Image-guided Surgery Research Articles

Sparse-view cone beam CT reconstruction using dual CNNs in projection domain and image domain

Cone beam computed tomography (CBCT) is used extensively in image-guided surgery and radiotherapy, but it induces ionizing radiation to the patients. Sparse-view CBCT is a main method to lower the radiation dose; however, it introduces streak artifacts in the reconstructed images. We develop a dual convolutional neural network architecture (DualCNN) to eliminate streak artifacts from sparse-view CBCT images. In the first part, we develop an interpolation CNN in the projection domain to restore the full-view projections from sparse-view projections. The restored full-view projections are then input to the Feldkamp–Davis–Kress algorithm for reconstructing the CBCT images. In the second part, we develop an image domain CNN to further improve the quality of the CBCT images. DualCNN is evaluated using real CBCT X-ray projection data of walnuts. Experimental results show that, DualCNN reconstructs good CT images with only a quarter number of full-view projections, and it achieves significantly higher performance than other representative methods in terms of qualitative and quantitative evaluations. DualCNN achieves a mean root-mean-square error of 0.0369, a mean peak-signal-to-noise ratio of 26.93 dB and a mean structural similarity of 0.732 in 3800 reconstructed images. Therefore, our DualCNN can significantly lower the CBCT radiation dose while maintaining good quality of reconstructed images.

Self-assembled NIR-II Fluorophores with Ultralong Blood Circulation for Cancer Imaging and Image-guided Surgery.

Complete excision of the last remaining 1-2% of tumor tissue without collateral damage remains particularly challenging. Herein, we report thiophenthiadiazole (TTD)-derived fluorophores L6-PEGnk (n = 1, 2, 5) as new-generation NIR-II (1000-1700 nm) probes with exceptional nonfouling performance and significantly high fluorescence quantum yields in water. L6-PEG2k can self-assemble into vesicular micelles and exhibited minimal immunogenicity, low binding affinities, ultralong blood circulation (t1/2 = 59.5 h), and a supercontrast ratio in vivo. Most importantly, L6-PEG2k achieved excellent in vivo CT-26 and U87MG tumor targeting and accumulation (>20 d) through intraperitoneal or intravenous injection. A subcutaneous U87MG tumor and orthotopic brain glioma were successfully resected under NIR-II FIGS in our animal model via intraperitoneal injection in an extended time window (48-144 h). This study highlights the potential of using L6-PEG2K as self-assembling molecular probes with long-circulation persistence for routine preoperative tumor assessment and precise intraoperative image-guided resection.

Pushing the boundaries of accuracy and reliability during stereotactic procedures: A prospective study on 526 biopsies comparing the frameless robotic and Image-Guided Surgery systems

IntroductionA 12-year long, prospective, single center study was conducted, comparing two frameless systems for brain biopsies: ROSA robotic-assisted stereotaxy and BrainLab Varioguide image-guided stereotaxy (Image Guided Surgery, IGS). MethodAll consecutive adult and pediatric patients undergoing frameless brain biopsies were included. Successfully achieving diagnosis was the primary endpoint, analysis of all periprocedural complications was the secondary endpoint, and the tertiary endpoint was the length of the procedure, with the aim of assessing of the learning curve for each operator over time. The results for the ROSA robot and the Varioguide system were compared and benchmarked to data from the literature. ResultsWe performed 526 on 516 patients, 314 with the ROSA robot (Group A) and 212 with the IGS Varioguide (Group B). Histological diagnosis was achieved in 97.4% of cases in Group A, versus 93.3% in Group B (p < 0.05). No statistically significant difference was found for secondary and tertiary endpoints. The complication rate appeared similar between the 2 frameless systems, with a hemorrhagic complications rate of 3.5% in Group A and 4.7% in Group B. Permanent neurological deterioration was only recorded in 0.8% of cases from Group B. Mortality was recorded in 0.3% in Group A and 0.4% in Group B. ConclusionThis study provides evidence to confirm that robotic surgery lives up to its promises of increased safety, accuracy, and reliability.

