Feasibility and effectiveness of treatment strategy of tandem high-dose chemotherapy and autologous stem cell transplantation in combination with 131 I-MIBG therapy for high-risk neuroblastoma

Incidence of subclinical and overt hypothyroidism in children treated with [131I]mIBG: a systematic review and meta-analysis

INTRODUCTION

Treatment with [131I]mIBG is commonly used in pediatric metastatic neuroblastoma (NB); however, unbound [131I]I might be taken up by the thyroid, causing hypothyroidism. To prevent this occurrence, thyroid blockade with iodine salts is commonly used; despite this precaution, thyroid dysfunction still occurs. This review and meta-analysis aim to clarify the mean frequency of hypothyroidism in children with NB treated with [131I]mIBG and to investigate the possible causes.

EVIDENCE ACQUISITION

The literature was searched for English-language scientific manuscripts describing the incidence of TSH elevation and overt hypothyroidism in children with NB treated with [131I]mIBG. Preclinical studies, small-case series, and reviews were excluded. A proportion meta-analysis was conducted to test the influence of potentially relevant factors (type and duration of thyroid blockade, year of the study, sample size) on the incidence of TSH elevation/overt hypothyroidism.

EVIDENCE SYNTHESIS

Eleven studies were included. The pooled percentage of TSH elevation was 0.41 (95% CI: 0.27-0.55); the duration of the thyroid blockade (P=0.004) was inversely correlated with the incidence of TSH elevation. Moreover, a TSH increase was more common in patients treated with potassium iodide (KI) alone than in those managed with a multi-drug thyroid blockade (P<0.001). The pooled percentage of children requiring hormone replacement therapy was 0.33 (95% CI: 0.16-0.49). As in the case of TSH elevation, a longer duration of the thyroid blockade (P=0.006) and a multi-pronged approach (P<0.001) were associated with a lower incidence of overt hypothyroidism.

CONCLUSIONS

Hypothyroidism appears to occur frequently in children treated with [131I]mIBG, which should be monitored closely after the radionuclide treatment to start hormone replacement therapy as soon as needed. The duration, as well as the type of thyroid blockade, seem to influence the incidence of hypothyroidism; however, more data from prospective evaluations are needed.

Radiopharmaceuticals: navigating the frontier of precision medicine and therapeutic innovation

This review article explores the dynamic field of radiopharmaceuticals, where innovative developments arise from combining radioisotopes and pharmaceuticals, opening up exciting therapeutic possibilities. The in-depth exploration covers targeted drug delivery, delving into passive targeting through enhanced permeability and retention, as well as active targeting using ligand-receptor strategies. The article also discusses stimulus-responsive release systems, which orchestrate controlled release, enhancing precision and therapeutic effectiveness. A significant focus is placed on the crucial role of radiopharmaceuticals in medical imaging and theranostics, highlighting their contribution to diagnostic accuracy and image-guided curative interventions. The review emphasizes safety considerations and strategies for mitigating side effects, providing valuable insights into addressing challenges and achieving precise drug delivery. Looking ahead, the article discusses nanoparticle formulations as cutting-edge innovations in next-generation radiopharmaceuticals, showcasing their potential applications. Real-world examples are presented through case studies, including the use of radiolabelled antibodies for solid tumors, peptide receptor radionuclide therapy for neuroendocrine tumors, and the intricate management of bone metastases. The concluding perspective envisions the future trajectory of radiopharmaceuticals, anticipating a harmonious integration of precision medicine and artificial intelligence. This vision foresees an era where therapeutic precision aligns seamlessly with scientific advancements, ushering in a new epoch marked by the fusion of therapeutic resonance and visionary progress.

Ten-Year Trends of Hematopoietic Stem Cell Transplantation in Korean Pediatric Cancer from the National Health Insurance Claims Data

PURPOSE

We aimed to determine the current application and survival trends of hematopoietic stem cell transplantation (HSCT) among Korean children and adolescents with cancer.

MATERIALS AND METHODS

Data of patients aged < 20 years with KCD-10 (Korean Classifications of Diseases, 10th revision) C codes and specific designation codes were collected from the National Health Insurance Service database. Thirty claim codes for HSCT were included, and data from 2009 to 2019 were analyzed.

RESULTS

The operational definition of pediatric cancer yielded an annual average of 2,000, with annual cases decreasing. In 2019, 221 HSCTs were performed, a decrease from the ten-year average of 276. Allografts outnumbered autografts with a ratio of 1.5:1. The source of allograft was bone marrow in 15% of patients in 2009; however, it substantially decreased to 3.3% in 2019. Furthermore, 70.5% of allogeneic HSCT used peripheral blood stem cell (PBSC) grafts, which increased to 89.3% by 2015. Cord blood utilization markedly decreased to 2.7% in 2018. The 5-year overall survival (OS) rate of all patients was 85.1%. Overall mortality decreased among patients who underwent recent HSCT, and they exhibited a higher 5-year OS rate.

