Introduction to interventional radiology's role in palliative care for children with cancer: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

As palliative care continues to be an area of increasing emphasis in pediatric oncology programs, it is important to raise awareness about minimally invasive, image-guided procedures that can supplement more conventional palliative interventions, such as systemic analgesics, external beam radiation, and locoregional anesthesia. These procedures, when performed for appropriately selected patients, can often facilitate discharge from an inpatient facility, and help patients meet their end-of-life goals. This article specifically discusses three palliative procedures performed by interventional radiologists that can assist pediatric palliative care teams in: (a) percutaneous thermal ablation of painful bone metastases, (b) cryoneurolysis, and (c) tunneled drainage catheter placement for malignant pleural effusions and ascites.

Introduction to interventional oncology: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Interventional radiology (IR) is a valuable resource when caring for pediatric solid tumor patients. As minimally invasive, image-guided procedures become more relied upon to answer challenging diagnostic questions and provide alternative therapeutic options, IR is poised to become a contributing member of the multidisciplinary oncology team. Improved imaging techniques allow for better visualization during biopsy procedures, transarterial locoregional treatments have the potential to deliver targeted cytotoxic therapy while limiting systemic side effects, and percutaneous thermal ablation can be used to treat chemo-resistant tumors of various solid organs. Additionally, interventional radiologists are able to perform routine, supportive procedures for oncology patients that include central venous access placement, lumbar punctures, and enteric feeding tube placements with high levels of technical success and excellent safety profiles.

Baseline Quality of Life in Pediatric Patients With Low-flow Vascular Malformations.

OBJECTIVE: The aim of this study was to quantify and describe baseline patient and parent-proxy health-related quality of life scores in patients with low-flow vascular malformations at a single, tertiary-care vascular anomalies clinic. STUDY DESIGN: This is a retrospective study of data collected on patients with low-flow vascular malformations between the ages of 2 to 25 who were seen at a single, tertiary-care center vascular anomalies clinic. A total of 266 patients are included in this study. RESULTS: Patients with lymphatic malformations report decreased quality of life scores as compared with venous malformations in the emotional, psychological, school, and social domains. Patients with lower extremity malformation report decreased quality of life scores as compared with head/neck, trunk, upper extremity, and multifocal malformations; most notably in the physical domain. CONCLUSIONS: Treatment of low-flow vascular malformations should aim to improve patient quality of life. The use of standardized health-related quality of life measures in this study quantifies baseline quality of life scores among patients with low-flow vascular malformations.

Coagulopathy and related complications following sclerotherapy of congenital venous malformations.

BACKGROUND: Congenital venous malformations (VMs) are low-flow vascular anomalies that can cause coagulation abnormalities. This phenomenon, referred to as localized intravascular coagulopathy (LIC), is characterized by elevated D-dimer, hypofibrinogenemia, and/or thrombocytopenia. Increased risk for LIC includes patients with an extensive VM, multifocal VM, and Klippel-Trenaunay and CLOVES syndromes. Peri-procedural anticoagulation has been given to prevent complications from LIC in patients undergoing surgical/interventional procedures; however, the rate of clinically relevant complications from sclerotherapy is largely unknown. The purpose of this study is to describe a single-institution's incidence of LIC in patients with VMs and coagulopathy-related complications following sclerotherapy. DESIGN/METHODS: Retrospective chart review of patients, 0-21 years of age, with VM who underwent sclerotherapy without peri-procedural anticoagulation and had coagulation profiles evaluated within 1 month prior to sclerotherapy. DATA COLLECTED: diagnosis type (high vs. low risk for LIC), coagulation profile (including PT/PTT, D-dimer, fibrinogen, and platelet count), sclerosant used, and post-procedure outcomes. Coagulopathy-related complications included clinically relevant bleeding, deep vein thrombosis (DVT), and pulmonary embolism (PE). RESULTS: N = 138 patients; 59.4% were female. The most common location of VM was the lower extremity (47.8%; 66/138). Of patients with high-risk VMs (29/138 [21%]), 11/29 (37.9%) had laboratory values consistent with LIC, whereas 5% (5/109) of low-risk VMs had LIC. In sum, 492 sclerotherapy procedures were performed with no complications of bleeding, DVT, or PE. CONCLUSION: Patients undergoing sclerotherapy for VM with abnormal coagulation profiles may not require peri-procedural low molecular weight heparin (LMWH). Further studies are needed to precisely define which patients would benefit from anticoagulation.

