Clinical, dosimetric, and reporting considerations for Y-90 glass microspheres in hepatocellular carcinoma: updated 2022 recommendations from an international multidisciplinary working group.

PURPOSE: In light of recently published clinical reports and trials, the TheraSphere Global Dosimetry Steering Committee (DSC) reconvened to review new data and to update previously published clinical and dosimetric recommendations for the treatment of hepatocellular carcinoma (HCC). METHODS: The TheraSphere Global DSC is comprised of health care providers across multiple disciplines involved in the treatment of HCC with yttrium-90 (Y-90) glass microsphere-based transarterial radioembolization (TARE). Literature published between January 2019 and September 2021 was reviewed, discussed, and adjudicated by the Delphi method. Recommendations included in this updated document incorporate both the results of the literature review and the expert opinion and experience of members of the committee. RESULTS: Committee discussion and consensus led to the expansion of recommendations to apply to five common clinical scenarios in patients with HCC to support more individualized efficacious treatment with Y-90 glass microspheres. Existing clinical scenarios were updated to reflect recent developments in dosimetry approaches and broader treatment paradigms evolving for patients presenting with HCC. CONCLUSION: Updated consensus recommendations are provided to guide clinical and dosimetric approaches for the use of Y-90 glass microsphere TARE in HCC, accounting for disease presentation, tumor biology, and treatment intent.

Novel Use of Time-Resolved Magnetic Resonance Angiography to Evaluate Retrograde Lumbar Vein Flow and Epidural Venous Plexus Enhancement in Chronic Headache Patients With and Without Nutcracker Physiology.

OBJECTIVE: Compression of the left renal vein by the superior mesenteric artery, known as nutcracker phenomenon (NCP), can cause retrograde flow and congestion in communicating venous systems. It has recently been speculated that NCP can result in retrograde flow and congestion of the lumbar veins and epidural venous plexus (EVP), thereby affecting the central nervous system. This study describes the novel use of time-resolved magnetic resonance angiography (trMRA) to evaluate for retrograde left second lumbar vein (L2LV) flow and early EVP enhancement in patients with chronic daily headache (CDH) with and without NCP. METHODS: A retrospective analysis was performed of 31 patients with CDH (27 females and 4 males; median age, 38 years [range, 18-63 years]) who underwent trMRA centered over the L2LV to evaluate the direction of blood flow and presence of early EVP enhancement from May 2020 to March 2022. Descriptive statistics were performed, and anatomic associations were analyzed in patients with and without retrograde L2LV flow and early EVP enhancement. The accuracy of magnetic resonance imaging findings in detecting these flow patterns was also assessed. RESULTS: Patients with NCP who demonstrated narrowing of the left renal vein, a positive beak sign ( P = 0.052), decreased aortomesenteric distance ( P = 0.038), and decreased SMA angle demonstrated increased rates of retrograde L2LV flow and early EVP enhancement. A positive beak sign was 83% specific, and an aortomesenteric distance of ≤6.5 mm was 61% sensitive and 83% specific for identifying retrograde L2LV flow with early regional EVP enhancement in patients with CDH. CONCLUSIONS: Retrograde L2LV flow with early EVP enhancement in CDH patients can be effectively evaluated using trMRA and was seen with greater propensity in those patients with NCP.

Hepatocellular carcinoma radiation segmentectomy treatment intensification prior to liver transplantation increases rates of complete pathologic necrosis: an explant analysis of 75 tumors.

PURPOSE: To verify the correlation between yttrium-90 glass microsphere radiation segmentectomy treatment intensification of hepatocellular carcinoma (HCC) and complete pathologic necrosis (CPN) at liver transplantation. METHODS: A retrospective, single center, analysis of patients with HCC who received radiation segmentectomy prior to liver transplantation from 2016 to 2021 was performed. The tumor treatment intensification cohort (n = 38) was prescribed radiation segmentectomy as per response recommendations identified in a previously published baseline cohort study (n = 37). Treatment intensification and baseline cohort treatment parameters were compared for rates of CPN. Both cohorts were then combined for an overall analysis of treatment parameter correlation with CPN. RESULTS: Sixty-three patients with a combined 75 tumors were analyzed. Specific activity, dose, and treatment activity were significantly higher in the treatment intensification cohort (all p < 0.01), while particles per cubic centimeter of treated liver were not. CPN was achieved in 76% (n = 29) of tumors in the treatment intensification cohort compared to 49% (n = 18) in the baseline cohort (p = 0.013). The combined cohort CPN rate was 63% (n = 47). ROC analysis showed that specific activity ≥ 327 Bq (AUC 0.75, p < 0.001), dose ≥ 446 Gy (AUC 0.69, p = 0.005), and treatment activity ≥ 2.55 Gbq (AUC 0.71, p = 0.002) were predictive of CPN. Multivariate logistic regression demonstrated that a specific activity ≥ 327 Bq was the sole independent predictor of CPN (p = 0.013). CONCLUSION: Radiation segmentectomy treatment intensification for patients with HCC prior to liver transplantation increases rates of CPN. While dose strongly correlated with pathologic response, specific activity was the most significant independent radiation segmentectomy treatment parameter associated with CPN.

