Guidelines for imaging and staging of neuroblastic tumors: consensus report from the International Neuroblastoma Risk Group Project

Development of a New Score Based on Image Defined Risk Factors to Standardize Surgical Risk in Neuroblastoma Resection - A SIOPEN Collaborative Study

BACKGROUND AND AIMS

Image Defined Risk Factors (IDRFs) assess surgical risk in neuroblastoma (NB) and guide neoadjuvant therapy. Despite chemotherapy IDRFs may persist in 70 % of cases. Several studies have suggested that not all IDRFs hold equal significance and that the presence of an IDRF does not inherently signify unresectability. This current study seeks to stratify and assign a score to each IDRF based on its impact on surgical risk.

METHODS

This collaborative study entailed retrospective collection of patient data from NB operations conducted between 2016 and 2020, together with the computation of a Surgical Complexity Index (SCI) for every patient. The SCI values obtained were correlated with preoperatively identified IDRFs. Mann-Whitney statistical test was employed to assign a relevance score to the association between individual IDRFs and SCI.

RESULTS

14 centers contributed 427 neuroblastoma index cases meeting study inclusion criteria. 303 patients had 1 or more IDRFs. The presence and number of IDRFs in all patients significantly correlated with the SCI value (p < 0.0001). The most frequently encountered IDRF was renal pedicle involvement. There was a significant association observed between clusters of abdominal IDRFs and the occurrence of post-operative complications (p < 0.05), while a weak association link was found with intra-operative complications. A relevance score for individual IDRFs allowed their stratification based on surgical risk. The most relevant IDRFs were extension within two anatomical body compartments, infiltration of the hepato-pancreatic block, encasement of the superior mesenteric artery and coeliac axis, and tumor compressing the trachea.

CONCLUSIONS

This current study has facilitated the assignment of a relevance score to each IDRF, correlating it with surgical risks. Considering this stratification of surgical risk alongside oncologic risk as defined by the neuroblastoma treatment patient risk grouping should facilitate a more precise definition of surgical objectives and the optimal conditions favoring gross tumor resection.

TYPE OF STUDY

Clinical Research - Study of Diagnostic Test.

LEVEL OF EVIDENCE

III.

Intra- and interobserver agreement in evaluation of image-defined risk factors on computed tomography in pediatric neuroblastoma

BACKGROUND

Image-defined risk factors (IDRFs) were introduced to provide a consensus approach for pre-treatment risk stratification on computed tomography (CT) and magnetic resonance imaging (MRI) in patients with neuroblastoma.

OBJECTIVE

To assess the intra- and inter-reader agreement of radiologists in identifying IDRFs on CT.

MATERIALS AND METHODS

Approval for this retrospective study was granted by our institutional research ethics board with a waiver of consent. CT studies of pediatric patients with neuroblastoma were assessed by seven radiologists in two rounds. Each CT was accompanied by a standard form to indicate presence or absence of IDRFs for each patient. At least a 4-week period between rounds, randomization, and relabeling of the CT studies was required to minimize recall bias. Finally, three of the seven radiologists conducted a subsequent consensus reading to determine true positive IDRFs in the cohort. Fleiss' kappa statistic was used to evaluate readers' agreements and Pearson's correlation assessed the correlation between years of experiences of radiologists and their performance in accurately (intra-reader agreement) detecting IDRFs.

RESULTS

A total of 31 children with a median age of 2.1 years (interquartile range (IQR) 1.1, 3.0; range 0-18; male=21 (67.7%)) were included and 251 total positive IDRFs were identified on their CT scans. The location of the primary tumor was in the neck in 1 patient (3.2%), within the chest in 2 patients (6.5%), within the abdomen in 27 patients (87.1%), and in the pelvis in 1 patient (3.2%). In determining IDRFs, the inter-reader agreement among radiologists was substantial: 0.65 (95% CI 0.60, 0.69) and the intra-reader agreement for each radiologist was substantial to near perfect, ranging from 0.67 (0.60, 0.70) to 0.86 (0.82, 0.90). The correlation between the number of years of experience of radiologists and their performances in accurately detecting IDRFs (their intra-reader agreements) was respectively low (r=45, P=0.30) for abdomino-pelvic IDRFs and high for organs' infiltration IDRFs (r=0.74, P=0.05).

CONCLUSION

The determination of IDRFs on CT is reproducible with significant agreement among radiologists. The two IDRF items with the lowest overall inter-reader agreements were "diaphragm infiltration" and "mesenteric infiltration."

Management of Ganglioneuroma and Ganglioneuroblastoma Intermixed: A United Kingdom Children's Cancer and Leukaemia Group (UK CCLG) Nationwide Study Report

BACKGROUND

Ganglioneuroblastoma intermixed (GNBi) and ganglioneuroma (GN) represent benign variants of peripheral neuroblastic tumours. While historically surgical resection was recommended, watchful active observation has become the accepted management for a subset of patients.

OBJECTIVES

To review clinical features, biology, natural history and management of a retrospective UK CCLG study cohort of GN and GNBi, and compare outcomes of patients treated with surgical resection or watchful active observation.

METHODS

Retrospective review of histologically confirmed non-metastatic GN and GNBi diagnosed between 1990 and 2020.

RESULTS

A total of 259 patients were identified (163 GN, 93 GNBi, median age 62 months). In all 201 (78%) had initial surgery and 58 (22%) were observed. Overall survival was 98%. Twenty-one of 58 observed (36%) required subsequent surgery due to progressive tumour growth (52%). Gross total resection (GTR) was achieved in 79% of patients with a 19% complication rate. GTR was obtained in a similar proportion of patients having initial surgery (65%) and delayed surgery (76%). Patients obtaining GTR were more likely to have complete symptom(s) control (43% vs. 24%). In 45 cases (39%), surgical pathology was different from pathology at biopsy, and in 14 (12%) the pathology changed from GN/GNBi to neuroblastoma/GNB nodular.

CONCLUSION

Watchful active observation can be a safe approach, with surgical resection reserved for symptomatic patients. However, a small proportion of patients in the observation group had their diagnosis revised to malignant at surgery. Careful assessment of surgical risk and expected benefits, after considering an initial period of observation, will allow clinicians to make optimal decisions for patients and their families.

Vascular encasement image defined risk factors independently predict surgical complications in neuroblastoma

BACKGROUND

Specific image defined risk factors (IDRF) immediately prior to surgery may be more relevant to paediatric oncology surgeons than pre-neoadjuvant IDRFs at diagnosis. The aim of this study was to determine IDRF subtypes that independently predict postoperative complications.

METHODS

We searched the New Zealand Children's Cancer Registry for all cases of neuroblastoma treated at a single paediatric oncology centre between January 2007 and February 2021 and determined the IDRF status on pre-operative imaging at diagnosis and after neoadjuvant therapy. Surgical complications (Clavien-Dindo grade) were correlated with total number of IDRFs (pre- and post-chemotherapy) and three subsets: vascular encasement (VE), invasive (I), and extensive (E).

RESULTS

Of 101 patients, 73 underwent surgical resection, and 32 (44%) had a surgical complication. Of the 54 IDRF-positive tumours, all were treated by neoadjuvant therapy and in 17, all IDRFs resolved. Complications correlated with the number of post-neoadjuvant therapy VE-IDRFs at OR 1.2 (95% CI 1.0-1.4, P = 0.02) and extensive IDRFs at OR 1.7 (95% CI 1.1-1.9, P = 0.02). Pre-neoadjuvant IDRF status was not independently associated with complications when controlling for post-neoadjuvant IDRF status. The total number of VE-IDRF reduced from 181 pre-neoadjuvant therapy to 86 post, with tumour encasing the aorta and/or vena cava being the most common.

CONCLUSIONS

The vascular encasement and extensive subtypes of IDRF may be more useful prognostic indicators of surgical complications than the total number of IDRFs. This may have implications for reporting IDRF status on preoperative imaging and surgical planning but needs validation in larger cohort studies.

