2017 PRETEXT: radiologic staging system for primary hepatic malignancies of childhood revised for the Paediatric Hepatic International Tumour Trial (PHITT)

Radiological and clinical signatures to differentiate hepatocellular carcinoma from hepatoblastoma in children older than 5 years of age: a feasibility study

BACKGROUND

Hepatoblastoma and hepatocellular carcinoma (HCC) are the most common primary malignant liver tumors in children. Although some characteristic imaging findings have been described in both hepatoblastoma and HCC, it is difficult to distinguish between these two tumors over the 5 years of age.

OBJECTIVE

To investigate clinical and radiological findings that may help differentiate hepatoblastoma and HCC over 5 years of age.

MATERIALS AND METHODS

From 2007 to 2022, 19 consecutive patients older than 5 years old diagnosed with primary liver malignancy were yielded from our radiology archive retrospectively. Imaging features, age, sex, treatment, and follow-up data were recorded.

RESULTS

A total of 19 patients (16 boys; median age 7.5, min-max 5-17), ten HCCs and nine hepatoblastomas, were included. Serum alpha-fetoprotein (sAFP) values were significantly higher in hepatoblastoma patients (n=9), compared to the HCC (n=10) (P=0.002). Tumor size and PRETEXT stages were higher in hepatoblastoma patients; however, there was no statistical difference (P=0.06). Initial MRI was available for six patients with hepatoblastoma and seven patients with HCC, and there was no difference regarding ADCmin values.

CONCLUSION

In the differential diagnosis of primary malignant liver tumor in a child older than 5 years of age, higher sAFP level may support the diagnosis of hepatoblastoma rather than HCC.

Tumor ablation in children

Tumor ablation represents an increasingly important topic in pediatric interventional radiology. Many ablative techniques are well known and established in the adult population, and the adoption of these techniques in the pediatric field is increasing. Image-guided tumor ablation represents a wide category of interventional radiology procedures that can be applied to both benign and malignant pediatric solid tumors. Tumor ablation, either alone or in combination with locoregional therapy, can have curative, debulking, or palliative effects on a wide variety of histological tumor types.

Image-Guided Biopsy for the Diagnosis and Molecular Profiling of Hepatoblastoma

INTRODUCTION

Studies on the use of image-guided percutaneous biopsy for hepatoblastoma (HB), and recommendations put forth by the pediatric hepatic international tumor trial (PHITT), are limited. It is unknown if sufficient tissue can be obtained for trial enrollment as well as molecular profiling, which will likely play a key role in informing future treatment strategies.

METHODS AND MATERIALS

Patients with HB who underwent percutaneous biopsy at initial diagnosis in interventional radiology (IR) over a 12-year period at a single center were included. Patient demographics, pretreatment extent of disease (PRETEXT) stage, tumor size, and procedure details were collected. Pathology reports and tumor genomic analysis, when performed, were assessed for specimen adequacy. Post-procedure records were assessed for hemoperitoneum.

RESULTS

A total of 33 percutaneous biopsies were performed on 32 patients [17 female; median age 1.3 years (IQR: 0.7-2.5 years); median weight 10.5 kg (IQR: 7.4-12.7 kg)]. Most (n = 27) had a single liver lesion, and most (n = 18) were PRETEXT II. A total of 15 were positive for at least one annotation factor. Median longest tumor axis was 9.3 cm (IQR: 5.0-13.5 cm). A total of 16 patients had concurrent non-targeted liver biopsy, per PHITT recommendations. An 18-gauge instrument was most commonly used (n = 24, 73%) with a median of 8 cores (IQR: 6-12) obtained. There were no instances of hemoperitoneum. Tissue was adequate for histologic diagnosis in 97% (n = 32), with histologic subtyping obtained in 94% (30/32). When available (n = 29), comparison with the subsequent surgical resection specimen showed subtype concordance in 15 (52%) patients and minor variations secondary to sampling or treatment effect in 14 patients. Molecular profiling was completed on 21/21 specimens (100%), with 19/21 (90%) showing potentially clinically significant variants, most commonly in CTNNB1 (16/21).

CONCLUSION

In this single-center study, percutaneous biopsy resulted in no serious adverse events, a high rate of diagnosis, and successful subtyping and molecular characterization of HB.

Surgical Strategy for Pediatric Liver Tumors Involving the Hepatic Venous Confluence and the Inferior Vena Cava

BACKGROUND

Pediatric liver tumors presenting as centrally located masses with contact to or even invasion of all three hepatic veins (HVs) and the inferior vena cava (IVC) present significant surgical challenges. While liver transplantation may be indicated in truly unresectable tumors, extended liver resection with vascular reconstruction can be an organ-preserving alternative.

OBJECTIVE

This study aimed to present a reference center's strategy for children with liver tumors involving the hepatic venous confluence or the retrohepatic IVC who underwent extended liver resection with vascular reconstruction.

METHODS

All pediatric patients undergoing major hepatectomy with reconstruction of an HV or the IVC over a 10-year study period were included. Preoperative imaging, surgical techniques, and short- and long-term postoperative data were analyzed.

RESULTS

From a total of 125 pediatric major hepatectomies, 17 children (15 hepatoblastoma, two undifferentiated embryonal sarcoma) underwent liver resection with vascular reconstruction of an HV or the IVC. In nine cases an HV was reconstructed, and in eight children, a partial resection of the IVC was performed. Total vascular exclusion of the liver was applied in 16/17 cases. No 90-day postoperative mortality, no major postoperative complication, and no local relapse occurred; 16/17 patients are alive without relapse at a median follow-up of 44 months (range 19-111).

CONCLUSION

This is the largest single-center series to report major hepatectomies with HV or IVC reconstruction in children. In specialized centers, these complex procedures are associated with excellent outcomes. Successful tumor resection can be achieved in selected cases even in locally advanced tumor stages.

A Novel Visual Model for Predicting Prognosis of Resected Hepatoblastoma: A Multicenter Study

RATIONALE AND OBJECTIVES

This study aimed to evaluate the application of a contrast-enhanced CT-based visual model in predicting postoperative prognosis in patients with hepatoblastoma (HB).

MATERIALS AND METHODS

We analyzed data from 224 patients across three centers (178 in the training cohort, 46 in the validation cohort). Visual features were extracted from contrast-enhanced CT images, and key features, along with clinicopathological data, were identified using LASSO Cox regression. Visual (DINOv2_score) and clinical (Clinical_score) models were developed, and a combined model integrating DINOv2_score and clinical risk factors was constructed. Nomograms were created for personalized risk assessment, with calibration curves and decision curve analysis (DCA) used to evaluate model performance.

RESULTS

The DINOv2_score was recognized as a key prognostic indicator for HB. In both the training and validation cohorts, the combined model demonstrated superior performance in predicting disease-free survival (DFS) [C-index (95% CI): 0.886 (0.879-0.895) and 0.873 (0.837-0.909), respectively] and overall survival (OS) [C-index (95% CI): 0.887 (0.877-0.897) and 0.882 (0.858-0.906), respectively]. Calibration curves showed strong alignment between predicted and observed outcomes, while DCA demonstrated that the combined model provided greater clinical net benefit than the clinical or visual models alone across a range of threshold probabilities.

CONCLUSION

The contrast-enhanced CT-based visual model serves as an effective tool for predicting postoperative prognosis in HB patients. The combined model, integrating the DINOv2_score and clinical risk factors, demonstrated superior performance in survival prediction, offering more precise guidance for personalized treatment strategies.

