Novel Image-Guided Simulator for Transcervical Intralaryngeal Injection Training.

OBJECTIVE(S): To assess the impact of a novel 3D-printed simulation model with Brainlab Image Guidance on enhancing otolaryngology residents' skills and confidence in performing transcervical intralaryngeal injection (TII) compared with conventional training methods. METHODS: Utilizing a 3D-printed larynx model derived from computed tomography (CT) scans, this study involved 16 otolaryngology residents divided into two groups for TII training: one with Brainlab Image Guidance (LMIG) and the other without (LM). Pre- and post-training evaluations measured participants' confidence while the Brainlab system measured the accuracy of their needle placements. RESULTS: After training, participants exhibited a significant increase in confidence with an average rise from 1.56 to 2.75 on a 5-point scale. The LMIG group outperformed the LM group in accuracy achieving statistically significant reductions in target distances after training (3.5 mm right, 3.6 mm left). The LMIG also demonstrated a significantly greater increase in procedural confidence over the LM group after training. CONCLUSION: The TII laryngeal model with Brainlab Image Guidance significantly improves procedural confidence and accuracy among otolaryngology residents, signifying potential advantage over a more conventional training approach. The model's realistic tactile and live instrument positioning feedback augments the process of surgical skill refinement in a controlled, risk-free, simulation environment. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Modeling and prediction of set­up errors in breast cancer image­guided radiotherapy using the Gaussian mixture model.

The aim of the present study was to develop a prediction model for set-up error distribution in breast cancer image-guided radiotherapy (IGRT) using a Gaussian mixture model (GMM). To achieve this, the image-guided set-up errors data of 80 patients with breast cancer were selected, and the GMM was used to develop the set-up errors distribution prediction model. The predicted error center points, covariance and probability were calculated and compared with the planning target volume (PTV) margin formula. A total of 1,200 sets of set-up errors in IGRT for breast cancer were collected. The results of the Gaussian model parameters showed that the set-up errors were mainly in the direction of µ1-µ4 center points. All the raw errors in the lateral, longitudinal and vertical directions were -6.30-4.60, -5.40-1.47 and -2.70-1.70 mm, respectively. According to the probability of each center, the set-up error was most likely to shift in the µ1 direction, reaching 0.53. The set-up errors of the other three centers, µ2, µ3 and µ4, were 0.11, 0.34 and 0.12, respectively. According to the covariance parameters of the GMM, the maximum statistical standard deviation of the set-up errors reached 29.06. In conclusion, the results of the present study demonstrated that the GMM can be used to quantitatively describe and predict the distribution of set-up errors in IGRT for breast cancer, and these findings could be useful as a reference for set-up error control and tumor PTV expansion in breast cancer radiotherapy without routine, daily IGRT.

Aspiration of Subdural Hygroma Using Augmented Reality Neuronavigation: A Case Report.

Augmented reality (AR) is emerging as a key technology in neurosurgery. Projecting three-dimensional (3D) anatomic models onto the surgical field provides unique operative information to make procedures safer and more efficient. A small footprint, rapid registration AR system was used for bedside guidance during aspiration of a subdural hygroma. A 77-year-old male presented for resection of a suprasellar tumor and subsequently developed a large bilateral subdural hygroma. We performed the aspiration of the hygroma at the bedside using AR guidance. The AR system allowed for precise needle placement during the aspiration. The aim of this report was to demonstrate the clinical feasibility of integrating a novel AR system into the clinical workflow of a bedside procedure. As AR continues to expand in the field, the benefits of this technology for various procedures will become more evident.

Radio-opaque contrast agents for liver cancer targeting with KIM during radiation therapy (ROCK-RT): an observational feasibility study.

BACKGROUND: This observational study aims to establish the feasibility of using x-ray images of radio-opaque chemoembolisation deposits in patients as a method for real-time image-guided radiation therapy of hepatocellular carcinoma. METHODS: This study will recruit 50 hepatocellular carcinoma patients who have had or will have stereotactic ablative radiation therapy and have had transarterial chemoembolisation with a radio-opaque agent. X-ray and computed tomography images of the patients will be analysed retrospectively. Additionally, a deep learning method for real-time motion tracking will be developed. We hypothesise that: (i) deep learning software can be developed that will successfully track the contrast agent mass on two thirds of cone beam computed tomography (CBCT) projection and intra-treatment images (ii), the mean and standard deviation (mm) difference in the location of the mass between ground truth and deep learning detection are ≤ 2 mm and ≤ 3 mm respectively and (iii) statistical modelling of study data will predict tracking success in 85% of trial participants. DISCUSSION: Developing a real-time tracking method will enable increased targeting accuracy, without the need for additional invasive procedures to implant fiducial markers. TRIAL REGISTRATION: Registered to ClinicalTrials.gov (NCT05169177) 12th October 2021.