Augmented Reality and Image-Guided Robotic Liver Surgery.

Simple SummaryRobotic surgery has gained much attention in liver resection for its potential to increase surgical dexterity in a minimally invasive scenario. Different series are reported in the literature with promising results, although strong evidence is lacking. In addition, the robotic system presents the advantage of creating a hybrid interface in which pre- and intra-operative imaging tools could be exploited alone or together in order to guide surgical resection. These technologies have been developed with the aim of increasing surgical safety and improving oncological results. However, some drawbacks are still present, and the literature lacks data given the relatively recent distribution of the robotic platform and of some of these technologies.Artificial intelligence makes surgical resection easier and safer, and, at the same time, can improve oncological results. The robotic system fits perfectly with these more or less diffused technologies, and it seems that this benefit is mutual. In liver surgery, robotic systems help surgeons to localize tumors and improve surgical results with well-defined preoperative planning or increased intraoperative detection. Furthermore, they can balance the absence of tactile feedback and help recognize intrahepatic biliary or vascular structures during parenchymal transection. Some of these systems are well known and are already widely diffused in open and laparoscopic hepatectomies, such as indocyanine green fluorescence or ultrasound-guided resections, whereas other tools, such as Augmented Reality, are far from being standardized because of the high complexity and elevated costs. In this paper, we review all the experiences in the literature on the use of artificial intelligence systems in robotic liver resections, describing all their practical applications and their weaknesses.

Abstract LBA048: Lymph node metastasis targeted intranodal delivery of docetaxel improves treatment outcome

Abstract Despite recent advances in diagnostic modalities and cancer treatment guidelines, systemic chemotherapy for the lymph node (LN) metastasis has poor treatment efficacy using conventional drugs. Therefore, a novel method, lymphatic drug delivery system (LDDS), has been proposed in a pre-clinical experiment that directly injects the anticancer drug into sentinel LNs to deliver into their downstream LNs, aiming to inhibit tumor cell growth in those LNs. The injection duration of chemotherapy drugs using the LDDS will be less than the intratumoral or intralesion methods used in the clinic, and systemic toxicity will be less than tumor-targeted therapy or systemic chemotherapy. Our previous results indicated that the treatment efficacy increased in LDDS treated groups than systemic delivery. Here, we show the improvement of treatment efficacy by increasing osmotic pressure and viscosity of the drug solvent delivered by LDDS using the metastatic LN mouse model. First, a metastatic LN mouse model was created by inoculating luciferase-expressing tumor cells into subiliac LN (SiLN) of MXH10/Mo/lpr mouse to induce metastasis into the proper axillary LN (PALN). Next, 10 mg/kg docetaxel (DTX) with increased osmotic pressure and viscosity were injected into tumor-inoculated SiLN with an injection rate of 2400 μL/min on day 7 post-inoculation to inhibit tumor cell growth in the inoculation and metastatic site. Luciferase activity decreases in PALNs and SiLNs were observed in groups between 1140 kPa, 1960 kPa, and 2780 kPa (4, 11, and 38 mPa·s) groups without inducing any side effects. By histology, no tumor cells were confirmed in those LNs of the 1960 kPa group. Then, DTX at 1960 kPa, 11 mPa·s was injected into tumor-inoculated SiLN on day 21 post-inoculation with different injection speeds and volumes. We found that DTX at 1960 kPa, 11 mPa·s injected at the injection rate of 200 μL/min with 400 μL volume, can inhibit tumor cell growth in the PALN and delay tumor growth SiLN. Furthermore, the antitumor effects depended on the tumor progression stage in the LNs, and the injection rates and volumes of administered drugs. We anticipate these optimal ranges as a starting point for developing more effective drug regimens to treat metastatic LNs with the LDDS. Moreover, administrable drugs in this novel method of ultrasound-guided LDDS or LDDS at intra-operative or image-guided surgery are not limited only to anticancer agents. Citation Format: Ariunbuyan Sukhbaatar, Shouta Sora, Mori Shiro, Tetsuya Kodama. Lymph node metastasis targeted intranodal delivery of docetaxel improves treatment outcome [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr LBA048.