The pediatric surgeon's perspective on the liver hanging maneuver: a case report and literature review

Introduction

The liver hanging maneuver (HM) is a well-established technique in hepatic surgery, primarily employed to optimize exposure and simplify parenchymal transection during liver resections. While its efficacy and safety have been extensively documented in adult populations, reports on its application in pediatric surgery are limited. This may be related to peculiarities of the liver anatomy and texture in children and to some specific issues of pediatric liver tumors, especially hepatoblastoma (HB).

Methods

This study reviews the technical adaptations, feasibility, and outcomes of the HM in children, focusing on its role in both routine liver resections and complex cases, such as the separation of conjoined twins. Data of patients treated with and without HM at our center were retrospectively analyzed and a review of recent literature on this topic was performed.

Results

A total of 16 pediatric patients (7 females) underwent HM during hepatic resections with a median age at surgery of 16 months (IQR: 8-22.5). No complications or mortality related to surgery were observed.

Discussion

Results demonstrate that with appropriate modifications, the HM is a safe and effective technique in children, offering advantages in minimizing bleeding while improving surgical efficiency.

International multidisciplinary consensus recommendations on clinical application of three-dimensional visualization in precision surgery for pediatric liver tumors

BACKGROUND

Pediatric liver tumors are predominantly primary malignant tumors, and complete tumor resection with sufficient preservation of liver tissue is crucial for improving prognosis. However, due to the delicate anatomical structure of the pediatric liver and the relatively large size of the tumors, especially in difficult cases, the surgical challenges are substantial. While precision liver surgery are widely applied in clinical practice, pediatric cases require more customized approaches. The application of three-dimensional (3D) visualization technology is crucial for enhancing surgical accuracy, allowing for precise preoperative planning and intraoperative guidance.

METHODS

This consensus was collaboratively developed by 36 experts from eight countries, using the Glaser's state-of-the-art method to review and refine the draft.

RESULTS

The final consensus resulted in 15 international multidisciplinary consensus recommendations on clinical application of 3D visualization in precision surgery for pediatric liver tumors.

CONCLUSION

This consensus will standardize the application of 3D visualization technology in precision surgery for pediatric liver tumors to improve outcomes and reduce risks.

Global, regional, and national epidemiology of hepatoblastoma in children from 1990 to 2021: a trend analysis

BACKGROUND AND PURPOSE

Hepatoblastoma is the most common primary liver cancer in children, yet comprehensive understanding of its epidemiology is limited globally. We aimed to estimate the global trend of hepatoblastoma in children from 1990 to 2021.

METHODS

We collected data on hepatoblastoma in children aged 0 to 10 years from 1990 to 2021, derived from Global Burden of Disease (GBD) 2021. Three disease burden indicators, including incidence, mortality, and disability-adjusted life-years (DALYs), were studied. The corresponding average annual percentage changes (AAPCs) were used to explore the temporal trends of hepatoblastoma.

RESULTS

In 2021, hepatoblastoma accounted for 4048 incident cases, 2416 deaths, and 213,478 DALYs globally. Incidence, mortality, and DALYs of hepatoblastoma decreased significantly from 1990 to 2021, with AAPCs of -2.12, -2.53, and -2.53. The highest incidence of hepatoblastoma was observed among those aged < 28 days in 2021 (2.57 per 100,000 individuals). Only high-income region showed an upward trend in incidence from 1990 to 2021, with an AAPC of 0.57. The Western Pacific region had the fastest decrease in the incidence, mortality, and DALY rate of hepatoblastoma. Human development level (HDI) was positively associated with the AAPC in incidence from 1990 to 2021, while HDI was negatively associated with the incidence, mortality, and DALY rate of hepatoblastoma in 2021.

CONCLUSION

Global efforts over the past 3 decades have substantially decreased the disease burden of hepatoblastoma in children. However, increases in the incidence of hepatoblastoma in high-income region merit attention. The highest disease burden of hepatoblastoma was observed in the neonatal period. Improved understanding of hepatoblastoma epidemiology may facilitate prevention and management.

Effect of surgical complications on outcomes of children with hepatoblastoma: a retrospective cohort study

PURPOSE

This study aimed to investigate the incidence of severe surgical complications among children with hepatoblastoma, identify their risk factors, and evaluate the influence of surgical complications on long-term outcomes.

METHODS

Children with hepatoblastoma who underwent liver resection at our hospital between September 1992 and January 2023 were included in this study. Clinical data were retrospectively reviewed, and patients were categorized into complication and non-complication groups based on the need for radiological or surgical interventions or massive intraoperative blood loss (> 80 mL/kg).

RESULTS

Out of the 40 patients, 9 experienced severe complications (massive blood loss, n = 7; bile leakage, n = 3; and common bile duct stricture, n = 1). The participation of experienced liver surgeons was significantly greater in the non-complication group than in the complication group. The median duration from surgery to the start of postoperative chemotherapy was significantly shorter in the non-complication group than in the complication group. The overall 5-year survival rate was significantly higher in the non-complication group than in the complication group.

CONCLUSION

Severe surgical complications were associated with a worse prognosis. An experienced liver surgeon should participate in technically demanding liver resections.

Case Report: Major right-sided hepatectomies in infants in Uzbekistan: a case series

INTRODUCTION

Liver resection is a critical surgical option for managing benign and malignant tumors, including rare and complex cases in pediatric patients. While such procedures are well-documented in adults, the surgical management of large liver neoplasms in infants poses unique challenges due to anatomical and physiological considerations, as well as the limited number of cases reported globally.

AIM

This study aimed to describe the initial experiences with major hepatectomies in infants with large liver neoplasms at our center.

MATERIALS AND METHODS

From December 2023 to May 2024, four major hepatectomies were performed in pediatric patients aged 5 to 11 months. Indications, perioperative data, and surgical outcomes were retrospectively analyzed.

RESULTS

The outcomes of the four patients in this case series demonstrate the feasibility and safety of major hepatectomies in infants with large liver neoplasms. Among the cases, three involved hepatoblastoma (PRETEXT stages 2-4), and one was an anastomosing hemangioma. Radical resection (R0) was achieved in all cases, with average intraoperative blood loss 120 ml, and only one patient requiring a blood transfusion. Postoperative complications were minimal, with two cases of mild to moderate post-hepatectomy liver insufficiency (Clavien-Dindo grades 1-2) and one bile leak (Clavien-Dindo grade 2) that resolved spontaneously. No perioperative mortality or tumor recurrence was observed during a six-month follow-up.

CONCLUSION

These results highlight the success of careful surgical planning, advanced techniques, and comprehensive perioperative management in achieving favorable outcomes for this high-risk patient population.

Evolving Global Etiology of Hepatocellular Carcinoma (HCC): Insights and Trends for 2024

The epidemiology of HCC is changing all over the world and the incidence of HCC is expected to continue increasing over the next 30 years. The changes are in the predisposing factors. Hepatitis B and hepatitis C as predisposing etiologies are decreasing while NAFLD/MAFLD is increasing. The increase in MAFLD is so great that despite the decrease in hepatitis B and C, the overall incidence of HCC is increasing. HCC in persons below the age of 20 years has distinct characteristics different from that of HCC in adults. The changing etiology of hepatocellular carcinoma has implications for the early detection, prevention, the stage of HCC at time of detection and in the treatment of HCC. The extent of these changes and their significance are discussed.

