Diagnostic value of 18F-FDG PET/CT in paediatric neuroblastoma: comparison with 131I-MIBG scintigraphy

Predictive value of 18 F-FDG PET/CT versus bone marrow biopsy and aspiration in pediatric neuroblastoma

BACKGROUND

Neuroblastoma (NB) is the most prevalent solid extracranial malignancy in children, often with bone marrow metastases (BMM) are present. The conventional approach for detecting BMM is bone marrow biopsy and aspiration (BMBA). 18 F-fluorodeoxyglucose-positron emission tomography/computed tomography (18 F-FDG PET/CT) has become a staple for staging and is also capable of evaluating marrow infiltration. The consensus on the utility of 18 F-FDG PET/CT for assessing BMM in NB patients is still under deliberation.

METHODS

This retrospective study enrolled 266 pediatric patients with pathologically proven NB. All patients had pretherapy FDG PET/CT. BMBA, clinical, radiological, and follow-up data were also collected. The diagnostic accuracy of BMBA and 18 F-FDG PET/CT was assessed.

RESULTS

BMBAs identified BMM in 96 cases (36.1%), while 18 F-FDG PET/CT detected BMI in 106 cases (39.8%) within the cohort. The initial sensitivity, positive predictive value (PPV), specificity, and negative predictive value (NPV) of 18 F-FDG PET/CT were 93.8%, 84.9%, 90.6%, and 96.3%, respectively. After treatment, these values were 92.3%, 70.6%, 97.3%, and 99.4%, respectively. The kappa statistic, which measures agreement between BMBA and 18 F-FDG PET/CT, was 0.825 before treatment and 0.784 after treatment, with both values indicating a substantial agreement (P = 0.000). Additionally, the amplification of MYCN and a positive initial PET/CT scan were identified as independent prognostic factors for overall survival (OS).

CONCLUSION

18 F-FDG-PET/CT is a valuable method for evaluating BMM in NB. The routine practice of performing a BMBA without discrimination may need to be reassessed. Negative result from 18 F-FDG-PET/CT could potentially spare children with invasive bone marrow biopsies.

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.

PET/MRI in Pediatric Neuroimaging: Primer for Clinical Practice

Modern pediatric imaging seeks to provide not only exceptional anatomic detail but also physiologic and metabolic information of the pathology in question with as little radiation penalty as possible. Hybrid PET/MR imaging combines exquisite soft-tissue information obtained by MR imaging with functional information provided by PET, including metabolic markers, receptor binding, perfusion, and neurotransmitter release data. In pediatric neuro-oncology, PET/MR imaging is, in many ways, ideal for follow-up compared with PET/CT, given the superiority of MR imaging in neuroimaging compared with CT and the lower radiation dose, which is relevant in serial imaging and long-term follow-up of pediatric patients. In addition, although MR imaging is the main imaging technique for the evaluation of spinal pathology, PET/MR imaging may provide useful information in several clinical scenarios, including tumor staging and follow-up, treatment response assessment of spinal malignancies, and vertebral osteomyelitis. This review article covers neuropediatric applications of PET/MR imaging in addition to considerations regarding radiopharmaceuticals, imaging protocols, and current challenges to clinical implementation.

FDG PETCT for assessing marrow involvement at staging pediatric nonhematological round cell malignancies

BACKGROUND AND HYPOTHESIS

Bone and lung are the common sites of metastasis in pediatric round cell tumors and its presence indicates poor outcomes. Staging workup for these malignancies thus includes bone marrow biopsy (BMB) along with evaluation of thorax, and tissue analysis for N MYCN status in neuroblastoma. BMB is an invasive procedure requiring general anesthesia with known disadvantages.With an aim of avoiding an invasive BMB a study was taken up to evaluate efficacy of FDG PET CT in detecting marrow involvement in neuroblastoma and rhabdomyosarcoma at staging.

MATERIALS AND METHOD

Prospective observational study evaluated 83 newly diagnosed treatment naïve patients of neuroblastoma (n = 43) and rhabdomyosarcoma (n = 42) who underwent conventional imaging of PETCT with CECT of local region along with a CT thorax and BMB (both iliac crest) done within 1 week. Findings of FDG PETCT were compared with bone marrow histology and accuracy parameters were calculated.

