Tripod Fixation of Periacetabular Metastatic Lesions Using the IlluminOss Device.

Background: Percutaneous tripod fixation of periacetabular lesions is performed at our institution for patients with metastatic bone disease and a need for quick return to systemic therapy. We have begun to use the IlluminOss Photodynamic Bone Stabilization System instead of the metal implants previously described in the literature because of the success of the IlluminOss implant in fixing fragility fractures about the pelvis. Description: At our institution, the procedure is performed in the interventional radiology suite in order to allow for the use of 3D radiographic imaging and vector guidance systems. The patient is positioned prone for the transcolumnar PSIS-to-AIIS implant and posterior column/ischial tuberosity implant or supine for the anterior column/superior pubic ramus implant. Following a small incision, a Jamshidi needle with a trocar is utilized to enter the bone at the chosen start point. A hand drill is utilized to advance the Jamshidi needle according to the planned vector; alternatively, a curved or straight awl can be utilized. The 1.2-mm guidewire is placed and reamed. We place both the transcolumnar and posterior column wires at the same time to ensure that there is no interference. The balloon catheter for the IlluminOss is assembled on the back table and inserted according to the implant technique guide. The balloon is inflated and observed on radiographs in order to ensure that the cavity is filled. Monomer is then cured, and the patient is flipped for the subsequent implant. Following placement of the 3 IlluminOss devices, adjunct treatments such as cement acetabuloplasty or cryoablation can be performed. Alternatives: Alternative treatments include traditional open fixation of impending or nondisplaced acetabular fractures in the operating room, or percutaneous implant placement in the operating room. Implant placement may be performed with the patient in the supine, lateral, or prone position, depending on surgeon preference. Alternative implants include standard metal implants such as plates and screws, or cement augmentation either alone or with percutaneous screws. Finally, ablation alone may be an alternative option, depending on tumor histology. Rationale: Open treatment of acetabular fractures is a more morbid procedure, given the larger incision, increased blood loss, longer time under anesthesia, and increased length of recovery. Percutaneous fixation may be performed in either the operating room or interventional radiology suite, depending on the specific equipment setup at an individual institution. At our institution, we prefer utilizing the interventional radiology suite as it allows for more precise implant placement through the use of an image-based vector guidance system and 3D fluoroscopy to accurately identify safe corridors. The use of percutaneous fixation allows for faster recovery and earlier return to systemic therapy. Because the IlluminOss implant is radiolucent, it allows for better evaluation of disease progression and can better accommodate nonlinear corridors or fill a lytic lesion to provide stability. Expected Outcomes: Postoperatively, we expect the patient to be weight-bearing as tolerated with use of an assistive device. We expect the small incisions to fully heal within 2 weeks. Patients should be able to return to systemic therapy as indicated earlier than with an open procedure. Important Tips: The use of a hand drill with the Jamshidi needle and trocar can help adjust a drilled pathway and allow for close adherence to a planned vector.Vector guidance systems can be useful to fully capture the area at risk for fracture and to provide maximal stability with the expandable implant, but they are not necessary to perform the procedure.Placing both posterior implants at the same time can be helpful to avoid interference. This is accomplished by drilling and placing the guidewire for both implants prior to reaming and placing the balloon implant. Acronyms and Abbreviations: CT = Computed tomographyPSIS = posterior superior iliac spineAIIS = anterior inferior iliac spine.

Ablation of Primary and Recurrent Thyroid Cancer: Current and Future Perspectives.

Thyroid cancer is the most common endocrine malignancy, and its incidence is increasing, driven in part by the advent of ultrasound, and subsequent increased detection of small, early thyroid cancers. Yet even for small tumors, thyroidectomy with lymph node dissection remains standard of care. Specific to well-differentiated thyroid cancer, surgery has come under scrutiny as a possible overtreatment, in light of stable and favorable survival rates even as guidelines have allowed fewer radical resections and lymph node dissections over time. Moreover, thyroid cancer unfortunately has a known recurrence rate regardless of therapy, and surgical re-intervention for local structural recurrence is eventually limited by scar. Radioactive iodine therapy, another accepted treatment, is minimally invasive but can only treat patients with iodine-avid tumors. For all of these reasons, image-guided thermal ablation has emerged as a valuable complementary tool as a thyroid-sparing, parathyroid-sparing, voice-sparing, repeatable, minimally invasive outpatient focal therapy for both primary and recurrent well-differentiated thyroid cancers. However, the data are still evolving, and this represents a new patient cohort for some interventional radiologists. Therefore, the goal of this review is to discuss the technique and evidence for ablation of patients with thyroid cancer.