[Primary outcomes after major anatomical liver resections in infants at the National Children's Medical Center]

OBJECTIVE

To analyze the results of major right-sided hemihepatectomies in infants with various neoplasms.

MATERIAL AND METHODS

There were 3 right-sided major hemihepatectomies in pediatric patients aged 5-10 months for different neoplasms between December 2023 and May 2024. Perioperative data of patients, indications for liver resection, and postoperative outcomes were retrospectively analyzed.

RESULTS. M

Ean age of patients was 7.3 months. The indications for liver resection were hepatoblastoma in two cases and anastomosing hemangioma in one case. Two patients underwent anatomical resection of the right hepatic lobe, and one patient underwent extended right-sided hemihepatectomy. Mean surgery time was 230 min, blood loss - 133 ml. No surgical complications were observed. Mean hospital-stay after surgery was 7.3 days. Patients with hepatoblastoma received postoperative chemotherapy. No recurrence of neoplasms was detected throughout the follow-up period.

CONCLUSION

Primary results of liver resections demonstrated feasibility and safety of radical major hemihepatectomies in pediatric patients with large liver neoplasms. These outcomes are comparable with world literature. Such interventions in infants necessitate substantial experience in hepatobiliary surgery. Patients with hepatoblastoma require post-hepatectomy chemotherapy. There is a need to develop primary outpatient services for liver tumor screening and timely diagnosis in pediatric patients.

Reappraisal of liver resection as an alternative to transplantation in locally advanced hepatoblastoma: A systematic review and analysis of pooled individual patient data

BACKGROUND

There is ongoing debate regarding liver transplantation (LT) versus liver resection (LR) for locally advanced hepatoblastoma. However, comparative studies are lacking. Consequently, a significant evidence gap persists, hindering the establishment of consensus guidelines. This study aimed to compare LT and LR for locally advanced hepatoblastoma, using predefined inclusion criteria to ensure comparable intervention groups.

METHODS

According to current Children's Oncology Group (COG) and SIOPEL (European Childhood Liver Tumour Study Group) recommendations, hepatoblastoma that requires LT evaluation was defined as either PRETEXT (PRE-Treatment EXTent of tumor) IV F+, POST-TEXT (POST-Treatment EXTent of tumor) IV, POST-TEXT P+, and/or POST-TEXT V+. A systematic literature search (Medline/Web-of-Science/Embase) was performed. Only patients who met the aforementioned criteria were included. Patient data were extracted individually and pooled.

RESULTS

A total of 189 patients with locally advanced hepatoblastoma from 55 studies met the specified criteria, with 111 undergoing LT and 78 LR. There were no significant differences between the two groups in age, alpha-fetoprotein (AFP), and PRETEXT stages. Local recurrence was more common after LR (14% vs. 3% in LT, p = .008), while distant recurrence was more often observed after LT (16% vs. 5% in LR, p = .035). Overall survival (OS) and event-free survival (EFS) did not differ significantly between LT and LR (5-year OS: LT = 75.3% [95% confidence interval: 66.5-85.2], LR = 87.6% [80.4-95.6], p = .140; 5-year EFS: LT = 68.5% [59.3-79.1], LR = 71.1% [60.7-83.3], p = .700).

CONCLUSION

Real-life data revealed that a considerable number of patients with locally advanced hepatoblastoma underwent LR. This analysis suggests that outcomes are similar and favorable for both approaches. LR can therefore be considered an effective alternative to LT in selected cases even in locally advanced hepatoblastoma.

Abdominal pain and distension in a 4-years-old child revealing an hepatoblastoma

Hepatoblastoma (HBL) stands as the primary liver tumor most frequently encountered in children, typically identified within the initial 5 years of life. Cases involving patients older than 5 years are very rare. We report the case of a 4-year-old male child who presented to the emergency department with acute onset abdominal pain and fever. Clinical examination revealed significant abdominal distension, correlated with an abdominal mass later confirmed.

Accuracy of contrast-enhanced CT in liver neoplasms in children under 2 years age

BACKGROUND

Multiple differentials exist for pediatric liver tumors under 2 years. Accurate imaging diagnosis may obviate the need for tissue sampling in most cases.

OBJECTIVE

To evaluate the imaging features and diagnostic accuracy of computed tomography (CT) in liver tumors in children under 2 years.

METHODS

Eighty-eight children under 2 years with treatment naive liver neoplasms and baseline contrast-enhanced CT were included in this institutional review board approved retrospective study. Two blinded onco-radiologists assessed these tumors in consensus. Findings assessed included enhancement pattern, lobulated appearance, cystic change, calcifications, central scar-like appearance, and metastases. The radiologists classified the lesion as hepatoblastoma, infantile hemangioma, mesenchymal hamartoma, rhabdoid tumor, or indeterminate, first based purely on imaging and then after alpha-fetoprotein (AFP) correlation. Multivariate analysis and methods of comparing means and frequencies were used for statistical analysis wherever applicable. Diagnostic accuracy, sensitivity, and positive predictive values were analyzed.

RESULTS

The mean age of the sample was 11.4 months (95% CI, 10.9-11.8) with 50/88 (57%) boys. The study included 72 hepatoblastomas, 6 hemangiomas, 4 mesenchymal hamartomas, and 6 rhabdoid tumors. Presence of calcifications, multilobular pattern of arterial enhancement, lobulated morphology, and central scar-like appearance was significantly associated with hepatoblastomas (P-value < 0.05). Fourteen out of eighty-eight lesions were called indeterminate based on imaging alone; six lesions remained indeterminate after AFP correlation. Pure radiology-based diagnostic accuracy was 81.8% (95% CI, 72.2-89.2%), which increased to 92.1% (95% CI, 84.3-96.7%) (P-value > 0.05) after AFP correlation, with one hepatoblastoma misdiagnosed as a rhabdoid tumor. If indeterminate lesions were excluded for biopsy, the accuracy would be 98.8% (95% CI, 93.4-99.9%).

CONCLUSION

CT had high accuracy for diagnosing liver neoplasms in the under 2-year age population after AFP correlation. Certain imaging features were significantly associated with the diagnosis of hepatoblastoma. A policy of biopsying only indeterminate lesions after CT and AFP correlation would avoid sampling in the majority of patients.

Clinical Characteristics and Outcomes of Neonatal Hepatoblastoma: A Single Center Study

OBJECTIVE

Hepatoblastoma (HB) diagnosed within one month following birth qualifies for a diagnosis of neonatal HB, whose prognosis is reportedly controversial, and its treatment is challenging. This study discussed the diagnosis, treatment, and outcomes of neonatal HB at a single center so as to enhance its overall management in the future.

METHODS

The clinical information of babies diagnosed with neonatal HB at our center from August 2009 to September 2023 were retrospectively analyzed for demographics, clinical features, therapy, and outcomes. The outcomes were estimated by the Kaplan-Meier analysis method.

RESULTS

The study comprised 79 patients aged less than one year old, among which 14 had neonatal HB whereas 65 were non-neonatal HB patients. No differences were found between groups regarding gender, birth weight, delivery details, parental age, clinical signs, or treatment strategies. Neonatal HB patients were more likely to have PRETEXT I-II, smaller tumor size, congenital diseases, and lower risk tumor grade (p < 0.05). Additionally, the AFP levels of all neonatal HB patients were greater than 10,000 ng/ml (p = 0.009) and they had higher levels of ferritin (p = 0.003) and hemoglobin (p = 0.021), but lower levels of serum total proteins (p = 0.001). The three-year survival rate (100% vs 90.8%) and three-year event-free survival rate (100% vs 86.2%) in the neonatal HB group were higher than the non-neonatal HB group.

