Radiogenomics of neuroblastomas: Relationships between imaging phenotypes, tumor genomic profile and survival

A subset of image-defined risk factors predict completeness of resection in children with high-risk neuroblastoma: An international multicenter study

BACKGROUND

Image-defined risk factors (IDRFs) were promulgated for predicting the feasibility and safety of complete primary tumor resection in children with neuroblastoma (NB). There is limited understanding of the impact of individual IDRFs on resectability of the primary tumor or patient outcomes. A multicenter database of patients with high-risk NB was interrogated to answer this question.

DESIGN/METHODS

Patients with high-risk NB (age <20 years) were eligible if cross-sectional imaging was performed at least twice prior to resection. IDRFs and primary tumor measurements were recorded for each imaging study. Extent of resection was determined from operative reports.

RESULTS

There were 211 of 229 patients with IDRFs at diagnosis, and 171 patients with IDRFs present pre-surgery. A ≥90% resection was significantly more likely in the absence of tumor invading or encasing the porta hepatis, hepatoduodenal ligament, superior mesenteric artery (SMA), renal pedicles, abdominal aorta/inferior vena cava (IVC), iliac vessels, and/or diaphragm at diagnosis or an overlapping subset of IDRFs (except diaphragm) at pre-surgery. There were no significant differences in event-free survival (EFS) and overall survival (OS) when patients were stratified by the presence versus absence of any IDRF either at diagnosis or pre-surgery.

CONCLUSION

Two distinct but overlapping subsets of IDRFs present either at diagnosis or after induction chemotherapy significantly influence the probability of a complete resection in children with high-risk NB. The presence of IDRFs was not associated with significant differences in OS or EFS in this cohort.

Modern surgical strategies in pediatric neuroblastoma: Evolving approaches and treatment principles

Neuroblastoma, the most common extracranial solid tumor in children under the age of 5, has been described as early as the 19th century, and its complexity has continued to intrigue researchers, as well as medical and surgical specialists. At one end of the phenotypic spectrum, neuroblastoma is self-limiting with minimal to no intervention required, while on the opposite end exists the challenge of refractory disease despite aggressive management and toxic systemic treatments. The goal of this review is to describe a comprehensive surgical perspective and contemporary approach to neuroblastoma.

Radiomics in differential diagnosis of Wilms tumor and neuroblastoma with adrenal location in children

OBJECTIVES

Machine learning methods can be applied successfully to various medical imaging tasks. Our aim with this study was to build a robust classifier using radiomics and clinical data for preoperative diagnosis of Wilms tumor (WT) or neuroblastoma (NB) in pediatric abdominal CT.

MATERIAL AND METHODS

This is a single-center retrospective study approved by the Institutional Ethical Board. CT scans of consecutive patients diagnosed with WT or NB admitted to our hospital from January 2005 to December 2021 were evaluated. Three distinct datasets based on clinical centers and CT machines were curated. Robust, non-redundant, high variance, and relevant radiomics features were selected using data science methods. Clinically relevant variables were integrated into the final model. Dice score for similarity of tumor ROI, Cohen's kappa for interobserver agreement among observers, and AUC for model selection were used.

RESULTS

A total of 147 patients, including 90 WT (mean age 34.78 SD: 22.06 months; 43 male) and 57 NB (mean age 23.77 SD:22.56 months; 31 male), were analyzed. After binarization at 24 months cut-off, there was no statistically significant difference between the two groups for age (p = .07) and gender (p = .54). CT clinic radiomics combined model achieved an F1 score of 0.94, 0.93 accuracy, and an AUC 0.96.

CONCLUSION

In conclusion, the CT-based clinic-radiologic-radiomics combined model could noninvasively predict WT or NB preoperatively. Notably, that model correctly predicted two patients, which none of the radiologists could correctly predict. This model may serve as a noninvasive preoperative predictor of NB/WT differentiation in CT, which should be further validated in large prospective models.

CLINICAL RELEVANCE STATEMENT

CT-based clinic-radiologic-radiomics combined model could noninvasively predict Wilms tumor or neuroblastoma preoperatively.

KEY POINTS

• CT radiomics features can predict Wilms tumor or neuroblastoma from abdominal CT preoperatively. • Integrating clinic variables may further improve the performance of the model. • The performance of the combined model is equal to or greater than human readers, depending on the lesion size.

Cadaveric analysis of surgical techniques and working space for retroperitoneal tumors as model for improving resection of neuroblastoma

PURPOSE

Neuroblastoma, the most common extracranial solid tumor in children under 5 years, often surrounds visceral arteries. This study aimed to analyze the working space provided by standardized surgical techniques at key arterial landmarks in adult cadavers.

METHODS

We assessed in eight adult cadavers the mobilization of the left colon, spleen and pancreas, right colon, duodenum and mesenteric root, access to the bursa omentalis. The average working space score (AWSS) was evaluated at the left and right renal artery, left and right side of the coeliac trunk, superior mesenteric and common hepatic artery. The score was defined as: (0) vessel not visible, (1) working space at the vessel ≤ 1x diameter of the aorta, (2) < 3x the diameter of the aorta, (3) ≥ 3x diameter of the aorta.

RESULTS

The maximum AWSS of 3 was achieved at key vascular landmarks through specific mobilization techniques.

CONCLUSION

Additional mobilization of spleen, pancreas and mesenteric root and access to the bursa omentalis increase surgical working space at major visceral arteries. The results of our investigation provide surgeons with a useful guide to prepare for abdominal neuroblastoma resection.

Recent Advancements and Innovations in Pediatric Precision Oncology

Precision oncology incorporates comprehensive genomic profiling into the individualized clinical care of pediatric cancer patients. In recent years, comprehensive pan-cancer analyses have led to the successful implementation of genomics-based pediatric trials and accelerated approval of novel targeted agents. In addition, disease-specific studies have resulted in molecular subclassification of myriad cancer types with subsequent tailoring of treatment intensity based on the patient's prognostic factors. This review discusses the progress of the field and highlights developments that are leading to more personalized cancer care and improved patient outcomes. Increased understanding of the evolution of precision oncology over recent decades emphasizes the tremendous impact of improved genomic applications. New technologies and improved diagnostic modalities offer further promise for future advancements within the field.

Image-defined risk factors associated with MYCN oncogene amplification in neuroblastoma and their association with overall survival

OBJECTIVE

The MYCN oncogene is a critical factor in the development and progression of neuroblastoma, and image-defined risk factors (IDRFs) are radiological findings used for the preoperative staging of neuroblastoma. This study aimed to investigate the specific categories of IDRFs associated with MYCN amplification in neuroblastoma and their association with overall survival.

METHOD

A retrospective analysis was conducted on a cohort of 280 pediatric patients diagnosed with neuroblastoma, utilizing a combination of clinical and radiological data. MYCN amplification status was ascertained through molecular testing, and the assessment of IDRFs was conducted using either contrast-enhanced computed tomography or magnetic resonance imaging. The specific categories of IDRFs associated with MYCN amplification and their association with overall survival were analyzed.

