[Effect of Brachytherapy Source Dwell Position on Dose Distribution in Cervical Cancer Therapy].

PURPOSE: To investigate the effect of different source dwell positions on dose distribution in the treatment of cervical cancer with brachytherapy. METHODS: Treatment planning data for cervical cancer patients were used. Treatment plans were created at 1 mm intervals, varying up to 5 mm. For intracavitary brachytherapy and intracavitary and interstitial brachytherapy, the following dose parameters were evaluated: 90% high-risk clinical target volume (HR-CTV D90%), rectum 2 cm3 dose (Rectum D2 cc), small intestine 2 cm3 dose (Small D2 cc), sigmoid colon 2 cm3 dose (Sigmoid D2 cc), bladder 2 cm3 dose (Bladder D2 cc), point A dose. RESULTS: In intracavitary brachytherapy, the HR-CTV D90%, Rectum D2 cc, Small D2 cc, and Sigmoid D2 cc doses increased as the source dwell position changed in the direction. On the other hand, the dose of Bladder D2 cc increased when the source position changed in the outward direction. The same trend was observed in the case of intracavitary and interstitial brachytherapy. CONCLUSION: It was shown that a 1 mm change in the source dwell position can affect the dose by up to 2% or more. The accuracy of the source dwell position is very important and should be checked before using the device.

MRI-compatible and sensorless haptic feedback for cable-driven medical robotics to perform teleoperated needle-based interventions.

PURPOSE: Surgical robotics have demonstrated their significance in assisting physicians during minimally invasive surgery. Especially, the integration of haptic and tactile feedback technologies can enhance the surgeon's performance and overall patient outcomes. However, the current state-of-the-art lacks such interaction feedback opportunities, especially in robotic-assisted interventional magnetic resonance imaging (iMRI), which is gaining importance in clinical practice, specifically for percutaneous needle punctures. METHODS: The cable-driven 'Micropositioning Robotics for Image-Guided Surgery' (µRIGS) system utilized the back-electromotive force effect of the stepper motor load to measure cable tensile forces without external sensors, employing the TMC5160 motor driver. The aim was to generate a sensorless haptic feedback (SHF) for remote needle advancement, incorporating collision detection and homing capabilities for internal automation processes. Three different phantoms capable of mimicking soft tissue were used to evaluate the difference in force feedback between manual needle puncture and the SHF, both technically and in terms of user experience. RESULTS: The SHF achieved a sampling rate of 800 Hz and a mean force resolution of 0.26 ± 0.22 N, primarily dependent on motor current and rotation speed, with a mean maximum force of 15 N. In most cases, the SHF data aligned with the intended phantom-related force progression. The evaluation of the user study demonstrated no significant differences between the SHF technology and manual puncturing. CONCLUSION: The presented SHF of the µRIGS system introduced a novel MR-compatible technique to bridge the gap between medical robotics and interaction during real-time needle-based interventions.

Development of prediction models based on risk scores for clinically significant prostate cancer on MRI/TRUS fusion biopsy.

BACKGROUND: The implementation of population screening for prostate cancer has increased the number of patients with biochemical suspicion. Prediction models may reduce the number of unnecessary biopsies by identifying patients who benefit the most from them. Our aim is to develop a prediction model that is easily applicable in patients with suspicion of prostate cancer in the urology clinic setting to avoid unnecessary biopsies. METHODS: We developed prediction models based on risk scores for the detection of prostate cancer and clinically significant prostate cancer using the TRIPOD guidelines. For this, we conducted an observational and retrospective review of computerised medical records of 204 patients undergoing prostate fusion biopsy between 2018 and 2021. We also reviewed other prediction models for prostate cancer including radiological parameters and targeted sampling of suspicious lesions. RESULTS: A total of 204 patients underwent a biopsy, 138 were diagnosed of prostate cancer, and from them, 60 of clinically significant prostate cancer. Multivariate regression and random forest analysis were performed. Age, PSA density, diameter of the index lesions and PIRADS score on MRI were identified as predictors with an Area Under the Curve ranging between 0.71 and 0.80 and acceptable calibration results. Risk scores may avoid between 21.7% and 48.1% of biopsies. CONCLUSION: Our prediction models are characterised by ease of use and may reduce unnecessary biopsies with satisfactory discrimination and calibration results while bringing benefits to the healthcare system and patients.