CONCLUSION

In Korea, the number of pediatric patients with cancer is declining; however, the ratio of transplants to all patients remains constant. Patients who recently underwent transplantation showed better survival rates, possibly due to HSCT optimization. Korea showed a substantially greater PBSC utilization in pediatric HSCT. An in-depth examination encompassing donor relations and cause of death with a prospective registry is required in future studies.

The Plasma Membrane Monoamine Transporter is Highly Expressed in Neuroblastoma and Functions as an mIBG Transporter

Neuroblastoma (NB) is a pediatric cancer with low survival rates in high-risk patients. 131I-mIBG has emerged as a promising therapy for high-risk NB and kills tumor cells by radiation. Consequently, 131I-mIBG tumor uptake and retention are major determinants for its therapeutic efficacy. mIBG enters NB cells through the norepinephrine transporter (NET), and accumulates in mitochondria through unknown mechanisms. Here we evaluated the expression of monoamine and organic cation transporters in high-risk NB tumors and explored their relationship with MYCN amplification and patient survival. We found that NB mainly expresses NET, the plasma membrane monoamine transporter (PMAT), and the vesicular membrane monoamine transporter 1/2 (VMAT1/2), and that the expression of these transporters is significantly reduced in MYCN-amplified tumor samples. PMAT expression is the highest and correlates with overall survival in high-risk NB patients without MYCN amplification. Immunostaining showed that PMAT resides intracellularly in NB cells and co-localizes with mitochondria. Using cells expressing PMAT, mIBG was identified as a PMAT substrate. In mitochondria isolated from NB cell lines, mIBG uptake was reduced by ∼50% by a PMAT inhibitor. Together, our data suggest that PMAT is a previously unrecognized transporter highly expressed in NB and could impact intracellular transport and therapeutic response to 131I-mIBG. SIGNIFICANCE STATEMENT: This study identified that plasma membrane monoamine transporter (PMAT) is a novel transporter highly expressed in neuroblastoma and its expression level is associated with overall survival rate in high-risk patients without MYCN amplification. PMAT is expressed intracellularly in neuroblastoma cells, transports meta-iodobenzylguanidine (mIBG) and thus could impact tumor retention and response to 131I-mIBG therapy. These findings have important clinical implications as PMAT could represent a novel molecular marker to help inform disease prognosis and predict response to 131I-mIBG therapy.

Timing and chemotherapy association for 131-I-MIBG treatment in high-risk neuroblastoma

Prognosis of high-risk neuroblastoma is dismal, despite intensive induction chemotherapy, surgery, high-dose chemotherapy, radiotherapy, and maintenance. Patients who do not achieve a complete metastatic response, with clearance of bone marrow and skeletal NB infiltration, after induction have a significantly lowersurvival rate. Thus, it's necessary to further intensifytreatment during this phase. 131-I-metaiodobenzylguanidine (131-I-MIBG) is a radioactive compound highly effective against neuroblastoma, with32% response rate in relapsed/resistant cases, and only hematological toxicity. 131-I-MIBG wasutilized at different doses in single or multiple administrations, before autologous transplant or combinedwith high-dose chemotherapy. Subsequently, it was added to consolidationin patients with advanced NB after induction, but an independent contribution against neuroblastoma and for myelotoxicity is difficult to determine. Despiteresults of a 2008 paper demonstratedefficacy and mild hematological toxicity of 131-I-MIBG at diagnosis, no center had included it with intensive chemotherapy in first-line treatment protocols. In our institution, at diagnosis, 131-I-MIBG was included in a 5-chemotherapy drug combination and administered on day-10, at doses up to 18.3 mCi/kg. Almost 87% of objective responses were observed 50 days from start with acceptable hematological toxicity. In this paper, we review the literature data regarding 131-I-MIBG treatment for neuroblastoma, and report on doses and combinations used, tumor responses and toxicity. 131-I-MIBG is very effective against neuroblastoma, in particular if given to patients at diagnosis and in combination with chemotherapy, and it should be included in all induction regimens to improve early responses rates and consequently long-term survival.