RESULTS

MYCN amplification was identified in 19.6% (55/280) of patients, with the majority of primary lesions located in the abdomen (53/55, 96.4%). Lesions accompanied by MYCN amplification exhibited significantly larger tumor volume and a greater number of IDRFs compared with those without MYCN amplification (P < 0.001). Both univariate and multivariate analyses revealed that coeliac axis/superior mesenteric artery encasement and infiltration of adjacent organs/structures were independently associated with MYCN amplification in abdominal neuroblastoma (P < 0.05). Patients presenting with more than four IDRFs experienced a worse prognosis (P = 0.017), and infiltration of adjacent organs/structures independently correlated with overall survival in abdominal neuroblastoma (P = 0.009).

CONCLUSION

The IDRFs are closely correlated with the MYCN amplification status and overall survival in neuroblastoma.

Computed Tomography-Based Radiomics Signature for Predicting Segmental Chromosomal Aberrations at 1p36 and 11q23 in Pediatric Neuroblastoma

OBJECTIVE

This study aimed to develop and assess the precision of a radiomics signature based on computed tomography imaging for predicting segmental chromosomal aberrations (SCAs) status at 1p36 and 11q23 in neuroblastoma.

METHODS

Eighty-seven pediatric patients diagnosed with neuroblastoma and with confirmed genetic testing for SCAs status at 1p36 and 11q23 were enrolled and randomly stratified into a training set and a test set. Radiomics features were extracted from 3-phase computed tomography images and analyzed using various statistical methods. An optimal set of radiomics features was selected using a least absolute shrinkage and selection operator regression model to calculate the radiomics score for each patient. The radiomics signature was validated using receiver operating characteristic curves to obtain the area under the curve and 95% confidence interval (CI).

RESULTS

Eight radiomics features were carefully selected and used to compute the radiomics score, which demonstrated a statistically significant distinction between the SCAs and non-SCAs groups in both sets. The radiomics signature achieved an area under the curve of 0.869 (95% CI, 0.788-0.943) and 0.883 (95% CI, 0.753-0.978) in the training and test sets, respectively. The accuracy of the radiomics signature was 0.817 and 0.778 in the training and test sets, respectively. The Hosmer-Lemeshow test confirmed that the radiomics signature was well calibrated.

CONCLUSIONS

Computed tomography-based radiomics signature has the potential to predict SCAs at 1p36 and 11q23 in neuroblastoma.

Prediction of High-Risk Neuroblastoma Among Neuroblastic Tumors Using Radiomics Features Derived from Magnetic Resonance Imaging: A Pilot Study

PURPOSE

This study aimed to predict high-risk neuroblastoma among neuroblastic tumors using radiomics features extracted from MRI.

MATERIALS AND METHODS

Pediatric patients (age≤18 years) diagnosed with neuroblastic tumors who had pre-treatment MR images available were enrolled from institution A from January 2010 to November 2019 (training set) and institution B from January 2016 to January 2022 (test set). Segmentation was performed with regions of interest manually drawn along tumor margins on the slice with the widest tumor area by two radiologists. First-order and texture features were extracted and intraclass correlation coefficients (ICCs) were calculated. Multivariate logistic regression (MLR) and random forest (RF) models from 10-fold cross-validation were built using these features. The trained MLR and RF models were tested in an external test set.

RESULTS

Thirty-two patients (M:F=23:9, 26.0±26.7 months) were in the training set and 14 patients (M:F=10:4, 33.4±20.4 months) were in the test set with radiomics features (n=930) being extracted. For 10 of the most relevant features selected, intra- and inter-observer variability was moderate to excellent (ICCs 0.633-0.911, 0.695-0.985, respectively). The area under the receiver operating characteristic curve (AUC) was 0.94 (sensitivity 67%, specificity 91%, and accuracy 84%) for the MLR model and the average AUC was 0.83 (sensitivity 44%, specificity 87%, and accuracy 75%) for the RF model from 10-fold cross-validation. In the test set, AUCs of the MLR and RF models were 0.94 and 0.91, respectively.

CONCLUSION

An MRI-based radiomics model can help predict high-risk neuroblastoma among neuroblastic tumors.

Imaging biomarkers and radiomics in pediatric oncology: a view from the PRIMAGE (PRedictive In silico Multiscale Analytics to support cancer personalized diaGnosis and prognosis, Empowered by imaging biomarkers) project

This review paper presents the practical development of imaging biomarkers in the scope of the PRIMAGE (PRedictive In silico Multiscale Analytics to support cancer personalized diaGnosis and prognosis, Empowered by imaging biomarkers) project, as a noninvasive and reliable way to improve the diagnosis and prognosis in pediatric oncology. The PRIMAGE project is a European multi-center research initiative that focuses on developing medical imaging-derived artificial intelligence (AI) solutions designed to enhance overall management and decision-making for two types of pediatric cancer: neuroblastoma and diffuse intrinsic pontine glioma. To allow this, the PRIMAGE project has created an open-cloud platform that combines imaging, clinical, and molecular data together with AI models developed from this data, creating a comprehensive decision support environment for clinicians managing patients with these two cancers. In order to achieve this, a standardized data processing and analysis workflow was implemented to generate robust and reliable predictions for different clinical endpoints. Magnetic resonance (MR) image harmonization and registration was performed as part of the workflow. Subsequently, an automated tool for the detection and segmentation of tumors was trained and internally validated. The Dice similarity coefficient obtained for the independent validation dataset was 0.997, indicating compatibility with the manual segmentation variability. Following this, radiomics and deep features were extracted and correlated with clinical endpoints. Finally, reproducible and relevant imaging quantitative features were integrated with clinical and molecular data to enrich both the predictive models and a set of visual analytics tools, making the PRIMAGE platform a complete clinical decision aid system. In order to ensure the advancement of research in this field and to foster engagement with the wider research community, the PRIMAGE data repository and platform are currently being integrated into the European Federation for Cancer Images (EUCAIM), which is the largest European cancer imaging research infrastructure created to date.

Phenomic Imaging

Human phenomics is defined as the comprehensive collection of observable phenotypes and characteristics influenced by a complex interplay among factors at multiple scales. These factors include genes, epigenetics at the microscopic level, organs, microbiome at the mesoscopic level, and diet and environmental exposures at the macroscopic level. "Phenomic imaging" utilizes various imaging techniques to visualize and measure anatomical structures, biological functions, metabolic processes, and biochemical activities across different scales, both in vivo and ex vivo. Unlike conventional medical imaging focused on disease diagnosis, phenomic imaging captures both normal and abnormal traits, facilitating detailed correlations between macro- and micro-phenotypes. This approach plays a crucial role in deciphering phenomes. This review provides an overview of different phenomic imaging modalities and their applications in human phenomics. Additionally, it explores the associations between phenomic imaging and other omics disciplines, including genomics, transcriptomics, proteomics, immunomics, and metabolomics. By integrating phenomic imaging with other omics data, such as genomics and metabolomics, a comprehensive understanding of biological systems can be achieved. This integration paves the way for the development of new therapeutic approaches and diagnostic tools.

Thoracoscopy for Pediatric Thoracic Neurogenic Tumors-A European Multi-Center Study

OBJECTIVES

To assess the efficacy of thoracoscopy and the outcome for children with thoracic neurogenic tumors.

METHODS

We performed a retrospective review of 15 European centers between 2000 and 2020 with patients who underwent thoracoscopy for a neurogenic mediastinal tumor. We assessed preoperative data, complications, and outcomes. Results were expressed with the median and range values.