Percutaneous image-guided treatment of aneurysmal bone cysts: is there a superior treatment option?

BACKGROUND: Aneurysmal bone cysts (ABCs) are often treated with intralesional surgery (curettage) with or without adjuvant treatments. Side effects and conflicting results regarding recurrence rates do not suggest one clearly superior therapy. Percutaneous therapeutic options including sclerotherapy and thermal ablation have gained popularity as potential alternatives. OBJECTIVE: The purpose of this retrospective review is to report this institution's experience and results of various image-guided minimally invasive treatments in a single institution series of cases referred to interventional radiology by orthopedic surgery after surgical failure or in patients with anatomically challenging ABCs. MATERIALS AND METHODS: This study identified all patients ≤18 years old who received percutaneous therapy for an ABC, including cryoablation, doxycycline sclerotherapy, microwave ablation or a combination of these modalities. Procedural details, complications, imaging follow-up and clinical follow-up were analyzed. RESULTS: A total of 21 patients received 41 procedures, with major complications seen in 7.7% (3/39) of procedures involving cryoablation or doxycycline sclerotherapy. Patients receiving cryoablation required an average of 1.7 procedures (median: 1 procedure, range: 1-4 procedures) while patients receiving doxycycline sclerotherapy required an average of 3 procedures (median: 2 procedures, range: 1-6 procedures). Patients were followed clinically and with computed tomography or magnetic resonance imaging (average: 23.9 months, range: 3.9-68.3 months). Follow-up imaging demonstrated improvement in 17 (85%) patients. Clinically, 93.8% (15/16) of patients who presented with fracture or pain had markedly reduced or absent pain as well as no fractures. CONCLUSION: Percutaneous image-guided treatment of ABCs demonstrates a favorable efficacy and safety profile. Adding cryoablation may lead to fewer total procedures than using doxycycline sclerotherapy alone.

Longitudinal outcomes one year following implicit bias training in medical students.

PURPOSE: Training in implicit bias is broadly recognized as important in medical education and is mandated by some accrediting bodies. This study examined medical students' retention of concepts immediately following and one-year post participation in an implicit bias workshop. METHODS: Study subjects were 272 third-year medical students who participated in workshops held between 2018-2020 that used the Implicit Associations Test (IAT) as a trigger for discussions in small groups. We developed a survey and administered it to students to capture their awareness of implicit bias pre-, post-, and one-year post-workshop attendance. Repeated Measures Analyses and independent-samples t-tests were used to examine for differences in responses on each of the seven survey items and a tabulated 7-item average of these seven items. RESULTS: Six of seven survey items and the tabulated 7-item average examined by Repeated Measures Analyses showed statistically significant increases between the pre-, post-, and one-year post-surveys (ps range: 0.01-0.07), with a small to moderate effect sizes (ƞp2s range: 0.01-0.07). Pairwise comparisons among these three surveys' results indicated statistically significant improvements between the pre- and the post-workshop surveys (ps range: 0.01-0.03) but no statistically significant differences between the post- and the one-year post-workshop surveys (ps range: 0.57-0.99). A separate sample of 17 off-cycle students who took the one-year post- workshop survey two years after the workshop did not differ statistically on the level of awareness of bias compared to those taking the same survey one year later, as examined by the two-group independent t-tests for the seven one-year post-workshop survey items (ps range: 0.56-0.99). CONCLUSIONS: The findings support one-year retention of knowledge and attitudes gained from an implicit bias workshop and suggest similar retention at two years. Future educational interventions that train learners to recognize and manage implicit and explicit behaviors in clinical practice are needed.

