb salvage for sarcoma

BACKGROUND

Technical errors during navigation-assisted bone tumor resection may occur by: (1) incorrect registration of images and corresponding anatomic points of bone sent to the navigation system; and (2) incorrect fusion of two or more images that have been transported to the navigation system.

QUESTIONS/PURPOSES

We investigated new methods of navigation surgery to minimize technical errors during the registration and image fusion processes and specifically asked whether a navigated cannula probe would reduce unnecessary soft tissue dissection, and allow percutaneous registration and implantation of a reference base tracker in the margin of bone to be resected.

METHODS

We performed direct MRI-guided navigation surgery without image fusion on a patient with osteosarcoma using absorbable pins as temporary implanted bone markers that prevent artifacts on MR images.

RESULTS

Direct MRI-guided navigation surgery was possible using bone markers. A navigated cannula probe allowed percutaneous registration and a navigated blade-shaped probe provided a real-time check on the narrow osteotomy gap. The surgical procedure was facilitated by implantation of a reference base tracker on the margin of bone to be resected.

CONCLUSIONS

Our modified technique of MRI-guided navigation surgery for patients with a malignant bone tumor may reduce processing errors by increased accuracy and be helpful for joint preserving surgery.

Joint-preserving limb salvage surgery under navigation guidance

BACKGROUND

Recently, the navigation system has been introduced to orthopedic oncology. It can apply MRI and/or CT images to intraoperative visualization. We performed navigation-assisted limb salvage surgeries on patients with a malignant bone tumor of the metaphysis of the long bone or the iliac bone while preserving the adjacent joint.

METHODS

When preoperative chemotherapy was estimated to be effective by imaging studies and the residual remaining epiphysis was expected to be more than 1 cm long after tumor resection with 1-2 cm of surgical margin, joint-preserving surgery was performed under navigation guidance. We carried out CT and MRI data fusion to use MR images as an intraoperative guide. A deep frozen strut allograft was placed in the defect for the restoration of anatomical continuity.

RESULTS

Resection margin measured on pathological examination was in accordance with that of the preoperative plan. The functional scores of all patients were satisfactory. There was no evidence of recurrence on the regional radiographs and CT on the chest until the last follow-up.

CONCLUSION

Navigation-assisted surgery can be indicated for limb salvage and it can help to preserve the adjacent joint in selected cases.

Reconstruction of the pelvis after resection of malignant bone tumours in children and adolescents

The predominant tumour of the pelvic region in children and adolescents is Ewing's sarcoma followed by osteosarcoma. Both tumours are treated by chemotherapy and the best chance of survival is offered by wide tumour resection. Compared to surgical treatment on the extremities, the resection and reconstruction of pelvic sarcomas remains challenging. Surgery of pelvic sarcomas shows higher rates of local recurrence and complications and a lower functional outcome than other localisations. Especially in children and adolescents the reconstruction methods have to focus additionally on the growing skeleton. According to the different types of pelvic resections and therefore the need of different reconstruction methods, the following article is based on Enneking's surgical classification of pelvic resections. Type I resections are best reconstructed with autografts implanted between the supracetabular osteotomy and the sacrum. Patients show the best functional results after this reconstruction. Periacetabular resections (type II) in small children do best with iliofemoral arthrodesis or pseudarthrosis; in larger adolescents the use of the pedestal Schoellner cup showed superior results over the prior saddle prosthesis. Type III resections are not reconstructed. Complete internal hemipelvectomy represents the most difficult situation, in children as well as in adults. High complication rates after allograft and endoprosthetic reconstruction have recently favoured the renaissance of a flail hip reconstruction or the hip transpositionplasty.

Development and validation of a three dimensional ultrasound based navigation system for tumor resection

BACKGROUND

Intraoperative navigation is a rapidly emerging procedure in orthopaedic surgery and neurosurgery. For abdominal tumors (e.g. liver metastasis) and soft tissue tumors there is only limited experience with navigation techniques due to problems of organ shift and tissue deformation. We have developed a navigation system for tumor resection in soft tissue based on 3D ultrasound imaging and optical tracking.

METHODS

Two different modes of navigation were evaluated and compared with conventional surgery in an experimental soft tissue model. Both techniques were based on 3D ultrasound and an optical tracking system for intraoperative real time registration of surgical instruments. These two techniques were used: a) Indirect navigation with ultrasound guided insertion of a tracked hook needle into the tumor; and b) Direct navigation using a 3D image which was obtained with an optically tracked 3D ultrasound probe. It was the aim of both techniques to achieve a circumferential resection margin of 2cm around the tumor.

RESULTS

A total of 23 resections were performed consisting of indirect (n=7) and direct (n=10) navigation and conventional surgery (n=6) as gold standard. For indirect navigation a median deviation from the ideal resection margin (accuracy) of 0.32cm was measured. Direct navigation showed an accuracy of 0.16cm compared to 0.42cm with conventional surgery. Navigated surgery showed for both techniques a significant increase of resection accuracy compared to conventional resection (p<0.05).

CONCLUSION

3D ultrasound based indirect and direct optoelectronic navigation for resection of soft tissue tumors is feasible and may improve intraoperative orientation with increased surgical precision.

MRI-guided laparoscopic and robotic surgery for malignancies

Endoscopic surgery has some clear benefits, but it also has some disadvantages in reducing surgeons' normal dexterity and limiting their ability to deal with difficult situations. Computer-aided surgery has been proposed to overcome some of the drawbacks of traditional minimally invasive surgery. The proposed systems make possible a secure, precise procedure with no limitations on the operator's freedom of movement. Image-guided surgery is a new technical tool in surgical oncology. Interventional magnetic resonance imaging (MRI) has entered a new stage in which computer-based techniques play an expanding role in planning, monitoring, and controlling procedures. MRI-guided surgery not only represents a technical challenge but is a transformation from conventional hand-eye coordination to interactive navigational operations. We have recently developed an MRI-guided robot-assisted interventional surgical system as well as an MRI-compatible endoscope. They allow the performance of precise image-guided interventional therapy and endoscopic surgery. MRI-guided laparoscopic surgery is now feasible for malignancies and will play an important part in the development of minimally invasive therapy.