RESULTS

We identified 119 patients with a median age of 4 years old (3 months-17 years). The diameter was 5.7 cm (1.1-15). INRG stage was L1 n = 46, L2 n = 56, MS n = 5, M n = 12. Of 69 patients with image-defined risk factors (IDRF), 29 had only (T9-T12) locations. Twenty-three out of 34 patients with preoperative chemotherapy had an 18 mm (7-24) decrease in diameter. Seven out of 31 patients lost their IDRF after chemotherapy. Fourteen had a conversion to thoracotomy. The length of the hospital stay was 4 days (0-46). The main complications included chylothorax (n = 7) and pneumothorax (n = 5). Long-term complications included Horner's syndrome (n = 5), back pain, and scoliosis (n = 5). Pathology was 53 neuroblastomas, 36 ganglioneuromas, and 30 ganglioneuroblastomas. Fourteen had a postoperative residue. With a median follow-up of 21 months (4-195), 9 patients had a recurrence, and 5 died of disease. Relapses were associated with tumor biology, histology, and the need for chemotherapy (p = 0.034, <0.001, and 0.015, respectively). Residues were associated with preoperative IDRF (excluding T9-T12 only) and the need for preoperative chemotherapy (p = 0.04 and 0.020).

CONCLUSION

Our results show that thoracoscopy is safe, with good outcomes for thoracic neurogenic tumors in selected cases. Surgical outcomes are related to the IDRFs, whereas oncologic outcomes are related to tumor histology and biology.

Role of MRI radiomics for the prediction of MYCN amplification in neuroblastomas

OBJECTIVES

We evaluate MR radiomics and develop machine learning-based classifiers to predict MYCN amplification in neuroblastomas.

METHODS

A total of 120 patients with neuroblastomas and baseline MR imaging examination available were identified of whom 74 (mean age ± standard deviation [SD] of 6 years and 2 months ± 4 years and 9 months; 43 females and 31 males, 14 MYCN amplified) underwent imaging at our institution. This was therefore used to develop radiomics models. The model was tested in a cohort of children with the same diagnosis but imaged elsewhere (n = 46, mean age ± SD: 5 years 11 months ± 3 years 9 months, 26 females and 14 MYCN amplified). Whole tumour volumes of interest were adopted to extract first-order histogram and second-order radiomics features. Interclass correlation coefficient and maximum relevance and minimum redundancy algorithm were applied for feature selection. Logistic regression, support vector machine, and random forest were employed as the classifiers. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic accuracy of the classifiers on the external test set.

RESULTS

The logistic regression model and the random forest both showed an AUC of 0.75. The support vector machine classifier obtained an AUC of 0.78 on the test set with a sensitivity of 64% and a specificity of 72%.

CONCLUSION

The study provides preliminary retrospective evidence demonstrating the feasibility of MRI radiomics in predicting MYCN amplification in neuroblastomas. Future studies are needed to explore the correlation between other imaging features and genetic markers and to develop multiclass predictive models.

KEY POINTS

• MYCN amplification in neuroblastomas is an important determinant of disease prognosis. • Radiomics analysis of pre-treatment MR examinations can be used to predict MYCN amplification in neuroblastomas. • Radiomics machine learning models showed good generalisability to external test set, demonstrating reproducibility of the computational models.

Association of image-defined risk factors with clinical features, tumor biology, and outcomes in neuroblastoma: a single-center retrospective study

Image-defined risk factors (IDRF) in neuroblastoma have been developed to predict tumor resectability and surgical complications; however, the potential prognostic value of IDRF in neuroblastoma has been variably reported. Previous studies did not report the IDRF status separately from the International Neuroblastoma Risk Group (INRG) stage. Moreover, the association between IDRF and clinical and pathological factors has not been discussed further. In this retrospective study, we investigated the clinical and biological features of neuroblastoma at different INRG stages based on IDRF. Event-free survival (EFS) and overall survival (OS) related to the INRG stage were analyzed using log-rank tests, and the prognostic value of the IDRF number and type was also evaluated. Among 72 patients, 182 IDRF at diagnosis were found in 79.2%. The distribution of the INRG stages was 10 L1 (13.9.0%), 25 L2 (34.7%), and 37 M/MS (51.4%). Patients with stage M/Ms had a larger tumor volume, a higher percentage of age ≥ 18 months, elevated lactate dehydrogenase (LDH) level, elevated ferritin level, and a higher percentage of COG high-risk compared with stage L1 and L2 patients. EFS and OS were similar for stage L1 and L2 tumors but were significantly poorer for metastatic disease. However, EFS (P = 0.06) and OS (P = 0.07) were similar for IDRF-negative and positive neuroblastomas. Patients with stage M/Ms with IDRF-positive had poorer EFS (P = 0.001) and OS (P < 0.001) compared with patients in stage L2. An IDRF ≥ 4, vascular IDRF, and infiltrative IDRF of the tumor were significant indicators of poor prognosis.   Conclusion: Our study indicates that increasing the INRG stages based on IDRF is associated with various unfavorable clinical features of neuroblastoma. The principal determinant of survival in neuroblastoma is the presence of metastatic disease more than IDRF alone at diagnosis. Both the number and type of IDRF have important clinical significance in the protocol planning of neuroblastoma, rather than just considering the absence or presence of IDRF. What is Known: • The International Neuroblastoma Risk Group Staging System (INRGSS) now employs image-defined risk factors (IDRFs) to stratify and stage disease. • The presence of IDRF at diagnosis are associated with higher rates of operative complications and incomplete surgical resection. What is New: • The principal determinant of survival from neuroblastoma is the presence of metastatic disease at diagnosis, more than IDRF alone. • IDRF number and type should also be considered during the diagnosis and treatment planning of neuroblastoma, rather than just considering the absence or presence of IDRF.

Changes in image-defined risk factors with neoadjuvant chemotherapy in pediatric abdominal neuroblastoma

PURPOSE

To observe the changes in image-defined risk factors (IDRFs) with neoadjuvant chemotherapy in pediatric abdominal neuroblastoma and to investigate the correlations between IDRF changes and histopathological features. In addition, this study also investigated the correlations between residual IDRFs after neoadjuvant chemotherapy and intraoperative complications.

METHODS

Forty-three patients with abdominal neuroblastoma who received neoadjuvant chemotherapy in our hospital from January 2015 to September 2021 were enrolled. Intraoperative records, histopathological features, and CT images at initial diagnosis and after neoadjuvant chemotherapy of all patients were retrospectively collected and analyzed.

RESULTS

A total of 245 IDRFs were found at initial diagnosis, with a median of 6 [5, 7] IDRFs per patient. After neoadjuvant chemotherapy, IDRFs significantly decreased to 156 (p < 0.001), with a median of 4 [3, 5] IDRFs remaining per patient. The majority of IDRFs (6/8, 75.00%) were significantly improved after neoadjuvant chemotherapy (p < 0.05), while tumor invasion of renal pedicles (p > 0.05) and adjacent structures (p > 0.05) was the least responsive IDRF. IDRFs in different types of neuroblastoma decreased significantly after neoadjuvant chemotherapy (p < 0.05), while they were not significant in neuroblastoma with low and intermediate mitosis-karyorrhexis indices (p > 0.05). The number of residual IDRFs correlated positively with the volumes of intraoperative blood loss (r = 0.399, p = 0.008), but not with the presence of intraoperative complications (r = 0.111, p = 0.478).

