Real-time US/cone-beam CT fusion imaging for percutaneous ablation of small renal tumours: a technical note

Renal Arteriography and C-arm CT-Guided Ablation (RenACAGA) for Thermal Ablation of Challenging Renal Tumors

PURPOSE

We present a technique that combines Renal arteriography with C-arm CT-Guided Ablation (RenACAGA) to improve tumor visualization, navigation and margin confirmation for percutaneous ablation of renal tumors.

MATERIALS AND METHODS

The RenACAGA technique was used for thermal ablation of challenging renal tumors (intraparenchymal or US-occult lesions). All patients treated with RenACAGA between January 1, 2022, and July 1, 2024, were retrospectively evaluated. Procedures were performed in the angiography suite, with catheterization of the renal artery for selective contrast infusion. C-arm CT and guidance software were used for tumor visualization and ablation needle placement. Pre- and post-ablation C-arm CTs were fused to assess ablation margins. Technical success and local tumor recurrence (LTR) rate were evaluated. Complications were graded according to the Common terminology criteria for adverse events (CTCAE) version 5.0.

RESULTS

Seven patients with 10 tumors were treated using the RenACAGA technique. All tumors were successfully identified, punctured and ablated (technical success 100%). During a median follow-up period of 8 months (range 7-25 months), no signs of tumor recurrence at the ablation site were observed (LTR rate 0%). One CTCAE grade 3 periprocedural complication was observed (urinary leakage through the needle tract), along with two CTCAE grade 1 complications (genitofemoral neuralgia (n = 1), and asymptomatic partial splenic infarction (n = 1)).

CONCLUSION

The RenACAGA technique was successfully used for renal tumor ablation. Further studies are warranted to establish the potential benefits of this technique in terms of superior tumor visualization, targeting, ablation margin assessment, and combination with embolization.

Robotic CBCT meets robotic ultrasound

PURPOSE

The multi-modality imaging system offers optimal fused images for safe and precise interventions in modern clinical practices, such as computed tomography-ultrasound (CT-US) guidance for needle insertion. However, the limited dexterity and mobility of current imaging devices hinder their integration into standardized workflows and the advancement toward fully autonomous intervention systems. In this paper, we present a novel clinical setup where robotic cone beam computed tomography (CBCT) and robotic US are pre-calibrated and dynamically co-registered, enabling new clinical applications. This setup allows registration-free rigid registration, facilitating multi-modal guided procedures in the absence of tissue deformation.

METHODS

First, a one-time pre-calibration is performed between the systems. To ensure a safe insertion path by highlighting critical vasculature on the 3D CBCT, SAM2 segments vessels from B-mode images, using the Doppler signal as an autonomously generated prompt. Based on the registration, the Doppler image or segmented vessel masks are then mapped onto the CBCT, creating an optimally fused image with comprehensive detail. To validate the system, we used a specially designed phantom, featuring lesions covered by ribs and multiple vessels with simulated moving flow.

RESULTS

The mapping error between US and CBCT resulted in an average deviation of 1.72 ± 0.62 mm. A user study demonstrated the effectiveness of CBCT-US fusion for needle insertion guidance, showing significant improvements in time efficiency, accuracy, and success rate. Needle intervention performance improved by approximately 50% compared to the conventional US-guided workflow.

CONCLUSION

We present the first robotic dual-modality imaging system designed to guide clinical applications. The results show significant performance improvements compared to traditional manual interventions.

Cone Beam computed tomography (CBCT) applications in image-guided minimally invasive procedures

Cone-Beam computed tomography (CBCT) obtains three-dimensional images using a two-dimensional detector. The use of CBCT in treatment planning and evaluation increases the safety and efficacy of minimally invasive procedures. This article reviews the technical considerations, main clinical applications, and future directions of CBCT in vascular and interventional radiology and interventional neuroradiology.