Advances in multimodal imaging for adrenal gland disorders: integrating CT, MRI, and nuclear medicine

Adrenal diseases pose significant diagnostic challenges due to the wide range of neoplastic and non-neoplastic pathologies. Radiologists have a crucial role in diagnosing and managing these conditions by, leveraging advanced imaging techniques. This review discusses the vital role of computed tomography (CT), magnetic resonance imaging (MRI), and nuclear medicine in adrenal imaging, and focuses on morphological and functional evaluations. First, the anatomy and physiology of the adrenal glands are described, followed by a discussion on ectopic adrenocortical adenomas and how they develop. The concepts and imaging findings of congenital diseases, such as congenital adrenal hyperplasia (CAH), adrenal rest tumors, and adrenocortical nodular disease, considering recent updates to the WHO Classification of Tumours (5th ed.) terminology are highlighted. The diagnostic value of dynamic contrast-enhanced CT and chemical-shift MRI for identifying adrenocortical adenomas are emphasized, alongside the use of adrenocortical scintigraphy such as 131I-adosterol scintigraphy for diagnosing Cushing's disease, Cushing's syndrome (CS), subclinical CS, and ectopic adrenocorticotropic hormone-producing tumors. Systemic complications associated with CS, and the diagnosis and treatment of pheochromocytomas, paragangliomas (PPGLs), and neuroblastomas, will also be discussed focusing on 123I-metaiodobenzylguanidine (MIBG) imaging and 131I-MIBG therapy. Pitfalls in 123I-MIBG imaging and the increasing importance of diagnosing hereditary PPGLs due to increased genetic testing are also be discussed. Additionally, the broad differential diagnosis for adrenal masses-including malignancies like adrenal carcinoma, metastases, and malignant lymphoma, as well as benign conditions like myelolipoma and ganglioneuroma, and complications, such as adrenal hemorrhage, infarction, and infections-will be outlined. The goal of this review was to provide an overview of adrenal diseases that includes the most recent information for radiologists to stay updated on the latest imaging techniques and advancements that can ensure accurate diagnosis and effective management.

Adult-onset pancreatic neuroblastoma: A case report with a literature review

Neuroblastoma is an aggressive malignancy commonly found in children, with adult patients being quite rare. Pancreatic neuroblastoma, even among adult cases, is especially rare. We present a case of a 26-year-old woman presented with mild abdominal pain and a palpable mass diagnosed as neuroblastoma affecting the pancreas. After initial diagnostic challenges, a biopsy confirmed the diagnosis of neuroblastoma. The patient thereafter underwent a course of neoadjuvant chemotherapy, followed by a complex surgical resection. This case highlights the importance of a comprehensive diagnostic approach, including repeated biopsies and the involvement of a multidisciplinary team in the management of rare presentations of adult neuroblastoma.

Evaluation of Image-Defined Risk Factor (IDRF) Assessment in Patients With Intermediate-risk Neuroblastoma: A Report From the Children's Oncology Group Study ANBL0531

BACKGROUND

The International Neuroblastoma Risk Group (INRG) classifier utilizes a staging system based on pretreatment imaging criteria in which image-defined risk factors (IDRFs) are used to evaluate the extent of locoregional disease. Children's Oncology Group (COG) study ANBL0531 prospectively examined institutional determination of IDRF status and compared that to a standardized central review.

METHODS

Between 9/2009-6/2011, patients with intermediate-risk neuroblastoma were enrolled on ANBL0531 and had IDRF assessment at treating institutions. Paired COG pediatric surgeons and radiologists performed blinded central review of diagnostic imaging for the presence or absence of IDRFs. Second blinded review was performed in cases of discordance. Comparison of local and central review was performed using the Kappa coefficient to determine concordance in IDRF assessment.

RESULTS

211 patients enrolled in ANBL0531 underwent IDRF assessment; 3 patients were excluded due to poor image quality. Central reviewer pairs agreed on the presence or absence of any IDRF in 170/208 (81.7%; κ = 0.48) cases. Thirteen (6.3%) cases could not be adjudicated after second blinded review. Radiologists were more likely to identify IRDFs as present than surgeons (p < 0.001). Local and central reviewers agreed on the presence or absence of any IDRF in only108/208 (51.9%; κ = 0.06) cases.

CONCLUSIONS

Among experienced pediatric surgeons and radiologists participating in central review, concordance was moderate, with agreement in 81.7% of cases. On comparison of local and central assessment of IDRFs, concordance was poor. These data indicate that greater standardization, education, technology, and training are needed to improve the assessment of IDRFs in children with neuroblastoma.

LEVEL OF EVIDENCE

Treatment Study, Level III.

Stratification of Anatomical Imaging Features Between High-Risk and Non-High-Risk Groups in Neuroblastoma

BACKGROUND

This study compared anatomical imaging features between high-risk and non-high-risk groups in neuroblastoma with at least one image-defined risk factor (IDRF). It also assessed the diagnostic performance of these features in identifying the high-risk group.

METHODS

A retrospective analysis of neuroblastoma patients with at least one IDRF was conducted. Imaging features, including estimated tumor volume and IDRFs, were compared between the two groups. The diagnostic performance of these features was assessed using receiver operating characteristic (ROC) curves, and the areas under the ROC curves (AUCs) along with their 95% confidence intervals (CIs) were calculated. Additionally, to internally validate their diagnostic performance, the bootstrap resampling method with 1000 bootstrap resamples was employed.

RESULTS

The study included 255 patients (185 high-risk cases, 70 non-high-risk cases). Significant differences were found in estimated tumor volume and IDRF number between the high-risk and non-high-risk groups (P < 0.001). The estimated tumor volume and the IDRF number-based cluster were independent risk factors, and their combination achieved an AUC of 0.801 (95% CI: 0.747-0.848) for high-risk group diagnosis, with the average AUC of the 1000 bootstrap samples of 0.800 (95% CI: 0.798-0.802). In abdominal lesions, specific IDRF categories differed between high-risk and non-high-risk groups (P < 0.05).

CONCLUSION

Our study reveals anatomical imaging differences between high-risk and non-high-risk groups in neuroblastoma with at least one IDRF.

Impact of the relationship between renal pedicles and tumors on surgical outcomes for non-high-risk abdominal neuroblastoma

PURPOSE

To assess the impact of the relationship between renal pedicles and tumors on surgical outcomes in patients with non-high-risk abdominal neuroblastoma.

METHODS

We retrospectively analyzed cases of neuroblastoma without metastasis treated at our hospital between March 2002 and December 2023. Cases in which surgical resection was performed were divided into three groups according to imaging findings at the time of diagnosis and before surgery: Group E (tumor encasing renal pedicles), Group C (tumor in contact with renal pedicles), and Group S (tumor separated from renal pedicles).

RESULTS

Among 256 neuroblastoma cases diagnosed during the study period, 27 non-high-risk cases that underwent surgery for partial abdominal tumor resection or greater were included. The numbers of cases in the S group, C group, and E group, respectively, were 7, 9, and 11 at diagnosis, and 8, 14, and 5 before surgery. Renal complications (combined concurrent renal resection and post-operative renal atrophy) were seen in five E group cases at the time of diagnosis, and two C group cases and three E group cases preoperatively.

CONCLUSION

In non-high-risk abdominal neuroblastomas, tumors encased in the renal pedicles have the highest risk of renal complications, followed by tumors in contact with the renal pedicles.

Robot-assisted laparoscopic adrenalectomy: Extended application in children

BACKGROUND

Minimally invasive surgery for paediatric adrenal tumours has evolved, but robot-assisted laparoscopic adrenalectomy (RALA) in children remains poorly studied. The current prospective study aims to demonstrate the safety and efficacy of RALA in treating children with adrenal tumours.

METHODS

A prospective institutional analysis of children presenting with neuroblastic and endocrine tumours treated with RALA was undertaken over a six year-period. For each child, clinical parameters were collected relating to diagnosis, surgery and outcomes.

RESULTS

A total 50 RALA were performed; 23 for unilateral neuroblastic tumours (87 % neuroblastomas) and 27 for endocrine tumours. Eight neuroblastic tumours (35 %) had image-defined risk factors (all due to tumour invading the renal pedicle). Median length of stay was two days. Resection margins were macroscopically clear in all cases. After median follow-up of 2.9 years (1.6-3.9), two children are under treatment for metastatic relapse (high-risk disease) and three died due to refractory disease. Sixteen children had endocrine tumours: pheochromocytoma (n = 13), or bilateral nodular adrenocortical hyperplasia with Cushing's syndrome (n = 14). One child required non-emergent conversion, and one complication occurred (grade IIIb) after median follow-up of 3.3 years (1.0-5.7).

CONCLUSIONS

The current study is the largest reported experience in the literature and confirms the safety and effectiveness of RALA in carefully selected children with adrenal tumours. Through an iterative process and in the setting of a dedicated paediatric robotic surgical team indications have been clarified and extended. The current study confirms RALA has particularly utility in patients with severe disease (IDRF + metastatic neuroblastomas) or genetic predisposition syndromes.