CONCLUSIONS

IDRFs in different types of neuroblastoma can be significantly improved after neoadjuvant chemotherapy, while IDRFs in neuroblastoma with low and intermediate mitosis-karyorrhexis indices might not be easily improved. At the same time, the number of residual IDRFs after neoadjuvant chemotherapy might not correlate with the occurrence of intraoperative complications in abdominal neuroblastoma.

A Random Forest-based Classifier for MYCN Status Prediction in Neuroblastoma using CT Images

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. Genomic amplification of MYCN is associated with poor outcomes and is detected in 16% of all NB cases. CT scans and MRI are the imaging techniques recommended for diagnosis and disease staging. The assessment of imaging features such as tumor volume, shape, and local extension represent relevant prognostic information. Radiogenomics have shown powerful results in the assessment of the genotype based on imaging findings automatically extracted from medical images. In this work, random forest was used to classify the MYCN amplification using radiomic features extracted from CT slices in a population of 46 NB patients. The learning model showed an area under the curve (AUC) of 0.85 ± 0.13, suggesting that radiomic-based methodologies might be helpful in the extraction of information that is not accessible by human naked eyes but could aid the clinicians on the diagnosis and treatment plan definition. Clinical relevance - This approach represents a random forest-based model to predict the MYCN amplification in NB patients that could give a faster, earlier, and repeatable analysis of the tumor along the time.

Incorporating Radiomics into Machine Learning Models to Predict Outcomes of Neuroblastoma

Neuroblastoma is one of the most common pediatric cancers. This study used machine learning (ML) to predict the mortality and a few other investigated intermediate outcomes of neuroblastoma patients non-invasively from CT images. Performances of multiple ML algorithms over retrospective CT images of 65 neuroblastoma patients are analyzed. An artificial neural network (ANN) is used on tumor radiomic features extracted from 3D CT images. A pre-trained 2D convolutional neural network (CNN) is used on slices of the same images. ML models are trained for various pathologically investigated outcomes of these patients. A subspecialty-trained pediatric radiologist independently reviewed the manually segmented primary tumors. Pyradiomics library is used to extract 105 radiomic features. Six ML algorithms are compared to predict the following outcomes: mortality, presence or absence of metastases, neuroblastoma differentiation, mitosis-karyorrhexis index (MKI), presence or absence of MYCN gene amplification, and presence of image-defined risk factors (IDRF). The prediction ranges over multiple experiments are measured using the area under the receiver operating characteristic (ROC-AUC) for comparison. Our results show that the radiomics-based ANN method slightly outperforms the other algorithms in predicting all outcomes except classification of the grade of neuroblastic differentiation, for which the elastic regression model performed the best. Contributions of the article are twofold: (1) noninvasive models for the prognosis from CT images of neuroblastoma, and (2) comparison of relevant ML models on this medical imaging problem.

BET and CDK Inhibition Reveal Differences in the Proliferation Control of Sympathetic Ganglion Neuroblasts and Adrenal Chromaffin Cells

Neuroblastoma arising from the adrenal differ from ganglionic neuroblastoma both genetically and clinically, with adrenal tumors being associated with a more severe prognosis. The different tumor properties may be linked to specific tumor founder cells in adrenal and sympathetic ganglia. To address this question, we first set up cultures of mouse sympathetic neuroblasts and adrenal chromaffin cells. These cultures were then treated with various proliferation inhibitors to identify lineage-specific responses. We show that neuroblast and chromaffin cell proliferation was affected by WNT, ALK, IGF1, and PRC2/EZH2 signaling inhibitors to a similar extent. However, differential effects were observed in response to bromodomain and extraterminal (BET) protein inhibitors (JQ1, GSK1324726A) and to the CDK-7 inhibitor THZ1, with BET inhibitors preferentially affecting chromaffin cells, and THZ1 preferentially affecting neuroblasts. The differential dependence of chromaffin cells and neuroblasts on BET and CDK signaling may indicate different mechanisms during tumor initiation in sympathetic ganglia and adrenal.

Advancing therapy for neuroblastoma

Neuroblastomas are tumours of sympathetic origin, with a heterogeneous clinical course ranging from localized or spontaneously regressing to widely metastatic disease. Neuroblastomas recapitulate many of the features of sympathoadrenal development, which have been directly targeted to improve the survival outcomes in patients with high-risk disease. Over the past few decades, improvements in the 5-year survival of patients with metastatic neuroblastomas, from <20% to >50%, have resulted from clinical trials incorporating high-dose chemotherapy with autologous stem cell transplantation, differentiating agents and immunotherapy with anti-GD2 monoclonal antibodies. The next generation of trials are designed to improve the initial response rates in patients with high-risk neuroblastomas via the addition of immunotherapies, targeted therapies (such as ALK inhibitors) and radiopharmaceuticals to standard induction regimens. Other trials are focused on testing precision medicine strategies for patients with relapsed and/or refractory disease, enhancing the antitumour immune response and improving the effectiveness of maintenance regimens, in order to prolong disease remission. In this Review, we describe advances in delineating the pathogenesis of neuroblastoma and in identifying the drivers of high-risk disease. We then discuss how this knowledge has informed improvements in risk stratification, risk-adapted therapy and the development of novel therapies.

A Novel Standard for Systematic Reporting of Neuroblastoma Surgery: The International Neuroblastoma Surgical Report Form (INSRF): A Joint Initiative by the Pediatric Oncological Cooperative Groups SIOPEN∗, COG∗∗, and GPOH∗∗∗

OBJECTIVE

To create the first structured surgical report form for NBL with international consensus, to permit standardized documentation of all NBL-related surgical procedures and their outcomes.

SUMMARY OF BACKGROUND DATA

NBL, the most common extracranial solid malignant tumor in children, covers a wide spectrum of tumors with significant differences in anatomical localization, organ or vessel involvement, and tumor biology. Complete surgical resection of the primary tumor is an important part of NBL treatment, but maybe hazardous, prone to complications and its role in high-risk disease remains debated. Various surgical guidelines exist within the protocols of the different cooperative groups, although there is no standardized operative report form to document the surgical treatment of NBL.

METHODS

After analyzing the treatment protocols of the SIOP Europe International Neuroblastoma Study Group, Children's Oncology Group, and Gesellschaft fuer Paediatrische Onkologie und Haematologie - German Association of Pediatric Oncology and Haematology pediatric cooperative groups, important variables were defined to completely describe surgical biopsy and resection of NBL and their outcomes. All variables were discussed within the Surgical Committees of SIOP Europe International Neuroblastoma Study Group, Children's Oncology Group, and Gesellschaft fuer Paediatrische Onkologie und Haematologie - German Association of Pediatric Oncology and Haematology. Thereafter, joint meetings were organized to obtain intercontinental consensus.

RESULTS

The "International Neuroblastoma Surgical Report Form" provides a structured reporting tool for all NBL surgery, in every anatomical region, documenting all Image Defined Risk Factors and structures involved, with obligatory reporting of intraoperative and 30 day-postoperative complications.

CONCLUSION

The International Neuroblastoma Surgical Report Form is the first universal form for the structured and uniform reporting of NBL-related surgical procedures and their outcomes, aiming to facilitate the postoperative communication, treatment planning and analysis of surgical treatment of NBL.