Endovascular management of nutcracker syndrome in an adolescent patient population.

BACKGROUND: Nutcracker syndrome is defined as left renal vein compression with concomitant clinical symptoms that include flank pain and hematuria. Historically, pediatric and adolescent patients with mild symptoms of nutcracker syndrome were simply observed while those with more severe symptoms underwent left renal vein transposition. Endovascular stenting of the left renal vein is a potentially efficacious and less invasive alternative for managing nutcracker syndrome in adolescents. OBJECTIVE: The purpose of this study was to investigate the technical feasibility, efficacy and safety of left renal vein stenting in adolescents with nutcracker syndrome. MATERIALS AND METHODS: We conducted a retrospective review of electronic medical records and imaging archives to identify adolescents undergoing endovascular stenting for nutcracker syndrome. We reviewed patient demographics including age, gender, presenting symptoms and diagnostic imaging findings. We compared pre- and post-stent deployment intravascular ultrasound (IVUS) and venography and evaluated patient symptoms in clinic up to 6 months following stent placement. RESULTS: Ten patients (average age 16 years, range 12-20 years) underwent 13 procedures. Initial symptoms included pain (n=10) and gross hematuria (n=5). Diagnostic imaging studies included CT abdomen pelvis (n=8), retroperitoneal US (n=6), MRI abdomen/pelvis (n=4), scrotal US (n=2), pelvic US (n=1) and renal Doppler US (n=2). Venography and IVUS demonstrated venous collaterals, proximal blanching at the left-renal-vein-IVC junction, pre-stenotic dilation and intraluminal compression. Most patients (n=9) experienced symptomatic resolution; however, three patients required reintervention to achieve asymptomatic status. No periprocedural complications occurred. CONCLUSION: In this carefully selected adolescent cohort, left renal vein stenting for nutcracker syndrome was often technically feasible, safe and effective in symptom management.

Facilitators and Barriers in Cross-Country Transport of Evidence-based Preventive Interventions: a Case Study Using the Family Check-Up.

This study is a qualitative analysis of facilitators and barriers in the dissemination of Family Check-Up (FCU), a U.S.-developed preventive intervention in Sweden. The FCU is inherently culturally flexible because it was designed to be tailored to each family's needs and context, including cultural norms and values. We present the FCU implementation framework (IF) as a conceptual framework for cross-country transport of the FCU and evidence-based programs (EBP) more generally. The FCU IF draws from implementation science literature and involves specifying barriers and facilitators related to implementation drivers (e.g., competency) at each implementation phase and applying these data to inform phase-specific, readiness-building activities for each driver. In addition to driver-related influences, barriers and facilitators specific to the FCU and the collaborative partnership between the U.S. and Swedish purveyors emerged in the data. The partnership's reliance on a hybrid bottom-up, top-down approach that balanced the Swedish purveyor's autonomy and cultural expertise with guidance from the U.S. purveyor facilitated adaptation of the FCU for Sweden. Relying on previously collected data, we also explored similarities and differences in barriers and facilitators to FCU scale-up in the United States versus Sweden. In general, across drivers, the same barriers and facilitators were salient. This study suggests that dissemination of culturally flexible EBPs guided by a dynamic implementation framework can facilitate cross-country transport of EBPs. This study promotes a culture of prevention by highlighting barriers, facilitators, and readiness-building strategies that influence the cross-cultural transportability of EBPs that prevent the onset and escalation of child problem behavior.

No place like home redesign: home-based clinical care as an interprofessional training model for medical and pharmacy students.