Vortex-assisted resin y90 delivery via 175 cm Truselect microcatheter: case factors for high residual despite double-flush protocol.

PURPOSE: To report efficiency of resin y90 delivery using SIROS via 175 cm TruSelect microcatheter with double-flush protocol (40 ml dextrose total). METHODS: IRB-approved retrospective review of all patients undergoing SIROS injection of y90 Sir-Spheres via TruSelect from 2019 through 2022 at one quaternary-care academic institution, including medical records. RESULTS: Included were 48 infusions in 25 patients across 11 cancer histologies. Mean planned, delivered, and residual activities were 28 ± 17, 27 ± 17, 1.1 ± 0.56 mCi respectively (mean residual 4.9% ± 2.8%) across flex-dosing precalibrations including 1-day, 2-day, and 3-day SIROS (4/51, 16/51, and 28/51). Mean liver treatment volume was 483 ± 306 ml with target dose mean of 128 ± 26 Gy in non-segmentectomy cases; Radiation segmentectomy was performed in 15/48 (31%). Arterial stasis was documented in 9/48 (19%) of cases. Use of a 3-day precalibrated SIROS dose, use of activity <10 mCi, treatment of smaller liver volumes (<200 ml) and documentation of stasis were associated with higher residual activity ( P  = 0.025, P  = 0.0007, P  = 0.0177, and P  = 0.049, respectively) were associated with higher residuals. CONCLUSION: Combining the new technologies of SIROS and the Truselect microcatheter with a double-flush protocol yielded <10% residual in 94% of y90 infusions. Future studies may clarify if the predictors of high residual dose seen here may warrant microcatheter-specific considerations for dosimetry or dose preparation at the Radiopharmacy level.

Salvage Cryoablation for Local Recurrences of Thyroid Cancer Inseparable from the Trachea and Neurovascular Structures.

PURPOSE: To demonstrate safety, feasibility, and effectiveness of cryoablation of recurrent papillary thyroid cancer ineligible for reoperation because of scarring, eligible for focal ablation as defined within 2015 American Thyroid Association guideline sections C16 and C17. MATERIALS AND METHODS: With multidisciplinary consensus, cryoablation was performed with curative intent for 15 tumors in 10 patients between January 2019 and July 2021. Demographics, procedural details, and serial postprocedural imaging findings were analyzed. RESULTS: The mean age was 72.5 years (range, 57-88 years), and 80% of the patients were women. The tumors (mean size, 16 mm ± 6; range, 9-29 mm) received 1 session of cryoablation with 100% technical success. The mean and median postcryoablation tumor volumetric involution rates were 88% and 99%, respectively, with 9 (60%) of 15 tumors involuting completely or down to the scar and 6 (40%) involuting partially at the end of the study period. Tumor size did not increase after cryoablation (0% local progression rate). All tumors abutted the trachea, skin, and/or vascular structures, and hydrodissection failed in all cases because of scarring. The major adverse event rate was 20% (3/15), with 2 cases of voice change and 1 case of Horner syndrome; all resolved at 6 months with no permanent sequelae. No vascular, tracheal, dermal, or infectious adverse events occurred during a mean follow-up of 242 days (range, 114-627 days). One patient died at 386 days after cryoablation because of unrelated cholangiocarcinoma. CONCLUSIONS: Cryoablation of local recurrences of papillary thyroid cancer abutting the trachea and/or neurovascular structures in the setting of hydrodissection failure because of scarring yielded a mean volumetric involution of 88%, primary efficacy of 60%, and objective response rate of 100% with no local recurrences or permanent complications during a mean follow-up of 242 days. The secondary efficacy and longer-term outcomes remain forthcoming.

Percutaneous Image-guided Cryoneurolysis: Applications and Techniques.

The expansion and dissemination of interventional cryoneurolysis in recent years has been fueled by the integration of advanced imaging guidance, the evolution of our understanding of neuropathologic processes after exposure of nerves to cold, and opportunities for its use beyond pain management. The clinical translation of cryoneurolysis through interventional radiology requires consideration of many factors, including (a) the supply and composition of target nerves, (b) the value of diagnostic injection with imaging guidance for confirmation, (c) the integration of advanced imaging guidance that allows safe ablation, (d) the difference between neoplastic and nonneoplastic causes of pain, (e) the phenomenon of percutaneously induced neuroregeneration, (f) the potential to manage conditions other than pain, (g) the consideration of protocols, (h) the limitations of current technology, and (i) the potential complications and adverse effects. Cryoneurolysis has societal and legislative endorsement as an effective nonopioid option for pain palliation. The Centers for Medicare and Medicaid Services (CMS) approved three new category III Current Procedural Terminology (CPT) codes specifically for the cryoablation of nerves with advanced imaging guidance. Interventional radiologists who are aware of nerve-directed strategies see eligible patients in their daily practice and have opportunities to bundle procedures (eg, celiac plexus block at the time of a biliary drain for pancreatic cancer with low bile duct obstruction), offering an avenue to serve the patient, reduce opioid dependence, allow faster discharge, and establish name recognition of interventional radiologists. Also, the ability to use CT to target deep structures accurately and swiftly, often with only local anesthesia, compared with the usual monitored anesthesia care in a surgical setting, may provide another avenue to build a cryoneurolysis practice. ©RSNA, 2022.