NIR-II emissive AIEgen photosensitizers enable ultrasensitive imaging-guided surgery and phototherapy to fully inhibit orthotopic hepatic tumors

Accurate diagnosis and effective treatment of primary liver tumors are of great significance, and optical imaging has been widely employed in clinical imaging-guided surgery for liver tumors. The second near-infrared window (NIR-II) emissive AIEgen photosensitizers have attracted a lot of attention with higher-resolution bioimaging and deeper penetration. NIR-II aggregation-induced emission-based luminogen (AIEgen) photosensitizers have better phototherapeutic effects and accuracy of the image-guided surgery/phototherapy. Herein, an NIR-II AIEgen phototheranostic dot was proposed for NIR-II imaging-guided resection surgery and phototherapy for orthotopic hepatic tumors. Compared with indocyanine green (ICG), the AIEgen dots showed bright and sharp NIR-II emission at 1250 nm, which extended to 1600 nm with high photostability. Moreover, the AIEgen dots efficiently generated reactive oxygen species (ROS) for photodynamic therapy. Investigations of orthotopic liver tumors in vitro and in vivo demonstrated that AIEgen dots could be employed both for imaging-guided tumor surgery of early-stage tumors and for ‘downstaging’ intention to reduce the size. Moreover, the therapeutic strategy induced complete inhibition of orthotopic tumors without recurrence and with few side effects.Graphical

In situ lymphoma imaging in a spontaneous mouse model using the Cerenkov Luminescence of F-18 and Ga-67 isotopes

Cerenkov luminescence imaging (CLI) is a promising approach to image-guided surgery and pathological sampling. It could offer additional advantages when combined to whole-body isotope tomographies. We aimed to obtain evidence of its applicability in lymphoma patho-diagnostics, thus we decided to investigate the radiodiagnostic potential of combined PET or SPECT/CLI in an experimental, novel spontaneous high-grade B-cell lymphoma mouse model (Bc.DLFL1). We monitored the lymphoma dissemination at early stage, and at clinically relevant stages such as advanced stage and terminal stage with in vivo 2-deoxy-2-[18F]fluoro-d-glucose (FDG) positron emission tomography (PET)/magnetic resonance imaging (MRI) and 67Ga-citrate single photon emission computed tomography (SPECT)/MRI. In vivo imaging was combined with ex vivo high resolution CLI. The use of CLI with 18F-Fluorine (F-18) and 67Ga-Gallium isotopes in the selection of infiltrated lymph nodes for tumor staging and pathology was thus tested. At advanced stage, FDG PET/MRI plus ex vivo CLI allowed accurate detection of FDG accumulation in lymphoma-infiltrated tissues. At terminal stage we detected tumorous lymph nodes with SPECT/MRI and we could report in vivo detection of the Cerenkov light emission of 67Ga. CLI with 67Ga-citrate revealed lymphoma accumulation in distant lymph node locations, unnoticeable with only MRI. Flow cytometry and immunohistochemistry confirmed these imaging results. Our study promotes the combined use of PET and CLI in preclinical studies and clinical practice. Heterogeneous FDG distribution in lymph nodes, detected at sampling surgery, has implications for tissue pathology processing and it could direct therapy. The results with 67Ga also point to the opportunities to further apply suitable SPECT radiopharmaceuticals for CLI.

Bay Leaf Extract-Based Near-Infrared Fluorescent Probe for Tissue and Cellular Imaging.