Proper program assessment is necessary to ensure the delivered curriculum aligns with the intended curriculum. No Place Like Home (NPLH) is an interprofessional experience in which a healthcare team provides clinical services to patients in a home environment. Following review of program evaluation data, we determined the original design of NPLH was not meeting the intended objectives, and NPLH was redesigned in January 2018. Changes include lengthening the experience, decreasing the team size, improving assessment tools and additional training for the preceptors. The revised curriculum includes a care team with a preceptor, a medical, and a pharmacy student who visit four to six patients on an assigned day. From May 1, 2018 to April 30, 2019, there were 320 students who participated in NPLH. The preceptor assessments of students across the five objectives had mean scores of 3.4-3.7 on a 4 point scale indicating that on average preceptors placed students between Demonstrates Competence and Demonstrates Excellence for all objectives. When students were asked to compare their ability to collaborate interprofessionally after NPLH to the time before, 79% stated Somewhat Better Now or Much Better Now. It is not sufficient to create interprofessional learning activities and assume learning objectives are being met. Ongoing performance assessment and curricular evaluation are essential to ensure such goals are achieved. When intended objectives are not being met, it is possible to make deliberate and purposeful changes to redirect interprofessional learning experiences while maintaining the integrity, novelty and uniqueness of the experience.

Catheter-Directed Pharmacologic Thrombolysis for Acute Submassive and Massive Pulmonary Emboli in Children and Adolescents-An Exploratory Report.

OBJECTIVES: The objective of this study is to report a single-center experience of the safety and efficacy of pulmonary artery catheter-directed thrombolysis for both massive and submassive pulmonary emboli in the pediatric and adolescent population. DESIGN: A 22-month retrospective review of the electronic medical record and picture archiving and communication system was performed of patients less than 21 years old, presenting with massive or submassive pulmonary emboli treated with pulmonary artery catheter-directed thrombolysis at a single, tertiary care pediatric hospital. Multiple variables were analyzed including indications, technical success, clinical efficacy, and complications. SETTING: A single, tertiary care pediatric hospital. PATIENTS: Nine patients (mean 13.9 yr; range 6-19 yr) with massive and/or submassive pulmonary emboli who underwent pulmonary artery catheter-directed thrombolysis met inclusion criteria. INTERVENTIONS: Catheter-directed thrombolysis. MEASUREMENTS AND MAIN RESULTS: Pulmonary emboli was diagnosed by CT angiography in all cases. Catheter-directed thrombolysis alone was clinically successful (defined as improved cardiopulmonary function following catheter-directed thrombolysis) in seven patients (78%) with two patients not improving following catheter-directed thrombolysis. There were no immediate bleeding complications from catheter-directed thrombolysis therapy. All patients were maintained on anticoagulation treatment following catheter-directed thrombolysis. Catheter-directed thrombolysis was technically successful (defined as successful placement of pulmonary artery infusion catheters with full or partial resolution of thrombus) in all cases. Follow-up pulmonary angiography at the cessation of catheter-directed thrombolysis revealed complete thrombus resolution in four patients (44%) and partial resolution in five patients (55%). Mean pulmonary artery pressures decreased in all patients (mean precatheter-directed thrombolysis pulmonary artery pressure = 37 ± 11 mm Hg; mean postcatheter-directed thrombolysis pulmonary artery pressure = 28 ± 10 mm Hg; p = 0.0164). CONCLUSIONS: Pulmonary artery catheter-directed thrombolysis is a technically feasible therapeutic option for children and adolescents with submassive and massive pulmonary emboli.

Technical Feasibility and Clinical Effectiveness of Transjugular Intrahepatic Portosystemic Shunt Creation in Pediatric and Adolescent Patients.