RESULT

The overall sensitivity, specificity, accuracy, positive-predictive value (PPV), negative-predictive value (NPV) of FDG PETCT for detection of marrow disease was 100%, 86.1%, 89.4%. 68.9% and 100%, respectively. Subset analysis showed sensitivity, specificity, PPV and NPV of 100%, 66%, 71.4% and 100%, respectively, for neuroblastoma, with rhabdomyosarcoma patients having few events NPV of 100% accuracy of 97.6%.

CONCLUSION

FDG PETCT with sensitivity and NPV of 100% can be considered as a first stop imaging and biopsy can be avoided in patients with a negative scan.

123I-Meta-Iodobenzylguanidine Single-Photon Emission Computerized Tomography/Computerized Tomography Scintigraphy in the Management of Neuroblastoma

Neuroblastoma is the most common pediatric extracranial solid tumor. High-risk neuroblastoma is the most frequent presentation with an overall survival of approximately 50%. ¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) scintigraphy in the assessment of the primary tumor and its metastases at diagnosis and after chemotherapy is a cornerstone imaging modality. In particular, the bulk of skeletal metastatic disease evaluated with ¹²³I-mIBG at diagnosis and the following chemotherapy has a prognostic value. Currently, single-photon emission computerized tomography/computerised tomography (SPECT/CT) is considered a fundamental part of ¹²³I-mIBG scintigraphy. ¹²³I-mIBG SPECT/CT is a highly specific and sensitive imaging biomarker and it has been the basis of all existing neuroblastoma trials requiring molecular imaging. The introduction of SPECT/CT has shown not only the heterogeneity of the mIBG uptake within the primary tumor but also the presence of completely mIBG nonavid metastatic lesions with mIBG-avid primary neuroblastomas. It is currently possible to semi-quantitatively assess tracer uptake with standardized uptake value, which allows a more precise evaluation of the tracer avidity and can help monitor chemotherapy response. The patchy mIBG uptake has consequences from a theranostic perspective and may partly explain the failure of some neuroblastomas to respond to ¹³¹I-mIBG molecular radiotherapy. Various positron emission tomography tracers, targeting different aspects of neuroblastoma cell biology, are being tested as possible alternatives to ¹²³I-mIBG.

Diagnostic Value of Seven Different Imaging Modalities for Patients with Neuroblastic Tumors: A Network Meta-Analysis

Objective

We performed a systematic review and network meta-analysis (NMA) to compare the diagnostic value of seven different imaging modalities for the detection of neuroblastic tumors in diverse clinical settings.

Methods

PubMed, Embase, Medline, and the Cochrane Library were searched to identify eligible studies from inception to Sep 29, 2020. Quality assessment of included studies was appraised with Quality Assessment of Diagnostic Accuracy Studies. Firstly, direct pairwise meta-analysis was conducted to calculate the pooled estimates of odds ratio (OR) and 95% confidence interval (CI) of the sensitivity, specificity, NPV, PPV, and DR. Next, NMA using Bayesian methods was performed. The superiority index was assessed to quantify the rank probability of a diagnostic test. The studies performed SPECT/CT or SPECT were analyzed separately from the ones only performed planar imaging.

Results

A total of 1135 patients from 32 studies, including 7 different imaging modalities, were eligible for this NMA. In the pairwise meta-analysis, ¹⁸F-FDOPA PET/CT had a relatively high value of all the outcomes (sensitivity: 10.195 [5.332–19.493]; specificity: 17.906 [5.950–53.884]; NPV: 16.819 [7.033–40.218]; PPV: 11.154 [4.216–29.512]; and DR 5.616 [3.609–8.739]). In the NMA, ¹⁸F-FDOPA PET/CT exhibited relatively high sensitivity in all subgroups (all data: 0.94 [0.87–0.98]; primary tumor: 0.89 [0.53–1]; bone/bone marrow metastases: 0.96 [0.83–1]; and primary tumor and metastases (P + M): 0.92 [0.80–0.97]), the highest specificity in the subgroup of P + M (0.85 [0.61–0.97]), and achieved the highest superiority index in the subgroups of all data (8.57 [1–15]) and P + M (7.25 [1–13]).