CONCLUSION

Neonatal HB patients have unique clinical features and can achieve an excellent prognosis following combined treatment with surgery and chemotherapy. Tumor resection, when carefully performed, was safe even in babies younger than one months old. Further and long-term studies are needed from a larger neonatal HB population.

LEVEL OF EVIDENCE

Level III.

CT Image Parameters for Predicting Surgical Risk and Outcome in Wilms Tumor

OBJECTIVE

This study determined preoperative image parameters for predicting surgical risk and outcome in Wilms tumor (WT).

METHODS

A total of 55 patients with WT were enrolled and classified into surgically low-risk (SLR) and surgically high-risk (SHR) groups. The relationship between imaging findings and surgical risk factors was analyzed, and a survival analysis was performed.

RESULTS

The number of patients in the SLR and SHR groups was 35 and 20, respectively. The abdominal aorta encasement, adrenal involvement, and tumor spillage of the computed tomography (CT) image parameters showed a statistically significant difference between the two groups (p-value = 0.021, 0.02, and < 0.01, respectively). Multivariable Cox regression analysis demonstrated that those three CT parameters significantly increased surgical risks (OR = 10.11 p-value = 0.043, OR = 7.61 p-value = 0.031, and OR = 55.57 p-value = < 0.001, respectively). The one-, two-, and five-year disease-free survival (DFS) rates were 83%, 78.2%, and 72.6%, respectively. The radiological parameters associated with poor survival were adrenal involvement and tumor spillage.

CONCLUSION

The abdominal aorta encasement, adrenal involvement, and tumor spillage in the preoperative CT image were strong evidence for predicting surgical risk and outcome in WT. These parameters could be beneficial for the surgeon in preoperative preparation and during the procedure.

Liver transplantation for pediatric liver malignancies

In the last few decades, collaboration between international pediatric oncology groups has resulted in significant improvement in survival after liver transplantation (LT) for pediatric liver tumors, and LT has become the accepted standard of care for unresectable pediatric liver tumors-either living donor liver transplantation or deceased donor liver transplantation. Hepatoblastoma and HCC are the common pediatric liver malignancies treated by LT, and LT is now the accepted treatment modality for unresectable nonmetastatic cases. The long-term survival rate is more than 80% in hepatoblastoma transplants. Furthermore, with the advent of living donor liver transplantation, the waitlist mortality, availability of a better graft quality with shorter ischemic times, and performance of LT with the appropriate timing between chemotherapy have all improved. Up to 80% of pediatric HCCs are unresectable, and studies have shown that LT for pediatric HCC has better outcomes than liver resection. Furthermore, LT has also shown better results than liver resection for cases of HCC not meeting Milan criteria. Given the rarity of pediatric liver malignancies and challenges in optimal management, a multidisciplinary treatment approach, research models building on what is already known, and consideration of newer treatment modalities are required for further improving the treatment of pediatric liver malignancies.

Surgery for hepatoblastoma in children with trisomy 18: a monocentric study

PURPOSE

Recently, children with trisomy 18 have been receiving more active treatment for malignancies. We report herein seven cases complete resection was achieved, and discuss multidisciplinary treatment for hepatoblastoma in patients with trisomy 18.

METHOD

The medical records of children with trisomy 18 who were treated at the study center between 2010 and 2023 were reviewed.

RESULT

Six of 69 patients had hepatoblastoma development, and three of these underwent multidisciplinary treatment. In addition, 6 patients had been referred by another hospital for treatment, and four of these underwent multidisciplinary treatment. Among the seven patients who underwent multidisciplinary treatment, three, two, and two were categorized in Pre-treatment Extent of Disease (PRETEXT) classification group I, II, and III, respectively. Neoadjuvant chemotherapy resulting in tumor reduction was performed in three cases. In all the cases, complete resection was achieved with pathologically safe margins. Perioperative complications included circulatory failure in one case and bile leakage in two cases. Adjuvant chemotherapy was administered in four cases. The postoperative observation period ranged from 3 months to 11 years, and all the patients are recurrence-free.

CONCLUSION

Children with trisomy 18 complicated with hepatoblastoma whose cardiopulmonary conditions are stable may be good candidates for chemotherapy and surgery.

Staging and Restaging Pediatric Abdominal and Pelvic Tumors: A Practical Guide

The most common abdominal malignancies diagnosed in the pediatric population include neuroblastoma, Wilms tumor, hepatoblastoma, lymphoma, germ cell tumor, and rhabdomyosarcoma. There are distinctive imaging findings and patterns of spread for each of these tumors that radiologists must know for diagnosis and staging and for monitoring the patient's response to treatment. The multidisciplinary treatment group that includes oncologists, surgeons, and radiation oncologists relies heavily on imaging evaluation to identify the best treatment course and prognostication of imaging findings, such as the image-defined risk factors for neuroblastomas, the PRETreatment EXtent of Disease staging system for hepatoblastoma, and the Ann Arbor staging system for lymphomas. It is imperative for radiologists to be able to correctly indicate the best imaging methods for diagnosis, staging, and restaging of each of these most prevalent tumors to avoid inconclusive or unnecessary examinations. The authors review in a practical manner the most updated key points in diagnosing and staging disease and assessing response to treatment of the most common pediatric abdominal tumors. ©RSNA, 2024 Supplemental material is available for this article.

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer

BACKGROUND

Hepatoblastoma and HCC are the most common malignant hepatocellular tumors seen in children. The aim of this study was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide real-time information about tumor response to therapy.

METHODS

For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye used clinically to identify malignant liver cells during surgery. We assessed ICG accumulation in cell lines using fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, including ICG, Glypican-3, and DAPI, and tested it with cell lines and noncancer control blood samples. We then used this panel to analyze whole-blood samples for CTC burden with a cohort of 15 patients with hepatoblastoma and HCC and correlated with patient characteristics and outcomes.

RESULTS

We showed that ICG accumulation is specific to liver cancer cells, compared to nonmalignant liver cells, non-liver solid tumor cells, and other nonmalignant cells, and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/Glypican-3/DAPI panel showed that it specifically tagged malignant liver cells. Using patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy.

CONCLUSIONS

Our novel ICG-based liquid biopsy test for CTCs can be used to specifically detect and quantify CTCs in the blood of pediatric patients with liver cancer.

Immunosuppression in liver transplant oncology: position paper of the Italian Board of Experts in Liver Transplantation (I-BELT)

Liver transplant oncology (TO) represents an area of increasing clinical and scientific interest including a heterogeneous group of clinical-pathological settings. Immunosuppressive management after LT is a key factor relevantly impacting result. However, disease-related guidance is still lacking, and many open questions remain in the field. Based on such a substantial lack of solid evidences, the Italian Board of Experts in Liver Transplantation (I-BELT) (a working group including representatives of all national transplant centers), unprecedently promoted a methodologically sound consensus conference on the topic, based on the GRADE approach. The group final recommendations are herein presented and commented. The 18 PICOs and Statements and their levels of evidence and grades of recommendation are reported and grouped into seven areas: (1) risk stratification by histopathological and bio-molecular parameters and role of mTORi post-LT; (2) steroids and HCC recurrence; (3) management of immunosuppression when HCC recurs after LT; (4) mTORi monotherapy; (5) machine perfusion and HCC recurrence after LT; (6) physiopathology of tumor-infiltrating lymphocytes and immunosuppression, the role of inflammation; (7) immunotherapy in liver transplanted patients. The interest in mammalian targets of rapamycin inhibitors (mTORi), for steroid avoidance and the need for a reduction to CNI exposure emerged from the consensus process. A selected list of unmet needs prompting further investigations have also been developed. The so far heterogeneous and granular approach to immunosuppression in oncologic patients deserves greater efforts for a more standardized therapeutic response to the different clinical scenarios. This consensus process makes a first unprecedented step in this direction, to be developed on a larger scale.