Gynecological brachytherapy hybrid training: The Tata Memorial Centre and BrachyAcademy experience.

PURPOSE: The lack of training is a significant barrier to practicing brachytherapy (BT). Tata Memorial Centre, alongside international BT experts and BrachyAcademy, developed a hybrid gynecological BT training module. This study outlines the preparation, organization, and execution of the 2022-2023 Mumbai training, evaluates its effectiveness, and highlights areas for improvement. MATERIALS AND METHODS: Participants were radiation oncologists (RO) and medical physicists (MP) with experience in gynecological BT aiming to transition to image-guided brachytherapy (IGBT). The training covered cervical, endometrial, vaginal, vulvar, periurethral cancers, and pelvic reirradiation. The hybrid course included online pre and postcourse homework assignments, a live workshop with hands-on training, a 6-month online follow-up, and a 12-month opportunity to share the transition experience. RESULTS: The December 2022 Mumbai live workshop spanned 2.5 days, attracting 39 participants from 8 countries (Asia, Africa, Australia/Oceania). Feedback rated the course 9/10, with 78% fully meeting expectations. Forty-four percent suggested extending hands-on training. At the 6-month follow-up, response rates were low (33% RO, 11% MP). Among responding RO, 70% reported practice changes after attending the course, 40% implemented IGBT concepts in clinical practice, and 50% increased confidence in image-guided procedures. Overall, 45% of respondent sites could strengthen their intracavitary/interstitial program, while others faced limitations due to lack of access to advanced BT applicators. CONCLUSION: The hybrid gynecological BT training concept was successfully executed. Areas for improvement include extending hands-on training and enhancing participant engagement postcourse. Structured steps beyond training may be needed to improve the utilization of advanced brachytherapy for gynecological cancers.

Clinical Outcome Comparison between CT-Guided Versus all MRI-Guided Scenarios in Brachytherapy for Cervical Cancer: A Single-Institute Experience.

OBJECTIVES: Image-guided adaptive brachytherapy (IGABT) is the standard of care for patients with cervical cancer. The objective of this study was to compare the treatment outcomes and adverse effects of computed tomography (CT)-guided and magnetic resonance imaging (MRI)-guided scenarios. MATERIALS AND METHODS: Data of patients with cervical cancer treated using external beam radiotherapy followed by IGABT from 2012 to 2016 were retrospectively reviewed. CT-guided IGABT was compared with the three modes of MRI-guided IGABT: pre-brachytherapy (MRI Pre-BT) without applicator insertion for fusion, planning MRI with applicator in-place in at least 1 fraction (MRI ≥1Fx), and MRI in every fraction (MRI EveryFx). Patient characteristics, oncologic outcomes, and late radiation toxicity were analyzed using descriptive, survival, and correlation statistics. RESULTS: Overall, 354 patients were evaluated with a median follow-up of 60 months. The 5-year overall survival (OS) rates were 61.5%, 65.2%, 54.4%, and 63.7% with CT-guided, MRI PreBT, MRI ≥1Fx, and MRI EveryFx IGABT, respectively with no significant differences (p = 0.522). The 5-year local control (LC) rates were 92.1%, 87.8%, 80.7%, and 76.5% (p = 0.133), respectively, with a significant difference observed between the CT-guided and MRI ≥1Fx (p = 0.018). The grade 3-4 late gastrointestinal toxicity rates were 6% in the CT-guided, MRI ≥1Fx, and MRI EveryFx, and 8% in MRI PreBT. The grade 3-4 late genitourinary toxicity rates were 4% in the CT-guided, 2% in MRI PreBT, 1% in MRI ≥1Fx, and none in MRI EveryFx. No significant differences were observed in the oncologic and toxicity outcomes among MRI PreBT, MRI ≥1Fx, and MRI EveryFx. CONCLUSIONS: CT-guided IGABT yielded an acceptable 5-year OS, LC, and toxicity profile compared with all MRI scenarios and is a potentially feasible option in resource-limited settings.