Fluoroscopy and Cone Beam CT Guidance in Robotic Interventions

Developments in robotic interventions have greatly affected the field of interventional radiology (IR), particularly when combined with imaging modalities such as fluoroscopy and cone-beam computed tomography (CBCT). The aim of this review is to compare and evaluate the safety, precision, and clinical outcomes of fluoroscopy and CBCT-guided robotic interventions in IR. An extensive search of the literature on PubMed and Google Scholar databases was conducted up to November 2024. Searched terms included "robotic interventions," "fluoroscopy guidance," "cone-beam CT guidance," and "robotic surgery." Literature review showed improved patient outcomes in robotic-assisted procedures, with fewer complications and higher success rates especially in anatomically challenging cases. Fluoroscopy-guided robotic interventions provide real-time imaging, allowing for accurate interventions while CBCT-guided procedures offer enhanced 3D visualization, reducing radiation exposure while maintaining high diagnostic accuracy and shorter needle puncture times. Both fluoroscopy and CBCT-guided robotic interventions play a critical role in advancing interventional radiology and are expected to improve procedural outcomes in IR.

Percutaneous cryoablation in soft tissue tumor management: an educational review

BACKGROUND

Percutaneous cryoablation (PCA), having shown effectiveness in treating liver, lung, prostate, breast, and kidney tumors, is now gaining attention for the treatment of soft tissue tumors. PCA functions by freezing tissue, which induces ice crystal formation and cell death without damaging collagen structures. Technical considerations include the selection and handling of cryoprobes and cryogenic agents, procedural duration, and choice of image guidance for precision. This review aims to synthesize the mechanisms, applications, and technical aspects of PCA in the treatment of soft tissue tumors.

METHODS

Adhering to PRISMA 2020 guidelines, a review was conducted of studies published prior to March 2024 that investigated PCA of soft tissue tumors. The review focused on technical and procedural aspects of cryoablation, cryobiological principles, cellular and tissue responses to extreme cold, intra- and post-procedure physiological mechanisms during and post-procedure, and main clinical applications.

RESULTS

PCA is efficient in treating soft tissue tumors, including desmoid tumors, vascular malformations, and abdominal wall endometriosis. Several cryobiological mechanisms are involved, notably ice crystal formation, cellular dehydration, osmotic effects, and the inflammatory response, all of which contribute to its efficacy. Key technical aspects include the choice of cryoprobes, cryogenic agents (argon gas or liquid nitrogen), and the duration and control of freezing/thawing cycles. PCA also frequently outperformed traditional treatments like surgery and radiotherapy in terms of pain reduction, tumor size reduction, and patient outcomes. Moreover, its nerve sideration properties make it effective under local anesthesia.

CONCLUSION

Demonstrating substantial pain reduction, tumor size decrease, and high technical success rates, PCA offers a promising and minimally invasive alternative for soft tissue tumor treatment.

CRITICAL RELEVANCE STATEMENT

Percutaneous cryoablation provides a minimally invasive, precise alternative for soft tissue tumor management, advancing clinical radiology by offering effective treatment with reduced patient risk and enhanced outcomes through image-guided procedures.

KEY POINTS

Percutaneous cryoablation (PCA) offers a promising, minimally invasive alternative for managing soft tissue tumors. PCA employs image-guided techniques to accurately target and treat tumors, ensuring high precision and control. PCA preserves structures like collagen, reduces pain, decreases tumor size, and generally enhances patient outcomes.

Perioperative, functional and oncologic outcomes of percutaneous ablation versus minimally invasive partial nephrectomy for clinical T1 renal tumors: outcomes from a pooled analysis

The objective of this study was to perform a comprehensive pooled analysis aimed at comparing the efficacy and safety of percutaneous ablation (PCA) versus minimally invasive partial nephrectomy (MIPN), including robotic and laparoscopic approaches, in patients diagnosed with cT1 renal tumors. We conducted a comprehensive search across four major electronic databases: PubMed, Embase, Web of Science, and the Cochrane Library, targeting studies published in English up to April 2024. The primary outcomes evaluated in this analysis included perioperative outcomes, functional outcomes, and oncological outcomes. A total of 2449 patients across 17 studies were included in the analysis. PCA demonstrated superior outcomes compared to MIPN in terms of shorter hospital stays (WMD: - 2.13 days; 95% Confidence Interval [CI]: - 3.29, - 0.97; p = 0.0003), reduced operative times (WMD: - 109.99 min; 95% CI: - 141.40, - 78.59; p < 0.00001), and lower overall complication rates (OR: 0.54; 95% CI: 0.40, 0.74; p = 0.0001). However, PCA was associated with a higher rate of local recurrence when compared to MIPN (OR: 3.81; 95% CI: 2.45, 5.92; p < 0.00001). Additionally, no significant differences were observed in major complications, estimated glomerular filtration rate decline, creatinine variation, overall survival, recurrence-free survival, and disease-free survival between the two treatment modalities. PCA presents a notable disadvantage regarding local recurrence rates in comparison to MIPN. However, PCA offers several advantages over MIPN, including shorter durations of hospital stay, reduced operative times, and lower complication rates, while achieving similar outcomes in other oncologic metrics.