The development of fluorescence dyes for near-infrared (NIR) fluorescence imaging has been a significant interest for deep tissue imaging. Among many imaging fluoroprobes, indocyanine green (ICG) and its analogues have been used in oncology and other medical applications. However, these imaging agents still experience poor imaging capabilities due to low tumor targetability, photostability, and sensitivity in the biological milieu. Thus, developing a biocompatible NIR imaging dye from natural resources holds the potential of facilitating cancer cell/tissue imaging. Chlorophyll (Chl) has been demonstrated to be a potential candidate for imaging purposes due to its natural NIR absorption qualities and its wide availability in plants and green vegetables. Therefore, it was our aim to assess the fluorescence characteristics of twelve dietary leaves as well as the fluorescence of their Chl extractions. Bay leaf extract, a high-fluorescence agent that showed the highest levels of fluorescence, was further evaluated for its tissue contrast and cellular imaging properties. Overall, this study confirms bay-leaf-associated dye as a NIR fluorescence imaging agent that may have important implications for cellular imaging and image-guided cancer surgery.

Macrophage-Mediated Porous Magnetic Nanoparticles for Multimodal Imaging and Postoperative Photothermal Therapy of Gliomas

Because of the blood-brain barrier and the high infiltration of glioma cells, the diagnostic accuracy and treatment efficiency of gliomas are still facing challenges. There is an urgent need to explore the integration of diagnostic and therapeutic methods to achieve an accurate diagnosis, guide surgery, and inhibit postoperative recurrence. In this work, we developed a macrophage loaded with a photothermal nanoprobe (MFe3O4-Cy5.5), which is able to cross the blood-brain barrier and accumulate into deep gliomas to achieve multimodal imaging and guided glioma surgery purposes. With desirable probing depth and high signal-to-noise ratio, Fe3O4-Cy5.5 can perform fluorescence, photoacoustic, and magnetic resonance imaging, which can distinguish brain tumors from the surrounding normal tissues and accurately guide glioma resection. Meanwhile, Fe3O4-Cy5.5 can effectively induce local photothermal therapy and inhibit the recurrence of glioma after surgery. These results demonstrate that the macrophage-mediated Fe3O4-Cy5.5, which can achieve a multimodal diagnosis, accurate imaging-guided surgery, and effective photothermal therapy, is a promising nanoplatform for gliomas.

Artificial Intelligence for Computer Vision in Surgery: A Call for Developing Reporting Guidelines.

Artificial Intelligence for Computer Vision in Surgery: A Call for Developing Reporting Guidelines.

Research on registration and navigation technology of augmented reality for ex-vivo hepatectomy.

The application of augmented reality technology to the partial hepatectomy procedure has high practical significance, but the existing augmented reality navigation system has major drawbacks in the display and registration methods, which result in low precision. The augmented reality surgical navigation system proposed in this study has been improved in the above two aspects, which can significantly improve the surgical accuracy. The use of optical see-through head-mounted displays for imaging displays can prevent doctors from reconstructing the patient's two-dimensional image information in their minds and reduce the psychological burden of doctors. In the registration process, the biomechanical properties of the liver are introduced, and a non-rigid registration method based on biomechanics is proposed and realized by a meshless algorithm. In addition, this study uses the moving grid algorithm to carry out clinical experiments on ex-vivo pig liver for experimental verification. The mark-based interactive registration error is 4.21 ± 1.6mm, and the registration error is reduced after taking the biomechanical properties of the liver into account, which is -0.153 ± 0.398mm. The cutting error of the liver model is 0.159 ± 0.292mm. In addition, with the aid of the navigation system proposed in this paper, the experiment of ex-vivo pig liver cutting was completed with an error of -1.164 ± 0.576mm. As a proof-of-concept study, the augmented reality navigation system proposed in this study improves the traditional image-guided surgery in terms of display and registration methods, and the feasibility of the system is verified by ex-vivo pig liver experiments. Therefore, the navigation system has a certain guiding significance for clinical surgery.

Precise Diagnosis and Therapy of Bone Cancer Using Near-Infrared Lights.