Radiation Segmentectomy for the Treatment of Solitary Hepatocellular Carcinoma: Outcomes Compared with Those of Surgical Resection.

PURPOSE: To investigate the outcomes of radiation segmentectomy (RS) versus standard-of-care surgical resection (SR). MATERIALS AND METHODS: A multisite, retrospective analysis of treatment-naïve patients who underwent either RS or SR was performed. The inclusion criteria were solitary hepatocellular carcinoma ≤8 cm in size, Eastern Cooperative Oncology Cohort performance status of 0-1, and absence of macrovascular invasion or extrahepatic disease. Target tumor and overall progression, time to progression (TTP), and overall survival rates were assessed. Outcomes were censored for liver transplantation. RESULTS: A total of 123 patients were included (RS, 57; SR, 66). Tumor size, Child-Pugh class, albumin-bilirubin score, platelet count, and fibrosis stage were significantly different between cohorts (P ≤ .01). Major adverse events (AEs), defined as grade ≥3 per the Clavien-Dindo classification, occurred in 0 patients in the RS cohort vs 13 (20%) patients in the SR cohort (P < .001). Target tumor progression occurred in 3 (5%) patients who underwent RS and 5 (8%) patients who underwent SR. Overall progression occurred in 19 (33%) patients who underwent RS and 21 (32%) patients who underwent SR. The median overall TTP was 21.9 and 29.4 months after RS and SR, respectively (95% confidence interval [CI], 15.5-28.2 and 18.5-40.3, respectively; P = .03). Overall TTP subgroup analyses showed no difference between treatment cohorts with fibrosis stages 3-4 (P = .26) and a platelet count of <150 × 109/L (P = .29). The overall progression hazard ratio for RS versus SR was not significant per the multivariate Cox regression analysis (1.16; 95% CI, 0.51-2.63; P = .71). The median overall survival was not reached for either of the cohorts. Propensity scores were calculated but were too dissimilar for analysis. CONCLUSIONS: RS and SR were performed in different patient populations, which limits comparison. RS approached SR outcomes, with a lower incidence of major AEs, in patients who were not eligible for hepatectomy.

Focal Nodular Hyperplasia and Focal Nodular Hyperplasia-like Lesions.

Focal nodular hyperplasia (FNH) is a benign lesion occurring in a background of normal liver. FNH is seen most commonly in young women and can often be accurately diagnosed at imaging, including CT, MRI, or contrast-enhanced US. In the normal liver, FNH frequently must be differentiated from hepatocellular adenoma, which although benign, is managed differently because of the risks of hemorrhage and malignant transformation. When lesions that are histologically identical to FNH occur in a background of abnormal liver, they are termed FNH-like lesions. These lesions can be a source of diagnostic confusion and must be differentiated from malignancies. Radiologists' familiarity with the imaging appearance of FNH-like lesions and knowledge of the conditions that predispose a patient to their formation are critical to minimizing the risks of unnecessary intervention for these lesions, which are rarely symptomatic and carry no risk for malignant transformation. FNH is thought to form secondary to an underlying vascular disturbance, a theory supported by the predilection for formation of FNH-like lesions in patients with a variety of hepatic vascular abnormalities. These include abnormalities of hepatic outflow such as Budd-Chiari syndrome, abnormalities of hepatic inflow such as congenital absence of the portal vein, and hepatic microvascular disturbances, such as those that occur after exposure to certain chemotherapeutic agents. Familiarity with the imaging appearances of these varied conditions and knowledge of their association with formation of FNH-like lesions allow radiologists to identify with confidence these benign lesions that require no intervention. Online supplemental material is available for this article. ©RSNA, 2022.