Recommendations for the use of nuclear medicine imaging in patients with neuroblastoma

Neuroblastoma (NB) is the most common extracranial solid cancer in children. Despite intensive multimodality treatment, long-term survival of patients with high-risk NB, which comprises more than half of all cases, remains poor. Nuclear medicine is key in diagnosis, staging, response assessment and long-term follow-up of NB. The emergence of novel tracers and the increasing complexity of studies require updated guidelines for nuclear medicine imaging in NB. Standardising diagnostic techniques are essential for improving study comparability and ensuring test quality. This article aims to provide a comprehensive review of NB radionuclide diagnostic imaging, including its characteristics, accuracy, advantages, and limitations. It offers practical recommendations to multidisciplinary teams responsible for treating patients with NB. This review summarises the opinions of leading experts from the Neuroblastoma Spanish Group within the Spanish Society of Paediatric Haematology and Oncology (SEHOP) and the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM).

Characterisation of Paediatric Neuroblastic Tumours by Quantitative Structural and Diffusion-Weighted MRI

Purpose: To determine the diagnostic accuracy of quantitative diffusion-weighted (DW) MRI apparent diffusion coefficient (ADC) and tumour volumes to differentiate between malignant (neuroblastoma (NB)) and benign types of neuroblastic tumours (ganglioneuroma (GN) and ganglioneuroblastoma (GNB)) using different region-of-interest (ROI) sizes. Materials and Methods: This single-centre retrospective study included malignant and benign paediatric neuroblastic tumours that had undergone DW MRI at diagnosis. The outcome was diagnostic accuracy of the tumour volume from structural and ADC DW MRI, in comparison to histopathology (reference standard). Results: Data from 40 patients (NB, n = 24; GNB, n = 6; GN, n = 10), 18 (45%) females and 22 (55%) males, with a median age at diagnosis of 21 months (NB), 64 months (GNB), and 133 months (GN), respectively, ranging from 0 to 193 months, were evaluated. The area under the receiver operating characteristic (AUROC) curve for ADC for discriminating between neuroblastic tumours' histopathology for a small ROI was 0.86 (95% CI: 0.75-0.98), and for a large ROI, 0.83 (95% CI: 0.71-0.96). An ADC cut-off value of 1.06 × 10-3 mm2/s was able to distinguish malignant from benign tumours with 83% (68-98%) sensitivity and 75% (95% CI: 54-98%) specificity. Tumour volume was not indicative of malignant vs. benign tumour diagnosis. Conclusions: In this study, both small and large ROIs used to derive ADC DW MRI metrics demonstrated high accuracy to differentiate malignant from benign neuroblastic tumours, with the ADC AUROC for the averaged multiple small ROIs being slightly greater than that of large ROIs, but with overlapping 95% CIs. This should be taken into consideration for standardisation of ROI-related data analysis by international initiatives.

Radiolabeled Somatostatin Analogs for Cancer Imaging

Somatostatin receptors (SSTR) are expressed by many tumours especially those related to neuro-endocrine origin and molecular functional imaging of SSTR expression using radiolabelled somatostatin analogs have revolutionized imaging of patients with these group of malignancies. Coming a long way from the first radiolabelled somatostatin analog 123I-Tyr-3-octreotide, there has been significant developments in terms of radionuclides used, the ligands and somatostatin derivatives. 111In-Pentetreotide extensively employed for imaging NETs at the beginning has now been replaced by 68Ga-SSA based PET-CT. SSA-PET/CT performs superior to conventional imaging modalities and has evolved in the mainframe for NET imaging. The advantages were multiple: (i) superior spatial resolution of PET versus SPECT, (ii) quantitative capabilities of PET aiding in disease activity and treatment response monitoring with better precision, (iii) shorter scan time and (iv) less patient exposure to radiation. The modality is indicated for staging, detecting the primary in CUP-NETs, restaging, treatment planning (along with FDG: the concept of dual-tracer PET-CT) as well as treatment response evaluation and follow-up of NETs. SSA PET/CT has also been incorporated in the guidelines for imaging of Pheochromocytoma-Paraganglioma, Medullary carcinoma thyroid, Meningioma and Tumor induced osteomalacia. At present, there is rising interest on (a) 18F-labelled SSA, (b) 64Cu-labelled SSA, and (c) somatostatin antagonists. 18F offers excellent imaging properties, 64Cu makes delayed imaging feasible which has implications in dosimetry and SSTR antagonists bind with the SST receptors with high affinity and specificity, providing high contrast images with less background, which can be translated to theranostics effectively. SSTR have been demonstrated in non-neuroendocrine tumours as well in the peer-reviewed literature, with studies demonstrating the potential of SSA PET/CT in Neuroblastoma, Nasopharyngeal carcinoma, carcinoma prostate (neuroendocrine differentiation) and lymphoma. This review will focus on the currently available SSAs and their history, different SPECT/PET agents, SSTR antagonists, comparison between the various imaging tracers, and their utility in both neuroendocrine and non-neuroendocrine tumors.

Inter-observer variability in assessing image-defined risk factors: implications for risk stratification in locoregional abdominopelvic neuroblastoma

PURPOSE

Risk stratification for locoregional neuroblastoma partially relies on image-defined risk factors (IDRFs). This study aimed to evaluate how inter-observer variability in assessing IDRFs impacts risk stratification in locoregional abdominopelvic neuroblastoma.

METHODS

A retrospective analysis was conducted on 123 patients who underwent upfront contrast-enhanced CT scans. Two radiologists independently assessed the presence of IDRFs. Patients were staged as either L1 (IDRF-negative) or L2 (IDRF-positive) according to the International Neuroblastoma Risk Group Staging System. Based on the radiologists' evaluations, 97 cases with sufficient clinical data were classified into risk groups using the revised Children's Oncology Group neuroblastoma risk classifier. The kappa values and 95% confidence intervals (CIs) were calculated to assess inter-radiologist agreement on IDRF evaluation and risk stratification.

RESULTS

There was low agreement between radiologists in assessing L1/L2 status with a kappa value of 0.28 (95% CI: 0.14-0.42). However, agreement for evaluating the number of IDRFs was good, with an intraclass correlation coefficient of 0.73 (95% CI: 0.64-0.80). Based on the first radiologist's evaluation, 13 patients were classified as low-risk, 52 as intermediate-risk, and 32 as high-risk. Based on the second radiologist's evaluation, 37 patients were classified as low-risk, 37 as intermediate-risk, and 23 as high-risk. The kappa value for risk stratification between the two radiologists was 0.47 (95% CI: 0.33-0.62).

CONCLUSION

Inter-observer variability in assessing IDRF presence may affect risk stratification in locoregional abdominopelvic neuroblastoma.

Tracking changes in image-defined risk factors during neoadjuvant chemotherapy and their predictive value for surgical outcomes based on the International Neuroblastoma Surgical Report Form

BACKGROUND

The capacity of presurgical image-defined risk factors (IDRFs) to predict secondary surgical outcomes in patients with neuroblastoma is controversial.

METHODS

The International Neuroblastoma Surgical Report Form (INSRF) was employed to retrospectively collect the clinical data of 53 patients diagnosed with neuroblastoma at our hospital from April 2014 to April 2020. IDRFs were identified at the time of diagnosis and reassessed during the course of neoadjuvant chemotherapy. Various statistical tests were used to evaluate the correlation between IDRFs and secondary surgical outcomes.

RESULTS

A total of 195 IDRFs were identified. Notably, by two courses of neoadjuvant chemotherapy, the number of "two body compartments," "intraspinal tumor extension," and "trachea-compressing" IDRFs decreased significantly (p = .001). The primary tumor volumes and the number of IDRFs decreased significantly by four courses of neoadjuvant chemotherapy, especially in "intraspinal tumor extension" IDRFs (p = .034). The median number of IDRF per patient was four (interquartile range [IQR]: 1-5) at diagnosis, which diminished to one (IQR: 1-3) subsequent to neoadjuvant chemotherapy. The presence of preoperative IDRFs was not associated with surgical complications (p = .286) or the extent of surgery (p = .188). However, the number of preoperative IDRFs linked to the extent of surgery (p = .002), not to operative complications (p = .669). Specifically, presurgery "renal vessel contact" IDRFs were predictive of surgical complications, while presurgery "infiltration of vital structures" IDRFs were associated with the extent of surgery.