Bone is a preferred site for both primary and metastasis tumors. Current diagnosis of osteopathia typically relies on noninvasive skeleton radiography technology. However, due to the limited resolution of ionizing radiation, accurate diagnosis and effective identification impairment areas are still lacking. Near-infrared (NIR) bioimaging, especially in the NIR-II (1000-1700 nm) regions, can provide high sensitivity and spatiotemporal resolution bioimaging compared to the conventional radiography. Thus, NIR bioimaging affords intraoperative visualization and imaging-guided surgery, aiming to overcome challenges associated with theranostics of osteopathia and bone tumors. The present review aimed to summarize the latest evidence on the use of NIR probes for the targeting bone imaging. We further highlight the recent advances in bone photoX (X presents thermal, dynamic, and immuno) therapy through NIR probes, in particular combination with other customized therapeutic agents could provide high-efficiency treatment for bone tumors.

Development of a New Image-Guided Neuronavigation System: Mixed-Reality Projection Mapping Is Accurate and Feasible.

Image-guided systems improve the safety, functional outcome, and overall survival of neurosurgery but require extensive equipment. To develop an image-guided surgery system that combines the brain surface photographic texture (BSP-T) captured during surgery with 3-dimensional computer graphics (3DCG) using projection mapping. Patients who underwent initial surgery with brain tumors were prospectively enrolled. The texture of the 3DCG (3DCG-T) was obtained from 3DCG under similar conditions as those when capturing the brain surface photographs. The position and orientation at the time of 3DCG-T acquisition were used as the reference. The correct position and orientation of the BSP-T were obtained by aligning the BSP-T with the 3DCG-T using normalized mutual information. The BSP-T was combined with and displayed on the 3DCG using projection mapping. This mixed-reality projection mapping (MRPM) was used prospectively in 15 patients (mean age 46.6 yr, 6 males). The difference between the centerlines of surface blood vessels on the BSP-T and 3DCG constituted the target registration error (TRE) and was measured in 16 fields of the craniotomy area. We also measured the time required for image processing. The TRE was measured at 158 locations in the 15 patients, with an average of 1.19±0.14 mm (mean±standard error). The average image processing time was 16.58 min. Our MRPM method does not require extensive equipment while presenting information of patients' anatomy together with medical images in the same coordinate system. It has the potential to improve patient safety.

ITVT-04. Management of intraoperative technological advances [intraoperative MRI, neuronavigation system using PET, and 5-aminolevulinic acid (5-ALA)–induced fluorescence image-guided surgery] for glioblastoma

Abstract OBJECTIVE The maximum resection of Glioblastoma (GBM) is the standard therapy and is expected to improve prognosis. Image-guided surgery using a neuronavigation system is the standard technique for glioma. However, due to the brain shift during surgery, intraoperative technologies, such as 5-ALA fluorescence and intraoperative MRI (IoMRI), are employed. Radiotracers are used during positron emission tomography (PET) for metabolic imaging and assist the evaluation of glioma metabolism. We compared the effectiveness of these intraoperative technologies. METHODS Between January 2016 and May 2021, 52 patients with gliomas underwent IoMRI. 21 patients were selected for 5-ALA fluorescence-guided resection of GBM and underwent multiple PET studies (MET, FLT, and FMISO). We graded fluorescence level as strong, vague, or none. Following tumor resection, we identified the fluorescence level and evaluated the residual volume of gadolinium-enhanced T1WI (T1-Gd) on IoMRI and at each PET study. After calculating the extent of resection (EOR) for T1-Gd, we compared the residual volume on T1-Gd for IoMRI and each PET study, between EOR ≥ 93% and EOR &amp;lt; 93%. RESULTS We detected strong 5-ALA fluorescence during induction and before tumor resection in all 21 (100%) patients with a newly-diagnosed and histopathologically-confirmed GBM. Following tumor resection, we noted an EOR ≥ 93% for T1-Gd in 12 cases (vague, 4; none, 8) and an EOR &amp;lt; 93% for T1-Gd in 9 cases (vague, 5; none, 4). The compared median residual volume (mL) with no fluorescence between EOR ≥ 93% and EOR &amp;lt; 93% for T1-Gd were T1-Gd (0.22, 0.74), MET (0.29, 3.31), FLT (0.24, 1.77), and FMISO (0.22, 1.02). CONCLUSIONS GBM cells are difficult to distinguish in cases without 5-ALA fluorescence. For cases without 5-ALA fluorescence, we were able to maximize the resection of GBM by extracting the area of MET accumulation.