Conclusion

¹⁸F-FDOPA PET/CT exhibited the best diagnostic performance in the comprehensive detection of primary tumor and metastases for neuroblastic tumors, followed by ⁶⁸Ga-somatostatin analogs, ¹²³I-meta-iodobenzylguanidine (MIBG), ¹⁸F-FDG, and ¹³¹I-MIBG tomographic imaging.

68Ga-DOTATATE and 123I-mIBG as imaging biomarkers of disease localisation in metastatic neuroblastoma: implications for molecular radiotherapy

PURPOSE

Iodine-131-labelled meta-iodobenzylguanidine (I-mIBG) and lutetium-177-labelled DOTATATE (Lu-DOTATATE) are used for molecular radiotherapy of metastatic neuroblastoma. These are taken up by the noradrenaline transporter (NAT) and the somatostatin receptor subtype 2 (SSTR-2), respectively. Scintigraphy of iodine-123-labelled meta-iodobenzylguanidine (I-mIBG) and gallium-68 DOTATATE (Ga-DOTATATE) PET are used to select patients for therapy. These demonstrate the extent and location of tumour, and avidity of uptake by cells expressing NAT and SSTR-2, respectively. This study compared the similarities and differences in the anatomical distribution of these two imaging biomarkers in an unselected series of patients with metastatic neuroblastoma undergoing assessment for molecular radiotherapy.

METHODS

Paired whole-body planar I-mIBG views and Ga-DOTATATE maximum intensity projection PET scans of metastatic neuroblastoma patients were visually compared. The disease extent was assessed by a semiquantitative scoring method.

RESULTS

Paired scans from 42 patients were reviewed. Ga-DOTATATE scans were positive in all patients, I-mIBG scans were negative in two. In two patients, there was a mismatch, with some lesions identified only on the I-mIBG scan, and others visible only on the Ga-DOTATATE scan.

CONCLUSION

Ga-DOTATATE and I-mIBG scans yield complementary information. For a more comprehensive assessment, consideration could be given to the use of both I-mIBG and Ga-DOTATATE imaging scans. Because of the heterogeneity of distribution of molecular targets revealed by these techniques, a combination of both I-mIBG and Lu-DOTATATE molecular radiotherapy may possibly be more effective than either alone.

Value of pretreatment 18F-FDG PET/CT in prognosis and the reflection of tumor burden: a study in pediatric patients with newly diagnosed neuroblastoma

Fluorine-18 fluorodeoxyglucose (18F-FDG) PET/CT has been commonly used in pediatric patients with newly diagnosed neuroblastoma (NB) for diagnosis. We retrospectively reviewed 40 pediatric patients with newly diagnosed NB who underwent 18F-FDG PET/CT. Clinicopathological factors and metabolic parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on PET/CT were evaluated as predictive factors for progression-free survival (PFS) and overall survival (OS) by univariate and multivariate analysis. Spearman rank correlation analyses were used to estimate the correlations between clinical factors and PET findings. The mean follow-up after 18F-FDG-PET/CT was 32.9 months. During the follow-up period 15 (37.5%) patients experienced progression, and 9 (22.5%) died. MTV (P=0.001) and TLG (p=0.004) remained significant predictive factors for tumor progression, along with lactate dehydrogenase (LDH), neuron-specific enolase (NSE) and bone metastasis. Univariate analysis showed that bone metastasis, LDH (>1064 IU/L), NSE (>364.4 ug/L), MTV (>191 cm3) and TLG (>341.41 g) correlated with PFS, and LDH (>1064 IU/L), NSE (>364.4 ug/L) and MTV (>191 cm³) correlated with OS (p<0.05). In multivariate analysis, MTV and bone metastasis were independent prognostic factors for PFS (p=0.001 and 0.023, respectively), and MTV remained the only independent prognostic factor for OS (p= 0.004). We also found that there were correlations between semiquantitative PET/CT parameters and clinical features in NB. Our results suggested that 18F-FDG PET/CT was a useful tool to predictive progression and to reflect tumor burden for patients with NB.

The Diagnostic Accuracy of PET(CT) in Patients With Neuroblastoma: A Meta-Analysis and Systematic Review

OBJECTIVE

The objective of this study was to evaluate the overall diagnostic value of PET(CT) in patients with neuroblastoma (NB) based on qualified studies.