CONCLUSION

The number of IDRFs decreased significantly by four courses of neoadjuvant chemotherapy. The number and type of presurgery IDRFs may predict secondary surgical outcomes, surpassing the mere consideration of their presence or absence.

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.

Unusual Location of Neuroblastoma: A Report of Two Cases

Neuroblastoma is the most common extra-cranial solid tumor in children under the age of five years and is the second most prevalent malignancy in children after acute lymphoblastic leukemia. We are presenting two cases of neuroblastoma in children presented as intra-pelvic masses. The first patient presented with urinary retention while the second patient presented with ataxia. The initial imaging including ultrasound, CT scan, and MRI showed a large solid mass in the pelvis in both patients with extension to the spinal canal through the neural foramina at different levels. The histopathological results confirmed pelvic neuroblastomas. These cases highlight the rare locations of neuroblastoma in children and emphasize the variable presentations of this rare location. Knowledge of possible presentations of neuroblastoma aids early detection and expedites the proper management, especially in emergency settings.

Therapeutic SHPRH-146aa encoded by circ-SHPRH dynamically upregulates P21 to inhibit CDKs in neuroblastoma

Recent research has underscored the significance of circular RNAs (circRNAs) in various cancers, including neuroblastoma (NB). Specifically, circ-SHPRH, a unique circRNA, has been revealed to inhibit tumor growth by sequestering miRNAs or producing the SHPRH-146aa protein. To explore circ-SHPRH's involvement in NB and its potential application in gene therapy, this study examined circ-SHPRH expression in 94 NB tissues and cell lines (SK-N-BE(2), SH-SY5Y) using real-time PCR and fluorescence in situ hybridization (FISH). Functional assays encompassing both overexpression and knockdown experiments in NB cell lines, as well as in vivo investigations, were conducted. RNA-seq analysis revealed a correlation between circ-SHPRH and the pathway of P21 (CDKN1A), a pivotal cell cycle regulator. Validation through PCR and other techniques confirmed that circ-SHPRH upregulated P21 expression. Furthermore, the regulatory role of circ-SHPRH in the P21-CDK pathway was corroborated through SHPRH-146aa expression analysis. Notably, adenovirus-mediated circ-SHPRH overexpression effectively curbed NB tumor growth in NSG mice, while combining circ-SHPRH with everolimus exhibited potential for NB treatment. This study elucidates the remarkable significance of circ-SHPRH in NB and its prospective utility in gene therapy, thereby paving the way for innovative therapeutic approaches.

Vasoactive Intestinal Peptide-Producing Neuroblastic Tumors: A Rare Cause of Refractory Diarrhea

Neuroblastic tumors are the most common malignant extracranial solid tumors of childhood. A small subgroup presents chronic incoercible diarrhea due to the tumor's production of vasoactive intestinal peptide (VIP). The hypothesis of an occult tumor is not always considered, which delays and impairs treatment. We aim to identify these patients' characteristics and help alert health professionals to the hypothesis of a neuroblastic tumor in children with chronic diarrhea refractory to the usual approach. We carried out an epidemiological study on all retrievable reports of neuroblastic tumors between 1975 and 2021 described in the Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), and Latin American & Caribbean Health Sciences Literature (LILACS) databases. Patient information was divided into categories, and we performed a descriptive analysis. We analyzed 96 cases; 83 (86.5%) cases had diarrhea prior to the diagnosis of the neoplasm, 49 (51%) were ganglioneuroblastomas, 69 (71.8%) were abdominal, and 59 of the 60 patients (98%) with reported acid-base disorders had hypokalemia. When serum VIP was reported, the majority of values varied between one and 20 times the upper reference limit. Seventy-two (75%) patients underwent complete tumor resection, and the overall survival rate was 70%. Serum VIP production by neuroblastic tumors is related to cell differentiation and better prognosis. Such children often require intensive hospital support to reverse the malnutrition and acid-base disorders related to this paraneoplastic syndrome. Its early diagnosis and treatment significantly change the prognosis and quality of life. We, therefore, suggest screening for neuroblastic tumors when health professionals encounter unmanageable chronic secretory diarrhea in children with no defined etiology in the usual investigations.

Adolescent- and adult-onset neuroblastic tumor: A retrospective multicenter observational study of patients diagnosed in France between 2000 and 2020

BACKGROUND

Adult- and adolescent-onset neuroblastomas are rare, with no established therapy. In addition, rare pheochromocytomas may harbor neuroblastic components. This study was designed to collect epidemiological, diagnostic and therapeutic data in order to better define the characteristics of malignant peripheral neuroblastic tumors (MPNT) and composite pheochromocytomas (CP) with MPNT.

PROCEDURE

Fifty-nine adults and adolescents (aged over 15 years) diagnosed with a peripheral or composite neuroblastic tumor, who were treated in one of 17 institutions between 2000 and 2020, were retrospectively studied.

RESULTS

Eighteen patients with neuroblastoma (NB) or ganglioneuroblastoma (GNB) had locoregional disease, and 28 patients had metastatic stage 4 NB. Among the 13 patients with CP, 12 had locoregional disease. Fifty-eight percent of the population were adolescents and young adults under 24 years of age. The probability of 5-year event-free survival (EFS) was 40% (confidence interval: 27%-53%).

CONCLUSIONS

Outcomes were better for patients with localized tumor than for patients with metastases. For patients with localized tumor, in terms of survival, surgical treatment was the best therapeutic option. Multimodal treatment with chemotherapy, surgery, radiotherapy, and immunotherapy-based maintenance allowed long-term survival for some patients. Adolescent- and adult-onset neuroblastoma appeared to have specific characteristics associated with poorer outcomes compared to pediatric neuroblastoma. Nevertheless, complete disease control improved survival. The presence of a neuroblastic component in pheochromocytoma should be considered when making therapeutic management decisions. The development of specific tools/resources (Tumor Referral Board, Registry, biology, and trials with new agents or strategies) may help to improve outcomes for patients.

A non-inferiority study of MRI versus CT for staging and image-defined risk factor assessment in the preoperative work-up of abdominopelvic neuroblastoma

BACKGROUND

Neuroblastoma accounts for 15 % of cancer deaths in children. Complete surgical resection is associated with a higher overall survival rate but also a higher morbidity rate. An international group of experts has defined a nomenclature of image-defined risk factors (IDRFs) for the determination of operability and the anticipation of reasonably foreseeable complications of surgery. However, there is no consensus on the optimal imaging modality (CT or MRI) for the assessment of IDRFs. The objective of the present study was to determine the non-inferiority of MRI vs. CT in the preoperative assessment of abdominopelvic neuroblastoma. The secondary objective was to assess the contribution of gadolinium contrast enhancement.

METHODS

All children diagnosed with abdominopelvic neuroblastoma and whose preoperative work-up included a contrast-enhanced CT or MRI scan of the abdomen and pelvis between January 2014 and January 2023 were included. To evaluate the IDRFs, all the images were reviewed in three steps: (i) non-contrast MRI scans, (ii) both non-contrast and contrast-enhanced MRI scans, and (iii) contrast-enhanced CT scans.

RESULTS

Twenty-five patients were found to be eligible, and fifteen were included. The mean time interval between MRI and preoperative CT was 23 days. In all patients, the identified IDRFs were similar for all three imaging modalities. Fourteen patients underwent full resection of the tumour. The surgical reports were fully consistent with the IDRFs described on CT and/or MRI.

CONCLUSION

A high-resolution three-dimensional T2 MRI sequence agreed fully with contrast-enhanced CT for the detection of IDRFs. Contrast-enhanced MRI did not add value. However, surgeons will need time to adapt to this MRI-based approach and learn how to interpret the results with confidence.

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.

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.

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.

Risk factors, impact and treatment of postoperative lymphatic leakage in children with abdominal neuroblastoma operated on by laparotomy

BACKGROUND

Lymphatic leakage is one of the postoperative complications of neuroblastoma. The purpose of this study is to summarize the clinical characteristics and risk factors of lymphatic leakage and try to find effective prevention and treatment measures.

METHODS

A retrospective study included 186 children with abdominal neuroblastoma, including 32 children of lymphatic leakage and 154 children of non-lymphatic leakage. The clinical information, surgical data, postoperative abdominal drainage, treatment of lymphatic leakage and prognosis of the two groups were collected and analyzed.