Fully automated radiotherapy treatment planning: A scan to plan challenge.

BACKGROUND AND PURPOSE: Over the past decade, tools for automation of various sub-tasks in radiotherapy planning have been introduced, such as auto-contouring and auto-planning. The purpose of this study was to benchmark what degree of automation is possible. MATERIALS AND METHODS: A challenge to perform automated treatment planning for prostate and prostate bed radiotherapy was set up. Participants were provided with simulation CTs and a treatment prescription and were asked to use automated tools to produce a deliverable radiotherapy treatment plan with as little human intervention as possible. Plans were scored for their adherence to the protocol when assessed using consensus expert contours. RESULTS: Thirteen entries were received. The top submission adhered to 81.8% of the minimum objectives across all cases using the consensus contour, meeting all objectives in one of the ten cases. The same system met 89.5% of objectives when assessed with their own auto-contours, meeting all objectives in four of the ten cases. The majority of systems used in the challenge had regulatory clearance (Auto-contouring: 82.5%, Auto-planning: 77%). Despite the 'hard' rule that participants should not check or edit contours or plans, 69% reported looking at their results before submission. CONCLUSIONS: Automation of the full planning workflow from simulation CT to deliverable treatment plan is possible for prostate and prostate bed radiotherapy. While many generated plans were found to require none or minor adjustment to be regarded as clinically acceptable, the result indicated there is still a lack of trust in such systems preventing full automation.

Application of motion prediction based on a long short-term memory network for imaging dose reduction in real-time tumor-tracking radiation therapy.

PURPOSE: To demonstrate the possibility of using a lower imaging rate while maintaining acceptable accuracy by applying motion prediction to minimize the imaging dose in real-time image-guided radiation therapy. METHODS: Time-series of three-dimensional internal marker positions obtained from 98 patients in liver stereotactic body radiation therapy were used to train and test the long-short-term memory (LSTM) network. For real-time imaging, the root mean squared error (RMSE) of the prediction on three-dimensional marker position made by LSTM, the residual motion of the target under respiratory-gated irradiation, and irradiation efficiency were evaluated. In the evaluation of the residual motion, the system-specific latency was assumed to be 100 ms. RESULTS: Except for outliers in the superior-inferior (SI) direction, the median/maximum values of the RMSE for imaging rates of 7.5, 5.0, and 2.5 frames per second (fps) were 0.8/1.3, 0.9/1.6, and 1.2/2.4 mm, respectively. The median/maximum residual motion in the SI direction at an imaging rate of 15.0 fps without prediction of the marker position, which is a typical clinical setting, was 2.3/3.6 mm. For rates of 7.5, 5.0, and 2.5 fps with prediction, the corresponding values were 2.0/2.6, 2.2/3.3, and 2.4/3.9 mm, respectively. There was no significant difference between the irradiation efficiency with and that without prediction of the marker position. The geometrical accuracy at lower frame rates with prediction applied was superior or comparable to that at 15 fps without prediction. In comparison with the current clinical setting for real-time image-guided radiation therapy, which uses an imaging rate of 15.0 fps without prediction, it may be possible to reduce the imaging dose by half or more. CONCLUSIONS: Motion prediction can effectively lower the frame rate and minimize the imaging dose in real-time image-guided radiation therapy.

Feasibility of Image-guided Navigation with Electromagnetic Tracking During Robot-assisted Sentinel Node Biopsy: A Prospective Study.