Hepatoblastoma Presenting as Rapidly Progressive Abdominal Mass in a Toddler-A Case Report

Abdominal mass in a toddler is a common condition encountered in clinical practice. The nature of abdominal mass in toddlers can be a developmental cyst or benign and malignant tumours from various intraabdominal organs. Round blue cell tumours arising from the kidney, adrenals, pancreas, and liver in toddlers present as abdominal masses and are potentially fatal even with systematic treatment. Hepatoblastoma, a small round blue cell tumour of childhood, is a rare hepatic tumour. We report a case of hepatoblastoma in a toddler in view of its diagnostic challenge.

Computer-assisted three-dimensional individualized extreme liver resection for hepatoblastoma in proximity to the major liver vasculature

BACKGROUND

The management of hepatoblastoma (HB) becomes challenging when the tumor remains in close proximity to the major liver vasculature (PMV) even after a full course of neoadjuvant chemotherapy (NAC). In such cases, extreme liver resection can be considered a potential option.

AIM

To explore whether computer-assisted three-dimensional individualized extreme liver resection is safe and feasible for children with HB who still have PMV after a full course of NAC.

METHODS

We retrospectively collected data from children with HB who underwent surgical resection at our center from June 2013 to June 2023. We then analyzed the detailed clinical and three-dimensional characteristics of children with HB who still had PMV after a full course of NAC.

RESULTS

Sixty-seven children diagnosed with HB underwent surgical resection. The age at diagnosis was 21.4 ± 18.8 months, and 40 boys and 27 girls were included. Fifty-nine (88.1%) patients had a single tumor, 39 (58.2%) of which was located in the right lobe of the liver. A total of 47 patients (70.1%) had PRE-TEXT III or IV. Thirty-nine patients (58.2%) underwent delayed resection. After a full course of NAC, 16 patients still had close PMV (within 1 cm in two patients, touching in 11 patients, compressing in four patients, and showing tumor thrombus in three patients). There were 6 patients of tumors in the middle lobe of the liver, and four of those patients exhibited liver anatomy variations. These 16 children underwent extreme liver resection after comprehensive preoperative evaluation. Intraoperative procedures were performed according to the preoperative plan, and the operations were successfully performed. Currently, the 3-year event-free survival of 67 children with HB is 88%. Among the 16 children who underwent extreme liver resection, three experienced recurrence, and one died due to multiple metastases.

CONCLUSION

Extreme liver resection for HB that is still in close PMV after a full course of NAC is both safe and feasible. This approach not only reduces the necessity for liver transplantation but also results in a favorable prognosis. Individualized three-dimensional surgical planning is beneficial for accurate and complete resection of HB, particularly for assessing vascular involvement, remnant liver volume and anatomical variations.

Pediatric Hepatoblastoma After Neoadjuvant Chemotherapy: Diagnostic Performance of MR in Staging POSTTEXT and Vascular Involvement

BACKGROUND

The assessment of resectability after neoadjuvant chemotherapy of hepatoblastoma is dependent on Post-Treatment EXTENT of Disease (POSTTEXT) staging and its annotation factors P (portal venous involvement) and V (hepatic venous/inferior vena cava [IVC] involvement), but MR performance in assessing them remains unclear.

PURPOSE

To assess the diagnostic performance of contrast-enhanced MR imaging for preoperative POSTTEXT staging and diagnosing vascular involvement in terms of annotation factors P and V in pediatric hepatoblastoma following neoadjuvant chemotherapy.

STUDY TYPE

Retrospective.

SUBJECTS

Thirty-five consecutive patients (17 males, median age, 24 months; age range, 6-98 months) with proven hepatoblastoma underwent preoperative MR imaging following neoadjuvant chemotherapy.

FIELD STRENGTH/SEQUENCE

3.0 T; T2-weighted imaging (T2WI), T2WI with fat suppression, diffusion weighted imaging, radial stack-of-the-star/Cartesian 3D Dixon T1-weighted gradient echo imaging.

ASSESSMENT

Three radiologists independently assessed the POSTTEXT stages and annotation factors P and V based on the 2017 PRE/POSTTEXT system. The sensitivities and specificities were calculated for 1) diagnosing each POSTTEXT stage; 2) discrimination of stages III and IV (advanced) from those stages I and II (non-advanced) hepatoblastomas; and 3) annotation factors P and V. The combination of pathologic findings and surgical records served as the reference standard.

STATISTICAL TESTS

Sensitivity, specificity, Fleiss kappa test.

RESULTS

The sensitivity and specificity ranges for discriminating advanced from non-advanced hepatoblastomas were 73.3%-80.0% and 80.0%-90.0%, respectively. For annotation factor P, they were 66.7%-100.0% and 90.6%, respectively. For factor V, they were 75.0% and 67.7%-83.9%, respectively. There was excellent, substantial, and moderate agreement on POSTTEXT staging (Fleiss kappa = 0.82), factors P (Fleiss kappa = 0.64), and factors V (Fleiss kappa = 0.60), respectively.

DATA CONCLUSION

MR POSTTEXT provides reliable discrimination between advanced and non-advanced tumors, and MR has moderate to excellent specificity at identifying portal venous and hepatic venous/IVC involvement.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Mutational signature, cancer driver genes mutations and transcriptomic subgroups predict hepatoblastoma survival

BACKGROUND

Hepatoblastoma is the most frequent pediatric liver cancer. The current treatments lead to 80% of survival rate at 5 years. In this study, we evaluated the clinical relevance of molecular features to identify patients at risk of chemoresistance, relapse and death of disease.

METHODS

All the clinical data of 86 children with hepatoblastoma were retrospectively collected. Pathological slides were reviewed, tumor DNA sequencing (by whole exome, whole genome or target) and transcriptomic profiling with RNAseq or 300-genes panel were performed. Associations between the clinical, pathological, mutational and transcriptomic data were investigated.

RESULTS

High-risk patients represented 44% of our series and the median age at diagnosis was 21.9 months (range: 0-208). Alterations of the WNT/ß-catenin pathway and of the 11p15.5 imprinted locus were identified in 98% and 74% of the tumors, respectively. Other cancer driver genes mutations were only found in less than 11% of tumors. After neoadjuvant chemotherapy, disease-specific survival and poor response to neoadjuvant chemotherapy were associated with 'Liver Progenitor' (p = 0.00049, p < 0.0001) and 'Immune Cold' (p = 0.0011, p < 0.0001) transcriptomic tumor subtypes, SBS35 cisplatin mutational signature (p = 0.018, p = 0.001), mutations in rare cancer driver genes (p = 0.0039, p = 0.0017) and embryonal predominant histological type (p = 0.0013, p = 0.0077), respectively. Integration of the clinical and molecular features revealed a cluster of molecular markers associated with resistance to chemotherapy and survival, enlightening transcriptomic 'Immune Cold' and Liver Progenitor' as a predictor of survival independent of the clinical features.