Study of upright patient positioning reproducibility in image-guided proton therapy for head and neck cancers.

PURPOSE: To evaluate the patient's positioning reproducibility during upright treatment with image-guided adaptive proton therapy (IGAPT) for head and neck cancers. MATERIALS AND METHODS: 10 head and neck (H&N) patients were treated with gantry-less IGAPT, which includes daily 3D computed tomography (CT) and two 2D kilovoltage radiographs before treatment and weekly 3DCT immediately after irradiation. All procedures were performed in the carbon chair on the 6 degrees of freedom robotic positioner. RESULTS: Prior to treatment we registered shifts in patient positioning using 3D/3D registration at the imaging isocenter: X  = -0.1 ± 3.9 (mean ± standard deviation) mm, Y = -3.7 ± 3.5 mm, Z = 0.5 ± 6.2 mm. The corresponding vector was applied to the robotic positioner to compensate for the registered shifts, after which the patients were moved to the treatment isocenter and the following shifts were obtained there using 2D/3D registration: X  = -0.31 ± 1.37 mm, Y = -0.02 ± 1.33 mm, Z = 0.59 ± 1.55 mm. Finally, the weekly follow-up 3D/3D registration showed X  = -0.2 ± 1.2 mm, Y = -0.0 ± 1.4 mm, Z = 2.3 ± 2.0 mm. CONCLUSIONS: A novel image-guided gantry-less PT facility showed reliable results in terms of patient positioning for H&N cases during clinical trials. This fact confirmed the suitability of using gantry-less PT for H&N treatment. A small, systematic shift in the vertical direction was detected in the follow-up 3D/3D registration. The effect of this shift will be investigated in further studies with pre/post treatment 2D/3D registration. The next phase of the clinical trial of this facility is dedicated to the thorax region.

Image-guided percutaneous microwave ablation for unresectable pancreatic cancers: A multicenter retrospective study.

OBJECTIVE: This study aims to assess the feasibility, effectiveness, and safety of image-guided percutaneous microwave ablation (PMWA) for unresectable pancreatic cancer. METHODS: In this retrospective study, 72 patients from four hospitals were enrolled between November 2009 and October 2022. Descriptive statistics were employed to describe the patients' characteristics and prognostic factors. The primary endpoint compassed the complete ablation rate (CAR), incidence of complications and the pain relief rate (PRR). RESULTS: The median age of the 72 patients was 61 (interquartile range (IQR) 52.5-67.0) years, with 62.5 % (45/72) being male. 26 cases received computed tomography (CT) guidance; 46 cases received ultrasound guidance. A total of 74 tumors were identified (2 in 2 patients), with 56.8 % (42/74) at the body and tail, and the rest at the head and neck. Overall, 73 ablation sessions were carried out, achieving a technical success rate (TSR) of 100 %. The CAR was 40.5 % (30/74). The median follow-up time was 4.6 (1-43.4) months. 50 % (36/72) of patients had died with a median overall survival (OS) of 5.6 (1-27) months. Regarding complications, 18.1 % (13/72) of cases were classified as grade I and II, and 9.8 % (7/72) as grade IIIa. Before surgery, 33 patients experienced pain symptoms, and the postoperative PRR was 96.7 % (32/33). The average pain score decreased from 6.3 (4-10) before surgery to 2.0 (0-8) after ablation (P<0.001). CONCLUSIONS: Image-guided PMWA for unresectable pancreatic cancer is safe and feasible, effectively relieving cancer pain and improving patients' the quality of life.