METHODS

PubMed, Cochrane, and Embase database were searched by the index words to identify the qualified studies, and relevant literature sources were also searched. The latest research was performed in April 2019. Heterogeneity of the included studies was tested, which was used to select proper effect model to calculate pooled weighted sensitivity, specificity, and diagnostic odds ratio (DOR). Summary receiver operating characteristic (SROC) analyses were also performed.

RESULTS

Eleven studies with 580 patients were involved in the meta-analysis to explore the diagnostic accuracy of PET(CT) for NB. PET(CT) has high diagnostic accuracy of NB: the global sensitivity was 91% (95% confidence interval [CI], 86%-94%), the global specificity was 78% (95% CI, 66%-86%), the global positive likelihood ratio was 4.07 (95% CI, 2.54-6.50), the global negative likelihood ratio was 0.12 (95% CI, 0.08-0.18), the global DOR was 27.43 (95% CI, 14.45-52.07), and the area under the SROC was high (area under the curve, 0.93; 95% CI, 0.90-0.95). Besides this, PET(CT) has high diagnostic accuracy of primary NB: the global sensitivity was 86% (95% CI, 73%-93%), the global specificity was 82% (95% CI, 57%-94%), the global positive likelihood ratio was 4.90 (95% CI, 1.63-14.72), the global negative likelihood ratio was 0.17 (95% CI, 0.07-0.40), the global DOR was 25.427 (95% CI, 3.988-162.098), and the area under the SROC was high (area under the curve, 0.91; 95% CI, 0.88-0.93). However, there has no significant accuracy of PET(CT) in NB with bone marrow.

CONCLUSIONS

This study provides a systematic review and meta-analysis of diagnostic accuracy studies of PET(CT) for NB. The results indicated that PET(CT) is a highly accurate diagnostic tool for NB.

Lymph node imaging of pediatric renal and suprarenal malignancies

Pediatric renal and suprarenal cancers are relatively rare malignancies, but are not without significant consequence to both the patient and caretakers. These tumors are often found incidentally and present as large abdominal masses. Standard of care management involves surgical excision of the mass, but contemporary treatment guidelines advocate for use of neoadjuvant or adjuvant chemotherapy for advanced stage disease, such as those cases with lymph node involvement (LNI). However, LNI detection is based primarily on surgical pathology and performing extended lymph node dissection can add significant morbidity to a surgical case. In this review, we focus on the use and performance of imaging modalities to detect LNI in Wilms’ tumor (WT), neuroblastoma, and pediatric renal cell carcinoma (RCC). We report on how imaging impacts management of these cases and the clinical implications of LNI. A literature search was conducted for studies published on imaging-based detection of LNI in pediatric renal and suprarenal cancers. Further review focused on surgical and medical management of those cases with suspected LNI. Current imaging protocols assisting in diagnosis and staging of pediatric renal and suprarenal cancers are generally limited to abdominal ultrasound and cross-sectional imaging, mainly computed tomography (CT). Recent research has investigated the role of more advance modalities, such as magnetic resonance imaging (MRI) and positron emission tomography (PET), in the management of these malignancies. Special consideration must be made for pediatric patients who are more vulnerable to ionizing radiation and have characteristic imaging features different from adult controls. Management of pediatric renal and suprarenal cancers is influenced by LNI, but the rarity of these conditions has limited the volume of clinical research regarding imaging-based staging. As such, standardized criteria for LNI on imaging are lacking. Nevertheless, advanced imaging modalities are being investigated and potentially represent more accurate and safer options.

Value of SPECT/CT in Diagnostic I-131 MIBG Scintigraphy in Patients with Neuroblastoma

Purpose

Diagnostic I-131 MIBG scintigraphy is an important imaging modality for evaluation of patients with neuroblastoma (NB) especially in centers where I-123 MIBG is not available. Single photon emission computed tomography/computed tomography (SPECT/CT) could potentially improve lesion detection over planar scintigraphy, but studies regarding its usefulness as an add-on to diagnostic I-131 MIBG scintigraphy are limited. This study aimed to determine the usefulness and factors related to usefulness of SPECT/CT in diagnostic I-131 MIBG scintigraphy in NB patients.