Methodological advances in the discovery of novel neuroblastoma therapeutics

INTRODUCTION

Neuroblastoma is a cancer of the sympathetic nervous system that causes up to 15% of cancer-related deaths among children. Among the ~1,000 newly diagnosed cases per year in Europe, more than half are classified as high-risk, with a 5-year survival rate <50%. Current multimodal treatments have improved survival among these patients, but relapsed and refractory tumors remain a major therapeutic challenge. A number of new methodologies are paving the way for the development of more effective and safer therapies to ultimately improve outcomes for high-risk patients.

AREAS COVERED

The authors provide a critical review on methodological advances aimed at providing new therapeutic opportunities for neuroblastoma patients, including preclinical models of human disease, generation of omics data to discover new therapeutic targets, and artificial intelligence-based technologies to implement personalized treatments.

EXPERT OPINION

While survival of childhood cancer has improved over the past decades, progress has been uneven. Still, survival is dismal for some cancers, including high-risk neuroblastoma. Embracing new technologies (e.g. molecular profiling of tumors, 3D in vitro models, etc.), international collaborative efforts and the incorporation of new therapies (e.g. RNA-based therapies, epigenetic therapies, immunotherapy) will ultimately lead to more effective and safer therapies for these subgroups of neuroblastoma patients.

Minimally invasive surgery for pediatric dumbbell neuroblastoma: systematic literature review and report of a single-stage neurosurgical and thoracoscopic approach

INTRODUCTION

Traditional surgical strategies for dumbbell neuroblastoma entail, among others, high risk of spinal deformity. Less invasive procedures might reduce these sequelae, however, there is small evidence comparing different strategies. Indications of minimally invasive surgery in neuroblastoma are still developing. Our aim is to identify and analyze different surgical approaches described in the recent literature and to suggest a minimally invasive option.

METHODS

A systematic review of the literature was conducted in PubMed (Jan 2000-Dec 2021) to identify reports describing surgical resection of dumbbell neuroblastoma in children, according to the PRISMA guidelines. Only full-text articles were included.

RESULTS

7 articles met the inclusion criteria which, added to the present case, represent a total of 43 patients. All were retrospective studies, most of them small series. Tumor location was mostly thoracic. Most of combined approaches were performed in two stages. Spinal deformity after surgery was reported in 3 patients. Minimally invasive approach was described in only one paper, with no reported cases of its use in a single-stage combined surgery. We also report, to our knowledge, the first single-stage posterior neurosurgical approach combined with thoracoscopy for resection of a dumbbell neuroblastoma in an infant.

CONCLUSION

Surgical resection of dumbbell neuroblastomas is challenging. There is no consensus on best surgical approach. Dumbbell tumors should not be considered a contraindication for minimally invasive surgery. A single stage and minimally invasive strategy is proposed.

Radiogenomics prediction for MYCN amplification in neuroblastoma: A hypothesis generating study

BACKGROUND

MYCN amplification represents a powerful prognostic factor in neuroblastoma (NB) and may occasionally account for intratumoral heterogeneity. Radiomics is an emerging field of advanced image analysis that aims to extract a large number of quantitative features from standard radiological images, providing valuable clinical information.

PROCEDURE

In this retrospective study, we aimed to create a radiogenomics model by correlating computed tomography (CT) radiomics analysis with MYCN status. NB lesions were segmented on pretherapy CT scans and radiomics features subsequently extracted using a dedicated library. Dimensionality reduction/features selection approaches were then used for features procession and logistic regression models have been developed for the considered outcome.

RESULTS

Seventy-eight patients were included in this study, as training dataset, of which 24 presented MYCN amplification. In total, 232 radiomics features were extracted. Eight features were selected through Boruta algorithm and two features were lastly chosen through Pearson correlation analysis: mean of voxel intensity histogram (p = .0082) and zone size non-uniformity (p = .038). Five-times repeated three-fold cross-validation logistic regression models yielded an area under the curve (AUC) value of 0.879 on the training set. The model was then applied to an independent validation cohort of 21 patients, of which five presented MYCN amplification. The validation of the model yielded a 0.813 AUC value, with 0.85 accuracy on previously unseen data.

CONCLUSIONS

CT-based radiomics is able to predict MYCN amplification status in NB, paving the way to the in-depth analysis of imaging based biomarkers that could enhance outcomes prediction.

CT-Based Radiomics Signature With Machine Learning Predicts MYCN Amplification in Pediatric Abdominal Neuroblastoma

Purpose

MYCN amplification plays a critical role in defining high-risk subgroup of patients with neuroblastoma. We aimed to develop and validate the CT-based machine learning models for predicting MYCN amplification in pediatric abdominal neuroblastoma.

Methods

A total of 172 patients with MYCN amplified (n = 47) and non-amplified (n = 125) were enrolled. The cohort was randomly stratified sampling into training and testing groups. Clinicopathological parameters and radiographic features were selected to construct the clinical predictive model. The regions of interest (ROIs) were segmented on three-phrase CT images to extract first-, second- and higher-order radiomics features. The ICCs, mRMR and LASSO methods were used for dimensionality reduction. The selected features from the training group were used to establish radiomics models using Logistic regression, Support Vector Machine (SVM), Bayes and Random Forest methods. The performance of four different radiomics models was evaluated according to the area under the receiver operator characteristic (ROC) curve (AUC), and then compared by Delong test. The nomogram incorporated of clinicopathological parameters, radiographic features and radiomics signature was developed through multivariate logistic regression. Finally, the predictive performance of the clinical model, radiomics models, and nomogram was evaluated in both training and testing groups.

Results

In total, 1,218 radiomics features were extracted from the ROIs on three-phrase CT images, and then 14 optimal features, including one original first-order feature and eight wavelet-transformed features and five LoG-transformed features, were identified and selected to construct the radiomics models. In the training group, the AUC of the Logistic, SVM, Bayes and Random Forest model was 0.940, 0.940, 0.780 and 0.927, respectively, and the corresponding AUC in the testing group was 0.909, 0.909, 0.729, 0.851, respectively. There was no significant difference among the Logistic, SVM and Random Forest model, but all better than the Bayes model (p <0.005). The predictive performance of the Logistic radiomics model based on three-phrase is similar to nomogram, but both better than the clinical model and radiomics model based on single venous phase.

Conclusion

The CT-based radiomics signature is able to predict MYCN amplification of pediatric abdominal NB with high accuracy based on SVM, Logistic and Random Forest classifiers, while Bayes classifier yields lower predictive performance. When combined with clinical and radiographic qualitative features, the clinics-radiomics nomogram can improve the performance of predicting MYCN amplification.

Neuroblastoma: the association of anatomical tumour site, molecular biology and patient outcomes

BACKGROUND

Numerous factors have been identified as carrying prognostic value in neuroblastoma (NB) and therefore incorporated in risk stratification of disease. Here, we investigate the association of anatomical site of NB with molecular biology and clinical outcomes.

METHODS

A total of 117 patients with NB were studied over a 30-year period. Tumour location was confirmed with computed tomography/magnetic resonance imaging. Data on molecular biology were obtained as testing became available. Chi-squared, Fisher's exact test and Kaplan-Meier log-rank tests were used for statistical analysis.