Promoting Surgical Resection through Future Liver Remnant Hypertrophy.

An inadequate future liver remnant (FLR) can preclude curative-intent surgical resection for patients with primary or secondary hepatic malignancies. For patients with normal baseline liver function and without risk factors, an FLR of 20% is needed to maintain postsurgical hepatic function. However, the FLR requirement is higher for patients who are exposed to systemic chemotherapy (FLR, >30%) or have cirrhosis (FLR, >40%). Interventional radiologic and surgical methods to achieve FLR hypertrophy are evolving, including portal vein ligation, portal vein embolization, radiation lobectomy, hepatic venous deprivation, and associating liver partition and portal vein ligation for staged hepatectomy. Each technique offers particular advantages and disadvantages. Knowledge of these procedures can help clinicians to choose the suitable technique for each patient. The authors review the techniques used to develop FLR hypertrophy, focusing on technical considerations, outcomes, and the advantages and disadvantages of each approach. Online supplemental material is available for this article. ©RSNA, 2022.

Interventional Management of Acquired Lymphatic Disorders.

The lymphatic system is a complex network of tissues, vessels, and channels found throughout the body that assists in fluid balance and immunologic function. When the lymphatic system is disrupted related to idiopathic, iatrogenic, or traumatic disorders, lymphatic leaks can result in substantial morbidity and/or mortality. The diagnosis and management of these leaks is challenging. Modern advances in lymphatic imaging and interventional techniques have made radiology critical in the multidisciplinary management of these disorders. The authors provide a review of conventional and clinically relevant variant lymphatic anatomy and recent advances in diagnostic techniques such as MR lymphangiography. A detailed summary of technical factors related to percutaneous lymphangiography and lymphatic intervention is presented, including transpedal and transnodal lymphangiography. Traditional transabdominal access and retrograde access to the central lymph nodes and thoracic duct embolization techniques are outlined. Newer techniques including transhepatic lymphangiography and thoracic duct stent placement are also detailed. For both diagnostic and interventional radiologists, an understanding of lymphatic anatomy and modern diagnostic and interventional techniques is vital to the appropriate treatment of patients with acquired lymphatic disorders. ©RSNA, 2022.

Prospective evaluation of lymphatic embolization as part of the treatment in dogs with presumptive idiopathic chylothorax.

OBJECTIVE: To describe the embolization technique and short-term clinical outcome in dogs undergoing lymphatic embolization (LE) as part of treatment for presumptive idiopathic chylothorax (IC). Additionally, to document findings in computed tomography lymphangiography (CTLa) following embolization. STUDY DESIGN: Prospective case series. ANIMALS: Eight client-owned dogs. METHODS: Dogs underwent CTLa followed by thoracic duct ligation (TDL), pericardiectomy (PC) and LE. A mixture of 3:1 lipiodol: n-butyl cyanoacrylate embolic solution was injected through a catheterized mesenteric lymphatic vessel via limited abdominal approach using intraoperative fluoroscopy. CTLa was scheduled for 12 weeks postoperatively, and long-term follow-up was obtained via telephone contact. RESULTS: LE was technically successful in six of the eight dogs; and clinically successful in five of the six dogs. In the unsuccessful dog, a diagnosis of lymphangiosarcoma was determined, and the owners elected for euthanasia. Five dogs who underwent successful LE underwent CTLa at 12 weeks. Complete resolution of pleural effusion occurred in three dogs and scant pleural effusion in two dogs. A robust lymphatic embolus preventing antegrade continuation of radiocontrast was documented in all five dogs. Five of the six dogs that underwent LE, were alive and clinically normal at 358-960 days postoperatively. CONCLUSIONS: LE is a feasible part of treatment for dogs with IC. Additionally, a robust lymphatic embolus and lack of radiocontrast flow past the embolus was documented at 12 weeks following surgery. CLINICAL SIGNIFICANCE: LE has the potential to reduce surgical failure by reducing efferent lymphatic chyle flow, occluding missed lymphatic branches and preventing the development of collateral branches.

Prognostic Significance of Neutrophil to Lymphocyte Ratio Dynamics in Patients with Hepatocellular Carcinoma Treated with Radioembolization Using Glass Microspheres.