PURPOSE: To examine the technical feasibility and clinical efficacy of transjugular intrahepatic portosystemic shunt (TIPS) creation in children and adolescents. MATERIALS AND METHODS: Retrospective review was performed of 59 patients (mean age 12.6 y [range, 1.5-20 y], mean weight 47.5 kg [range, 11.4-112.2 kg], mean Model for End-stage Liver Disease/Pediatric End-stage Liver Disease score 12.5 [range, 6-33]) who underwent 61 TIPS attempts at 3 tertiary children's hospitals from 2001 to 2017 for acute esophageal or gastroesophageal variceal bleeding, primary and secondary prevention of variceal bleeding, and refractory ascites. Pediatric liver disease etiologies included biliary atresia, cystic fibrosis, and ductal plate anomalies. Technical, hemodynamic, and clinical success and patency rates were reported at 1, 6, 12, and 24 months. Statistical analysis evaluated reasons for clinical failure. Kaplan-Meier analysis measured clinical success, patency, and transplant-free survival. RESULTS: Technical success was 93.4% (57/61) in 59 consecutive patients. Most common TIPS indications were treating and preventing esophageal and gastroesophageal variceal bleeding (57/59; 96.6%). Hemodynamic success was 94% (47/50). Clinical success was 80.7% (45/56). Two-year clinical success for acute variceal bleeding and ascites was 94.1% and 100%, respectively. Overall patency at 1, 6, 12, and 24 months was 98.0%, 97.8%, 94.3%, and 91.3%. Two-year transplant-free survival was 88.8%. Overall and major complication rates were 21.2% (13/61) and 8.2% (5/61), with 3 mortalities. Gradient reduction < 12 mm Hg correlated with clinical success (P < .01). CONCLUSIONS: TIPS creation in pediatric patients is technically feasible and clinically efficacious for treatment and prevention of esophageal and gastroesophageal variceal hemorrhage. High 2-year clinical success, patency, and survival rates should encourage providers to consider portosystemic shunts as a bridge to liver transplantation.

Congenital Limb Overgrowth Syndromes Associated with Vascular Anomalies.

Congenital limb length discrepancy disorders are frequently associated with a variety of vascular anomalies and have unique genetic and phenotypic features. Many of these syndromes have been linked to sporadic somatic mosaicism involving mutations of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, which has an important role in tissue growth and angiogenesis. Radiologists who are aware of congenital limb length discrepancies can make specific diagnoses based on imaging findings. Although genetic confirmation is necessary for a definitive diagnosis, the radiologist serves as a central figure in the identification and treatment of these disorders. The clinical presentations, diagnostic and imaging workups, and treatment options available for patients with Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular anomalies, epidermal nevi, and scoliosis/spinal deformities) syndrome, fibroadipose vascular anomaly, phosphatase and tensin homolog mutation spectrum, Parkes-Weber syndrome, and Proteus syndrome are reviewed. ©RSNA, 2019.

Cone-beam computed tomography guidance with navigational overlay for percutaneous lung nodule biopsy.

BACKGROUND: Cone-beam CT is increasingly used in pediatric interventional radiology procedures. However, the feasibility or safety of using this mode of imaging guidance for percutaneous lung nodule biopsy in children has not been assessed. OBJECTIVE: To retrospectively evaluate safety and diagnostic accuracy of percutaneous lung nodule biopsy in people treated at a pediatric hospital using cone-beam CT with navigational overlay. MATERIALS AND METHODS: Thirty-six consecutive patients from two large tertiary-care children's hospitals with lung nodules of 48 mm or smaller underwent percutaneous lung nodule biopsy using cone-beam CT with navigational overlay. We evaluated patient demographics, pre- and post-biopsy diagnoses, number of biopsy passes, complications, radiation exposure and technical success. RESULTS: Percutaneous lung nodule biopsy was performed for 37 nodules in 36 patients (23 males, 13 females, median age 15.5 years, range 8 months to 23 years). One patient underwent biopsy of two nodules at a single procedure. Median patient weight was 55 kg (range 8-97 kg). Pre-biopsy diagnoses included metastatic sarcoma or other solid tumor (n=11), leukemia/lymphoma (n=13), infection (n=10), chronic granulomatous disease (n=2) and post-transplant lymphoproliferative disorder (PTLD; n=1). Mean number of passes was 5 (range 2-15). Mean pre-procedure international normalized ratio (INR) was 1.1 and platelet count 193 × 109/L. Diagnostic specimens were obtained in 32 of 36 patients (89%). Thirteen complications were encountered in 12 patients (33% of cohort), including 9 pneumothoraces (4 requiring chest tubes); 1 hemothorax, which required a chest tube; and 3 self-limited pulmonary hemorrhages. Mean and median radiation doses were as follows: fluoroscopy time 3 min and 2.4 min, dose-area product (DAP) (recorded in 31 patients) 23,402 Gy·cm2 and 12,453 Gy·cm2, and air kerma 88 mGy and 58 mGy. CONCLUSION: Percutaneous lung nodule needle biopsy can be performed accurately using cone-beam CT with navigational overlay.