INNV-09. SURGICAL STRATEGIES FOR OLDER PATIENTS WITH GLIOBLASTOMA

Abstract OBJECTIVE Though image-guided surgery with intraoperative magnetic resonance imaging (IoMRI) is associated with higher extent of resection, we aimed to determine the clinical outcome of its use, compared to other less time-consuming intraoperative ultrasound (IoUS), in this patient population. METHODS Clinical data of 221 consecutive patients aged 70 years or older, who underwent surgical resection for GBM with intraoperative ultrasonography (IoUS) alone or combination of IoMRI + IoUS at Yale New Haven Hospital and Memorial Sloan Kettering Cancer Center were retrospectively reviewed. Variables were analyzed, and comparative analyses were performed, including predictors of overall survival. RESULTS The addition of IoMRI was not superior to IoUS alone in terms of overall survival (OS) (HR=0.85, 95% CI 0.49-1.47; P= 0.56) or Karnofsky Performance Score (KPS) at 6 weeks postoperatively (OR=0.51, 95% CI 0.22-1.15; P= 0.102). On the contrary, the length of surgery (LOSx) was significantly longer (P&amp;lt; 0.0001) in the IoMRI group. Postoperative complications were significantly less in the IoUS-only group (OR=0.17, 95% CI 0.3-0.46; P=0.002) and in patients who had a preoperative KPS score of 70 or higher (OR=0.092, 95% CI 0.018-0.47; P=0.004). Patients with relatively lower preoperative KPS scores (&amp;lt; 70) showed significant clinical improvement at 6 weeks postoperatively (P=0.0002). Patients with postoperative complications were more likely to have lower KPS scores at 6 weeks postoperatively (OR=0.30, 95% CI 0.10-0.89; P= 0.031), while increased extent of resection was associated with improved KPS scores at 6 weeks postoperatively (OR=2.171, 95% CI 1.22-3.87; P= 0.009). CONCLUSION Aggressive management with surgical resection should be considered in older patients with GBM, even those with relatively poor KPS scores. The use of IoMRI in this patient population does not appear to yield any survival benefit over IoUS but instead significantly prolongs the length of surgery, increasing the risk for potential postoperative complications.

Aggregation-induced emission luminogens for image-guided surgery in non-human primates

During the past two decades, aggregation-induced emission luminogens (AIEgens) have been intensively exploited for biological and biomedical applications. Although a series of investigations have been performed in non-primate animal models, there is few pilot studies in non-human primate animal models, strongly hindering the clinical translation of AIE luminogens (AIEgens). Herein, we present a systemic and multifaceted demonstration of an optical imaging-guided surgical operation via AIEgens from small animals (e.g., mice and rabbits) to rhesus macaque, the typical non-human primate animal model. Specifically, the folic conjugated-AIE luminogen (folic-AIEgen) generates strong and stable fluorescence for the detection and surgical excision of sentinel lymph nodes (SLNs). Moreover, with the superior tumor/normal tissue ratio and rapid tumor accumulation, folic-AIEgen successfully images and guides the precise resection of invisible cancerous metastases. Taken together, the presented strategies of folic-AIEgen based fluorescence intraoperative imaging and visualization-guided surgery show potential for clinical applications.

Fully automated segmentation in temporal bone CT with neural network: a preliminary assessment study