Predicting and Avoiding Complications in Percutaneous Nephrolithotomy in the Era of Personalized Medicine: A Scoping Review.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) is associated with a wide range of complications. This review aims to explore how recent technological advancements and personalized medicine can help prevent or predict these complications. METHODS: A scoping review was conducted according to the PRISMA-SCR guidelines and registered on the Open Science Framework in April 2024. A literature search was performed on PUBMED, Web of Science, and Scopus databases. This review focused on predictive AI models, 3D surgical models, intrasurgical image guidance, and biomarkers. Articles meeting the following criteria were included: publication between 2019 and 2024, written in English, involving human participants, and discussing technological advancements or personalized medicine in the context of complications in PCNL. RESULTS: Of the 11,098 articles searched, 35 new studies were included. We identified a few articles on predictive AI models. Several studies demonstrated that 3D presurgical models and virtual models could enhance surgical planning and reduce complications. New intrasurgical image and guidance systems showed the potential in reducing bleeding and radiation exposure. Finally, several biomarkers were identified as predictors of sepsis and other complications. CONCLUSION: This scoping review highlights the potential of emerging technologies in reducing and predicting PCNL complications. However, larger prospective studies are required for validation.

The Impact of Navigation in Lumbar Spine Surgery: A Study of Historical Aspects, Current Techniques and Future Directions.

Background/Objectives: We sought to improve accuracy while minimizing radiation hazards, improving surgical outcomes, and preventing potential complications. Despite the increasing popularity of these systems, a limited number of papers have been published addressing the historical evolution, detailing the areas of use, and discussing the advantages and disadvantages, of this increasingly popular system in lumbar spine surgery. Our objective was to offer readers a concise overview of navigation system history in lumbar spine surgeries, the techniques involved, the advantages and disadvantages, and suggestions for future enhancements to the system. Methods: A comprehensive review of the literature was conducted, focusing on the development and implementation of navigation systems in lumbar spine surgeries. Our sources include PubMed-indexed peer-reviewed journals, clinical trial data, and case studies involving technologies such as computer-assisted surgery (CAS), image-guided surgery (IGS), and robotic-assisted systems. Results: To develop more practical, effective, and accurate navigation techniques for spine surgery, consistent advancements have been made over the past four decades. This technological progress began in the late 20th century and has since encompassed image-guided surgery, intraoperative imaging, advanced navigation combined with robotic assistance, and artificial intelligence. These technological advancements have significantly improved the accuracy of implant placement, reducing the risk of misplacement and related complications. Navigation has also been found to be particularly useful in tumor resection and minimally invasive surgery (MIS), where conventional anatomic landmarks are lacking or, in the case of MIS, not visible. Additionally, these innovations have led to shorter operative times, decreased radiation exposure for patients and surgical teams, and lower rates of reoperation. As navigation technology continues to evolve, future innovations are anticipated to further enhance the capabilities and accessibility of these systems, ultimately leading to improved patient outcomes in lumbar spine surgery. Conclusions: The initial limited utilization of navigation system in spine surgery has further expanded to encompass almost all fields of lumbar spine surgeries. As the cost-effectiveness and number of trained surgeons improve, a wider use of the system will be ensured so that the navigation system will be an indispensable tool in lumbar spine surgery. However, continued research and development, along with training programs for surgeons, are essential to fully realize the potential of these technologies in clinical practice.

Evolution of Neurosurgical Robots: Historical Progress and Future Direction.

In 1985, Professor KWOH first introduced robots into neurosurgery. Since then, advancements of stereotactic frames, radiographic imaging, and neuronavigation have led to the dominance of classic stereotactic robots. A comprehensive retrieval was performed using academic databases and search agents to acquire professional information, with a cutoff date of June, 2024. This reveals a multitude of emerging technologies are coming to the forefront, including tremor filtering, motion scaling, obstacle avoidance, force sensing, which have made significant contributions to the high efficiency, high precision, minimally invasive, and exact efficacy of robot-assisted neurosurgery. Those technologies have been applied in innovative magnetic resonance-compatible neurosurgical robots, such as Neuroarm and Neurobot, with real-time image-guided surgery. Despite these advancements, the major challenge is considered as magnetic resonance compatibility in terms of space, materials, driving, and imaging. Future research directions are anticipated to focus on 1) robotic precise perception; 2) artificial intelligence; and 3) the advancement of telesurgery.

Opportunities and challenges of upright patient positioning in radiotherapy.

