Cone-Beam CT With Enhanced Needle Guidance and Augmented Fluoroscopy Overlay: Applications in Interventional Radiology.

Digital flat-panel detector cone-beam CT (CBCT), introduced in the early 2000s, was historically used in interventional radiology primarily for liver-directed therapies. However, contemporary advanced imaging applications, including enhanced needle guidance and augmented fluoroscopy overlay, have evolved substantially over the prior decade and now work synergistically with CBCT guidance to overcome limitations encountered with other imaging modalities. CBCT with advanced imaging applications has become increasingly used to facilitate a broad range of minimally invasive procedures, particularly relating to pain and musculoskeletal interventions. Potential advantages of CBCT with advanced imaging applications include greater accuracy for complex needle paths, improved targeting in the presence of metal artifact, enhanced visualization during injection of contrast medium or cement, increased ease when space in the gantry is limited, and reduced radiation doses versus conventional CT guidance. Nonetheless, CBCT guidance remains underutilized, partly relating to lack of familiarity with the technique. This article describes the practical implementation of CBCT with enhanced needle guidance and augmented fluoroscopy overlay and depicts the technique's application for an array of interventional radiology procedures, including epidural steroid injections, celiac plexus block and neurolysis, pudendal block, spine ablation, percutaneous osseous ablation fixation and osteoplasty, biliary recanalization, and transcaval type II endoleak repair.

Vertebral Body Bone Ablation with and without a Saline-Infused System in a Porcine Model.

The purpose of this study was to evaluate the effect of bone radiofrequency (RF) ablation in the spine with and without controlled saline infusion. RF ablation with and without controlled saline infusion was performed in the vertebral bodies of 2 swine with real-time temperature and impedance recordings. Histology and magnetic resonance (MR) imaging results were reviewed to evaluate the ablation zone size, breach of spinal canal, and damage to the spinal cord and nerves. There was no difference in maximum and mean temperatures between controlled saline and noninfusion groups. The impedance and power output were not significantly different between the groups. MR imaging and histopathology demonstrated ablation zones confined within the vertebral bodies. Ablation zone size correlated on MR imaging and histopathology by groups. No ablation effect, breach of posterior cortex, spinal cord injury, or nerve or ganglion injury was observed at any level using MR imaging or histology. Controlled saline infusion does not appear to impact bone RF ablation and, specifically, does not increase the ablation zone size.

Radiology Environmental Impact: What Is Known and How Can We Improve?

The healthcare sector generates approximately 10% of the total carbon emissions in the United States. Radiology is thought to be a top contributor to the healthcare carbon footprint due to high energy-consuming devices and waste from interventional procedures. In this article, we provide a background on Radiology's environmental impact, describe why hospitals should add sustainability as a quality measure, and give a framework for radiologists to reduce the carbon footprint through quality improvement and collaboration.

Comprehensive Palliative Musculoskeletal Interventional Radiology Care for Patients with Cancer.

Substantial advances in percutaneous image-guided minimally invasive musculoskeletal oncologic interventions offer a robust armamentarium for interventional radiologists for management of cancer. The authors outline the most recent advances in such interventions and the role of interventional radiologists in managing cancer in modern-era practice. Percutaneous minimally invasive musculoskeletal interventions including thermal ablation, cementation with or without osseous reinforcement by implants, osteosynthesis, neurolysis, and embolization, as well as palliative injections, have been successfully used by interventional radiologists to achieve durable, timely, safe, effective palliation in a multidisciplinary setting and have been progressively incorporated into the management paradigm for patients with cancer with musculoskeletal involvement. Familiarity with the described interventions and implementation of procedural safety measures, combined with integration of these procedures into clinical practice with the support of the National Comprehensive Cancer Network and the American College of Radiology, as well as continued technologic advances in procedural equipment design, will further enhance the role of interventional radiologists in cancer management. ©RSNA, 2022.

Local Control of Cancers With Various Ablation Techniques.

Metastatic disease to the bone and soft tissue creates significant morbidity because of pain resulting in decreased functional status. Palliative chemotherapy and radiation therapy were historically the mainstays of pain reduction. Minimally invasive technologies such as image-guided ablation and cementoplasty have become common in interventional radiology. Advances in image guidance and ablation technologies have improved the multidisciplinary approach in the management of bone and soft-tissue disease. The minimally invasive nature of the interventions allows prompt initiation or continuation of chemotherapy and radiation therapy. These safe and efficacious procedures have improved patient quality of life by decreasing pain and improving function.