RESULTS

The incidence of lymphatic leakage in this cohort was 14% (32 children). Through univariate analysis of lymphatic leakage group and non-lymphatic leakage group, we found that lymphatic leakage increased the complications, prolonged the time of abdominal drainage and hospitalization, and delayed postoperative chemotherapy (p < 0.05). In this cohort, the median follow-up time was 46 (95% CI: 44-48) months. The follow-up data of 7 children were partially missing. 147 children survived, of which 23 had tumor recurrence (5 children recurred in the surgical area). 37 children died, of which 32 had tumor recurrence (9 children recurred in the operation area). In univariate analysis, there was no statistical difference in overall survival (p = 0.21) and event-free survival (p = 0.057) between lymphatic leakage group and non-lymphatic leakage group, while 3-year cumulative incidence of local progression was higher in lymphatic leakage group (p = 0.015). However, through multivariate analysis, we found that lymphatic leakage did not affect event-free survival, overall survival and cumulative incidence of local progression in children with neuroblastoma. Resection of 5 or more lymphatic regions was an independent risk factor for lymphatic leakage after neuroblastoma surgery. All 32 children with lymphatic leakage were cured by conservative treatment without surgery. Of these, 75% (24/32) children were cured by fat-free diet or observation, 25% (8/32) children were cured by total parenteral nutrition. The median drain output at diagnosis in total parenteral nutrition group was higher than that in non-total parenteral nutrition group (p < 0.001). The cut-off value was 17.2 ml/kg/day.

CONCLUSIONS

Lymphatic leakage does not affect the prognosis of children with neuroblastoma, but long-term drain output caused by lymphatic leakage will still adversely affect postoperative complications and follow-up treatment, which requires attention and active treatment measures. More attention should be paid to the children with 5 or more lymphatic regions resection, and the injured lymphatic vessels should be actively found and ligated after tumor resection to reduce the postoperative lymphatic leakage. Early application of total parenteral nutrition is recommended for those who have drain output at diagnosis of greater than 17.2 ml/kg/day.

LEVEL OF EVIDENCE

Level III, Treatment study (Retrospective comparative study).

Long Non-Coding RNAs in Neuroblastoma: Pathogenesis, Biomarkers and Therapeutic Targets

Neuroblastoma is the most common malignant extracranial solid tumor of childhood. Recent studies involving the application of advanced high-throughput "omics" techniques have revealed numerous genomic alterations, including aberrant coding-gene transcript levels and dysfunctional pathways, that drive the onset, growth, progression, and treatment resistance of neuroblastoma. Research conducted in the past decade has shown that long non-coding RNAs, once thought to be transcriptomic noise, play key roles in cancer development. With the recent and continuing increase in the amount of evidence for the underlying roles of long non-coding RNAs in neuroblastoma, the potential clinical implications of these RNAs cannot be ignored. In this review, we discuss their biological mechanisms of action in the context of the central driving mechanisms of neuroblastoma, focusing on potential contributions to the diagnosis, prognosis, and treatment of this disease. We also aim to provide a clear, integrated picture of future research opportunities.

Anti-Hu antibody associated paraneoplastic neurological syndrome in a child with ganglioneuroblastoma: A rare case report and literature review

RATIONALE

Paraneoplastic neurological syndrome with anti-Hu antibody (Hu-PNS) is a neurological disorder that occur in patients with malignancy. The syndrome has a wide range of presentations and can present before diagnosis of primary malignancy. Familiarity with these paraneoplastic neurological syndromes can help early recognition and take appropriate regimens.

PATIENTS CONCERNS

Diagnosis and treatment of Hu-PNS.

DIAGNOSES

This is retrospective study that analyzed the clinical data of this case. Through retrospective analysis and targeted antibody screening, serum anti-Hu antibody was detected. Subsequent spinal imaging revealed a mass in the paraspinal region, which was confirmed as ganglioneuroblastoma by pathologic examination.

INTERVENTIONS

The child was treated with a course of intravenous immunoglobulin and radical surgical operation without chemotherapy.

OUTCOMES

The neurological symptoms were gradually improved and no signs indicate disease progression or tumor recurrence.

LESSONS

Hu-PNS has rarely been reported in children with ganglioneuroblastomas. They can mimic non-neoplastic processes, making detection and diagnosis difficult. Serum and/or cerebrospinal fluid onconeural antibody can strongly indicate occult cancers. Early detection of paraneoplastic neurological syndromes can help take appropriate regimens and improve prognosis.

MR Imaging of Pediatric Neuroblastoma: Is Gadolinium Enhancement Necessary for Evaluation of Image-Defined-Risk Factors?

Background: Pre-treatment stratification and outcomes of neuroblastoma patients often depend on the assessment of image-defined risk factors (IDRFs) on MR Imaging, usually using Gadolinium-contrast materials which are cautioned in pediatrics. We aimed to address whether gadolinium contrast-enhanced sequences are necessary to identify the presence/absence of IDRFs. Methods: Patients with neuroblastoma with MR imaging were retrospectively identified from 2005 to 2021. Ninety confirmed IDRFs were evaluated in 23 patients. Corresponding MR studies were anonymized, randomized, and independently evaluated by 3 fellowship-trained pediatric radiologists. Each radiologist assessed the studies twice. At the first reading, all enhanced sequences were omitted, while in the second reading, the full study with enhanced sequences were included. Consensus reading was obtained among readers. Inter- and intra-rater agreements using Kappa statistics (κ) as well as the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of non-enhanced MR in assessing IDRFs with respect to enhanced MR were calculated. Results: There were substantial (ĸ: 0.64-0.73) intra-reader agreements, and moderate to substantial (ĸ: 0.57-0.62) inter-reader agreements among radiologists in identifying IDRFs using non-enhanced MR. Non-enhanced MR had a sensitivity of 87.8% (95% CI [79-94]), specificity of 93% (89-96), PPV of 82.3 (73-89), NPV of 95.4 (92-98), and accuracy of 91.6 (88-94) in identifying IDRFs. However, 5/23 patients (21.7%) had a change in staging with the inclusion of contrast sequences. Conclusion: Although contrast sequences have a role in IDRF assessment, the majority can be adequately assessed on MR without gadolinium-contrast enhancement. Validation in a larger cohort is an important next step.

Predicting event-free survival after induction of remission in high-risk pediatric neuroblastoma: combining 123I-MIBG SPECT-CT radiomics and clinical factors

BACKGROUND

Accurately quantifying event-free survival after induction of remission in high-risk neuroblastoma can lead to better subsequent treatment decisions, including whether more aggressive therapy or milder treatment is needed to reduce unnecessary treatment side effects, thereby improving patient survival.

OBJECTIVE

To develop and validate a 123I-metaiodobenzylguanidine (MIBG) single-photon emission computed tomography-computed tomography (SPECT-CT)-based radiomics nomogram and evaluate its value in predicting event-free survival after induction of remission in high-risk neuroblastoma.

MATERIALS AND METHODS

One hundred and seventy-two patients with high-risk neuroblastoma who underwent an 123I-MIBG SPECT-CT examination were retrospectively reviewed. Eighty-seven patients with high-risk neuroblastoma met the final inclusion and exclusion criteria and were randomized into training and validation cohorts in a 7:3 ratio. The SPECT-CT images of patients were visually analyzed to assess the Curie score. The 3D Slicer software tool was used to outline the region of interest of the lumbar 3-5 vertebral bodies on the SPECT-CT images. Radiomics features were extracted and screened, and a radiomics model was constructed with the selected radiomics features. Univariate and multivariate Cox regression analyses were used to determine clinical risk factors and construct the clinical model. The radiomics nomogram was constructed using multivariate Cox regression analysis by incorporating radiomics features and clinical risk factors. C-index and time-dependent receiver operating characteristic curves were used to evaluate the performance of the different models.

RESULTS

The Curie score had the lowest efficacy for the assessment of event-free survival, with a C-index of 0.576 and 0.553 in the training and validation cohorts, respectively. The radiomics model, constructed from 11 radiomics features, outperformed the clinical model in predicting event-free survival in both the training cohort (C-index, 0.780 vs. 0.653) and validation cohort (C-index, 0.687 vs. 0.667). The nomogram predicted the best prognosis for event-free survival in both the training and validation cohorts, with C-indices of 0.819 and 0.712, and 1-year areas under the curve of 0.899 and 0.748, respectively.