Objective.Upright positioning has seen a surge in interest as a means to reduce radiotherapy (RT) cost, improve patient comfort, and, in selected cases, benefit treatment quality. In particle therapy (PT) in particular, eliminating the need for a gantry can present massive cost and facility footprint reduction. This review discusses the opportunities of upright RT in perspective of the open challenges.Approach.The clinical, technical, and workflow challenges that come with the upright posture have been extracted from an extensive literature review, and the current state of the art was collected in a synergistic perspective from photon and particle therapy. Considerations on future developments and opportunities are provided.Main results.Modern image guidance is paramount to upright RT, but it is not clear which modalities are essential to acquire in upright posture. Using upright MRI or upright CT, anatomical differences between upright/recumbent postures have been observed for nearly all body sites. Patient alignment similar to recumbent positioning was achieved in small patient/volunteer cohorts with prototype upright positioning systems. Possible clinical advantages, such as reduced breathing motion in upright position, have been reported, but limited cohort sizes prevent resilient conclusions on the treatment impact. Redesign of RT equipment for upright positioning, such as immobilization accessories for various body regions, is necessary, where several innovations were recently presented. Few clinical studies in upright PT have already reported promising outcomes for head&neck patients.Significance.With more evidence for benefits of upright RT emerging, several centers worldwide, particularly in PT, are installing upright positioning devices or have commenced upright treatment. Still, many challenges and open questions remain to be addressed to embed upright positioning firmly in the modern RT landscape. Guidelines, professionals trained in upright patient positioning, and large-scale clinical studies are required to bring upright RT to fruition.

Reduction of post-radiotherapy urinary toxicity via intrafractional MV-kV prostate location monitoring.

PURPOSE/OBJECTIVE(S): We hypothesized that an in-house developed system using MV and kV image guidance (MKIG) to ensure correct prostate positioning during SBRT could potentially avoid unwanted doses to non-target tissues, leading to reduced toxicities. MATERIALS/METHODS: We built a 3D MKIG platform that accurately tracks prostate implanted fiducials in real-time and clinically translated the system to replace a commercial approach, intrafraction motion review (IMR), which only tracks fiducials in the 2D kV views. From 2017 to 2019, 150 prostate cancer patients were treated with SBRT and monitored by MKIG. The motion trace of the fiducials alerts therapists to interrupt and reposition the prostate when displacement exceeds a 1.5 mm threshold. A comparison cohort of 121 patients was treated with the same dose regimen and treatment technique but managed by IMR. Statistics of intrafractional patient shifts and delivery time were collected to evaluate the workflow efficacy. The incidence of grade ≥2 urinary toxicities was analyzed to assess clinical complications. The median follow-up time was 3.7 years (0.2 to 8.2 years). RESULTS: MKIG treatments had more treatment shifts (1.09 vs. 0.28) and a longer average delivery time per fraction (579±205s vs. 357±117s) than IMR treatments. Three-quarters (75%) of shifts resulting from MKIG were ≤3mm, vs. 51% in IMR, indicating that MKIG detected and corrected smaller deviations. The incidence of grade ≥2 urinary toxicity was lower in the MKIG than IMR cohort: 10.7% vs. 19.8% (p=0.047). On multivariate analysis of late urinary toxicity, only high (>7) pre-RT IPSS (p<0.043) and the use of MKIG were selected (p< 0.029). CONCLUSIONS: Automated and quantitative MKIG introduced minimal workflow impact and was superior to IMR in localizing the prostate during SBRT, which correlated with a clinically significant reduction in late urinary toxicity. Further clinical testing via randomized trial will be required to validate the impact on outcomes.

Intra-fractional corrections and clinical outcomes in frameless image-guided radiosurgery for trigeminal neuralgia.