RESULTS

Tumour originated in the thoracic region (thoracic NB, TNB) in 15 patients (13%), adrenal gland (adrenal NB, ANB) in 88 patients (75%) and abdominal/paravertebral chain (paravertebral NB, PVNB) in 14 patients (12%). Overall survival (OS) for ANB was significantly lower (38%; P = 0.015). ANB cases were more frequently diagnosed at stage IV (69%; P = 0.001). MYCN amplification was noted in 33% of ANB cases and associated with lower OS (17% versus 62% MYCN non-amplified ANB; P = 0.01). The vast majority of TNB and PVNB were non-MYCN amplified (100% and 86%, respectively) and carried better prognosis (OS 86% and 83%, respectively). Forty-two percent of ANB cases were diploid and had lower OS (20% versus 71% hyperdiploid ANB; P = 0.079). TNB and PVNB were found to be mostly hyperdiploid (86% and 100%, respectively) with better OS (83% and 33%, respectively). Segmental chromosomal alterations had prognostic significance in those with PVNB (P = 0.03).

CONCLUSION

TNB tumours have better outcomes than adrenal tumours. This may be due to varied factors reported here including non-metastatic disease at presentation, non-amplification of the MYCN oncogene and overall favourable molecular biology characteristics.

Association of image-defined risk factors with clinical features, histopathology, and outcomes in neuroblastoma

BACKGROUND

Clinical, molecular, and histopathologic features guide treatment for neuroblastoma, but obtaining tumor tissue may cause complications and is subject to sampling error due to tumor heterogeneity. We hypothesized that image-defined risk factors (IDRFs) would reflect molecular features, histopathology, and clinical outcomes in neuroblastoma.

METHODS

We performed a retrospective cohort study of 76 patients with neuroblastoma or ganglioneuroblastoma. Diagnostic CT scans were reviewed for 20 IDRFs, which were consolidated into five IDRF groups (involvement of multiple body compartments, vascular encasement, tumor infiltration of adjacent organs/structures, airway compression, or intraspinal extension). IDRF groups were analyzed for association with clinical, molecular, and histopathologic features of neuroblastoma.

RESULTS

Patients with more IDRF groups had a higher risk of surgical complications (OR = 3.1, p = 0.001). Tumor vascular encasement was associated with increased risk of surgical complications (OR = 5.40, p = 0.009) and increased risk of undifferentiated/poorly differentiated histologic grade (OR = 11.11, p = 0.013). Tumor infiltration of adjacent organs and structures was associated with decreased survival (HR = 8.90, p = 0.007), MYCN amplification (OR = 9.91, p = 0.001), high MKI (OR = 6.20, p = 0.003), and increased risk of International Neuroblastoma Staging System stage 4 disease (OR = 8.96, p < 0.001).

CONCLUSIONS

The presence of IDRFs at diagnosis was associated with high-risk clinical, molecular, and histopathologic features of neuroblastoma. The IDRF group tumor infiltration into adjacent organs and structures was associated with decreased survival. Collectively, these findings may assist surgical planning and medical management for neuroblastoma patients.

Mediastinal and hilar soft tissue mass-like lesions in congenital unilateral pulmonary vein atresia: A retrospective review of seven pediatric patients

BACKGROUND

Congenital unilateral pulmonary vein atresia (CUPVA) is known to lead to the formation of an abnormal confluent mediastinal and hilar soft tissue mass, thoracic hypoplasia, and interlobular septal thickening on the affected side. The purpose of the present study is to investigate the frequency and severity of mediastinal soft tissue mass-like lesions and examine other abnormal findings associated with CUPVA.

METHODS

We retrospectively reviewed seven children with CUPVA who underwent contrast-enhanced CT scans and measured the soft tissue mass volume in the bilateral mediastinum (affected and normal side). The location of abnormal soft tissue was divided into three anatomical sections (paratracheal, peribronchial, and the dorsal aspect of the left atrium). The relationships among soft tissue volume and anatomical section were statistically evaluated. Also, the presence of thoracic hypoplasia, small ipsilateral pulmonary arteries, interlobular septal thickening, and ground-glass opacities were investigated.

RESULTS

In all cases, CT scans confirmed the presence of confluent soft tissue mass-like lesions in the affected mediastinum. The soft tissue volume on the affected side was 5.5-fold greater than the volume on the normal side (average: 18.0 cm³ and 4.25 cm³ respectively, P < 0.01). Thoracic hypoplasia and interlobular septal thickening were found in all patients. Small pulmonary arteries and ground-glass opacities were present in six of the seven patients.

CONCLUSION

Abnormal mediastinal and hilar soft tissue is commonly found in patients with CUPVA. So, if we encounter the mediastinal soft tissue mass in patients with CUPVA, no further test will be indicated.

Radiogenomics of neuroblastoma in pediatric patients: CT-based radiomics signature in predicting MYCN amplification

OBJECTIVES

To construct a CT-based radiomics signature and assess its performance in predicting MYCN amplification (MNA) in pediatric patients with neuroblastoma.

METHODS

Seventy-eight pediatric patients with neuroblastoma were recruited (55 in training cohort and 23 in test cohort). Radiomics features were extracted automatically from the region of interest (ROI) manually delineated on the three-phase computed tomography (CT) images. Selected radiomics features were retained to construct radiomics signature and a radiomics score (rad-score) was calculated by using the radiomics signature-based formula. A clinical model was established with clinical factors, including clinicopathological data, and CT image features. A combined nomogram was developed with the incorporation of a radiomics signature and clinical factors. The predictive performance was assessed by receiver operating characteristics curve (ROC) analysis and decision curve analysis (DCA).

RESULTS

The radiomics signature was constructed using 7 selected radiomics features. The clinical radiomics nomogram, which was based on the radiomics signature and two clinical factors, showed superior predictive performance compared with the clinical model alone (area under the curve (AUC) in the training cohort: 0.95 vs. 0.82, the test cohort: 0.91 vs. 0.70). The clinical utility of clinical radiomics nomogram was confirmed by DCA.

CONCLUSIONS

This proposed CT-based radiomics signature was able to predict MNA. Combining the radiomics signature with clinical factors outperformed using clinical model alone for MNA prediction.

KEY POINTS

• A CT-based radiomics signature has the ability to predict MYCN amplification (MNA) in neuroblastoma. • Both pre- and post-contrast CT images are valuable in predicting MNA. • Associating the radiomics signature with clinical factors improved the predictive performance of MNA, compared with clinical model alone.

Trapdoor anterior thoracotomy for cervicothoracic and apical thoracic neuroblastoma in children

PURPOSE

Cervicothoracic and apical thoracic neuroblastoma pose unique surgical challenges. We report our experience with the trapdoor anterior thoracotomy (TAT) approach to overcome these difficulties.

METHODS

Retrospective review of our centre's neuroblastoma database was conducted. Patients who underwent TAT at our centre were included, their demographic data and clinical reports were analyzed.

RESULTS

A total of 21 patients underwent TAT for neuroblastoma, mean age at surgery of 3.5 (0.3-7.9) years, male to female ratio was 11:10. Fifteen patients had cervicothoracic tumors while 6 had apical thoracic tumors. All except 2 were primary tumors. They were stage M (n = 12), MS (n = 1), and L2 (n = 8). At pre-operative assessment, 19 patients had image-defined risk factor (IDRF), including dual compartmental involvement (n = 15), trachea/bronchus compression (n = 4), encasement of carotid (n = 5), subclavian (n = 11), and vertebral arteries (n = 6). Four underwent upfront surgery while 17 received pre-operative chemotherapy of 2-8 (mean 3.9) cycles. All patients accomplished gross total resection. None had MYCN amplification. The postoperative complications included Horner's syndrome (n = 21), Klumpke's palsy (n = 1), winged scapula (n = 1), phrenic nerve palsy (n = 1), and bronchomalacia (n = 2).