BACKGROUND AND OBJECTIVE: Image-guided surgical navigation (IGSN) can enhance surgical precision and safety. The expansion of minimally invasive surgery has increased the demand for integration of these navigation systems into robot-assisted surgery. Our objective was to evaluate the integration of electromagnetic tracking with IGSN in robot-assisted sentinel lymph node biopsy (SLNB). METHODS: We conducted a prospective feasibility study to test the use of IGSN in SLNB. In total, 25 patients scheduled for SLNB at The Netherlands Cancer Institute were included (March 2022 to March 2023). SLNB using IGSN was performed using a standardised technique with a da Vinci robot (Intuitive Surgical, Sunnyvale, CA, USA) in four-arm configuration. Feasibility was determined as the percentage of sentinel nodes (SNs) successfully identified via IGSN. Successful SN resection was defined as SNs correctly localised via navigation and validated ex vivo with a gamma probe. Surgeon feedback on the robot-assisted IGSN workflow was evaluated using the System Usability Scale (SUS). KEY FINDINGS AND LIMITATIONS: In accordance with the protocol, the first five patients were used for workflow optimisation, and the subsequent 20 patients were included in the analysis. IGSN led to successful identification of 91% (50/55) of the SNs. There were no complications associated with navigation. The surgeon feedback (SUS) was 60.9, with lowest scores reported for the user interface and workflow integration. CONCLUSIONS: IGSN during robot-assisted surgery was feasible and safe. The technique allowed identification and removal of predefined small pelvic lymph nodes. PATIENT SUMMARY: We carried out a study on the feasibility of imaging-guided navigation in robot-assisted prostate surgery. Our results show that this technique is feasible, safe, and effective.

Increased lung cancer recurrence following transthoracic needle biopsy.

Background: Computed tomography (CT)-guided transthoracic needle biopsy (TNB) could damage lung structures and may disseminate tumor cells into the airway, blood vessels, and pleural cavity, affecting post-operative outcomes. Several studies have investigated the effects of TNB on the prognosis of patients, but the effects remain unclear. This study aimed to investigate whether TNB increases the risk of recurrence of resected stage IA non-small cell lung cancer (NSCLC). Methods: In this retrospective study, we enrolled 1,077 patients with stage IA NSCLC who underwent curative resection from 2010 to 2020. Recurrence risk factors were evaluated using Cox regression analyses. A multiple logistic regression model, including age, sex, smoking history, total tumor size, invasive tumor size, histology, histologic differentiation, lymphatic invasion, vascular invasion, perineural invasion, and the number of harvested lymph nodes (LNs), was used to calculate the propensity score. Results: According to the pre-operative TNB, patients were classified into the no-TNB (n=823) and TNB (n=190) groups. After propensity score matching analysis, 380 patients were included in the no-TNB group (1:2 matching). Multivariable Cox analysis revealed that pre-operative TNB was a negative prognostic factor in patients with surgically resected stage IA NSCLC [hazard ratio (HR), 3.15; 95% confidence interval (CI): 1.49-6.67; P=0.003]. The 5-year locoregional and overall recurrence-free survival (RFS) rates were significantly lower in the TNB group than in the no-TNB group (88.3% vs. 96.8%, P=0.001; and 84.2% vs. 93.7%, P=0.02, respectively). Conclusions: For patients with stage IA NSCLC, pre-operative TNB was a negative prognostic factor for recurrence. Surgical diagnosis and treatment without pre-operative tissue diagnosis may be considered first in patients with clinically early lung cancer.

The Future of Artificial Intelligence in Surgery.