CONCLUSIONS

Response to neoadjuvant chemotherapy and survival in children treated for hepatoblastoma are associated with genomic and pathological features independently of the clinical features.

Transplant oncology - Current indications and strategies to advance the field

Liver transplantation (LT) was originally described by Starzl as a promising strategy to treat primary malignancies of the liver. Confronted with high recurrence rates, indications drifted towards non-oncologic liver diseases with LT finally evolving from a high-risk surgery to an almost routine surgical procedure. Continuously improving outcomes following LT and evolving oncological treatment strategies have driven renewed interest in transplant oncology. This is not only reflected by constant refinements to the criteria for LT in patients with HCC, but especially by efforts to expand indications to other primary and secondary liver malignancies. With new patient-centred oncological treatments on the rise and new technologies to expand the donor pool, the field has the chance to come full circle. In this review, we focus on the concept of transplant oncology, current indications, as well as technical and ethical aspects in the context of donor organs as precious resources.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (1) pre-transplant evaluation

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment in end-stage liver disease. Imaging is a key element for successful organ-transplantation to assist surgical planning. So far, only limited data regarding the best radiological approach to prepare children for liver transplantation is available.

OBJECTIVES

In an attempt to harmonize imaging surrounding pediatric liver transplantation, the European Society of Pediatric Radiology (ESPR) Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phase. This paper reports the responses on preoperative imaging.

MATERIAL AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted and 22 institutions from 11 countries returned the survey. From 2018 to 2020, the participating centers collectively conducted 1,524 transplantations, with a median of 20 transplantations per center per annum (range, 8-60).

RESULTS

Most sites (64%) consider ultrasound their preferred modality to define anatomy and to plan surgery in children before liver transplantation, and additional cross-sectional imaging is only used to answer specific questions (computed tomography [CT], 90.9%; magnetic resonance imaging [MRI], 54.5%). One-third of centers (31.8%) rely primarily on CT for pre-transplant evaluation. Imaging protocols differed substantially regarding applied CT scan ranges, number of contrast phases (range 1-4 phases), and applied MRI techniques.

CONCLUSION

Diagnostic imaging is generally used in the work-up of children before liver transplantation. Substantial differences were noted regarding choice of modalities and protocols. We have identified starting points for future optimization and harmonization of the imaging approach to multicenter studies.

An update on diagnosis and treatment of hepatoblastoma

Hepatoblastoma (HB) remains the most common paediatric liver tumour and survival in children with hepatoblastoma has improved considerably since the advent of sequential surgical regimens of chemotherapy based on platinum-based chemotherapeutic agents in the 1980s. With the advent of modern diagnostic imaging and pathology techniques, new preoperative chemotherapy regimens and the maturation of surgical techniques, new diagnostic and treatment options for patients with hepatoblastoma have emerged and international collaborations are investigating the latest diagnostic approaches, chemotherapy drug combinations and surgical strategies. Diagnosis of hepatoblastoma relies on imaging studies (such as ultrasound, computed tomography, and magnetic resonance imaging), alpha-fetoprotein (AFP) levels, and histological confirmation through biopsy. The standard treatment approach involves a multimodal strategy with neoadjuvant chemotherapy followed by surgical resection. In cases where complete resection is not feasible or tumors exhibit invasive characteristics, liver transplantation is considered. The management of metastatic and recurrent hepatoblastoma poses significant challenges, and ongoing research focuses on developing targeted therapies and exploring the potential of immunotherapy. Further studies are necessary to gain a better understanding of the etiology of hepatoblastoma, develop prevention strategies, and personalize treatment approaches. We aim to review the current status of diagnosis and treatment of hepatoblastoma.

Successful Treatment for Hepatoblastoma in Trisomy 18: A Case Report

Children with trisomy 18 tend to develop hepatoblastoma. Since the introduction of appropriate management for organ malfunction, individuals with trisomy 18 have come to have a longer life expectancy. However, the predisposition to hepatoblastoma becomes a significant issue for the quality of a case. Here, we present a rare multifocal hepatoblastoma involving predominantly Couinaud segments 5 and 7 in a 10-month-old boy with trisomy 18. Though the first-line cisplatin monotherapy resulted in unsatisfactory tumor shrinkage, the second-line neoadjuvant chemotherapy administrating irinotecan and vincristine gave rise to significant tumor reduction in volume, leading to the completion of partial resection of the liver without the microscopic residual disease. The patient has been free from recurrence for 44 months. Because anatomical right hepatectomy can cause circulatory instability, including acute onset of pulmonary hypertension in trisomy 18 patients, physicians should balance treatment benefits and potential adverse effects. Our successful experience utilizing a combination of efficacious and less cardiotoxic neoadjuvant chemotherapy followed by the partial hepatectomy encourages physicians to treat a patient with trisomy 18 and tackle hepatoblastoma with a genetic background.

Computed tomography imaging phenotypes of hepatoblastoma identified from radiomics signatures are associated with the efficacy of neoadjuvant chemotherapy

BACKGROUND

Though neoadjuvant chemotherapy has been widely used in the treatment of hepatoblastoma, there still lacks an effective way to predict its effect.

OBJECTIVE

To characterize hepatoblastoma based on radiomics image features and identify radiomics-based lesion phenotypes by unsupervised machine learning, intended to build a classifier to predict the response to neoadjuvant chemotherapy.

MATERIALS AND METHODS

In this retrospective study, we segmented the arterial phase images of 137 cases of pediatric hepatoblastoma and extracted the radiomics features using PyRadiomics. Then unsupervised k-means clustering was applied to cluster the tumors, whose result was verified by t-distributed stochastic neighbor embedding (t-SNE). The least absolute shrinkage and selection operator (LASSO) regression was used for feature selection, and the clusters were visually analyzed by radiologists. The correlations between the clusters, clinical and pathological parameters, and qualitative radiological features were analyzed.

RESULTS

Hepatoblastoma was clustered into three phenotypes (homogenous type, heterogenous type, and nodulated type) based on radiomics features. The clustering results had a high correlation with response to neoadjuvant chemotherapy (P=0.02). The epithelial ratio and cystic components in radiological features were also associated with the clusters (P=0.029 and 0.008, respectively).

CONCLUSIONS

This radiomics-based cluster system may have the potential to facilitate the precise treatment of hepatoblastoma. In addition, this study further demonstrated the feasibility of using unsupervised machine learning in a disease without a proper imaging classification system.

Quantitative ctDNA Detection in Hepatoblastoma: Implications for Precision Medicine

Hepatoblastoma is characterized by driver mutations in CTNNB1, making it an attractive biomarker for a liquid biopsy approach utilizing circulating tumor DNA (ctDNA). This prospective observational study sought to ascertain the feasibility of ctDNA detection in patients with hepatoblastoma and explore its associations with established clinical indicators and biomarkers, including serum Alpha-fetoprotein (AFP). We obtained 38 plasma samples and 17 tumor samples from 20 patients with hepatoblastoma. These samples were collected at various stages: 10 at initial diagnosis, 17 during neoadjuvant chemotherapy, 6 post-operatively, and 5 at disease recurrence. Utilizing a bespoke sequencing assay we developed called QUENCH, we identified single nucleotide variants and deletions in CTNNB1 ctDNA. Our study demonstrated the capability to quantitate ctDNA down to a variant allele frequency of 0.3%, achieving a sensitivity of 90% for patients at initial diagnosis, and a specificity of 100% at the patient level. Notably, ctDNA positivity correlated with tumor burden, and ctDNA levels exhibited associations with macroscopic residual disease and treatment response. Our findings provide evidence for the utility of quantitative ctDNA detection in hepatoblastoma management. Given the distinct detection targets, ctDNA and AFP-based stratification and monitoring approaches could synergize to enhance clinical decision-making. Further research is needed to elucidate the interplay between ctDNA and AFP and determine the optimal clinical applications for both methods in risk stratification and residual disease detection.