Thermal Protection Strategies and Neuromonitoring during Ablation.

Advanced interventional pain management approaches seek to lesion neural targets to achieve desirable analgesia; however, equally important is preservation of motor and sensory function for regional bystander nerves. The topic of neuroprotection is also relevant for thermal ablation of metastatic bone tumors in the vicinity of neural structures. This report aims to provide an IR-directed framework of thermoprotective techniques available during thermal ablation.

Interventional Radiology Regional Anesthesia Approaches for Intra- and Postprocedural Pain Control.

Effective pain control enables procedural success and improved patient satisfaction in interventional radiology. Regional anesthesia techniques are now established for intraoperative and postoperative anesthesia during major surgery, and interventional radiologists (IRs) can readily apply these injections for intraprocedural nerve blocks that can reduce anesthetic requirements and ensure durable analgesia postprocedure. Moreover, IR is poised to advance this field with novel blocks unique to IR needs and by blocking deep plexi safely reachable with CT guidance (e.g., hepatic hilar plexus, aorticorenal plexus blocks). This report aims to provide a succinct IR-directed primer for image-guided nerve blocks usable in the interventional radiology suite.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors.

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

Radiologic-pathologic analysis of increased ethanol localization and ablative extent achieved by ethyl cellulose.

Ethanol provides a rapid, low-cost ablative solution for liver tumors with a small technological footprint but suffers from uncontrolled diffusion in target tissue, limiting treatment precision and accuracy. Incorporating the gel-forming polymer ethyl cellulose to ethanol localizes the distribution. The purpose of this study was to establish a non-invasive methodology based on CT imaging to quantitatively determine the relationship between the delivery parameters of the EC-ethanol formulation, its distribution, and the corresponding necrotic volume. The relationship of radiodensity to ethanol concentration was characterized with water-ethanol surrogates. Ex vivo EC-ethanol ablations were performed to optimize the formulation (n = 6). In vivo ablations were performed to compare the optimal EC-ethanol formulation to pure ethanol (n = 6). Ablations were monitored with CT and ethanol distribution volume was quantified. Livers were removed, sectioned and stained with NADH-diaphorase to determine the ablative extent, and a detailed time-course histological study was performed to assess the wound healing process. CT imaging of ethanol-water surrogates demonstrated the ethanol concentration-radiodensity relationship is approximately linear. A concentration of 12% EC in ethanol created the largest distribution volume, more than eight-fold that of pure ethanol, ex vivo. In vivo, 12% EC-ethanol was superior to pure ethanol, yielding a distribution volume three-fold greater and an ablation zone six-fold greater than pure ethanol. Finally, a time course histological evaluation of the liver post-ablation with 12% EC-ethanol and pure ethanol revealed that while both induce coagulative necrosis and similar tissue responses at 1-4 weeks post-ablation, 12% EC-ethanol yielded a larger ablation zone. The current study demonstrates the suitability of CT imaging to determine distribution volume and concentration of ethanol in tissue. The distribution volume of EC-ethanol is nearly equivalent to the resultant necrotic volume and increases distribution and necrosis compared to pure ethanol.

Minimally Invasive Management of Zinner's Syndrome with Same-Session Robot-Assisted Seminal Vesiculectomy and Ipsilateral Nephroureterectomy Using a Single Geometry of Trocars.