Methods

Usefulness of SPECT/CT for lesion detection, lesion localization, resolving suspicious findings, and clarifying the nature of lesions on anatomical imaging were retrospectively reviewed in 86 diagnostic planar I-131 MIBG scintigrams with add-on SPECT/CT.

Results

SPECT/CT detected additional lesions in 23.2%(20/86), helped localize lesions in 21.1%(8/38), resolved suspicious findings in 85.7%(6/7), determined functional status of lesions on anatomical imaging in 94.4%(17/18), and changed diagnosis from a negative to a positive study in 19.5%(8/41). Independent predictors of SPECT/CT being useful included presence of suspicious findings on planar imaging (OR 99.08; 95% C.I. 6.99-1404.41; p = 0.001), positive findings on planar imaging (OR 4.61; 95% C.I. 1.05, 20.28; p < 0.001), and presence of structural lesions on anatomical imaging (OR 32.54; 95% C.I. 5.37-196.96; p < 0.001).

Conclusion

SPECT/CT is a useful add-on to diagnostic planar I-131 MIBG scintigraphy. Predictors of usefulness of SPECT/CT include suspicious or positive findings on planar scintigraphy and the presence of structural lesions on anatomical imaging.

Advances in the Surgical Treatment of Neuroblastoma

OBJECTIVE

This study was to review the efficacy of surgical resections in different clinical situations for a better understanding of the meaning of surgery in the treatment of neuroblastoma (NB).

DATA SOURCES

The online database ScienceDirect (201-2018) was utilized. The search was conducted using the keywords "neuroblastoma," "neuroblastoma resection," "neuroblastoma surgery," and "high-risk neuroblastoma."

STUDY SELECTION

We retrospectively analyzed of patients who underwent surgical resections in different clinical situations. The article included findings from selected relevant randomized controlled trials, systematic reviews, and meta-analyses or good-quality observational studies. Abstracts only, letters, and editorial notes were excluded. Full-text articles and abstracts were extracted and reviewed to identify key articles discussing surgery management of NB, which were then selected for critical analysis.

RESULTS

A total of 7800 English language articles were found containing references to NB (201-2018). The 163 articles were searched which were related to the surgical treatment of NB (201-2018). Through the analysis of these important articles, we found that the treatments of NB at low- and intermediate-risk groups were basically the same. High-risk patients remained controversial.

CONCLUSIONS

NB prognosis varies tremendously based on the stage and biologic features of the tumor. After reviewing the relevant literature, patients with low-risk disease are often managed with surgical resection or observation alone with tumors likely to spontaneously regress that are not causing symptoms. Intermediate patients are treated with chemotherapy with the number of cycles depending on their response as well as surgical resection of the primary tumor. High-risk patients remain controversial. Multidisciplinary intensive treatment is essential, especially for patients who received subtotal tumor resection. Minimally invasive surgery for the treatment of NBs without image-defined risk factors in low- to high-risk patients is safe and feasible and does not compromise the treatment outcome. We conclude that ≥90% resection of the primary tumor is both feasible and safe in most patients with high-risk NB. New targeted therapies are crucial to improve survival.

Comparison of diagnosing and staging accuracy of PET (CT) and MIBG on patients with neuroblastoma: Systemic review and meta-analysis

To perform a systemic review and meta-analysis of the diagnostic accuracy of PET (CT) and metaiodobenzylguanidine (MIBG) for diagnosing neuroblastoma (NB), electronic databases were searched as well as relevant references and conference proceedings. The diagnostic accuracy of MIBG and PET (CT) was calculated for NB, primary NB, and relapse/metastasis of NB based on their sensitivity, specificity, and area under the summary receiver operating characteristic curve (AUSROC) in terms of per-lesion and per-patient data. A total of 40 eligible studies comprising 1134 patients with 939 NB lesions were considered for the meta-analysis. For the staging of NB, the per-lesion AUSROC value of MIBG was lower than that of PET (CT) [0.8064±0.0414 vs. 0.9366±0.0166 (P<0.05)]. The per-patient AUSROC value of MIBG and PET (CT) for the diagnosis of NB was 0.8771±0.0230 and 0.6851±0.2111, respectively. The summary sensitivity for MIBG and PET (CT) was 0.79 and 0.89, respectively. The summary specificity for MIBG and PET (CT) was 0.84 and 0.71, respectively. PET (CT) showed higher per-lesion accuracy than MIBG and might be the preferred modality for the staging of NB. On the other hand, MIBG has a comparable diagnosing performance with PET (CT) in per-patient analysis but shows a better specificity.