CONCLUSION

123I-MIBG SPECT-CT-based radiomics can accurately predict the event-free survival of high-risk neuroblastoma after induction of remission The constructed nomogram may enable an individualized assessment of high-risk neuroblastoma prognosis and assist clinicians in optimizing patient treatment and follow-up plans, thereby potentially improving patient survival.

Percutaneous biopsy for the diagnosis, risk stratification, and molecular profiling of neuroblastoma: A single-center retrospective study

PURPOSE

To determine whether percutaneous core needle biopsy (PCNB) is adequate for the diagnosis and full molecular characterization of newly diagnosed neuroblastoma.

MATERIALS AND METHODS

Patients with newly diagnosed neuroblastoma who underwent PCNB in interventional radiology at a single center over a 5-year period were included. Pre-procedure imaging and procedure details were reviewed. Rates of diagnostic success and sufficiency for International Neuroblastoma Pathology Classification (INPC), risk stratification, and evaluation of genomic markers utilized in the Children's Oncology Group risk stratification, and status of the anaplastic lymphoma kinase (ALK) gene were assessed.

RESULTS

Thirty-five patients (13 females, median age 2.4 years [interquartile range, IQR: 0.9-4.4] and median weight 12.4 kg [IQR: 9.6-18]) were included. Most had International Neuroblastoma Risk Group Stage M disease (n = 22, 63%). Median longest axis of tumor target was 8.8 cm [IQR: 6.1-12]. A 16-gauge biopsy instrument was most often used (n = 20, 57%), with a median of 20 cores [IQR: 13-23] obtained. Twenty-five specimens were assessed for adequacy, and 14 procedures utilized contrast-enhanced ultrasound guidance. There were two post-procedure bleeds (5.7%). Thirty-four of 35 procedures (97%) were sufficient for histopathologic diagnosis and risk stratification, 94% (n = 32) were sufficient for INPC, and 85% (n = 29) were sufficient for complete molecular characterization, including ALK testing. Biologic information was otherwise obtained from bone marrow (4/34, 12%) or surgery (1/34, 2.9%). The number of cores did not differ between patients with sufficient versus insufficient biopsies.

CONCLUSION

In this study, obtaining multiple cores with PCNB resulted in a high rate of diagnosis and successful molecular profiling for neuroblastoma.

Comparison between whole-body magnetic resonance imaging and whole-body metaiodobenzylguanidine scintigraphy in the evaluation of primary tumor and metastases in neuroblastoma

BACKGROUND

Whole-body metaiodobenzylguanidine (131 I-MIBG) scintigraphy is the gold standard method to detect neuroblastoma; however, it depends on radioactive material and is expensive. In contrast, whole-body magnetic resonance imaging (WB-MRI) is affordable in developing countries and has been shown to be effective in the evaluation of solid tumors. This study aimed to compare the sensitivity and specificity of WB-MRI with MIBG in the detection of primary tumors and neuroblastoma metastases.

PROCEDURE

This retrospective study enrolled patients with neuroblastoma between 2013 and 2020. All patients underwent WB-MRI and MIBG at intervals of up to 15 days. The results were marked in a table that discriminated anatomical regions for each patient. Two experts evaluated, independently and in anonymity, the WB-MRI images, and two others evaluated MIBG. The results were compared in terms of sensitivity and specificity, for each patient, considering MIBG as the gold standard. This study was approved by the UNIFESP Ethics Committee.

RESULTS

Thirty patients with neuroblastoma were enrolled in this study. The age ranged from 1 to 15 years, with a mean of 5.7 years. The interval between exams (WB-MRI and MIBG) ranged from 1 to 13 days, with an average of 6.67 days. Compared to MIBG, WB-MRI presented a sensitivity and specificity greater than or equal to 90% for the detection of primary neuroblastoma in bones and lymph nodes. When we consider the patient without individualizing the anatomical regions, WB-MRI presented sensitivity of 90% and specificity of 73.33%.

CONCLUSION

In conclusion, WB-MRI is a sensitive and specific method to detect neuroblastoma in bone and lymph nodes and highly sensible to primary tumor diagnosis, suggesting that this test is a viable alternative in places where MIBG is difficult to access. Studies with a larger number of cases are necessary for definitive conclusions.

Ganglioneuromas in Childhood: Hacettepe Experience With 70 Cases

BACKGROUND

Ganglioneuromas (GNs) are rare benign peripheral neuroblastic tumors (PNTs). We shared our institutional experience with childhood GNs.

METHODS

Records of the children with PNTs between January 1995 and December 2021 were reviewed, and cases with histopathological diagnoses of GN were identified. Clinical, laboratory, radiological, and histopathological findings, image-defined risk factors (IDRFs), procedures, and overall outcomes were recorded.

RESULTS

Of 668 cases with PNTs, 70 (10.4%) had GNs. The median age was 7.4 years (range, 2.6-15.7 years) (girls/boys, 41/29). Common presenting complaints were abdominal pain and cough; 33/70 cases (47.1%) were diagnosed incidentally. Primary tumors were in the abdomen in 41/70, the thorax in 25/70, the neck in 3 cases, and the pelvis in one. The median tumor size was 6.5 cm (range, 1.4-17). Fifty cases (71.4%) were staged as INRG-L1; 20 cases with IDRFs (15 single, five >1) were staged as INRG-L2. Complete and partial tumor resections were performed in 58/70 and 6/70 cases, while 6 had no resection. The overall complication rate was 17.1% (11/64). At a median follow-up of 9 years, five were lost to follow-up; 65 were alive. One patient with gross residue underwent total resection due to progression 13 years after the surgery, and one in the unresected group was lost to follow-up. Ten other cases without a complete resection experienced no tumor progression.

CONCLUSIONS

Ganglioneuromas are benign PNTs, and most are free of IDRFs. Even without complete resection, long-term outcomes are excellent. Guidelines should be devised considering the high surgical complication rates and benign course of GNs.

LEVEL OF EVIDENCE

Case series, IV.

Evaluation of clinical and imaging features for differentiating rhabdomyosarcoma from neuroblastoma in pediatric soft tissue

Background

In this study, we developed a nomogram predictive model based on clinical, CT, and MRI parameters to differentiate soft tissue rhabdomyosarcoma (RMS) from neuroblastoma (NB) in children preoperatively.

Materials and methods

A total of 103 children with RMS (n=37) and NB (n=66) were enrolled in the study from December 2012 to July 2023. The clinical and imaging data (assessed by two experienced radiologists) were analyzed using univariate analysis, and significant factors were further analyzed by multivariable logistic regression using the forward LR method to develop the clinical model, radiological model, and integrated nomogram model, respectively. The diagnostic performances, goodness of fit, and clinical utility of the integrated nomogram model were assessed using the area under the curve (AUC) of the receiver operator characteristics curve (ROC) with a 95% confidence interval (95% CI), calibration curve, and decision curve analysis (DCA) curves, respectively. Diagnostic efficacy between the model and radiologists' interpretations was examined.

Results

The median age at diagnosis in the RMS group was significantly older than the NB group (36.0 months vs. 14.5 months; P=0.003); the fever rates in RMS patients were significantly lower than in patients with NB (0.0% vs.16.7%; P=0.022), and the incidence of palpable mass was higher in patients with RMS compared with the NB patients (89.2% vs. 34.8%; P<0.001). Compare NB on image features: RMS occurred more frequently in the head and neck and displayed homogeneous density on non-enhanced CT than NB (48.6% vs. 9.1%; 35.3% vs. 13.8%, respectively; all P<0.05), and the occurrence of characteristics such as calcification, encasing vessels, and intraspinal tumor extension was significantly less frequent in RMS children compared to children with NB (18.9% vs. 84.8%; 13.5% vs. 34.8%; 2.7% vs. 50.0%, respectively; all P <0.05). Two, three, and four features were identified as independent parameters by multivariate logistic regression analysis to develop the clinical, radiological, and integrated nomogram models, respectively. The AUC value (0.962), calibration curve, and DCA showed that the integrated nomogram model may provide better diagnostic performance, good agreement, and greater clinical net benefits than the clinical model, radiological model, and radiologists' subjective diagnosis.

Conclusion

The clinical and imaging features-based nomogram has potential for helping radiologists distinguish between pediatric soft tissue RMS and NB patients preoperatively, and reduce unnecessary interventions.