Purpose: Precision targeting is crucial to successful stereotactic radiosurgery for trigeminal neuralgia (TGN). We investigated the impact of intra-fractional 6-dimensional corrections during frameless image-guided radiosurgery (IGRS) for pain outcome in TGN patients. Materials and methods: A total of 41 sets of intra-fractional corrections from 35 patients with TGN treated by frameless IGRS from 2009 to 2013 were retrospectively studied. For each IGRS, the intra-fractional 6-dimensional shifts were conducted at 6 couch angles. Clinical pain outcome was recorded according the Barrow Neurological Institute (BNI) 5-points score. The relationship in 6-dimensional corrections and absolute translational distances between patients with pain relief score points <2 versus ≥2 were analyzed. Results: The absolute mean lateral, longitudinal, and vertical translational shifts were 0.46 ± 0.15 mm, 0.36 ± 0.16 mm and 0.21 ± 0.08 mm, respectively, with 97% of translational shifts being within 0.7 mm. The absolute mean lateral (pitch), longitudinal (roll), and vertical (yaw) rotational corrections are 0.33 ± 0.24°, 0.18 ± 0.09°, and 0.27 ± 0.15°, respectively, with 97% of rotational corrections being within 0.6°. The median follow-up duration for pain outcome was 26 months after IGRS. The average calculated absolute shift for patients with pain relief <2 and ≥2 BNI points, were 0.228 ± 0.008 mm and 0.259 ± 0.007 mm, respectively. There was no statistically significant difference in the translational shifts, rotational corrections or absolute distances between these two patient groups. Conclusions: Our data demonstrate high spatial targeting accuracy of frameless IGRS for TGN with only nominal intra-fraction 6-dimensional corrections.

Portable ultrasound-guided keyhole evacuation of intracerebral hemorrhage: a detailed case report highlighting technical nuances.

Intracerebral hemorrhage (ICH) is a common neurosurgical emergency that is associated with high morbidity and mortality. Minimally invasive or endoscopic hematoma evacuation has emerged in recent years as a viable alternative to conventional large craniotomies. However, accurate trajectory planning and placement of the tubular retractor remains a challenge. We describe a novel technique for handheld portable ultrasound-guided minimally invasive endoscopic evacuation of supratentorial hematomas. A 64-year-old male diagnosed right hematoma (48.5 mL) at the basal ganglia was treated with emergent ultrasound-guided endoscopic transtubular evacuation through a small craniotomy. Ultrasound-guidance facilitated optimal placement of the tubular retractor into the long axis of the hematoma, and allowed for near-total evacuation, reducing iatrogenic tissue damage by mitigating the need for wanding or repositioning of the retractor. The emergence of a new generation of small portable phased array ultrasound probes with improved resolution and clarity has broadened ultrasound's clinical applications.

Explicitly encoding the cyclic nature of breathing signal allows for accurate breathing motion prediction in radiotherapy with minimal training data.

Background and purpose: Active breathing motion management in radiotherapy consists of motion monitoring, quantification and mitigation. It is impacted by associated latencies of a few 100 ms. Artificial neural networks can successfully predict breathing motion and eliminate latencies. However, they require usually a large dataset for training. The objective of this work was to demonstrate that explicitly encoding the cyclic nature of the breathing signal into the training data enables significant reduction of training datasets which can be obtained from healthy volunteers. Material and methods: Seventy surface scanner breathing signals from 25 healthy volunteers in anterior-posterior direction were used for training and validation (ratio 4:1) of long short-term memory models. The model performance was compared to a model using decomposition into phase, amplitude and a time-dependent baseline. Testing of the models was performed on 55 independent breathing signals in anterior-posterior direction from surface scanner (35 lung, 20 liver) of 30 patients with a mean breathing amplitude of (5.9 ± 6.7) mm. Results: Using the decomposed breathing signal allowed for a reduction of the absolute root-mean square error (RMSE) from 0.34 mm to 0.12 mm during validation. Testing using patient data yielded an average absolute RMSE of the breathing signal of (0.16 ± 0.11) mm with a prediction horizon of 500 ms. Conclusion: It was demonstrated that a motion prediction model can be trained with less than 100 datasets of healthy volunteers if breathing cycle parameters are considered. Applied to 55 patients, the model predicted breathing motion with a high accuracy.

Magnetic Particle Imaging-Guided Thermal Simulations for Magnetic Particle Hyperthermia.