BackgroundSegmentation of important structures in temporal bone CT is the basis of image-guided otologic surgery. Manual segmentation of temporal bone CT is time- consuming and laborious. We assessed the feasibility and generalization ability of a proposed deep learning model for automated segmentation of critical structures in temporal bone CT scans.MethodsThirty-nine temporal bone CT volumes including 58 ears were divided into normal (n = 20) and abnormal groups (n = 38). Ossicular chain disruption (n = 10), facial nerve covering vestibular window (n = 10), and Mondini dysplasia (n = 18) were included in abnormal group. All facial nerves, auditory ossicles, and labyrinths of the normal group were manually segmented. For the abnormal group, aberrant structures were manually segmented. Temporal bone CT data were imported into the network in unmarked form. The Dice coefficient (DC) and average symmetric surface distance (ASSD) were used to evaluate the accuracy of automatic segmentation.ResultsIn the normal group, the mean values of DC and ASSD were respectively 0.703, and 0.250 mm for the facial nerve; 0.910, and 0.081 mm for the labyrinth; and 0.855, and 0.107 mm for the ossicles. In the abnormal group, the mean values of DC and ASSD were respectively 0.506, and 1.049 mm for the malformed facial nerve; 0.775, and 0.298 mm for the deformed labyrinth; and 0.698, and 1.385 mm for the aberrant ossicles.ConclusionsThe proposed model has good generalization ability, which highlights the promise of this approach for otologist education, disease diagnosis, and preoperative planning for image-guided otology surgery.

Recent Progresses in NIR-I/II Fluorescence Imaging for Surgical Navigation.

Cancer is still one of the main causes of morbidity and death rate around the world, although diagnostic and therapeutic technologies are used to advance human disease treatment. Currently, surgical resection of solid tumors is the most effective and a prior remedial measure to treat cancer. Although medical treatment, technology, and science have advanced significantly, it is challenging to completely treat this lethal disease. Near-infrared (NIR) fluorescence, including the first near-infrared region (NIR-I, 650–900 nm) and the second near-infrared region (NIR-II, 1,000–1,700 nm), plays an important role in image-guided cancer surgeries due to its inherent advantages, such as great tissue penetration, minimal tissue absorption and emission light scattering, and low autofluorescence. By virtue of its high precision in identifying tumor tissue margins, there are growing number of NIR fluorescence-guided surgeries for various living animal models as well as patients in clinical therapy. Herein, this review introduces the basic construction and operation principles of fluorescence molecular imaging technology, and the representative application of NIR-I/II image-guided surgery in biomedical research studies are summarized. Ultimately, we discuss the present challenges and future perspectives in the field of fluorescence imaging for surgical navigation and also put forward our opinions on how to improve the efficiency of the surgical treatment.

Using physiological parameters measured by hyperspectral imaging to detect colorectal cancer.

The accurate detection of malignant tissue during colorectal surgery impacts operation outcome. The non-invasive spectral imaging combined with machine learning (ML) methods showed to be promising for tumor identification. However, large spectral range implies large computing time. To reduce the number of features, ML methods (e.g. logistic regression and convolutional neuronal network CNN) were evaluated based on four physiological tissue parameters to automatically classify cancer and healthy mucosa in resected colon tissue. A ROC AUC of 0.81 was achieved with the CNN. This study shows that the use of only specific wavelengths bands can detect cancer.Clinical Relevance- These outcomes support the possibility to automatically classify colon tumor based on physiological parameters calculated using only specific wavelength bands. Hence, future image-guided colorectal surgeries can be performed with real-time multispectral imaging.

Spatial Detection of the Shafts of Fractured Femur for Image-Guided Robotic Surgery.

Femur fractures due to traumatic forces often require surgical intervention. Such surgeries require alignment of the femur in the presence of large muscular forces up to 500 N. Currently, orthopedic surgeons perform this alignment manually before fixation, leading to extra soft tissue damage and inaccurate alignment. One of the limitations of femoral fracture surgery is the limited vision and two-dimensional nature of X-ray images, which typically guide the surgeon in diagnosing the position of the femur. Other limitations include the lack of precise intraoperative planning and the process of trial-and-error alignment. To alleviate the issues discussed, we develop a marker-based approach for detecting the position of femur fragments using two X-ray images. The relative spatial position of the femur fragments plays a key role in guiding an innovative robotic system, named Robossis, for femur fracture alignment surgeries. Using the derived three-dimensional data, we simulate pre-programmed movements to visualize the proposed steps of the alignment method, while the bone fragments are attached to the robot. Ultimately, Robossis aims to improve the accuracy of femur alignment, which results in improved patient outcomes.