Review on Pediatric Malignant Focal Liver Lesions with Imaging Evaluation: Part II

Malignant focal liver lesions (FLLs) represent various kinds of epithelial and mesenchymal tumors. In pediatric patients, the understanding of pediatric liver diseases and associated imaging manifestations is essential for making accurate diagnosis and differential diagnosis. This paper will discuss the latest knowledge of the common pediatric malignant FLLs, including undifferentiated embryonal sarcoma, rhabdomyosarcoma, epithelioid hemangioendothelioma, angiosarcoma, and malignant rhabdoid tumor. Medical imaging features are not only helpful for clinical diagnosis, but can also be useful in the evaluation and follow-up of pre- and post-treatment. The future perspectives of contrast-enhanced ultrasound (CEUS) enhancement patterns of FLLs in pediatric patients are also mentioned.

Evaluating the clinical efficacy and limitations of indocyanine green fluorescence-guided surgery in childhood hepatoblastoma: A retrospective study

BACKGROUND

Indocyanine green (ICG) fluorescence guided surgery has been used to treat childhood hepatoblastoma (HB), but the advantages and disadvantages of this technique have not been fully discussed. The purpose of this study is to summarize the experience and to explore the clinical value of this technique for children with HB.

METHODS

45 children with HB who underwent ICG fluorescence guided surgery (n = 22) and general surgery (n = 23) in our center from January 2020 to December 2022 were enrolled retrospectively.

RESULTS

All the liver tumors in the ICG group showed hyperfluorescence, including total and partial fluorescent types. With the help of ICG navigation, minimally invasive surgery was performed in 3 cases. 18.2 % of cases with tumors could not be accurately identified under white light, but could be identified by fluorescence imaging. The fluorescent cutting lines of 59.1 % of cases were consistent with the safe cutting lines. In 36.4 % of cases, the fluorescence boundary was not clear because of tumor necrosis. In 36.4 % of cases, the fluorescence could not be detected on the inner edge of the tumors because of the depth. A total of 29 ICG (+) suspicious lesions were found during the operations, of which 5 were true positive lesions.

CONCLUSION

ICG fluorescence guided surgery is safe and feasible in children with HB. This technique is helpful for locating tumors, determining margin and finding small lesions with negative imaging, especially in minimally invasive surgery. However, preoperative chemotherapy, tumor necrosis, tumor depth, and ICG administration impact the effect of fluorescence imaging.

Navigating relapsed hepatoblastoma: Predictive factors and surgical treatment strategy

OBJECTIVE

Hepatoblastoma (HB) is the most common primary hepatic malignancy in childhood. Relapse occurs in more than 50% of high-risk patients with a high mortality due to ineffective salvage therapies. The purpose of this study is to identify risk factors for relapsed HB and predictors of survival in a single tertiary referral center.

METHODS

A retrospective chart review showed 129 surgically treated HB patients from October 2004 to July 2020. Of the cohort, 22 patients presented with relapsed HB. Relapse was defined as re-appearance of malignancy after 4 weeks of normalized AFP and disappearance of all tumors on imaging.

RESULTS

Patients with relapsed HB had a 5-year overall survival (OS) of 45.4% compared to 93.1% in those without relapse (p = 0.001). When comparing PRETEXT IV, microvascular invasion, metastatic disease, and age on multivariate logistic regression, only PRETEXT IV was an independent risk factor for relapsed HB with an OR of 2.39 (95% CI: 1.16-4.96; p = 0.019). Mixed epithelial and mesenchymal HB (12/19, 63.2%) was the most common histology of primary tumors while pure epithelial HB (13/15, 86.6%) was the most common relapsed histology. Combination of surgical and medical therapy for relapsed disease was predictive of survival with an HR of 16.3 (95% CI: 1.783-149.091; p = 0.013) compared to only chemotherapy.

CONCLUSIONS

This study demonstrates that PRETEXT IV staging is an independent predictor of relapsed disease. The most common relapsed histology was epithelial, suggesting a potential selection or resistance of this component. Surgical resection is a critical component of multimodal therapy for relapsed HB.

Review on Pediatric Malignant Focal Liver Lesions with Imaging Evaluation: Part I

Malignant focal liver lesions (FLLs) are commonly reported in adults but rarely seen in the pediatric population. Due to the rarity, the understanding of these diseases is still very limited. In children, most malignant FLLs are congenital. It is very important to choose appropriate imaging examination concerning various factors. This paper will outline common pediatric malignant FLLs, including hepatoblastoma, hepatocellular carcinoma, and cholangiocarcinoma and discuss them against the background of the latest knowledge on comparable/similar tumors in adults. Medical imaging features are of vital importance for the non-invasive diagnosis and follow-up of treatment of FLLs in pediatric patients. The use of CEUS in pediatric patients for characterizing those FLLs that remain indeterminate on conventional B mode ultrasounds may be an effective option in the future and has great potential to be integrated into imaging algorithms without the risk of exposure to ionizing radiation.

Prognostic value of systemic inflammation response index in hepatoblastoma patients receiving preoperative neoadjuvant chemotherapy

Introduction

Inflammation is closely associated with tumor development and patient prognosis. The objective of this study is to assess the prognostic value of the preoperative inflammatory indexes in pediatric hepatoblastoma patients who receive neoadjuvant chemotherapy.

Methods

A retrospective analysis was performed on clinical and pathological data of 199 hepatoblastoma patients who underwent hepatectomy with preoperative neoadjuvant chemotherapy from January 2015 to June 2020. The receiver operating characteristic curve was used to evaluate the prognostic value of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI) in predicting OS and EFS. Patients were grouped based on optimal cutoff values of preoperative inflammatory indexes. Survival rates were calculated using the Kaplan-Meier method, and survival outcomes were compared between groups using the log-rank test. Univariate and multivariate Cox proportional hazards regression models were used to identify independent prognostic factors, and a nomogram was constructed using R software to predict the probability of OS.

Results

The receiver operating characteristic curve showed prognostic value for OS, not EFS, in preoperative inflammatory indexes. Patients were categorized into low/high groups: SII ≤ 266.70/higher, NLR ≤ 1.24/higher, PLR ≤ 85.25/higher, and SIRI ≤ 0.72/higher. High NLR, PLR, SII, and SIRI groups had significantly lower 5-year OS than their low counterparts (all p-value < 0.05). The Cox analysis identified four independent prognostic factors: SIRI (HR=2.997, 95% CI: 1.119-8.031), microvascular invasion (HR=2.556, 95% CI: 1.14-5.73), the post-treatment extent of disease (POSTTEXT) staging (IV vs. I: HR=244.204, 95% CI:11.306-5274.556), and alpha-fetoprotein (>100 ng/ml: HR=0.11, 95% CI: 0.032-0.381) for hepatoblastoma patients with neoadjuvant chemotherapy. High SIRI group had more patients with adverse NLR, SII, and POSTTEXT III (all p-value < 0.05). Independent prognostic factors led to an OS nomogram with a concordance index of 0.85 (95% CI: 0.78-0.91, p-value = 1.43e-27) and the calibration curve showed a good fit between the prediction curve and the true curve.