Percutaneous Image-Guided Treatment of Benign Musculoskeletal Tumors in Children.

Percutaneous ablation of benign musculoskeletal tumors in children has become an area of significant clinical growth over the last decade. With growing research interest, the technologies available and techniques used are becoming increasingly safe and effective. We review some of the more common ablation technologies and their utility in several common benign bone and soft tissue tumors that occur in children and young adults.

Image-guided placement of percutaneous de novo low-profile gastrojejunostomy tubes in the pediatric population: a study of feasibility and efficacy.

BACKGROUND: De novo low-profile gastrojejunostomy tubes in pediatric patients offer less external catheter bulk and decreased propensity for dislodgement as children become more mobile. While small cohort studies have evaluated de novo placement of coaxial, adjustable-length, percutaneous gastrojejunostomy (GJ) tubes in children, placement of de novo low-profile GJ tubes in pediatric patients has not been analyzed. OBJECTIVE: This study evaluates technical feasibility, safety and clinical efficacy of percutaneous, retrograde placement of de novo low-profile GJ tubes in infants and children. MATERIALS AND METHODS: Following institutional review board approval, all de novo low-profile GJ tube placements in patients were retrospectively reviewed between May 2014 and May 2017. Technical parameters of fluoroscopy time, tube size, T-fasteners and complications were recorded. Clinical data, including age, indication, weight gain and complications, were analyzed. RESULTS: Thirty-four de novo low-profile GJ tubes were placed in 34 patients (median age: 9.4 months, range: 2 months-11.8 years; median pre-procedural weight: 7.5 kg, range: 2.9-31.6 kg). Twenty-one 14-Fr and 13 16-Fr GJ tubes were placed with technical success rate of 100%. Average weight gain 3 months' post procedure was 1.1 kg (range: 0.3-4.8 kg) and average weight percentile for age increase was 9.6% (range: -48.9% to 53.5%). One major complication occurred following balloon inflation within the tract causing pain requiring urgent replacement of the GJ tube. Minor complications occurred in 11 patients (32%): accidental dislodgement (n=9), skin irritation (n=4), tube dysfunction (n=2), leakage (n=2) and tube migration into the esophagus (n=1). CONCLUSION: Percutaneous, antegrade, image-guided placement of de novo low-profile GJ tubes is technically feasible, safe and clinically efficacious in appropriately selected pediatric patients.

Transsplenic splenoportography and portal venous interventions in pediatric patients.

BACKGROUND: Data regarding transsplenic portal venous access for diagnostic imaging and endovascular intervention in children are limited, possibly due to concerns regarding high bleeding risks and resultant underutilization. OBJECTIVE: To investigate the safety and utility of transsplenic splenoportography and portal venous interventions in children. MATERIALS AND METHODS: A retrospective review was performed of all pediatric patients undergoing percutaneous transsplenic portal venous access and intervention at two large tertiary pediatric institutions between January 2012 and April 2017 was performed. Parameters assessed included procedural indications, procedural and relevant prior imaging, technical details of the procedures, laboratory values and clinical follow-up. RESULTS: Transsplenic portal venous access was achieved in all patients. Diagnostic transsplenic splenoportography was performed in 22 patients and was 100% successful at providing the desired anatomical and functional information. Four transsplenic portal venous interventions were performed with 100% success: meso-Rex shunt angioplasty, snare targeted transjugular intrahepatic portosystemic shunt (TIPS) creation through cavernous transformation, pharmacomechanical thrombectomy for acute thrombosis, and transplant portal vein angioplasty. Intraperitoneal bleeding occurred in 2/26 (7.7%) and one case required transfusion (3.8%). No cases of hemorrhage were observed when transsplenic access size was 4 Fr or smaller. CONCLUSION: Transsplenic splenoportography in children is safe and effective when noninvasive imaging methods have yielded incomplete information. Additionally, a transsplenic approach has advantages for complex portal interventions. Bleeding risks are proportional to tract access size and may be mitigated by tract embolization.