Precision Medicine and PET-Computed Tomography in Pediatric Malignancies

Fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) PET-computed tomography (CT) plays a significant role in diagnosis, staging, therapy selection, and therapy assessment of multiple pediatric malignancies and facilitating precision medicine delivery in pediatric patients. In patients with Hodgkin lymphoma, interim fludeoxyglucose ¹⁸F-FDG PET/CT is highly sensitive and specific for predicting survival and multiple trials with FDG PET/CT-based adaptive therapies are currently ongoing. It is superior to iodine-131 metaiodobenzylguanidine (¹³¹I-MIBG) scintigraphy and bone scintigraphy for detecting metastases in neuroblastoma patients and sarcoma patients. It may predict histologic differentiation and neoadjuvant therapy assessment in Wilms tumor.

Management of Neuroblastoma: ICMR Consensus Document

Neuroblastoma (NBL) is the most common extra-cranial solid tumor in childhood. High-risk NBL is considered challenging and has one of the least favourable outcomes amongst pediatric cancers. Primary tumor can arise anywhere along the sympathetic chain. Advanced disease at presentation is common. Diagnosis is established by tumor biopsy and elevated urinary catecholamines. Staging is performed using bone marrow and mIBG scan (FDG-PET/bone scan if mIBG unavailable or non-avid). Age, stage, histopathological grading, MYCN amplification and 11q aberration are important prognostic factors utilized in risk stratification. Low-risk disease including Stage 1 and asymptomatic Stage 2 disease has an excellent prognosis with non-mutilating surgery alone. Perinatal adrenal neuroblastoma may be managed with close observation alone. Intermediate-risk disease consisting largely of unresectable/symptomatic Stage 2/3 disease and infants with Stage 4 disease has good outcome with few cycles of chemotherapy followed by surgical resection. Paraspinal neuroblastomas with cord compression are treated emergently, typically with upfront chemotherapy. Asymptomatic Stage 4S disease may be followed closely without treatment. Organ dysfunction and age below 3 mo would warrant chemotherapy in 4S. High-risk disease includes older children with Stage 4 disease and MYCN amplified tumors. High-risk disease has a suboptimal outcome, though the survival is improving with multimodality therapy including autologous stem cell transplant and immunotherapy. Relapse after multimodality therapy is difficult to salvage. Late presentation, lack of transplant facility, malnutrition and treatment abandonment are additional hurdles for survival in India. The review provides a consensus document on management of NBL for developing countries, including India.

Risk Stratification of Pediatric Patients With Neuroblastoma Using Volumetric Parameters of 18F-FDG and 18F-DOPA PET/CT

PURPOSE

This study determined the prognostic value of volumetric parameters derived from pretreatment F-FDG and F-DOPA PET/CT of neuroblastoma and their correlation with clinical and histopathologic features.

PATIENTS AND METHODS

A total of 25 children with neuroblastoma underwent pretreatment F-FDG and F-DOPA PET/CT within 4 weeks. The SUVmax of primary tumors on F-FDG and F-DOPA PET were recorded as SUVFDG and SUVDOPA, respectively. For volumetric parameters of primary tumors, 40% of SUVmax was used to generate volume of interest. If the 40% of SUVmax was below 2.5, an SUV threshold of 2.5 was used instead. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), dopaminergic tumor volume (DTV), and total lesion F-DOPA activity (TLDA) were recorded as F-FDG and F-DOPA volumetric parameters. All indices were compared between groups distinguished by survival status and clinical features, including bone marrow involvement, lymph node metastasis, amplification of the MYCN oncogene, invasive features on anatomic images, and risk categories. The Kaplan-Meier method and log-rank test were used to compare the survival curves between groups.