Image guidance in osteoplasty and fixation.

Oncology patients, particularly those with breast, colorectal, prostate, renal and pancreatic cancers, are living longer due to advances in detection, and treatment. Unfortunately, this has come with a commensurate increase in the prevalence of osseous metastases and skeletal related events approaching 100,000 new patients each year. Patients are now experiencing serious morbidity and mortality due to pathologic fractures, altered structural mechanics, and cancer related bone pain. This patient population poses challenges for conventional open surgical and/or medical management often due to disease extent, location, and, in general, poor surgical candidacy. Percutaneous techniques may also be challenging under image guidance due to limited ability to use traditional orthopedic corridors, loss of cortical landmarks with destructive lesions, and need for live image guidance. Modern angiography suites with cone beam computed tomography (CBCT) and advanced imaging applications including needle guidance, 3D fusion, tumor segmentation, and angio-CT have facilitated the development of novel minimally invasive techniques for pain palliation and stabilization. The interventional radiologist is uniquely positioned to harness these advanced imaging applications and offer effective, safe, minimally invasive treatment options to patients with neoplastic disease within the axial, and appendicular skeletons. The focus of this article is to address the technical aspects of patient preparation, positioning, advanced imaging system capabilities, guidance strategies, and pitfalls during osteoplasty and fixation procedures.

Vertebroplasty, Kyphoplasty, and Implant-Based Mechanical Vertebral Augmentation.

Vertebral compression fractures are a global public health issue with a quantifiable negative impact on patient morbidity and mortality. The contemporary approach to the treatment of osteoporotic fragility fractures has moved beyond first-line nonsurgical management. An improved understanding of biomechanical forces, consequential morbidity and mortality, and the drive to reduce opioid use has resulted in multidisciplinary treatment algorithms and significant advances in augmentation techniques. This review will inform musculoskeletal radiologists, interventionalists, and minimally invasive spine surgeons on the proper work-up of patients, imaging features differentiating benign and malignant pathologic fractures, high-risk fracture morphologies, and new mechanical augmentation device options, and it describes the appropriate selection of devices, complications, outcomes, and future trends.

Musculoskeletal Oncologic Interventions: Proceedings from the Society of Interventional Radiology and Society of Interventional Oncology Research Consensus Panel.

Musculoskeletal interventions are increasingly used with palliative and curative intent in the multidisciplinary treatment of oncology patients with bone and soft-tissue tumors. There is an unmet need for high-quality evidence to guide broader application and adoption of minimally invasive interventional technologies to treat these patients. Therefore, the Society of Interventional Radiology Foundation and the Society of Interventional Oncology collaborated to convene a research consensus panel to prioritize a research agenda addressing the gaps in the current evidence. This article summarizes the panel's proceedings and recommendations for future basic science and clinical investigation to chart the course for interventional oncology within the musculoskeletal system. Key questions that emerged addressed the effectiveness of ablation within specific patient populations, the effect of combination of ablation with radiotherapy and/or immunotherapy, and the potential of standardization of techniques, including modeling and monitoring, to improve the consistency and predictability of treatment outcomes.

Minimally Invasive Stabilization with or without Ablation for Metastatic Periacetabular Tumors.

BACKGROUND: Metastatic bone disease in the periacetabular region represents a potentially devastating problem for patients. Surgical treatment can offer pain relief and restore function. We describe a series of patients treated with minimally invasive osteoplasty and screw fixation with or without ablation. METHODS: Thirty-eight patients with 16 different metastatic tumor subtypes were managed with osteoplasty and screw fixation with or without ablation at a single institution. A retrospective review was performed to determine functional outcomes with use of the 1993 Musculoskeletal Tumor Society (MSTS) score as well as changes in narcotic usage. RESULTS: MSTS scores improved for all patients following surgery. Narcotic usage decreased in >80% of patients. Approximately half of the operations were outpatient procedures. Complications were minimal, there were no delays in chemotherapy or radiation due to surgical wound concerns, and there were no surgery-related deaths. The mean duration of follow-up was 9 months, with a 39% survival rate at the time of writing. Six of the 12 patients who survived for >1 year required additional procedures at a mean of 12 months (range, 4 to 23 months). CONCLUSIONS: Treatment of periacetabular metastatic disease with minimally invasive stabilization with or without ablation provides pain relief and functional improvement with lower complication rates than previously reported open reconstruction techniques. The minimally invasive approach allows for rapid initiation of chemotherapy and radiation. Patients with particularly aggressive cancers that are poorly responsive to systemic therapies and radiation may have progression of disease and may require additional procedures. Conversion to total hip arthroplasty was uncomplicated, and the cement and screw constructs were retained, providing a stable base for the arthroplasty reconstruction. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Endovascular treatment of a sacral dural arteriovenous fistula.