PURPOSE: To study the prognostic significance of neutrophil and lymphocyte dynamics in patients with hepatocellular carcinoma (HCC) treated with radioembolization. METHODS: A retrospective, single-center review of clinical records and treatment parameters (liver volume treated, administered activity, and radiation dose) in consecutive patients who received radioembolization for HCC was performed between August 20, 2015, and May 24, 2019. Neutrophil and lymphocyte variables associated with overall survival (OS) were determined by Barcelona Clinic Liver Cancer (BCLC) stage and were correlated with radioembolization treatment parameters. Statistical methods included Wilcoxon signed-rank test, univariate, and multivariate Cox regression analysis; receiver operating characteristic analysis; and the Kaplan-Meier method. RESULTS: One hundred sixty-three patients with a median 67.0 years of age were included for analysis. Eighty-one percent of patients received segmental radioembolization with a median treatment dose of 358 Gray (interquartile range 256-497). The post-treatment lymphocyte count decreased significantly in 94.5 % (p < 0.001) of patients but was not predictive of OS (p = 0.248). The pre-procedure neutrophil to lymphocyte ratio (NLRpre) was not predictive of OS (p = 0.891), and the 1-month post-procedure NLR was a borderline independent predictor of OS (p = 0.05). The NLR ratio (NLRR = NLRpost-procedure/NLRpre) (Hazard ratio [HR], 1.31; 95% Cl, 1.04-1.66) and change in NLR (ΔNLR= NLRpost-procedure - NLRpre) (HR, 1.09; 95% CI, 1.02-1.15) were associated with worse OS in BCLC C patients. NLRR (> 3.17) and ΔNLR (> 3.74) were independent predictors when adjusted for tumor presentation, treatment parameters, and liver function. Volume of liver treated and administered activity positively correlated with NLRR and ΔNLR (p < 0.001). CONCLUSION: A decrease in lymphocyte count is common after radioembolization, but of little clinical impact. Neither pre-treatment or post-treatment NLR was a predictor of survival in our study population. NLRR and ΔNLR were independent predictors of survival in BCLC stage C disease and had positive correlations with volume of liver tissue treated and administered activity.

Natural History of Incidental Enhancing Nodules on Cone-Beam Computed Tomography during Transarterial Therapy of Hepatocellular Carcinoma.

PURPOSE: To evaluate the natural history of incidental enhancing nodules (IENs) on contrast-enhanced cone-beam computed tomography (CT) during transarterial treatment of hepatocellular carcinoma (HCC). MATERIAL AND METHODS: A single-center retrospective analysis of 100 patients with HCC who underwent contrast-enhanced cone-beam CT prior to transarterial treatment from August 2015 to June 2019 was performed. Inclusion criteria were patients with segmental distribution sublobar HCC, contrast-enhanced cone-beam CT of the target lesion and nontarget liver parenchyma, and follow-up cross-sectional imaging. Patients with IENs ≥3 mm that did not meet imaging criteria for HCC were analyzed. Exclusion criteria included biphenotypic tumors and IEN present inside the treated area of the liver. RESULTS: Fifty-six patients demonstrated 154 IENs on contrast-enhanced cone-beam CT, of which 13 IENs (8.5%) progressed to HCC. The mean primary tumor size was 29 mm (range: 10.2-189 mm). Ten patients had ≥4 IENs, and 46 patients had 1-3 IENs. The mean IEN size was 6.8 mm (range: 3.0-16.3 mm). The median follow-up interval after contrast-enhanced cone-beam CT was 282 days (interquartile range: 143-522). Increased alpha-fetoprotein before treatment (≥15.5 ng/mL, P = .035), having ≥4 IENs (P = .020), and hepatitis C virus (P = .015) were significantly correlated with IEN progression to HCC. No statistically significant differences were identified in baseline neutrophil-to-lymphocyte ratio, targeted HCC characteristics (size, macrovascular invasion, infiltrative pattern, enhancement pattern, and satellite lesions), and IEN size between those with IEN progression to HCC and those without. CONCLUSIONS: Most IENs of ≥3 mm on contrast-enhanced cone-beam CT in patients with segmental distribution sublobar HCC do not progress to HCC. Patients with segmental distribution sublobar HCC with ≥4 IENs, alpha-fetoprotein elevation (≥15.5 ng/mL), or hepatitis C virus have an increased risk of IEN progression to HCC.

Pathologic Response of Hepatocellular Carcinoma Treated with Yttrium-90 Glass Microsphere Radiation Segmentectomy Prior to Liver Transplantation: A Validation Study.