A Pictorial Review of I-123 MIBG Imaging of Neuroblastoma Utilizing a State-of-the-Art CZT SPECT/CT System

The field of nuclear medicine is entering a new era of gamma-camera technology. Solid-state SPECT/CT systems will gradually replace the thallium-activated sodium-iodide NaI(Tl) systems. This digital technology allows drastic improvements in image quality, radiotracer dose reduction, and procedure efficiency. This pictorial review presents our initial experience on an NM/CT 870 CZT system (GE Healthcare), equipped with dual-head cadmium zinc telluride (CZT) detectors, for I-123 metaiodobenzylguanidine (MIBG) imaging in pediatric neuroblastoma. On planar imaging, CZT shows greater image quality than at conventional gamma-camera using the Infinia Hawkeye (GE Healthcare). Physiologic structures such as salivary glands and myocardium show sharper borders with a more notable signal-to-noise ratio at CZT than conventional gamma camera. On SPECT imaging, the CZT scanner, combined with resolution recovery, demonstrates either comparable or greater image quality at 80% of the conventional gamma camera’s acquisition time. Due to the 2.46-mm detector pixel with fully registered collimator holes matching each pixel and direct conversion of photons into electrical signals, the CZT gamma camera system provides significant advantages in photon localization and energy resolution.

Trap-Door Thoracotomy and Clamshell Thoracotomy as Surgical Approaches for Neuroblastoma and Other Thoracic Tumors in Children

Solid tumors of the cervicothoracic junction, the posterior mediastinum, or bilateral dorsal thoracic tumors represent a challenge in pediatric surgical oncology. The aim of this study was to evaluate trap-door thoracotomy and clamshell thoracotomy as surgical approaches. A single-center retrospective study of children with solid tumors in these specific localizations was performed. From 2015 to 2023, 26 children (17 girls; 9 boys) were treated at a median age of 54 months (range 8-229). Tumor resection was performed for neuroblastoma (n = 11); metastatic disease (n = 7); malignant rhabdoid tumor (n = 4); Ewing sarcoma (n = 1); inflammatory myofibroblastic tumor (n = 1); rhabdomyosarcoma (n = 1); and neurofibroma (n = 1). The surgical goal of macroscopic complete excision was achieved in all of the 14 children who underwent trap-door thoracotomy and in 11 of the 12 children who underwent clamshell thoracotomy. There were no major complications. At a median follow-up of 8 months (range 0-60), the disease was under local control or in complete remission in 66.7% of the children. In conclusion, surgical resection of solid tumors of the cervicothoracic junction in children can be performed safely and successfully with trap-door thoracotomy and with clamshell thoracotomy for posterior mediastinal or bilateral dorsal thoracic tumors.

Successful endoscopic approach for peripheral neuroblastic tumors in children

BACKGROUND

Recently, reports of endoscopic approaches for neuroblastoma, ganglioneuroblastoma, and ganglioneuroma (peripheral neuroblastic tumor; PNTs) have been increasing. This study aimed to clarify the indications for endoscopic surgery for PNTs.

METHODS

Pediatric patients who underwent endoscopic surgery for PNTs at our institution were included in this study. Image-defined risk factors (IDRFs) were analyzed using preoperative computed tomography (CT).

RESULTS

Twenty-four patients underwent endoscopic surgery for PNTs. The diagnoses included neuroblastoma (n = 11), ganglioneuroma (n = 10), and ganglioneuroblastoma (n = 3). Regarding the tumor site, there were 18 cases of adrenal tumors, five cases of mediastinal tumors, and one case of retroperitoneal tumors. Image-defined risk factors were positive in eight cases (contacted with a renal vessel, n = 6; compression of principal bronchi, n = 2). Complete resection was accomplished in 21 cases (14 of 16 IDRF-negative cases and seven of eight IDRF-positive cases). All patients survived without recurrence during the follow-up period.

CONCLUSIONS

The CT findings of contact with renal vessels and compression of principal bronchi do not seem to be indicators of incomplete resection. An endoscopic approach to PNTs in pediatric patients is feasible with a good prognosis if patients are selected strictly.

Predictive value of 2-deoxy-2-fluorine-18-fluoro-D-glucose positron emission tomography/computed tomography parameters for MYCN amplification in high-risk neuroblastoma

OBJECTIVES

To investigate the predictive value of 2-deoxy-2-fluorine-18-fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) parameters for MYCN amplification in high-risk neuroblastoma (HR-NB).

MATERIALS AND METHODS

A retrospective analysis was performed by reviewing 68 HR-NB patients who underwent MYCN testing and 18F-FDG PET/CT imaging at our hospital between January 2018 and December 2019. Based on the results of MYCN testing, patients were categorized into either the MYCN-amplified (MNA) or MYCN non-amplified (MYCN-NA) group. The 18F-FDG PET/CT parameters, including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), peak standardized uptake value (SUVpeak), tumor metabolic volume (MTV), total lesion glycolysis (TLG), coefficient of variation (COV), and areas under the curve of cumulative SUV-volume histogram index (AUC-CSH index) were evaluated. Independent predictors were identified through univariate and multivariate logistic regression analyses, and their diagnostic performance was evaluated using the receiver-operating characteristic (ROC) curve.

RESULTS

Univariate logistic regression analysis revealed that SUVpeak was significantly associated with MYCN amplification. Multivariate logistic regression analysis showed that SUVpeak was an independent predictor of MYCN amplification in HR-NB [Odds ratio (OR) = 0.673, 95 % confidence interval (95 % CI): 0.494-0.917, P = 0.012]. ROC curve analysis demonstrated that the predictive model including SUVpeak had higher diagnostic performance [area under the curve (AUC): 0.790, 95 % CI: 0.677-0.881, sensitivity: 0.861, specificity: 0.591, positive predictive value (PPV): 0.820, negative predictive value (NPV): 0.722] compared to using SUVpeak alone (AUC: 0.640, 95 % CI: 0.514-0.752, sensitivity: 0.630, specificity: 0.682, PPV: 0.806, NPV: 0.469).

CONCLUSION

SUVpeak can predict the MYCN amplification in HR-NB patients. The predictive model constructed by combining SUVpeak and age can distinguish MYCN status in HR-NB non-invasively with superior efficacy compared to using SUVpeak alone.

Renal preservation in high-risk retroperitoneal neuroblastoma: Impact on survival and local progression

BACKGROUND

Retroperitoneal neuroblastomas predominantly encroach upon critical structures, complicating surgical intervention and yielding elevated rates of surgery-associated complications. The kidney and renal vasculature represent the organs most susceptible to retroperitoneal neuroblastoma infiltration. Prior investigations have revealed high nephrectomy incidence and a paucity of renal-preserving surgical approaches.

METHODS

A retrospective analysis was undertaken, examining patients with retroperitoneal neuroblastoma who underwent surgical procedures from January 2018 to December 2019 at Beijing Children's Hospital.

RESULTS

The study encompassed 225 patients, presenting a median age of 37 months. Concomitant nephrectomy and tumor excision were performed in 11 (4.9%) patients, while 214 (95.1%) patients successfully preserved their kidneys during surgery. Among the patients who retained their kidneys, 8 (3.5%) experienced renal atrophy postoperatively. Predominant rationales for simultaneous nephrectomy included tumor invasion into the renal hilum (n = 9), markedly diminished function of the affected kidney (n = 2), and ureteral infiltration (n = 1). Subsequent to a median follow-up duration of 43 months, the outcomes demonstrated no considerable divergence in overall survival (OS) and event-free survival (EFS) between the nephrectomy and renal-preserving cohorts among high-risk (HR) neuroblastoma patients. Among the eight HR children who underwent nephrectomy, four experienced local recurrence. The nephrectomy cohort exhibited a significantly elevated cumulative incidence of local progression (CILP) relative to the renal-preserving group.

CONCLUSION

In high-risk retroperitoneal neuroblastoma patients, nephrectomy does not enhance CILP, EFS, or OS. The guiding surgical tenet involves preserving the kidney while striving for gross total resection of the primary neoplasm, barring instances of severe deterioration of the affected renal function.

[Surgery for abdominal neuroblastoma in children]

This review is devoted to surgical approach for neurogenic tumors in children. The authors discuss epidemiological data, history of surgical approaches, preoperative imaging and risk factors. A special attention is paid to the influence of surgical interventions for various neuroblastomas on overall and event-free survival in pediatric population, as well as the most common surgical complications and modern approaches to their treatment.