Conclusions

SIRI is an independent prognostic factor of hepatoblastoma patients receiving neoadjuvant chemotherapy. The OS nomogram based on SIRI, POSTTEXT staging, MiVI, and AFP can be used to assess the prognosis of those patients.

Guide to use of ferumoxytol for hepatic vascular assessment as part of dual contrast MRI

Magnetic resonance imaging (MRI) assessment of hepatic vasculature can be challenging in the setting of liver disease and liver lesions. The widely used hepatobiliary contrast agent gadoxetate is an extracellular contrast agent that provides excellent soft tissue characterization but has limitations as a vascular contrast agent. Ferumoxytol is an iron oxide nanoparticle with superparamagnetic properties that can be used as blood pool contrast agent to provide dedicated vascular assessment. We provide a detailed protocol for evaluation of pediatric liver vasculature using ferumoxytol, after imaging of the parenchyma with gadoxetate. We provide multiple examples and discuss practical considerations when incorporating ferumoxytol into practice.

Critical elements of pediatric liver cancer surgery

The appropriate management of pediatric liver malignancies, primarily hepatoblastoma and hepatocellular carcinoma, requires an in depth understanding of contemporary preoperative risk stratification, experience with advanced hepatobiliary surgery, and a good relationship with one's local or regional liver transplant center. While chemotherapy regimens have become more effective, operative indications more well-defined, and overall survival improved, the complexity of liver surgery in small children provides ample opportunity for protocol violation, inadequate resection, and iatrogenic morbidity. These guidelines represent the distillation of contemporary literature and expert opinion as a means to provide a framework for preoperative planning and intraoperative decision-making for the pediatric surgeon.

Surgical Management and Outcomes of Patients with Multifocal Hepatoblastoma

OBJECTIVE

To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence.

BACKGROUND

Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver.

METHODS

We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed.

RESULTS

A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence.

CONCLUSIONS

Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered.

LEVEL OF EVIDENCE

III.

Genome-wide mapping of cancer dependency genes and genetic modifiers of chemotherapy in high-risk hepatoblastoma

A lack of relevant genetic models and cell lines hampers our understanding of hepatoblastoma pathogenesis and the development of new therapies for this neoplasm. Here, we report an improved MYC-driven hepatoblastoma-like murine model that recapitulates the pathological features of embryonal type of hepatoblastoma, with transcriptomics resembling the high-risk gene signatures of the human disease. Single-cell RNA-sequencing and spatial transcriptomics identify distinct subpopulations of hepatoblastoma cells. After deriving cell lines from the mouse model, we map cancer dependency genes using CRISPR-Cas9 screening and identify druggable targets shared with human hepatoblastoma (e.g., CDK7, CDK9, PRMT1, PRMT5). Our screen also reveals oncogenes and tumor suppressor genes in hepatoblastoma that engage multiple, druggable cancer signaling pathways. Chemotherapy is critical for human hepatoblastoma treatment. A genetic mapping of doxorubicin response by CRISPR-Cas9 screening identifies modifiers whose loss-of-function synergizes with (e.g., PRKDC) or antagonizes (e.g., apoptosis genes) the effect of chemotherapy. The combination of PRKDC inhibition and doxorubicin-based chemotherapy greatly enhances therapeutic efficacy. These studies provide a set of resources including disease models suitable for identifying and validating potential therapeutic targets in human high-risk hepatoblastoma.

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer

Background and Aims

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common malignant hepatocellular tumors seen in children. The aim of this work was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide information about the real-time state of tumors in response to therapies.

Methods

For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye that is used clinically to identify malignant liver cells in the body during surgery. We assessed ICG accumulation in cell lines with fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, ICG, Glypican-3 (GPC3), and DAPI and tested this panel with cell lines and non-cancer control blood samples. We then used this panel to analyze whole blood samples for CTC burden with a cohort of 14 HB and HCC patients and correlated with patient characteristics and outcomes.

Results

We showed that ICG accumulation is specific to liver cancer cells, compared to non-malignant liver cells, non-liver solid tumor cells, and non-malignant cells and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/GPC3/DAPI panel showed that it specifically tagged malignant liver cells. With patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy.

Conclusions

Our novel ICG-based liquid biopsy test for CTCs can be used to specifically count CTCs in the blood of pediatric liver cancer patients.

Impact and implications

This manuscript represents the first report of circulating tumor cells in the blood of pediatric liver cancer patients. The novel and innovative assay for CTCs shown in this paper will facilitate future work examining the relationship between CTC numbers and patient outcomes, forming the foundation for incorporation of liquid biopsy into routine clinical care for these patients.

Graphical abstract

Overview of novel liquid biopsy test for circulating tumor cells for pediatric liver cancer. Figure made with Biorender.

Role of Preoperative Hepatobiliary Scintigraphy in Children Requiring Liver Resection

PURPOSE

The risk of posthepatectomy liver failure (PHLF) remains an important concern following major liver resection. Assessment of future remnant liver function (FRLF) by hepatobiliary scintigraphy has shown its significance to prevent PHLF after major liver resection in adults with a threshold value of FRLF greater than 2.7%/min per m2. However, such data for pediatric patients were not published.

METHODS

A total of 77 pediatric patients with liver tumors who underwent 1-stage liver resection were included in this study. Assessment of FRLF, future remnant liver volume (FRLV), and the ratio of remnant liver volume to body weight (RLV-BWR) was performed before the surgery.

RESULTS

All patients had RLV-BWR values of more than 0.5%/kg. Future remnant liver volume values ranged from 19% to 89%, and FRLF values ranged from 1.8% to 31.8%/min per m2. Only 7 of 77 patients had FRLV values less than 25%, but their FRLF values exceeded 2.7%/min per m2. Two patients developed grade A and grade B PHLF.

CONCLUSION

Future remnant liver volume and the RLV-BWR can be used in most pediatric patients for the assessment of liver before hepatectomy. According to our data, implementation of FRLF assessment using hepatobiliary scintigraphy can be most beneficial for children with FRLV of less than 25%. The cutoff value of FRLV greater than 25% can be slightly decreased with minimal risk of developing PHLF. However, to establish a new cutoff value for FRLV in children, further prospective studies including larger numbers of patients with FRLV of less than 25% are needed.

Update on the Role of Imaging in Staging of Common Pediatric Abdominal Tumors

Neuroblastoma, Wilms tumor, and hepatoblastoma are the most common pediatric abdominal malignancies. Management of these diseases is a multidisciplinary process that continues to evolve based on the results of international collaborative trials and advances in understanding of tumor biology. Each of these tumors has unique characteristics and behavior which are reflected in their respective staging systems. It is important for clinicians involved in the care of children with abdominal malignancies to be familiar with current staging guidelines and imaging recommendations. This article reviews the current role of imaging in the management of these common pediatric abdominal malignancies, with emphasis on initial staging.

Introduction to the COG Diagnostic Imaging Committee/SPR Oncology Committee White Papers: Rationale and methods

Pediatric cancer is a rare disease. Because of this, many sites do not have experience providing imaging for specific tumor types. The Children's Oncology Group Diagnostic Imaging Committee and the Society for Pediatric Radiology Oncology Committee are comprised of radiologists with expertise in pediatric cancer imaging. Recently, this group endeavored to create a series of 23 White Papers designed to provide evidence-based imaging recommendations and minimum achievable imaging protocols. The purpose of this manuscript is to describe the methods employed in authoring the White Paper series.