PURPOSE: To evaluate the pathologic outcomes of hepatocellular carcinoma (HCC) treated with Yttrium-90 radiation segmentectomy using glass microspheres prior to liver transplantation and explore parameters associated with pathologic necrosis. MATERIALS AND METHODS: A single-institution retrospective analysis of HCC patients who received radiation segmentectomy prior to liver transplantation from November 2016 to May 2020 was performed. Patients were included if the treatment angiosome encompassed the entire tumor and could be correlated with available gross pathology. Archived histology slides were reviewed for percentage of pathologic necrosis. Thirty-three patients with 37 tumors were evaluated. The median tumor size was 2.3 cm (range, 1-6.7 cm). RESULTS: All tumors received a single treatment. The median time from radiation segmentectomy to transplantation was 206 days (range, 58-550 days). Objective response per Modified Response Evaluation Criteria in Solid Tumors (mRECIST) was 92% (complete response, 76%; partial response, 16%). A total of 68% (n = 25) of tumors demonstrated ≥99% pathologic necrosis. Complete pathologic necrosis was present in 53% and 75% of tumors treated with >190 Gy (n = 18) and >500 Gy (n = 8) single-compartment Medical Internal Radiation Dose, respectively. Complete response per mRECIST, posttreatment angiosome T1 hypointensity, dose >190 Gy, microsphere specific activity >297 Bq, and a longer time between treatment and transplant were associated with ≥99% tumor necrosis (P < .05). No posttransplant tumor recurrences occurred within a median follow-up of 604 days (range, 138-1,223 days). CONCLUSIONS: Radiation segmentectomy can serve as an ablative modality for the treatment of HCC prior to liver transplant.

Percutaneous direct pancreatic duct intervention in management of pancreatic fistulas: a primary treatment or temporizing therapy to prepare for elective surgery.

BACKGROUND: This study evaluates preliminary results of image-guided percutaneous direct pancreatic duct intervention in the management of pancreatic fistula after surgery or pancreatitis when initially ineligible for surgical or endoscopic therapy. METHODS: Between 2001 and 2018 the medical records of all patients that underwent percutaneous pancreatic duct intervention for radiographically confirmed pancreatic fistula initially ineligible for surgical or endoscopic repair were reviewed for demographics, clinical history, procedure details, adverse events, procedure related imaging and laboratory results, ability to directly catheterized the main pancreatic duct, and whether desired clinical objectives were met. RESULTS: In 10 of 11patients (6 male and 5 female with mean age 60.5, range 39-89) percutaneous pancreatic duct cannulation was possible. The 10 duct interventions included direct ductal suction drainage in 7, percutaneous duct closure in 3 and stent placement in 1. Pancreatic fistulas closed in 7 of 10, 2 were temporized until elective surgery, and 1 palliated until death from malignancy. The single patient with failed duct cannulation resolved the fistula with prolonged catheter drainage of the peri-pancreatic cavity. There were no major adverse events related to intervention. CONCLUSION: In patients with pancreatic fistulas initially ineligible for endoscopic therapy or elective surgery, direct percutaneous pancreatic duct interventions are possible, can achieve improvement without major morbidity or mortality, and can improve and maintain the medical condition of patients in preparation for definitive surgery.

Transarterial Yttrium-90 Radioembolization of Hepatocellular Carcinoma Perfused by the Cystic Artery: Multi-institutional Feasibility Study.

PURPOSE: To assess the safety and efficacy of transarterial yttrium-90 radioembolization via the cystic artery for patients with hepatocellular carcinoma (HCC) adjacent to the gallbladder with cystic artery supply. MATERIALS AND METHODS: This retrospective study included 17 patients treated at 4 institutions. Patients with HCC perfused by the cystic artery who received ablative-dose radioembolization were included. Median tumor size was 3.8 cm (range, 2.0-8.8 cm). Fourteen patients (82%) had Child-Pugh class A cirrhosis and 3 (18%) had class B cirrhosis. Adverse events, tumor response, and time to progression were analyzed. RESULTS: Median dose to the tissue perfused by the cystic artery was 340 Gy (range, 200-720 Gy). There were no occurrences of acute cholecystitis warranting invasive intervention. Four patients (24%) experienced transient right upper quadrant pain, with symptom resolution within 3 mo. Six patients (35%) exhibited gallbladder wall edema on follow-up imaging. Two (12%) and 0 grade 3/4 increases in alkaline phosphatase and bilirubin were observed, respectively. Follow-up imaging demonstrated complete response in 13 target tumors (76%) and partial response in 4 (24%). There were no cases of target tumor progression during a median follow-up of 9 mo (range, 3-72 mo). CONCLUSIONS: Direct infusion of 90Y microspheres via the cystic artery appears to have an acceptable safety profile, without resulting in acute cholecystitis warranting invasive intervention. In selected patients with HCC in whom other treatments may be contraindicated and the tumor is supplied via the cystic artery, treatment with selective ablative radioembolization can be considered.