Artificial intelligence in interventional radiology: state of the art

Artificial intelligence (AI) has demonstrated great potential in a wide variety of applications in interventional radiology (IR). Support for decision-making and outcome prediction, new functions and improvements in fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging, specifically in the field of IR, have all been investigated. Furthermore, AI represents a significant boost for fusion imaging and simulated reality, robotics, touchless software interactions, and virtual biopsy. The procedural nature, heterogeneity, and lack of standardisation slow down the process of adoption of AI in IR. Research in AI is in its early stages as current literature is based on pilot or proof of concept studies. The full range of possibilities is yet to be explored.Relevance statement Exploring AI's transformative potential, this article assesses its current applications and challenges in IR, offering insights into decision support and outcome prediction, imaging enhancements, robotics, and touchless interactions, shaping the future of patient care.Key points• AI adoption in IR is more complex compared to diagnostic radiology.• Current literature about AI in IR is in its early stages.• AI has the potential to revolutionise every aspect of IR.

Percutaneous tumor ablation versus image guided robotic-assisted partial nephrectomy for cT1b renal cell carcinoma: a comparative matched-pair analysis (UroCCR 80)

BACKGROUND

Partial nephrectomy (PN) is the gold standard treatment for cT1b renal tumors. Percutaneous guided thermal ablation (TA) has proven oncologic efficacy with low morbidity for the treatment of small renal masses (<3 cm). Recently, 3D image-guided robot-assisted PN (3D-IGRAPN) has been described, and decreased perioperative morbidity compared to standard RAPN has been reported. Our objective was to compare two minimally invasive image-guided nephron-sparing procedures (TA vs. 3D-IGRAPN) for the treatment of cT1b renal cell carcinomas (4.1-7 cm).

METHODS

Patients treated with TA and 3D-IGRAPN for cT1b renal cell carcinoma, prospectively included in the UroCCR database (NCT03293563), were pair-matched for tumor size, pathology, and RENAL score. The primary endpoint was the local recurrence rate between the two groups. Secondary endpoints included metastatic evolution, perioperative complications, decrease in renal function, and length of hospitalization.

RESULTS

A total of 198 patients were included and matched into two groups of 72 patients. The local recurrence rate was significantly higher in the TA group than that in the 3D-IGRAPN group (4.2% vs. 15.2%, P=0.04). Metastatic evolution and perioperative outcomes such as major complications, eGFR decrease, and length of hospitalization did not differ significantly between the two groups.

CONCLUSIONS

3D-IGRAPN resulted in a significantly lower local recurrence rate and comparable rates of complications and metastatic evolution compared with thermal ablation.

Robotics in Interventional Radiology: Review of Current and Future Applications

This review is a brief overview of the current status and the potential role of robotics in interventional radiology. Literature published in the last decades, with an emphasis on the last 5 years, was reviewed and the technical developments in robotics and navigational systems using CT-, MR- and US-image guidance were analyzed. Potential benefits and disadvantages of their current and future use were evaluated. The role of fusion imaging modalities and artificial intelligence was analyzed in both percutaneous and endovascular procedures. A few hundred articles describing results of single or several systems were included in our analysis.

CT renal arteriography as a novel imaging guidance for the percutaneous ablation of small renal tumors

PURPOSE

To report procedural data and outcomes of a novel image guidance technique, CT renal arteriography (CTRA), performed to target and ablate small intraparenchymal renal tumors.

MATERIALS AND METHODS

We retrospectively analyzed data of 2 patients undergoing CTRA-guided ablation for 3 renal intraparenchymal tumors, from February to March 2023. We previously evaluated tumor visibility with US/CEUS, and in all cases conspicuity was poor, whereas contrast-enhanced CT (CECT) clearly depicted all hypervascular nodules. Our primary endpoint was CTRA-guidance feasibility for renal ablation, defined as the precise probe deployment inside the target tumor. The secondary endpoint was CTRA-guided ablation technical success, intended as the inclusion of the whole tumor inside the necrotic volume, with 5 mm safety margins. RENAL scores, complications, procedural time, dose length product (DLP), serum creatinine variation and hospital stay length were also recorded.