Spinal dural arteriovenous fistula (SDAVF) is a rare pathological communication between arterial and venous vessels within the spinal dural sheath. Clinical presentation includes progressive spinal cord symptoms including gait difficulty, sensory disturbances, changes in bowel or bladder function, and sexual dysfunction. These fistulas are most often present in the thoracolumbar region. Diagnoses of SDVAFs are commonly missed, possibly due to the low index of suspicion, non-specific symptoms and challenging imaging. In this case report, we describe a rare presentation of a sacral SDAVF which was detected by collective efforts between endovascular neurosurgery and interventional radiology. We outline the diagnostic and imaging challenges we faced to discover the fistula. In particular, mechanical pump injection instead of hand injection during angiography was required to reveal the fistula. Following identification, the fistula was successfully treated endovascularly by using onyx (ethylene vinyl alcohol glue), a less invasive alternative to surgical intervention.

Minimally Invasive Stabilization of Periacetabular Metastasis.

Metastatic bone disease to the pelvis can lead to lower quality of life and function secondary to pain. Historically, treatment was palliative with radiation therapy and chemotherapy used to reduce pain. The Harrington procedure and subsequent modifications improved pain and function. In the subset of patients with complications, this would delay potential life-prolonging interventions such as chemotherapy and radiation therapy. Percutaneous palliative pain procedures including ablation and cementoplasty have been developed by interventional radiology for pelvic lesions and have been shown to be safe and efficacious. Additionally, percutaneous methods of pelvic fracture fixation have been developed. Modern image guidance technologies have allowed an expanded multidisciplinary approach to pelvic metastatic disease in a minimally invasive fashion with combinations of ablation, internal fixation, and cementation to improve patient quality of life and outcomes with decreased morbidity and rapid return to radiation and systemic therapies.

Pelvis weight-bearing ability after minimally invasive stabilizations for periacetabular lesion.

Periacetabular metastatic lesions cause debilitating weight-bearing pain and pose a risk of pelvic pathologic fracture. Minimally invasive percutaneous stabilization is an alternative palliative therapy over extensive open reconstructive surgeries. This study aimed to investigate the biomechanical behaviors of three distinct techniques of percutaneous periacetabular stabilization. A total of 20 composite hemipelves custom-made to contain Harrington type III periacetabular lesion based on a patient's computed tomograpy scans were assigned to treatment groups of cementoplasty alone using polymethyl methacrylate (Cement), screw fixation alone using ischial and posterior-to-anterior screws (Screws), cement-augmented screws (Screws&Cement), and a control group (Untreated). All hemipelves were loaded in a mechanical test configuration mimicking a single-legged stance, and failure load, failure deformation, and construct stiffness were determined. In the experiments, Screws&Cement demonstrated the highest yield strength (4711 ± 362 N) and was 12% higher than Cement (4005 ± 304 N, p = 0.019), 125% higher than Screws (2097 ± 359 N, p < 0.0001), and 184% higher than Untreated (1658 ± 254 N, p < 0.0001). No significant difference in yield strength was found between Screws and Untreated. Screws&Cement also demonstrated the highest stiffness (1013 ± 92 N/mm), followed by Cement (893 ± 49 N/mm), and both groups were significantly stiffer than Screws (543 ± 114 N/mm, p < 0.0001) and Untreated (580 ± 91 N/mm, p < 0.0001 for Screws&Cement, and p = 0.0003 for Cement). This study demonstrated that a cement-augmented periacetabular reconstruction is an effective option for percutaneous treatment of Harrington III periacetabular metastatic lesion. The addition of pelvic screws over cementoplasty significantly improved the pelvis load-bearing strength. When large periacetabular lesions are present, augmented screw fixation appears to be the superior choice of treatment.

Advanced Interventional Pain Management Approach to Neoplastic Disease Outside the Spine.