Background: Seminal vesicle cyst is an extremely rare condition, which is frequently congenital and associated with Zinner's syndrome. This syndrome represents a constellation of seminal vesicle cyst, ipsilateral or contralateral renal agenesis or renal dysplasia, ureteral ectopia, and ejaculatory duct obstruction. We report a young symptomatic patient undergoing robot-assisted laparoscopic excision of a huge seminal vesicle cyst during which an atrophic ipsilateral kidney was discovered incidentally and managed by nephroureterectomy in the same session without changing trocar positions. Case Presentation: A 23-year-old male patient presented with a 2-year history of lower urinary tract symptoms, perineal pain, and recurrent urinary tract infections. Ultrasonography revealed the absence of left kidney and a fluid-filled cystic lesion located behind the bladder on the left side, which was consistent with cystic dilatation of the left seminal vesicle. MRI confirmed the diagnosis of a huge cystic structure originating from the left seminal vesicle and identified the presence of a rudimentary left ureter without an associated renal unit. Cystoscopy revealed bulging of the bladder neck at 6 o'clock position and the ureteral orifices at normal positions and configurations. Based on these findings, the clinical diagnosis was established as Zinner's syndrome. The present case was performed by Da Vinci Si robotic platform using the 5-trocar technique. Conclusion: Robot-assisted laparoscopic excision is a safe and feasible option to treat large seminal vesicle cysts, which may be a component of Zinner's syndrome. Simultaneous upper urinary tract interventions, such as nephroureterectomy, can be employed by redocking the robot and repositioning the patient, using the same layout of robotic trocars.

False-Positive Pancreatic Uptake Detected on 68Ga-PSMA PET/CT: A Priority Changing Incidental Finding While Assessing the Need for a Prostate Biopsy.

A 72-year-old man underwent Ga-PSMA PET/CT because of an elevated prostate-specific antigen level despite prior prostatectomy. Besides low-intensity prostatic PSMA reactivities, a faintly PSMA-positive lesion in the pancreatic corpus drew attention, which seemed suggestive of a primary pancreatic cancer on the subsequent MRI and therefore had to be excised. The final diagnosis was pT3 low-grade neuroendocrine tumor. PSMA-positive incidentalomas, detected on Ga-PSMA PET/CT, can reveal more clinically significant extraprostatic disorders.

Evidence-based medical oncology and interventional radiology paradigms for liver-dominant colorectal cancer metastases.

Colorectal cancer metastasizes predictably, with liver predominance in most cases. Because liver involvement has been shown to be a major determinant of survival in this population, liver-directed therapies are increasingly considered even in cases where there is (limited) extrahepatic disease. Unfortunately, these patients carry a known risk of recurrence in the liver regardless of initial therapy choice. Therefore, there is a demand for minimally invasive, non-surgical, personalized cancer treatments to preserve quality of life in the induction, consolidation, and maintenance phases of cancer therapy. This report aims to review evidence-based conceptual, pharmacological, and technological paradigm shifts in parenteral and percutaneous treatment strategies as well as forthcoming evidence regarding next-generation systemic, locoregional, and local treatment approaches for this patient population.

Isolated omental metastasis of renal cell carcinoma after extraperitoneal open partial nephrectomy: A case report.

INTRODUCTION: Metachronous metastatic spread of clinically localized renal cell carcinoma (RCC) affects almost 1/3 of the patients. They occur most frequently in lung, liver, bone and brain. Isolated omental metastasis of RCC has not been reported so far. CASE PRESENTATION: A 62-year-old patient previously diagnosed and treated due to pulmonary sarcoidosis has developed an omental metastatic lesion 13 years after having undergone open extraperitoneal partial nephrectomy for T1 clear-cell RCC. Constitutional symptoms and imaging findings that were attributed to the presence of a sarcomatoid paraneoplastic syndrome triggered by the development this metastatic focus complicated the diagnostic work-up. Biopsy of the [18F]-fluorodeoxyglucose (+) lesions confirmed the diagnosis of metastatic RCC and the patient was managed by the resection of the omental mass via near-total omentectomy followed by targeted therapy with a tyrosine kinase inhibitor. DISCUSSION: Late recurrence of RCC has been reported to occur in 10-20% of the patients within 20 years. Therefore lifelong follow up of RCC has been advocated by some authors. Diffuse peritoneal metastases have been reported in certain RCC subtypes with adverse histopathological features. However, isolated omental metastasis without any sign of peritoneal involvement is an extremely rare condition. CONCLUSION: To our knowledge, this is the first reported case of metachronously developed, isolated omental metastasis of an initially T1 clear-cell RCC. Constitutional symptoms, despite a long interval since nephrectomy, should raise the possibility of a paraneoplastic syndrome being associated with metastatic RCC. Morphological and molecular imaging studies together with histopathological documentation will be diagnostic.

Osteolytic mass bridging two cervical vertebrae: Unusual presentation of a vertebral body hemangioma.

Vertebral hemangioma is the most common spinal axis tumor. This rare presentation of a vertebral hemangioma extended contiguously from one cervical vertebra to another, encasing the vertebral artery, and thereby mimicking other tumors of the spine. We discuss the differential diagnosis of bridging vertebral masses.