RESULTS

A confident deployment of the probe tip inside the nodule was accomplished in all 3 cases, with a 100% of correct targeting. We observed immediate technical success after all 3 ablations. The 3 nodules had a RENAL score <7 points, and we encountered no complications due to line placement or ablation. The average time from preablative to postablative CTRA was 54 min (50-58min), with a DLP of 3632mGy*cm (2807-4458mGy*cm). Serum creatinine didn't show a significant variation after the procedures; both patients were hospitalized for 2 days.

CONCLUSION

Preliminary data showed that CTRA-guidance might provide unique advantages over conventional CECT-guidance to assist the ablation of small renal intraparenchymal tumor not visualized on US/CEUS.

Analysis of the Effect of Percutaneous Cone Shaping in Patients with Osteoporotic Vertebral Fractures

Objective. To study and analyze the clinical effect of percutaneous cone shaping in patients with osteoporotic vertebral fractures. Methods. A total of 100 patients with vertebral osteoporotic fracture treated in our hospital from June 2019 to September 2020 were selected, and there were 50 patients with vertebral osteoporotic fracture in each group. Patients could be divided into two groups according to different treatment plans: one group was vertebroplasty patients for group A, and the other group was nonsurgical treatment patients for group B. The incidence of complications during treatment and follow-up was recorded in both groups. Results. According to a study, both groups of patients completed the treatment and follow-up, no patients lost to follow-up or death, the VAS scores and ADL scores of patients before treatment were higher, and there was no significant difference at baseline ( $P>0.05$ ). After different treatment methods, the VAS score and ADL score of group A showed good improvement after treatment compared with that before treatment, and there were certain differences within the group, with statistical significance ( $P<0.05$ ). Intragroup comparison. The VAS scores of group B at 1 week, 1 month, 3 months, and 12 months after treatment were all superior to those before treatment, and the ADL scores at 1 month, 3 months, and 12 months after treatment were all superior to those before treatment, with statistically significant differences ( $P<0.05$ ). VAS scores and ADL scores showed good improvement 1 day, 1 week, and 1 month after treatment compared with those before treatment. However, there were no significant differences in the VAS score and ADL score between the two groups at 3 and 12 months after treatment. The incidence of complications in group A is lower than that in group B. The incidence of complications in group A is as follows: there was 1 case of recurrent vertebral fracture and 1 case of urinary tract infection, and the overall incidence of complications was 4.00%. In group B, there were 1 case of recurrent fracture, 3 cases of bedsore, 2 cases of urinary tract infection, and 2 cases of pulmonary infection, and the incidence of total complications was 16.00%. After comparison between groups, there was a significant difference in the incidence of complications between the two groups, and the difference was statistically significant ( $P<0.05$ ). Conclusions. Percutaneous cone plasty can provide rapid relief of pain symptoms in patients with osteoporotic vertebral fractures and significantly improve their daily activities. However, there was no significant difference in long-term recovery from group B. In terms of the incidence of complications, the incidence of complications in group A was lower than that in group B after certain treatment.

Ultrasound Image Features under Decomposition Algorithm to Analyze the Nursing Intervention on Patients with Colon Polyps Undergoing Endoscopic Resection

Based on the ultrasonic imaging and endoscopic resection of the intelligent segmentation algorithm, this study is aimed at exploring whether nursing intervention can promote the good recovery of patients with colon polyps, hoping to find a new method for clinical treatment of the colon polyps. Patients with colon polyps were divided into an experimental group (fine nursing) and a control group (general nursing). The colonoscopy polyp ultrasound image was preprocessing to select the seed points and background points. The random walk decomposition algorithm was applied to calculate the probability of each marked point, and then, the marked image was outputted. The accuracy of the intelligent segmentation algorithm was 81%. The incidence of complications in the experimental group was 4.83%, which was lower than 16.66% in the control group, and the difference was statistically obvious (P < 0.05). Perioperative refined nursing intervention for colon polyp patients undergoing endoscopic electrosurgical resection can decrease postoperative adverse reactions; reduce postoperative mucosal perforation, blood in the stool, abdominal pain, and small bleeding; lower the incidence of postoperative complications; and allow patients to recover quickly, enhancing the life comfort of patient.