Neoplastic disease of the musculoskeletal system may result in serious morbidity and mortality secondary to cancer related bone pain, pathologic fracture, altered structural mechanics, and involvement of adjacent structures.1 Recent advances in cancer detection and treatment have allowed more patients to live longer. The prevalence of osseous metastatic disease has increased to 100,000 new patients developing bone metastases each year.2 These patients are seeing long-term exposure to chemotherapy and radiation leading to increased skeletal events, morbidity, and a negative impact on quality of life. Bone metastases in conjunction with poor bone quality often prevent surgical therapy. Utilization of thermal ablation in this patient population is supported by contemporary literature and offers a minimally invasive approach to pain palliation, local tumor control, and decreased morbidity with unique advantages compared to surgery or radiation.3 In addition to spine disease, interventional radiologists are able to meaningfully impact pelvic, shoulder girdle, and long bone metastases. Adding to ablation we have in our repertoire the ability to provide structural support utilizing cement and/or screw fixation as an adjunct for both pain palliation and mechanical stabilization.4-6 These novel therapies have allowed more patients with metastatic disease to be treated. The focus of this chapter is to highlight importance of patient selection, ablative modality selection, integration of cementoplasty (also described as osteoplasty) and osseous fixation, and procedural techniques/strategy in the pelvis and other common sites of bone metastases outside the spine.

Ultrasound-guided diagnostic deep peroneal nerve blocks prior to potential neurectomy: a retrospective review.

OBJECTIVE: To describe our technical and preliminary clinical experience with ultrasound-guided diagnostic deep peroneal nerve (DPN) blocks for patients considering deep peroneal neurectomy. MATERIALS AND METHODS: Retrospective analysis of ultrasound-guided diagnostic DPN blocks performed in the anterior lower leg in patients pursuing deep peroneal neurectomy for foot pain not directly attributable to the DPN. Patient age, sex, foot laterality, diagnosis, nerve block complications, location of the DPN with respect to vascular landmarks in the lower leg, pain relief from nerve block, and pain relief from neurectomy (if performed) were recorded. RESULTS: Twenty-six DPN blocks were performed for 25 feet, of which a majority had pain attributable to midfoot osteoarthritis (22/25). Variable DPN locations with respect to vascular landmarks in the lower leg were observed, including lateral to the anterior tibial artery (12/25), anterior to the artery (5/25), medial to the artery (3/25), lateral to the lateral paired vein (4/25), and 1-cm lateral to the artery (1/25). After DPN blocks, patients reported pain relief in 22/25 feet. Of the eleven patients who proceeded to have a deep peroneal neurectomy, ten reported improved foot pain. CONCLUSION: Diagnostic deep peroneal nerve blocks for patients considering deep peroneal neurectomy for denervation therapy should be performed in the anterior lower leg where the anterior tibial vessels serve as anatomic landmarks. Those who perform DPN blocks with ultrasound guidance should be aware of variable DPN position with respect to the vascular landmarks.

The Role of Ablation in Cancer Pain Relief.

PURPOSE OF REVIEW: The purpose of this article is to describe the concepts of ablation techniques for pain relief in symptomatic oncologic patients. Controversies concerning techniques and products will be addressed. RECENT FINDINGS: Despite conventional pain palliative techniques, cancer patients often endorse unresolved somatic and neuropathic pain that can present as a great burden to quality of life. In non-operative patients, several techniques have been applied to minimize opioid dependence. While radiotherapy is often considered as a non-invasive option, percutaneous ablation has been advanced as a minimally-invasive alternative with clear procedural and outcome advantages. Similar to radiation therapy, percutaneous ablation techniques can act either upon nerve structures responsible for pain mediation signals (neurolysis) or directly upon the tumor to relieve tumor-mediated inflammation and decompress tumor compression of adjacent structures. Percutaneous ablation provides valuable neurolysis and tumor-directed pain palliative effects to be incorporated into clinical guidelines for pain reduction in oncologic patients. Selection among different ablation techniques should be based upon an individually tailored approach, to include consideration of all treatment modalities.

Management of Acute Cholecystitis during Neoadjuvant Therapy in Patients with Pancreatic Adenocarcinoma.