Magnetic particle hyperthermia (MPH) enables the direct heating of solid tumors with alternating magnetic fields (AMFs). One challenge with MPH is the unknown particle distribution in tissue after injection. Magnetic particle imaging (MPI) can measure the nanoparticle content and distribution in tissue after delivery. The objective of this study was to develop a clinically translatable protocol that incorporates MPI data into finite element calculations for simulating tissue temperatures during MPH. To verify the protocol, we conducted MPH experiments in tumor-bearing mouse cadavers. Five 8-10-week-old female BALB/c mice bearing subcutaneous 4T1 tumors were anesthetized and received intratumor injections of Synomag®-S90 nanoparticles. Immediately following injection, the mice were euthanized and imaged, and the tumors were heated with an AMF. We used the Mimics Innovation Suite to create a 3D mesh of the tumor from micro-computerized tomography data and spatial index MPI to generate a scaled heating function for the heat transfer calculations. The processed imaging data were incorporated into a finite element solver, COMSOL Multiphysics®. The upper and lower bounds of the simulated tumor temperatures for all five cadavers demonstrated agreement with the experimental temperature measurements, thus verifying the protocol. These results demonstrate the utility of MPI to guide predictive thermal calculations for MPH treatment planning.

First Experience With Augmented Reality Guidance for Cerebral Embolic Protection During TAVR.

Background: Augmented reality (AR) guidance holds potential to improve transcatheter interventions by enabling visualization of and interaction with patient-specific 3-dimensional virtual content. Positioning of cerebral embolic protection devices (CEP) during transcatheter aortic valve replacement (TAVR) increases patient exposure to radiation and iodinated contrast, and increases procedure time. AR may enhance procedural guidance and facilitate a safer intervention. Objectives: The purpose of this study was to develop and test a novel AR guidance system with a custom user interface that displays virtual, patient-specific 3-dimensional anatomic models, and assess its intraprocedural impact during CEP placement in TAVR. Methods: Patients undergoing CEP during TAVR were prospectively enrolled and assigned to either AR guidance or control groups. Primary endpoints were contrast volume used prior to filter placement, times to filter placement, and fluoroscopy time. Postprocedure questionnaires were administered to assess intraprocedural physician experience with AR guidance. Results: A total of 24 patients presenting for TAVR were enrolled in the study (12 with AR guidance and 12 controls). AR guidance eliminated the need for aortic arch angiograms prior to device placement thus reducing contrast volume (0 mL vs 15 mL, P < 0.0001). There was no significant difference in the time required for filter placement or fluoroscopy time. Postprocedure questionnaires indicated that AR guidance increased confidence in wiring of the aortic arch and facilitated easier device placement. Conclusions: We developed a novel AR guidance system that eliminated the need for additional intraprocedural angiograms prior to device placement without any significant difference in time to intervention and offered a subjective improvement in performance of the intervention.

Comparing regularized Kelvinlet functions and the finite element method for registration of medical images to sparse organ data.

Image-guided surgery collocates patient-specific data with the physical environment to facilitate surgical decision making. Unfortunately, these guidance systems commonly become compromised by intraoperative soft-tissue deformations. Nonrigid image-to-physical registration methods have been proposed to compensate for deformations, but clinical utility requires compatibility of these techniques with data sparsity and temporal constraints in the operating room. While finite element models can be effective in sparse data scenarios, computation time remains a limitation to widespread deployment. This paper proposes a registration algorithm that uses regularized Kelvinlets, which are analytical solutions to linear elasticity in an infinite domain, to overcome these barriers. This algorithm is demonstrated and compared to finite element-based registration on two datasets: a phantom liver deformation dataset and an in vivo breast deformation dataset. The regularized Kelvinlets algorithm resulted in a significant reduction in computation time compared to the finite element method. Accuracy as evaluated by target registration error was comparable between methods. Average target registration errors were 4.6 ± 1.0 and 3.2 ± 0.8 mm on the liver dataset and 5.4 ± 1.4 and 6.4 ± 1.5 mm on the breast dataset for the regularized Kelvinlets and finite element method, respectively. Limitations of regularized Kelvinlets include the lack of organ-specific geometry and the assumptions of linear elasticity and infinitesimal strain. Despite limitations, this work demonstrates the generalizability of regularized Kelvinlets registration on two soft-tissue elastic organs. This method may improve and accelerate registration for image-guided surgery, and it shows the potential of using regularized Kelvinlets on medical imaging data.

An Image-Guided Percutaneous Core Needle Biopsy for Accurate Assessment of Musculoskeletal Tumors: A Targeted Diagnosis.