RESULTS

The median follow-up period was 28.2 months. Nonsurvivors (20%) tended to have lower SUVDOPA, DTV, and TLDA (P ≤ 0.05), and higher SUVFDG, MTV, and TLG (all P < 0.05). Lower F-DOPA uptake is associated with bone marrow and lymph node metastases (all P < 0.05). Higher F-FDG uptake is associated with MYCN amplification (all P < 0.05) and anatomic invasive features of tumors such as vascular encasement or adjacent organ invasion (TLG, P = 0.05). Only volumetric indices (DTV, TLDA, MTV, and TLG) significantly differed among risk groups (all P < 0.05).

CONCLUSIONS

Pretherapeutic F-DOPA and F-FDG PET provided complementary information, and both can be served for risk stratification. Volumetric indices of F-DOPA and F-FDG PET correlate more highly with risk grouping.

Clinical Significance of Pretreatment FDG PET/CT in MIBG-Avid Pediatric Neuroblastoma

PURPOSE

¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging is well known to have clinical significance in the initial staging and response evaluation of the many kinds of neoplasms. However, its role in the pediatric neuroblastoma is not clearly defined. In the present study, the clinical significance of FDG-PET/computed tomography (CT) in ¹²³I- or ¹³¹I-metaiodobenzylguanidine (MIBG)-avid pediatric neuroblastoma was investigated.

METHODS

Twenty patients with neuroblastoma who undertook pretreatment FDG PET/CT at our institute between 2008 and 2015 and showed MIBG avidity were retrospectively enrolled in the present study. Clinical information-including histopathology, and serum markers-and several PET parameters-including SUVmax of the primary lesion (Psuv), target-to-background ratio (TBR), metabolic tumor volume (MTV), and coefficient of variation (CV)-were analyzed. The prognostic effect of PET parameters was evaluated in terms of progression-free survival (PFS).

RESULTS

Total 20 patients (4.5 ± 3.5 years) were divided as two groups by disease progression. Six patients (30.0 %) experienced disease progression and one patient (5.0 %) died during follow-up period. There were not statistically significant in age, stage, MYCN status, primary tumor size, serum lactate dehydrogenase (LDH), neuron-specific enolase (NSE), and ferritin level between two groups with progression or no progression. However, Psuv (p = 0.017), TBR (p = 0.09), MTV (p = 0.02), and CV (p = 0.036) showed significant differences between two groups. In univariate analysis, PFS was significantly associated with Psuv (p = 0.021) and TBR (p = 0.023).

CONCLUSIONS

FDG-PET parameters were significantly related with progression of neuroblastoma. FDG-PET/CT may have the potential as a valuable modality for evaluating prognosis in the patients with MIBG-avid pediatric neuroblastoma.

Prognostic value of pretreatment FDG PET in pediatric neuroblastoma

PURPOSE

This study aimed to evaluate the prognostic value of pretreatment (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in pediatric neuroblastoma patients.

METHODS

The study included 50 pediatric neuroblastoma patients who underwent diagnostic work-up FDG PET before any treatment. The maximum standardized uptake value (SUV(max)) of the primary tumor lesion (P(max)), the SUV(max) of all the tumor lesions, including the primary tumor lesion and metastatic lesions (T(max)), and the uptake ratio of T(max) to mean SUV of normal liver tissue (T(max)/L(mean)) were calculated and tested as prognostic factors.

RESULTS

Of the 50 patients, 15 (30.0%) experienced disease progression and 21 (42.0%) died during the follow-up period. On univariate analysis, the histopathology, tumor stage, bone marrow involvement, serum levels of lactate dehydrogenase (LDH), neuron-specific enolase, and ferritin, primary tumor size, P(max), T(max), and T(max)/L(mean) were significant prognostic factors for disease progression-free survival (PFS), whereas the tumor stage, serum level of LDH, T(max), and T(max)/L(mean) were determined to be significant for predicting overall survival (OS). On multivariate analysis, the histopathology and serum level of LDH were independent prognostic factors for PFS, and only the T(max)/L(mean) was an independent prognostic factor for OS. The 2-year PFS and OS rates were over 80.0% in patients with low FDG uptake, meanwhile, patients with high FDG uptake showed the 2-year PFS of less than 30.0% and OS of less than 55.0%.

CONCLUSION

FDG PET was an independent prognostic factor for OS in neuroblastoma patients. FDG PET can provide effective information on the prognosis for neuroblastoma patients.