BACKGROUND: Patients with localized pancreatic cancer (PC) can develop acute cholecystitis during neoadjuvant therapy; optimal management remains undefined. METHODS: Consecutive patients with localized PC who had indwelling biliary stents and received neoadjuvant therapy were reviewed. Time from stent placement to the development of acute cholecystitis was calculated. Patients were categorized as having surgical versus nonoperative management of cholecystitis. Time to PC resection was defined as the time from the start of treatment to pancreatic resection. RESULTS: Of the 283 patients with indwelling biliary stents, acute cholecystitis occurred in 17 (6%) patients. The median time from the date of stent placement to the development of cholecystitis was 2.3 months [interquartile range (IQR) 4.6 months]. Acute cholecystitis was managed with cholecystostomy tube placement in 15 (88%) patients and cholecystectomy in 2 (12%). In total, 189 (67%) of the 283 patients completed all intended neoadjuvant therapy and surgery; 10 (59%) of the 17 patients with cholecystitis (10 of 15 managed with a cholecystostomy tube and 0 of 2 managed with cholecystectomy) and 179 (67%) of the 266 patients without cholecystitis (p = 0.47). The median time to PC resection was 3.2 months for the 179 patients without cholecystitis and 3.6 months for the 10 patients with cholecystitis (p = 1.00). CONCLUSIONS: Acute cholecystitis occurred in 6% of patients with indwelling biliary stents during neoadjuvant therapy. Management with a cholecystostomy tube did not delay the completion of neoadjuvant therapy and surgery and should be considered the optimal management of this complication.

Minimally Invasive Stabilization Using Screws and Cement for Pelvic Metastases: Technical Considerations for the Pelvic "Screw and Glue" Technique.

Metastatic disease involving the pelvis is common, often resulting in significant pain and disability. Several percutaneous interventions for unstable pelvic metastatic disease have been described, including osteoplasty, ablation, and screw fixation, that when used alone or in combination can significantly reduce pain and disability from metastatic bone disease. While it is possible to make a significant impact in patient care with basic principles and techniques, certain advanced techniques can extend the application of percutaneous interventions while minimizing morbidity.

Percutaneous cryoablation for the treatment of extra-abdominal desmoid tumors.

BACKGROUND: Desmoid tumors are rare locally invasive, benign neoplasms that develop along aponeurotic structures. Current treatment is complicated by associated morbidity and high recurrence rates. METHODS: A retrospective, single-institution review identified 23 patients (age: 16-77) with extra-abdominal desmoid tumors who received CT-guided percutaneous cryoablation as either a first-line (61%) or salvage (39%) treatment in 30 sessions between 2014 and 2018. Median maximal lesion diameter was 69 mm (range: 11-209). Intent was curative in 52% and palliative in 48%. Contrast-enhanced cross-sectional imaging was obtained before and after treatment in addition to routine clinical follow-up. RESULTS: Technical success was achieved in all patients. The median follow-up was 15.4 months (3.5-43.4). Symptomatic improvement was demonstrated in 89% of patients. At 12 months, the average change in viable volume was -80% (range -100% to + 10%) and response by modified response evaluation criteria in solid tumors (mRECIST) was CR 36%, PR 36%, and SD 28% No rapid postablation growth or track seeding was observed. Four patients underwent repeat cryoablation for either residual or recurrent disease. Two patients sustained a major procedural complication consisting of significant neuropraxia. CONCLUSION: Cryoablation for desmoid tumors demonstrates a high degree of symptom improvement and local tumor control on early follow-up imaging with relatively low morbidity.

Magnetic Resonance-Guided Focused Ultrasound: A Brief Review With Emphasis on the Treatment of Extra-abdominal Desmoid Tumors.

Magnetic resonance-guided focused ultrasound (MRgFUS) utilizes high-intensity focused ultrasound to noninvasively, thermally ablate lesions within the body while sparing the intervening tissues. Magnetic resonance imaging provides treatment planning and guidance, and real-time magnetic resonance thermometry provides continuous monitoring during therapy. Magnetic resonance-guided focused ultrasound is ideally suited for the treatment of extra-abdominal desmoid fibromatosis due to its noninvasiveness, lack of ionizing radiation, low morbidity, and good safety profile. Conventional treatments for these benign tumors, including surgery, radiation, and chemotherapy, can carry significant morbidity. Magnetic resonance-guided focused ultrasound provides a safe and effective alternative treatment in this often-young and otherwise healthy patient population. While there is considerable experience with MRgFUS for treatment of uterine fibroids, painful bone lesions, and essential tremor, there are few reports in the literature of its use for treatment of benign or malignant soft tissue tumors. This article reviews the principles and biologic effects of high-intensity focused ultrasound, provides an overview of the MRgFUS treatment system and use of magnetic resonance thermometry, discusses the use of MRgFUS for the treatment of extra-abdominal desmoid tumors, and provides several case examples.