CONCLUSION

Gross total resection of cervicothoracic and apical thoracic neuroblastoma can be accomplished by TAT with minimal morbidity.

How well do image-defined risk factors (IDRFs) predict surgical outcomes and survival in patients with neuroblastoma? A systematic review and meta-analysis

INTRODUCTION

Since their introduction to the International Neuroblastoma Risk Group (INRG) staging system in 2009, the role of Image-Defined Risk Factors (IDRFs) in predicting outcomes has been studied in heterogeneous populations with varying results. We conducted a systematic review and meta-analysis in order to determine quantitative measures of precisely how well pre-treatment IDRFs predict surgical outcomes and survival.

METHODS

A systematic review was performed for studies between January 1990 and July 2019 that compared surgical outcomes and/or survival in pediatric neuroblastoma patients with one or more IDRFs to patients without IDRFs. Summary risk ratios (RR) and hazard ratios (HR) were calculated using a random-effects model.

RESULTS

19 retrospective cohort studies were included, representing data from 1132 patients. The risk ratio (RR) of incomplete surgical resection in IDRF-positive patients compared to IDRF-negative patients was 2.45 (95% CI 1.51-3.97). The RR of surgical complications was 2.30 (95% CI 1.46-3.61). The hazard ratio (HR) for 5-year EFS was 2.08 (95% CI 2.93-4.13) while the 5-year HR for OS was 2.44 (95% CI 1.46-4.08).

CONCLUSION

IDRF-positive neuroblastoma patients have a higher risk of incomplete surgical resection, surgical complications, and 5-year mortality and/or relapse. Our results affirm that IDRFs remain a useful prognostic tool for neuroblastoma patients both for short and long-term outcomes.

LEVEL OF EVIDENCE

II.

Effects of preoperative chemotherapy on neuroblastoma with MYCN amplification: a surgeon’s perspective

Background

Preoperative chemotherapy plays an important role in the surgical management of unresectable neuroblastoma. Its response to chemotherapy has been variable due to the tumor’s heterogeneity. We aimed to evaluate the effects of preoperative chemotherapy on MYCN-amplified (MYCNA) neuroblastoma that would impact on surgical resection.

Methods

Patients with MYCNA neuroblastoma who received preoperative chemotherapy followed by surgical resection performed at our center were included. The tools of response evaluated included tumor volume reduction (TVR), reduction in image-defined risk factors (IDRFs), percentage tumor necrosis (Nec), and surgical complications.

Results

Among 62 patients evaluated, mean age was 3.0 (range, 0.9–11.8) years, and primary tumors were distributed in the abdomen (n=59), pelvis (n=2), and thorax (n=1). The patients were in stages L2 (n=14) and M (n=48). Surgery was performed after median of 4 (range, 2–10) cycles of chemotherapy. On completion of preoperative chemotherapy, 41 (66.1%) patients had TVR >65%, 24 (42.9%) responded with reduced IDRFs, 47 (75.8%) tumors had Nec >50%, and 27 patients suffered 31 surgical complications. Majority (83.9%) continued to have IDRFs at surgery. IDRFs commonly encountered were encasement of renal pedicles (n=50), superior mesenteric artery (n=46), celiac axis (n=45), and aorta/vena cava (n=44), and most remained refractory to resolution. Patients with TVR >65% were associated with Nec >50% (87.5% vs 54.5%, p=0.004) and reduced IDRFs (46.3% vs 19%, p=0.035), but not with the incidence of surgical complications.

Conclusions

Majority of MYCNA neuroblastomas were highly chemosensitive as they experienced high TVR, reduced IDRFs, and high Nec, and hence created favorable conditions for surgical resection. Poor responders and persistent IDRFs that were commonly refractory to preoperative chemotherapy remained a surgical challenge.

Nomograms based on preoperative multiparametric magnetic resonance imaging for prediction of molecular subgrouping in medulloblastoma: results from a radiogenomics study of 111 patients

Background

Novel biological insights have led to consensus classification of medulloblastoma into 4 distinct molecular subgroups-wingless (WNT), sonic hedgehog (SHH), Group 3, and Group 4. We aimed to predict molecular subgrouping in medulloblastoma based on preoperative multiparametric magnetic resonance imaging (MRI) characteristics.

Methods

A set of 19 MRI features were evaluated in 111 patients with histologic diagnosis of medulloblastoma for prediction of molecular subgrouping. MRI characteristics were correlated with molecular subgroups derived from tissue samples in 111 patients (WNT = 17, SHH = 44, Group 3 = 27, and Group 4 = 23). Multinomial logistic regression of imaging parameters was performed on a training cohort (TC) of 76 patients, representing two-thirds of randomly selected patients from each of 4 molecular subgroups, to generate binary nomograms. Validation of these nomograms was performed on the remaining 35 patients as the validation cohort (VC).

Results

Medulloblastoma subgroups could be accurately predicted by preoperative MRI features in 74% of cases. Predictive accuracy was excellent for SHH (95%), acceptably high for Group 4 (78%), modest for Group 3 (56%) and worst for WNT (41%) subgroup medulloblastoma. SHH-specific nomogram was associated with excellent correlation between TC and VC, with area under the curve (AUC) of 0.939 and 0.991, respectively. AUC for Group 4 was acceptable at 0.851 and 0.788 in TC and VC, respectively; however, these values were consistently suboptimal in WNT and Group 3 medulloblastoma.

Conclusion

The predictive accuracy of MRI-based nomograms was excellent for SHH and encouraging for Group 4 medulloblastoma. Further work is needed for Group 3 and WNT-pathway medulloblastoma.

Multidisciplinary surgical strategy for dumbbell neuroblastoma: A single-center experience of 32 cases

INTRODUCTION

Prognosis of dumbbell neuroblastoma (NBL) is mainly determined by the sequelae induced by the tumor itself and the neurosurgical approach. However, after primary chemotherapy, surgical management of the residual tumor, especially the spinal canal component, remains controversial.

METHODS

We conducted a single-center retrospective cohort study over the last 15 years (2002-2017) including patients treated for NBL with spinal canal extension focusing on timing and type of surgery, complications, and functional and oncological follow-up.

RESULTS

Thirty-two children (14 M, 18 F) were managed for NBL, with the majority (26) presenting with NBL stroma poor while four had ganglioneuroblastoma intermixed, one nodular, and one ganglioneuroma. All but two patients received neoadjuvant chemotherapy. Upfront laminotomy for spinal cord decompression was performed in two patients; nine patients had extraspinal surgery with a follow-up neurosurgical procedure in seven cases; eight patients had initial neurosurgery followed by an extraspinal procedure, while six patients underwent a combined multidisciplinary approach. With a median follow up of 3.6 years (0.1-14.9), 29 patients (90.6) are alive and two out of three (19, 65.5%) have functional sequelae.

CONCLUSION

Patients with NBL with persistent spinal canal extension of the tumor after neoadjuvant chemotherapy treated at our center had outcomes that compare favorably with the literature. This is likely due to the multidisciplinary approach to optimal surgical strategy and continuous evaluation of the respective risks of tumor progression. Neurological disability results from initial spinal cord compression or the radicular sacrifice required for tumor resection.