Until recently, innovations in surgery were largely represented by extensions or augmentations of the surgeon's perception. This includes advancements such as the operating microscope, tumor fluorescence, intraoperative ultrasound, and minimally invasive surgical instrumentation. However, introducing artificial intelligence (AI) into the surgical disciplines represents a transformational event. Not only does AI contribute substantively to enhancing a surgeon's perception with such methodologies as three-dimensional anatomic overlays with augmented reality, AI-improved visualization for tumor resection, and AI-formatted endoscopic and robotic surgery guidance. What truly makes AI so different is that it also provides ways to augment the surgeon's cognition. By analyzing enormous databases, AI can offer new insights that can transform the operative environment in several ways. It can enable preoperative risk assessment and allow a better selection of candidates for procedures such as organ transplantation. AI can also increase the efficiency and throughput of operating rooms and staff and coordinate the utilization of critical resources such as intensive care unit beds and ventilators. Furthermore, AI is revolutionizing intraoperative guidance, improving the detection of cancers, permitting endovascular navigation, and ensuring the reduction in collateral damage to adjacent tissues during surgery (e.g., identification of parathyroid glands during thyroidectomy). AI is also transforming how we evaluate and assess surgical proficiency and trainees in postgraduate programs. It offers the potential for multiple, serial evaluations, using various scoring systems while remaining free from the biases that can plague human supervisors. The future of AI-driven surgery holds promising trends, including the globalization of surgical education, the miniaturization of instrumentation, and the increasing success of autonomous surgical robots. These advancements raise the prospect of deploying fully autonomous surgical robots in the near future into challenging environments such as the battlefield, disaster areas, and even extraplanetary exploration. In light of these transformative developments, it is clear that the future of surgery will belong to those who can most readily embrace and harness the power of AI.

Protocol-based CT-guided brachytherapy for patients with prostate cancer and previous rectal extirpation-a curative approach.

OBJECTIVE: There are numerous curative treatment possibilities for prostate cancer. In patients who have undergone rectal extirpation for rectal cancer treatment, curative options are limited due to anatomic changes and previous irradiation of the pelvis. In this analysis, we validate the feasibility of CT-guided transperineal interstitial brachytherapy for this specific scenario. PATIENTS AND METHODS: We analyzed the treatment procedures and outcomes of 5 patients with metachronic nonmetastatic prostate cancer. Ultrasound-guided brachytherapy was not possible in any of the patients. Of these 5 patients, 3 were treated for prostate cancer using temporary brachytherapy with Ir-192 only, and 2 were treated with external-beam radiation therapy and temporary brachytherapy as a boost. CT-guided brachytherapy was performed in all patients. We analyzed the feasibility, efficacy, treatment-related toxicity, and quality of life (EORTC-30, IEFF, IPSS, and ICIQ questionnaires) of the treatments. RESULTS: Median follow-up was 35 months. Two out of five patients received boost irradiation (HDR 2â€¯× 9 Gy, PDR 30 Gy). Three out of five patients were treated with PDR brachytherapy in two sessions up to a total dose of 60 Gy. Dosimetric parameters were documented as median values as follows: V100 94.7% (94.5-98.4%), D2bladder 64.3% (50.9-78.3%), D10urethra 131.05% (123.2%-141.2%), and D30urethra 122.45% (116.2%-129.5%). At the time of analysis, no biochemical recurrence had been documented. Furthermore, neither early nor late side effects exceeding CTCAE grade 2 were documented. CONCLUSION: CT-guided transperineal brachytherapy of the prostate in patients with previous rectal surgery and radiation therapy is safe and represents a possible curative treatment option. Brachytherapy can be considered for patients with metachronic prostate cancer in this specific scenario, albeit preferably in experienced high-volume centers.

Upper rectal fixation with an endorectal balloon in prostate cancer radiotherapy.

Purpose: Despite the efficacy of endorectal balloon (ERB) in reducing rectal radiation dose, the effectiveness of upper rectal fixation remains to be evaluated. The purpose of this study was to evaluate the impact of ERB on upper rectal fixation in patients diagnosed with localized prostate cancer. Materials: Cine MRI was performed in 46 patients with localized prostate cancer to assess the stability of the anterior rectal wall with and without ERB by calculating the standard deviation of the normalized signal intensity at the level of the midgland or the seminal vesicle. Results: The standard deviation of the normalized signal intensity for the anterior rectal wall decreased significantly with the use of ERB both at the level of the midgland (p < 0.05) and the seminal vesicle (p < 0.05). The standard deviation of the anterior rectal wall at the level of the seminal vesicle was significantly higher than at the level of the midgland without ERB (p < 0.05). But with ERB, the standard deviation of the normalized signal intensity at the level of the seminal vesicle became comparable to that at the level of the midgland (p = 0.392). Conclusion: The anterior rectal wall is stabilized by ERBs not only at the level of the midgland but also at the level of the seminal vesicle. ERBs can transform the rectum from a moving and deformable organ into a static and rigid organ.