Role of interventional radiology in managing pediatric liver tumors : Part 2: percutaneous interventions.

Hepatoblastoma and hepatocellular carcinoma (HCC) are the most common pediatric liver malignancies, with hepatoblastoma occurring more commonly in younger children and HCC occurring more commonly in older children and adolescents. Although surgical resection (including transplant when necessary) and systemic chemotherapy have improved overall survival rate for hepatoblastoma to approximately 80% from 30%, a number of children with this tumor type are not eligible for operative treatment. In contradistinction, pediatric HCC continues to carry a dismal prognosis with an overall 5-year survival rate of 30%. The Paediatric Hepatic International Tumour Trial (PHITT) is an international trial aimed at evaluating both existing and emerging oncologic therapies for primary pediatric liver tumors. Interventional radiology offers a number of minimally invasive procedures that aid in diagnosis and therapy of pediatric liver tumors. For diagnosis, the PHITT biopsy guidelines emphasize and recommend percutaneous image-guided tumor biopsy. Additionally, both percutaneous and endovascular procedures provide therapeutic alternatives that have been, to this point, only minimally utilized in the pediatric population. Specifically, percutaneous ablation offers a number of cytotoxic technologies that can potentially eradicate disease or downstage children with unresectable disease. Percutaneous portal vein embolization is an additional minimally invasive procedure that might be useful to induce remnant liver hypertrophy prior to extended liver resection in the setting of a primary liver tumor. PHITT offers an opportunity to collect data from children treated with these emerging therapeutic options across the world. The purpose of this manuscript is to describe the potential role of minimally invasive percutaneous transhepatic procedures, as well as review the existing data largely stemming from the adult HCC experience.

Role of interventional radiology in managing pediatric liver tumors : Part 1: Endovascular interventions.

Primary liver malignancies are rare in children. Hepatoblastoma and hepatocellular carcinoma (HCC) together represent the overwhelming majority of cases. Overall survival of hepatoblastoma approaches 80% with multimodal treatment approaches that include chemotherapy, surgery and transplantation. However, there remains a subset of children with hepatoblastoma in whom resection or transplantation is not possible. The 5-year survival for children diagnosed with HCC is less than 30% and remains a significant therapeutic challenge. The poor outcomes for children with primary liver tumors motivate investigation of new therapeutic alternatives. Interventional oncology offers a broad scope of percutaneous and transcatheter endovascular cancer therapies that might provide clinical benefits. Minimally invasive approaches are distinct from medical, surgical and radiation oncologic treatments, and in adults these approaches have been established as the fourth pillar of cancer care. Transarterial chemoembolization is a minimally invasive locoregional treatment option performed by interventional radiologists with level-I evidence as standard of care in adults with advanced liver malignancy; transarterial chemoembolization in adults has served to prolong disease-free progression, downstage and bridge patients for surgical and transplant interventions, and improve overall survival. However, while several groups have reported that transarterial chemoembolization is feasible in children, the published experience is limited primarily to small retrospective case series. The lack of prospective trial evidence has in part limited the utilization of transarterial chemoembolization in the pediatric patient population. The purpose of this article is to provide an overview of the role of interventional radiology in the diagnosis and endovascular management of hepatic malignancies in children.