[Imaging of abdominal tumors in childhood and adolescence : Part II: relevant intra-abdominal and retroperitoneal tumor entities]

Abdominal and pelvic tumors in children and adolescents can be manifested intra-abdominally and also often in the retroperitoneum. The most important pediatric primary retroperitoneal space-occupying lesions are nephroblastoma (Wilms' tumor) and neuroblastoma, whereby imaging plays a decisive role in the diagnostics and differentiation of the two entities. Benign tumors of the mesentery and gastrointestinal tract occur more frequently in children than malignant lesions. The benign entities include lipoma, polyps and vascular tumors, such as lymphatic malformations. Of the malignant sarcomas, abdominal rhabdomyosarcomas (RMS) occur relatively often in childhood and adolescence. The most frequent pediatric abdominal lymphoma is Burkitt's lymphoma, an aggressive subtype of non-Hodgkin's lymphoma. Relevant tumor entities in childhood are also germ cell tumors, which originate from the genitals (gonadal) or can be extragonadally manifested. The benignancy or malignancy of germ cell tumors ranges from benign teratomas to highly malignant entities, such as yolk sac tumors. The germ cell tumors, just as all pediatric abdominal mass lesions, show a broad spectrum of tumor aggressiveness, malignancy and therefore also prognosis and mortality for the affected children and adolescents.

Association between image-defined risk factors and neuroblastoma outcomes

BACKGROUND

The current neuroblastoma (NBL) staging system employs image-defined risk factors (IDRFs) to assess numerous anatomic features, but the impact of IDRFs on surgical and oncologic outcomes is unclear.

METHODS

The Vanderbilt Cancer Registry identified children treated for NBL from 2002 to 2017. Tumor volume (TV) and IDRFs were measured radiographically at diagnosis and before resection. Perioperative and oncologic outcomes were evaluated.

RESULTS

At diagnosis of 106 NBL, 61% were IDRF positive. MYCN-amplified and undifferentiated NBL had more IDRFs than nonamplified and more differentiated tumors (p = 0.001 and p = 0.01). Of 86 NBLs resected, 43% were IDRF positive, which associated with higher stage, risk, and TV (each p < 0.001). The presence of IDRF at resection was also associated with increased blood loss (p < 0.001), longer operating times (p < 0.001), greater incidence of intraoperative complications (p = 0.03), more frequent ICU admissions postoperatively (p < 0.001), and longer hospital stays (p < 0.001). IDRF negative and positive tumors did not have significantly different rates of gross total resection (p = 0.2). Five-year relapse-free and overall survival was similar for IDRF negative and positive NBL (p = 0.9 and p = 0.8).

CONCLUSIONS

IDRFs at diagnosis were associated with larger, less differentiated, advanced stage, and higher risk NBL and at resection with increased operative difficulty and perioperative morbidity. However, the frequency of gross total resection and patient survival after resection were not associated with the presence of IDRFs.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

Level III.

Radiogenomics: bridging imaging and genomics

From diagnostics to prognosis to response prediction, new applications for radiomics are rapidly being developed. One of the fastest evolving branches involves linking imaging phenotypes to the tumor genetic profile, a field commonly referred to as "radiogenomics." In this review, a general outline of radiogenomic literature concerning prominent mutations across different tumor sites will be provided. The field of radiogenomics originates from image processing techniques developed decades ago; however, many technical and clinical challenges still need to be addressed. Nevertheless, increasingly accurate and robust radiogenomic models are being presented and the future appears to be bright.

Radiogenomics of rectal adenocarcinoma in the era of precision medicine: A pilot study of associations between qualitative and quantitative MRI imaging features and genetic mutations

OBJECTIVE

To investigate associations between genetic mutations and qualitative as well as quantitative features on MRI in rectal adenocarcinoma at primary staging.

METHODS

In this retrospective study, patients with rectal adenocarcinoma, genome sequencing, and pretreatment rectal MRI were included. Statistical analysis was performed to evaluate associations between qualitative features obtained from subjective evaluation of rectal MRI and gene mutations as well as between quantitative textural features and gene mutations. For the qualitative evaluation, Fisher's Exact test was used to analyze categorical associations and Wilcoxon Rank Sum test was used for continuous clinical variables. For the quantitative evaluation, we performed manual segmentation of T2-weighted images for radiomics-based quantitative image analysis. Thirty-four texture features consisting of first order intensity histogram-based features (n = 4), second order Haralick textures (n = 5), and Gabor-edge based Haralick textures were computed at two different orientations. Consensus clustering was performed with 34 computed texture features using the K-means algorithm with Euclidean distance between the texture features. The clusters resulting from the algorithm were then used to enumerate the prevalence of gene mutations in those clusters.

RESULTS

In 65 patients, 45 genes were mutated in more than 3/65 patients (5%) and were included in the statistical analysis. Regarding qualitative imaging features, on univariate analysis, tumor location was significantly associated with APC (p = 0.032) and RASA1 mutation (p = 0.032); CRM status was significantly associated with ATM mutation (p = 0.021); and lymph node metastasis was significantly associated with BRCA2 (p = 0.046) mutation. However, these associations were not significant after adjusting for multiple comparisons. Regarding quantitative imaging features, Cluster C1 had tumors with higher mean Gabor edge intensity compared with cluster C2 (θ = 0°, p = 0.018; θ = 45°, p = 0.047; θ = 90°, p = 0.037; cluster C3 (θ = 0°, p = 0.18; θ = 45°, p = 0.1; θ = 90°, p = 0.052), and cluster C4 (θ = 0°, p = 0.016; θ = 45°, p = 0.033; θ = 90°, p = 0.014) suggesting that the cluster C1 had tumors with more distinct edges or heterogeneous appearance compared with other clusters.

CONCLUSIONS

Although this preliminary study showed promising associations between quantitative features and genetic mutations, it did not show any correlation between qualitative features and genetic mutations. Further studies with larger sample size are warranted to validate our preliminary data.

Origin and initiation mechanisms of neuroblastoma

Neuroblastoma is an embryonal malignancy that affects normal development of the adrenal medulla and paravertebral sympathetic ganglia in early childhood. Extensive studies have revealed the molecular characteristics of human neuroblastomas, including abnormalities at genome, epigenome and transcriptome levels. However, neuroblastoma initiation mechanisms and even its origin are long-standing mysteries. In this review article, we summarize the current knowledge about normal development of putative neuroblastoma sources, namely sympathoadrenal lineage of neural crest cells and Schwann cell precursors that were recently identified as the source of adrenal chromaffin cells. A plausible origin of enigmatic stage 4S neuroblastoma is also discussed. With regard to the initiation mechanisms, we review genetic abnormalities in neuroblastomas and their possible association to initiation mechanisms. We also summarize evidences of neuroblastoma initiation observed in genetically engineered animal models, in which epigenetic alterations were involved, including transcriptomic upregulation by N-Myc and downregulation by polycomb repressive complex 2. Finally, several in vitro experimental methods are proposed that hopefully will accelerate our comprehension of neuroblastoma initiation. Thus, this review summarizes the state-of-the-art knowledge about the mechanisms of neuroblastoma initiation, which is critical for developing new strategies to cure children with neuroblastoma.