Contrast-enhanced US versus US-guided biopsy for abdominal and pelvic neoplasm in paediatric patients: a propensity score matching study.

OBJECTIVE: To compare the diagnostic performance of CEUS-guided biopsy (CEUS-GB) and ultrasound-guided biopsy (US-GB) in evaluating abdominal and pelvic (abdominopelvic) neoplasms in paediatric patients. METHODS: Patients aged < 18 years with abdominopelvic tumours who underwent either CEUS-GB or US-GB between April 2005 and May 2022 were retrospectively evaluated. Tumours diagnosed as malignancies by pathology were considered true-positive findings. Benign lesions were identified by pathology or clinical follow-up of at least 6 months. The diagnostic performance of the two groups was compared using propensity score matching (PSM). Complications were also analysed. RESULTS: The present study included 764 paediatric patients (437 boys; median age, 24 months; interquartile range, 10-60 months); 151 were in the CEUS-GB group, and 613 were in the US-GB group. The sample adequacy rate was 100% (151 of 151) for the CEUS-GB group, which was greater than the 97.4% (597 of 613) for the US-GB group (p < 0.001). The overall diagnostic accuracy of the CEUS-GB group and US-GB group was 98.7% (149 of 151) versus 97.3% (581 of 597) in the total cohort (p = 0.551) and 98.7% (149 of 151) versus 92.7% (140 of 151) in the PSM cohort (p = 0.020). Two patients (0.3%) in the US-GB group experienced complications (Common Terminology Criteria for Adverse Events (CTCAE), grade 1-2) correlated with the biopsy. No adverse reactions occurred in the CEUS-GB group. CONCLUSION: CEUS-GB of abdominopelvic tumours in paediatric patients is an effective and safe procedure with greater diagnostic accuracy than US-GB, especially for tumours with necrotic areas. CLINICAL RELEVANCE STATEMENT: Contrast-enhanced US-guided biopsy of solid abdominal and pelvic tumours in paediatric patients is an effective and safe procedure with greater diagnostic accuracy than US-guided biopsy, especially for tumours with necrotic areas. KEY POINTS: Contrast-enhanced ultrasound (CEUS) may be superior to conventional ultrasound at guiding biopsy of abdominopelvic masses in paediatric patients. CEUS-guided core needle biopsy of abdominopelvic masses in children was safe and resulted in a diagnostic yield of 98.7%. CEUS guidance should be considered in this population when colour Doppler US is unable to determine a biopsy site.

[FreeArcs Knife: a Novel Stereotactic Radiosurgery System].

This paper describes the design of an innovative linear accelerator image-guided radiosurgery (IGRS) device, which is based on a composite twofold rotary gantry structure. The paper discusses five aspects of the innovative device: its overall composition, the safety net space created by the accelerator radiation head as it rotates around the patient's longitudinal axis, the non-coplanar spherical coverage in the direction of the incidence angle for quasi-4π delivery, the structural features of the composite twofold rotary gantry, and the processes of treatment planning and implementation. It elaborates on the device's manufacturing feasibility, safety, effectiveness, accuracy, and efficiency. The conclusion is that this innovative device design holds significant development value and market promotion potential.

Role of Qualitative and Quantitative Indocyanine Green Angiography to Assess Mastectomy Skin Flaps Perfusion: A Prospective Monocentric Experience.