Increasing Yttrium-90 Dose Conformality Using Proximal Radioembolization Enabled by Distal Angiosomal Truncation for the Treatment of Hepatic Malignancy.

PURPOSE: To evaluate safety and feasibility of improving radiation dose conformality via proximal radioembolization enabled by distal angiosomal truncation where selective administration was not practical. MATERIALS AND METHODS: Hepatic malignancies treated via angiosomal truncation between January 2017 and March 2019 were retrospectively evaluated. Thirty-three patients (8 women, 25 men; mean age, 62.2 y; range, 36-78 y) underwent 39 treatments. Of treatments, 74.3% (n = 29) were for hepatocellular carcinomas, 10.2% (n = 4) were for cholangiocarcinomas, and 15.4% (n = 6) were for metastatic tumors (1 colorectal adenocarcinoma, 1 pancreatic adenocarcinoma, 3 melanomas, and 1 endometroid carcinoma). Truncation was achieved using temporary embolic devices including a microvascular plug, detachable coil, gelatin slurry, and balloon microcatheter, after which proximal radioembolization was performed. Range of treatment activity was 0.47-5.75 GBq. Technetium-99m macroaggregated albumin and bremsstrahlung single photon emission computed tomography (CT)/CT threshold analysis was conducted to delineate and compare distribution of activity within the treatment angiosome before and after radioembolization. RESULTS: Dosimetric analysis of 14 patients demonstrated a significant reduction in nontarget liver radiation exposure at 5, 20, and 40% thresholds (P = .002, P = .001, and P = .008, respectively). There were no grade 3 or higher adverse events. There was no significant change in Albumin-Bilirubin grade and Eastern Cooperative Oncology Group Performance Status (P = .09 and P = .74) before and 3 months after the procedure. Truncated arteries were patent on subsequent angiography in 11 cases and on MR angiography or CT angiography in 38 of 39 cases. CONCLUSIONS: Proximal radioembolization enabled by distal angiosomal truncation is safe and decreases nontarget parenchymal radioembolization dose in cases not amenable to selective administration.

Immunotherapy and the Interventional Oncologist: Challenges and Opportunities-A Society of Interventional Oncology White Paper.

Interventional oncology is a subspecialty field of interventional radiology that addresses the diagnosis and treatment of cancer and cancer-related problems by using targeted minimally invasive procedures performed with image guidance. Immuno-oncology is an innovative area of cancer research and practice that seeks to help the patient's own immune system fight cancer. Both interventional oncology and immuno-oncology can potentially play a pivotal role in cancer management plans when used alongside medical, surgical, and radiation oncology in the care of cancer patients.

Laparoscopic access to the liver and application of laparoscopic microwave ablation in 2 dogs with liver neoplasia.

OBJECTIVE: To determine laparoscopic accessibility of liver lobes and access to the hilus and describe laparoscopic microwave ablation (LMWA) in 2 dogs with hepatic neoplasia. STUDY DESIGN: Experimental/descriptive case series. SAMPLE POPULATION: Six canine cadavers and 2 clinical dogs. METHODS: Cadavers in dorsal recumbency underwent laparoscopic assessment of the liver. A 17 gauge MWA probe was inserted to create an ablation zone at the most proximal aspect of the hilus. The distance from the center of each ablation zone to the most proximal aspect of the corresponding hilus was determined. Two dogs with hepatic neoplasia underwent LMWA. RESULTS: All lobes of the canine liver were accessible via laparoscopy. The median (interquartile range) distances from the ablation zones to the hilus for the caudate process, left lateral, left middle, quadrate, right lateral, and right middle lobes were 2.2 (1.2-2.6), 2.1 (1-4.4), 1.5 (1.4-3.7), 2, 1, 2.5 (1-4.1) cm, respectively. Histopathologic diagnoses treated by LMWA included metastatic hemangiosarcoma and primary hepatocellular carcinoma. Laparoscopic microwave ablation was technically feasible, and no complications from the procedure resulted. CONCLUSION: Laparoscopic access to the hilus of each liver lobe is possible via a ventrodorsal approach provided reverse Trendelenburg and lateral rotation is used, especially for the right lateral lobe. Laparoscopic microwave ablation is feasible in some dogs with hepatic neoplasia. The indications for and efficacy of LMWA for hepatic neoplasia in dogs requires additional investigation. CLINICAL SIGNIFICANCE: Laparoscopic access to all liver lobes and MWA of some neoplastic lesions is feasible in a canine pilot study.