Neuroblastoma with superficial soft tissue mass as the first symptom: case reports with atypical ultrasonic image and literature review

Neuroblastoma is one of the most common tumors in children. Cases where an isolated soft-tissue metastasis mass is the initial symptom are rare, with only four such cases reported to date. We describe the imaging findings of ten cases of neuroblastoma patients in our hospital with superficial soft tissue mass (SSTM) as the primary symptom. The main ultrasound finding of SSTM was hypoechoic masses or scattered speck-like hyperechoic masses. However, when this type of SSTM is caused by soft tissue metastasis, the location is often atypical, and ultrasound findings are difficult to distinguish from other benign diseases. Therefore, this research should remind clinicians to recognize atypical presentations of this common childhood malignant tumor. Radiologists should also consider the possibility of neuroblastoma when finding this type of SSTM with atypical ultrasound features.

Image-defined risk factors in localized thoracic neuroblastoma and ganglioneuroma

BACKGROUND

The pretreatment International Neuroblastoma Risk Group Staging System (INRGSS) discriminates localized tumors L1/L2 depending on the absence/presence of image-defined risk factors (IDRFs) at diagnosis. Referring to this new staging system, we assessed initial imaging of localized thoracic neuroblastoma (NB) and ganglioneuroma (GN) and the extent of initial tumor resection.

METHODS

Patients with localized thoracic NB/GN from the German clinical trials NB97 and NB2004 were included. Imaging at diagnosis and operative reports were reviewed retrospectively. IDRFs were assessed centrally and correlated to International Neuroblastoma Staging System (INSS) stage and extent of tumor resection. Additionally, we analyzed data on surgery-related complications.

RESULTS

Imaging series of 88 patients were available for central review. In 18 children, no IDRF was present, 28 exhibited one IDRF, 42 two or more IDRFs, resulting in 70 patients with L2 disease. The most frequently observed IDRF was encasement of any vessel (n = 38). Initial surgical resection was aimed for in 45 patients (L1: n = 11; L2: n = 34). Complete and gross total resection rates were higher children with L2 NB (n = 8/25 L1, n = 17/25 L2 vs. n = 2/15 L1, n = 13/15 L2, respectively). The proportion of surgical complications was very similar between INRGSS L1 and L2 (n = 4/11 vs. n = 17/34). All complications were manageable, and no surgery-related deaths were observed.

CONCLUSION

In this retrospective cohort, the extent of resection and the rate of surgical complications did not differ substantially between patients classified as L1/L2, indicating that INRGSS L2 does not equate unresectability. It appeared that individual IDRFs differ in value. Larger studies are needed to assess the significance and therapeutic/prognostic impact of such findings.

Synthesis and preliminary evaluation of benzylaminoimidazoline derivatives as novel norepinephrine transporter ligands

A series of benzylaminoimidazoline derivatives was synthesized and evaluated for norepinephrine transporter (NET) targeting. Among them, N-(3-iodobenzyl)-4,5-dihydro-1H-imidazol-2-amine (Compound 9) displayed the highest affinity for NET (IC50  = 5.65 ± 0.97 μM). The corresponding radiotracer [125 I]9 was further prepared by copper-mediated radioiodination and evaluated both in vitro and in vivo. The cellular uptake results suggested that [125 I]9 was specifically taken up by the NET-expressing SK-N-SH cell line. Biodistribution studies showed that [125 I]9 accumulated in the heart (5.54 ± 1.24 %ID/g at 5 min p.i. and 0.79 ± 0.08 %ID/g at 2 h p.i.) and adrenal gland (14.83 ± 3.47 %ID/g at 5 min p.i. and 3.87 ± 0.24 %ID/g at 2 h p.i.). The uptake in the heart and adrenal gland could be significantly inhibited by preinjection of desipramine (DMI). These results indicated that the benzylaminoimidazoline derivatives retained affinity for NET, which could provide structure-activity relationship data for further studies.

Nonspecific Gastrointestinal Symptoms as the First Sign of Ganglioneuroblastoma Intermixed-Case Report and Literature Review

Nonspecific gastrointestinal symptoms remain a problem for pediatricians because, out of a thousand trivial cases, there are rare diseases that require in-depth diagnostics and extensive knowledge to identify them. These complaints may be caused by a neoplastic process. We present the case of a 5-year-old boy whose diagnostic pathway lasted about 3 months. He was admitted to hospital due to severe abdominal pain. Physical examination revealed a bloated, hard, and painful abdomen. In the standing X-ray, the features of intestinal obstruction were visualized. An ultrasound examination showed a possible malignant lesion in the location of the left adrenal gland. After the surgical removal of the pathological mass and histopathological examination, the diagnosis of ganglioneuroblastoma intermixed was made. This tumor, along with neuroblastoma, ganglioneuroma, and ganglioneuroblastoma nodular, belongs to neuroblastic tumors (NTs), which originate from primitive cells of the sympathetic nervous system. NTs are quite rare, but they are still the majority of extracranial solid tumors in children, and their symptoms often appear relatively late when the neoplastic process is already advanced. The purpose of this review is to present current information about ganglioneuroblastoma, with a special emphasis on nonspecific gastrointestinal symptoms as first sign of this tumor and its diagnostics.

Characteristics of image defined risk factors on outcomes for primary resection of neuroblastoma

Background

The presence of image‑defined risk factors (IDRF) in neuroblastoma plays a large role in decision making for primary resection versus neoadjuvant chemotherapy. This study investigates how the number and type of IDRFs affect surgical outcomes for primary resection of neuroblastoma.

Materials and methods

A retrospective review was performed including patients diagnosed with neuroblastoma with at least one IDRF who underwent primary resection of their tumor between 2003 and 2017. Cross sectional imaging was reviewed by a single pediatric radiologist for determination of IDRFs. Surgical outcomes were compared by <5 versus ≥5 IDRFs and vascular or non‑vascular involvement.

Results

A total of 28 patients were included in the study, 18 with <5 IDRFs and 10 with ≥5 IDRFs. Fifteen patients had vascular involvement and 13 did not. Nine were adrenal, 6 were cervicothoracic, and 5 were abdominal non-adrenal. Patients with ≥5 IDRFs were found to have an increased rate of complications (40% vs 0%; p<0.01), operative time (318 vs 148 min; p<0.01), estimated blood loss (187 mL vs 45 mL; p<0.01), length of stay (9.6 vs 4.9 days; p<0.01), and hospital readmission (20% vs 0%; p = 0.04). No differences were found in degree of resection (p = 0.06). All complications occurred with vascular involvement IDRFs compared to non‑vascular IDRFs (27% vs 0%; p = 0.04).

Conclusion

The presence of ≥5 IDRFs and vascular involvement increases complications associated with primary resection of neuroblastoma. Our findings underscore the importance of neoadjuvant chemotherapy prior to resection. Further studies are required to determine how different IDRFs influence surgical risk.

Current Status and Future Perspective on Molecular Imaging and Treatment of Neuroblastoma

Neuroblastoma is the most common extracranial solid tumor in children and arises from anywhere along the sympathetic nervous system. It is a highly heterogeneous disease with a wide range of prognosis, from spontaneous regression or maturing to highly aggressive. About half of pediatric neuroblastoma patients develop the metastatic disease at diagnosis, which carries a poor prognosis. Nuclear medicine plays a pivotal role in the diagnosis, staging, response assessment, and long-term follow-up of neuroblastoma. And it has also played a prominent role in the treatment of neuroblastoma. Because the structure of metaiodobenzylguanidine (MIBG) is similar to that of norepinephrine, 90% of neuroblastomas are MIBG-avid. 123I-MIBG whole-body scintigraphy is the standard nuclear imaging technique for neuroblastoma, usually in combination with SPECT/CT. However, approximately 10% of neuroblastomas are MIBG nonavid. PET imaging has many technical advantages over SPECT imaging, such as higher spatial and temporal resolution, higher sensitivity, superior quantitative capability, and whole-body tomographic imaging. In recent years, various tracers have been used for imaging neuroblastoma with PET. The importance of patient-specific targeted radionuclide therapy for neuroblastoma therapy has also increased. 131I-MIBG therapy is part of the front-line treatment for children with high-risk neuroblastoma. And peptide receptor radionuclide therapy with radionuclide-labeled somatostatin analogues has been successfully used in the therapy of neuroblastoma. Moreover, radioimmunoimaging has important applications in the diagnosis of neuroblastoma, and radioimmunotherapy may provide a novel treatment modality against neuroblastoma. This review discusses the use of current and novel radiopharmaceuticals in nuclear medicine imaging and therapy of neuroblastoma.

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.