Background Accurate diagnosis of musculoskeletal tumors is essential for guiding appropriate treatment strategies. Percutaneous core needle biopsy (PCNB) is increasingly recognized as a valuable method for obtaining tissue samples for histopathological examination. This study aims to evaluate the diagnostic accuracy and clinical utility of PCNB in diagnosing musculoskeletal tumors. Methodology A total of 152 cases suspected of musculoskeletal tumors underwent PCNB at our tertiary care center between 2020 and 2023. Pre-biopsy evaluation included comprehensive clinical assessment and imaging studies. Core biopsies were performed under image guidance, with specimens sent for histopathological examination and culture sensitivity analysis. Diagnostic yield, accuracy, and performance metrics of PCNB were assessed. Results PCNB demonstrated a diagnostic yield of 93.4%. However, in cases where initial biopsies were inconclusive, repeat core biopsy or open biopsy provided the necessary diagnostic clarity. PCNB demonstrated a remarkable diagnostic accuracy of 97.9%, with a specificity and positive predictive value of 100%. There were no post-biopsy complications and no instances of local recurrence from the biopsy tract. Conclusions PCNB can be a reliable method for diagnosing musculoskeletal tumors, offering high diagnostic accuracy and minimal complications. The utilization of image guidance enhances precision and reduces the risk of complications. PCNB proves effective in diagnosing both primary tumors and bone infections, facilitating timely and appropriate treatment strategies in orthopedic oncology.

Enabling extracorporeal ultrasound imaging with the da Vinci robot for transoral robotic surgery: a feasibility study.

PURPOSE: Transoral robotic surgery (TORS) is a challenging procedure due to its small workspace and complex anatomy. Ultrasound (US) image guidance has the potential to improve surgical outcomes, but an appropriate method for US probe manipulation has not been defined. This study evaluates using an additional robotic (4th) arm on the da Vinci Surgical System to perform extracorporeal US scanning for image guidance in TORS. METHODS: A stereoscopic imaging system and da Vinci-compatible US probe attachment were developed to enable control of the extracorporeal US probe from the surgeon console. The prototype was compared to freehand US by nine operators in three tasks on a healthy volunteer: (1) identification of the common carotid artery, (2) carotid artery scanning, and (3) identification of the submandibular gland. Operator workload and user experience were evaluated using a questionnaire. RESULTS: The robotic US tasks took longer than freehand US tasks (2.09x longer; p = 0.001 ) and had higher operator workload (2.12x higher; p = 0.004 ). However, operator-rated performance was closer (avg robotic/avg freehand = 0.66; p = 0.017 ), and scanning performance measured by MRI-US average Hausdorff distance provided no statistically significant difference. CONCLUSION: Extracorporeal US scanning for intraoperative US image guidance is a convenient approach for providing the surgeon direct control over the US image plane during TORS, with little modification to the existing operating room workflow. Although more time-consuming and higher operator workload, several methods have been identified to address these limitations.

An Imaging-Compatible Oral Retractor System for Transoral Robotic Surgery.

This study aimed to develop and validate a Computed Tomography (CT)/Magnetic Resonance Imaging (MRI)-compatible polymer oral retractor system to enable intraoperative image guidance for transoral robotic surgery (TORS). The retractor was designed based on standard-of-care metallic retractors and 3D (three-dimensional) printed with carbon fiber composite and nylon. The system was comprehensively evaluated in bench-top and cadaveric experiments in terms of its ability to enable intraoperative CT/MR images during TORS, functionality including surgical exposure and working volume, usability, compatibility with da Vinci surgical systems, feasibility for disinfection or sterilization, and robustness over an extended period of time. The polymer retractor system enabled the acquisition of high-resolution and artifact-free intraoperative CT/MR images during TORS. With an inter-incisive distance of 42.55 mm and a working volume of 200.09 cm3, it provided surgical exposure comparable to standard-of-care metallic retractors. The system proved intuitive and compatible with da Vinci S, Xi, and Single Port systems, enabling successful mock surgical tasks performed by surgeons and residents. The retractor components could be effectively disinfected or sterilized for clinical use without significant compromise in material strength, with STERRAD considered the optimal method. Throughout a 2 h mock procedure, the retractor system showed minimal displacements (<1.5 mm) due to surrounding tissue deformation, with insignificant device deformation. The 3D-printed polymer retractor system successfully enabled artifact-free intraoperative CT/MR imaging in TORS for the first time and demonstrated feasibility for clinical use. This breakthrough opens the door to surgical navigation with intraoperative image guidance in TORS, offering the potential to significantly improve surgical outcomes and patients' quality of life.