Safety of Radioembolization in the Setting of Angiographically Apparent Arterioportal Shunting.

PURPOSE: To retrospectively analyze adverse events (AE) in patients with hepatocellular carcinoma (HCC) treated with yttrium-90 radioembolization in the setting of angiographically apparent arterioportal shunts (APSs). MATERIALS AND METHODS: Thirty-two patients with HCC underwent radioembolization with APSs from January 2011 to September 2016, totaling 34 administrations using resin (6) and glass (28) microspheres. APSs were graded angiographically as segmental (9), ipsilobar (15), contralobar (7), or main portal (2), according to portal perfusion. Tumors were categorized as solitary (9), multifocal (7), or infiltrative (16). Both unilobar (25) and bilobar (7) disease was treated. Child Pugh Score was A (22), B (10), or C (2), with a median Model for End-Stage Liver Disease (MELD)/Na-MELD of 8/8.5. Median procedure dose was 132.6 Gy. AEs were graded using Combined Terminology Criteria for Adverse Events (CTCAE) version 4.0. Tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors (mRECIST). RESULTS: CTCAE grade ≥3 AEs were observed in 22% of patients. Barcelona Clinic Liver Cancer (BCLC) C patients with nonsegmental shunts who received lobar administrations had a grade ≥3 AE rate of 38% compared with the remaining cohort, which was 12% (P = .076). No events were reported in patients with segmental shunts (P = .023). Imaging analysis revealed mRECIST complete response (17), partial response (13), stable disease (3), and progressive disease (1). Overall survival at 6 months and 12 months was 72% and 57%, respectively. CONCLUSIONS: Radioembolization in the setting of APS may have a higher AE profile than reported literature when BCLC-C patients with nonsegmental shunts receive lobar administrations. Segmental shunts are generally well tolerated.

Comparison of Bleeding Complications between Transplenic versus Transhepatic Access of the Portal Venous System.

PURPOSE: To evaluate the incidence of bleeding complications between transplenic (TS) and transhepatic (TH) access in portal venous interventions. MATERIALS AND METHODS: Retrospective review of patients who underwent TS or TH access for portal venous system interventions from January 2000 to August 2017. Only procedures with clinical and laboratory follow-up were included (n = 148). Twenty-four TS procedures were performed in 22 patients, and 124 TH procedures were performed in 114 patients. The main indications were for angioplasty/stent, embolization of varices/shunt, or portal vein embolization, with no difference between the groups. Mean patient age and sex were not significantly different between the groups (P values .445 and .682, respectively). Mean follow up was 2.3 years (range 0.1-14.2). There was no significant difference between the international normalized ratio (P = .300) and platelets (P = .234) before the procedure between the 2 cohorts. RESULTS: Technical success of vascular access and procedural success was achieved in 22/24 (91.6%) TS procedures and 120/124 (96.8%) TH procedures (P = .238). There was no significant difference in bleeding complications between the 2 groups (3/24 [12.5%] TS vs 10/124 [8.1%] TH; P = .44). There was no significant difference in major bleeding complications (SIR classification ≥ C; 1/24 [4.2%] TS vs 4/124 [3.2%] TH; P = .789).There was no significant difference in the hemoglobin before or after the procedure (g/dL), with average change -1.1 g/dL (range -3.4 to +1.0) in the TS group and 1.0 g/dL (range -4.5 to +1.9) in the TH group (P = .540). Finally, there was no significant difference in proportion of patients requiring blood transfusion after the procedure (P = .520), with 2 (8.3%) in the TS group requiring an average of 4 units (range 2-6) and 17 (13.7%) in the TH group requiring an average of 3.5 units (range 1-26). CONCLUSIONS: These data suggest no significant difference in bleeding complications between TS and TH access for portal venous interventions.