INTRODUCTION: Mastectomy skin flap (MSF) necrosis remains a significant complication in breast reconstruction. This study aims to identify a correlation between the qualitative and quantitative analysis of the MSF perfusion grade and the skin necrosis rate 1 month after surgery using indocyanine green angiography (ICGA), focusing on lag time and perfusion metrics. METHODS: Consecutive women scheduled for nipple/skin-sparing/skin-reducing mastectomy between May 2020 and October 2022 were prospectively enrolled. Patients were divided into Group 1 in the absence of superficial and full-thickness necrosis (SN; FTN) and Group 2 in the presence of both. Demographic data, lag time T1 (time between ICG injection and the initial perfusion of the least perfused MSF area), ICG-Q1, and ICG-Q% (absolute and relative perfusion values of the least vascularized area) were collected. RESULTS: 76 breasts were considered. FTN was reported in 8 breasts (10.5%) and SN in 4 (5.2%). The 2 groups statistically differ in T1 (Group2 > Group1), ICG-Q1, and ICG-Q% (Group1 > Group2) (P < 0.05). T1 longer than 170 seconds, body mass index, previous chemo/radiotherapy, arterial hypertension, breast weight, type of surgery, and ICG quantitative values can help in predicting MSF necrosis. CONCLUSIONS: MSF qualitative and quantitative perfusion evaluation can be helpful to prevent MSF necrosis. However, it should be considered together with the patient's characteristics, the type of surgery, and T1. In this way, it is possible to predict the risk of MSF necrosis and plan the best reconstructive strategy.

Virtual Reality Head-Mounted Display (HMD) and Preoperative Patient-Specific Simulation: Impact on Decision-Making in Pediatric Urology: Preliminary Data.

AIM OF THE STUDY: To assess how virtual reality (VR) patient-specific simulations can support decision-making processes and improve care in pediatric urology, ultimately improving patient outcomes. PATIENTS AND METHODS: Children diagnosed with urological conditions necessitating complex procedures were retrospectively reviewed and enrolled in the study. Patient-specific VR simulations were developed with medical imaging specialists and VR technology experts. Routine CT images were utilized to create a VR environment using advanced software platforms. The accuracy and fidelity of the VR simulations was validated through a multi-step process. This involved comparing the virtual anatomical models to the original medical imaging data and conducting feedback sessions with pediatric urology experts to assess VR simulations' realism and clinical relevance. RESULTS: A total of six pediatric patients were reviewed. The median age of the participants was 5.5 years (IQR: 3.5-8.5 years), with an equal distribution of males and females across both groups. A minimally invasive laparoscopic approach was performed for adrenal lesions (n = 3), Wilms' tumor (n = 1), bilateral nephroblastomatosis (n = 1), and abdominal trauma in complex vascular and renal malformation (ptotic and hypoplastic kidney) (n = 1). Key benefits included enhanced visualization of the segmental arteries and the deep vascularization of the kidney and adrenal glands in all cases. The high depth perception and precision in the orientation of the arteries and veins to the parenchyma changed the intraoperative decision-making process in five patients. Preoperative VR patient-specific simulation did not offer accuracy in studying the pelvic and calyceal anatomy. CONCLUSIONS: VR patient-specific simulations represent an empowering tool in pediatric urology. By leveraging the immersive capabilities of VR technology, preoperative planning and intraoperative navigation can greatly impact surgical decision-making. As we continue to advance in medical simulation, VR holds promise in educational programs to include even surgical treatment of more complex urogenital malformations.

Cone-beam CT with a noncircular (sine-on-sphere) orbit: imaging performance of a clinical system for image-guided interventions.

Purpose: We aim to compare the imaging performance of a cone-beam CT (CBCT) imaging system with noncircular scan protocols (sine-on-sphere) to a conventional circular orbit. Approach: A biplane C-arm system (ARTIS Icono; Siemens Healthineers) capable of circular and noncircular CBCT acquisition was used, with the latter orbit (sine-on-sphere, "Sine Spin") executing a sinusoidal motion with ± 10 deg tilt amplitude over the half-scan orbit. A test phantom was used for the characterization of image uniformity, noise, noise-power spectrum (NPS), spatial resolution [modulation transfer function (MTF) in axial and oblique directions], and cone-beam artifacts. Findings were interpreted using an anthropomorphic head phantom with respect to pertinent tasks in skull base neurosurgery. Results: The noncircular scan protocol exhibited several advantages associated with improved 3D sampling-evident in the NPS as filling of the null cone about the f z spatial frequency axis and reduction of cone-beam artifacts. The region of support at the longitudinal extrema was reduced from 16 to ∼ 12 cm at a radial distance of 6.5 cm. Circular and noncircular orbits exhibited nearly identical image uniformity and quantum noise, demonstrating cupping of - 16.7 % and overall noise of ∼ 27 HU . Although both the radially averaged axial MTF ( f x , y ) and 45 deg oblique MTF ( f x , y , z ) were ∼ 20 % lower for the noncircular orbit compared with the circular orbit at the default full reconstruction field of view (FOV), there was no difference in spatial resolution for the medium reconstruction FOV (smaller voxel size). Differences in the perceptual image quality for the anthropomorphic phantom reinforced the objective, quantitative findings, including reduced beam-hardening and cone-beam artifacts about structures of interest in the skull base. Conclusions: Image quality differences between circular and noncircular CBCT orbits were quantitatively evaluated on a clinical system in the context of neurosurgery. The primary performance advantage for the noncircular orbit was the improved sampling and elimination of cone-beam artifacts.

Current state, challenges, and future perspective of adaptive radiotherapy: A narrative review of nasopharyngeal carcinoma.

Patients with nasopharyngeal carcinoma often experience weight loss and tumor regression during the course of radiotherapy that lasts for up to 6-7 weeks. Adaptive radiotherapy is a systematic feedback control approach based on image-guided technology that adjusts these changes and optimizes the radiotherapy plans according to new imaging findings during treatment. There is growing evidence that adaptive radiotherapy can reduce side effects, improve the quality of life, and enhance disease control. However, the routine application of adaptive radiotherapy for nasopharyngeal remains relatively limited. This review discusses the necessity, clinical benefits, and limitations of adaptive radiotherapy, and presents the current state, challenges, and future perspective of adaptive radiotherapy strategies for nasopharyngeal carcinoma.

Automatic segmentation of high-risk clinical target volume and organs at risk in brachytherapy of cervical cancer with a convolutional neural network.

PURPOSE: This study aimed to design an autodelineation model based on convolutional neural networks for generating high-risk clinical target volumes and organs at risk in image-guided adaptive brachytherapy for cervical cancer. MATERIALS AND METHODS: A novel SERes-u-net was trained and tested using CT scans from 98 patients with locally advanced cervical cancer who underwent image-guided adaptive brachytherapy. The Dice similarity coefficient, 95th percentile Hausdorff distance, and clinical assessment were used for evaluation. RESULTS: The mean Dice similarity coefficients of our model were 80.8%, 91.9%, 85.2%, 60.4%, and 82.8% for the high-risk clinical target volumes, bladder, rectum, sigmoid, and bowel loops, respectively. The corresponding 95th percentile Hausdorff distances were 5.23mm, 4.75mm, 4.06mm, 30.0mm, and 20.5mm. The evaluation results revealed that 99.3% of the convolutional neural networks-generated high-risk clinical target volumes slices were acceptable for oncologist A and 100% for oncologist B. Most segmentations of the organs at risk were clinically acceptable, except for the 25% sigmoid, which required significant revision in the opinion of oncologist A. There was a significant difference in the clinical evaluation of convolutional neural networks-generated high-risk clinical target volumes between the two oncologists (P<0.001), whereas the score differences of the organs at risk were not significant between the two oncologists. In the consistency evaluation, a large discrepancy was observed between senior and junior clinicians. About 40% of SERes-u-net-generated contours were thought to be better by junior clinicians. CONCLUSION: The high-risk clinical target volumes and organs at risk of cervical cancer generated by the proposed convolutional neural networks model can be used clinically, potentially improving segmentation consistency and efficiency of contouring in image-guided adaptive brachytherapy workflow.