Therapy resistance in neuroblastoma: Mechanisms and reversal strategies

Neuroblastoma is one of the most common pediatric solid tumors that threaten the health of children, accounting for about 15% of childhood cancer-related mortality in the United States. Currently, multiple therapies have been developed and applied in clinic to treat neuroblastoma including chemotherapy, radiotherapy, targeted therapy, and immunotherapy. However, the resistance to therapies is inevitable following long-term treatment, leading to treatment failure and cancer relapse. Hence, to understand the mechanisms of therapy resistance and discover reversal strategies have become an urgent task. Recent studies have demonstrated numerous genetic alterations and dysfunctional pathways related to neuroblastoma resistance. These molecular signatures may be potential targets to combat refractory neuroblastoma. A number of novel interventions for neuroblastoma patients have been developed based on these targets. In this review, we focus on the complicated mechanisms of therapy resistance and the potential targets such as ATP-binding cassette transporters, long non-coding RNAs, microRNAs, autophagy, cancer stem cells, and extracellular vesicles. On this basis, we summarized recent studies on the reversal strategies to overcome therapy resistance of neuroblastoma such as targeting ATP-binding cassette transporters, MYCN gene, cancer stem cells, hypoxia, and autophagy. This review aims to provide novel insight in how to improve the therapy efficacy against resistant neuroblastoma, which may shed light on the future directions that would enhance the treatment outcomes and prolong the survival of patients with neuroblastoma.

Treatment outcomes among high-risk neuroblastoma patients receiving non-immunotherapy regimen: Multicenter study on behalf of the Thai Pediatric Oncology Group

BACKGROUND

Neuroblastoma is the most common extracranial malignant solid tumor during childhood. Despite intensified treatment, patients with high-risk neuroblastoma (HR-NBL) still carry a dismal prognosis. The Thai Pediatric Oncology Group (ThaiPOG) proposed the use of a multimodality treatment to improve outcomes of HR-NBL in non-immunotherapy settings.

METHODS

Patients with HR-NBL undergoing ThaiPOG protocols (ThaiPOG-NB-13HR or -18HR) between 2013 and 2019 were retrospectively reviewed. Patient demographic data, treatment modalities, outcomes, and prognostic factors were evaluated and analyzed.

RESULTS

A total of 183 patients with HR-NBL undergoing a topotecan containing induction regimen were enrolled in this study. During the consolidation phase (n = 169), 116 patients (68.6%) received conventional chemotherapy, while 53 patients (31.4%) underwent hematopoietic stem cell transplantation (HSCT). The 5-year overall survival (OS) and event-free survival (EFS) were 41.2% and 22.8%, respectively. Patients who underwent HSCT had more superior 5-year EFS (36%) than those who received chemotherapy (17.1%) (p = .041), although they both performed similarly in 5-year OS (48.7% vs. 39.8%, p = .17). The variation of survival outcomes was observed depending on the number of treatment modalities. HSCT combined with metaiodobenzylguanidine (MIBG) treatment and maintenance with 13-cis-retinoic acid (cis-RA) demonstrated a desirable 5-year OS and EFS of 65.6% and 58.3%, respectively. Poorly or undifferentiated tumor histology and cis-RA administration were independent factors associated with relapse and survival outcomes, respectively (p < .05).

CONCLUSION

A combination of HSCT and cis-RA successfully improved the outcomes of patients with HR-NBL in immunotherapy inaccessible settings.

KSNM60 in Nuclear Endocrinology: from the Beginning to the Future

Nuclear endocrinology is the main ignitor for founding the Korean Society of Nuclear Medicine (KSNM) in the early 1960s by outstanding pioneering medical doctors. Management of thyroid diseases required nuclear medicine technology in the early days of the KSNM and was rapidly developed by advancements in nuclear medicine technology. Nuclear thyroidology remains one of the main clinical applications in nuclear medicine worldwide. Nuclear medicine technology provides essential information for diagnosing and assessing diseases of the parathyroid glands, pituitary gland, and neuroendocrine tumors (NETs). In addition, therapeutic nuclear medicine is essential for managing nonresectable NETs. Nuclear endocrinology remains a major section in clinical nuclear medicine, and members of the KSNM have contributed to progressing better management of benign and malignant endocrine diseases. This review summarizes the historical activities and milestone contributions to nuclear endocrinology made by the members of the KSNM over the past 60 years to congratulate the KSNM on its 60-year anniversary.

KSNM60 in Non-thyroidal Radionuclide Therapy: Leaping into the Future

This year, the Korean Society of Nuclear Medicine (KSNM) is celebrating its 60th anniversary. Treatment, as well as diagnosis, has played a very important role in the development of nuclear medicine. Since I-131 was used for thyroid therapy in 1959, other radionuclide therapy is still being used, and attempts to use new radionuclide are increasing. In this review, we briefly summarize and introduce the therapies such as radioimmunotherapy, transarterial radioembolization, radionuclide therapy for neuroendocrine tumors, peptide receptor radionuclide therapy, control of metastatic bone pain, radiation synovectomy, radionuclide brachytherapy, alpha particle therapy, and boron neutron capture therapy, which has been being attempted so far in the field of nuclear medicine.

Factors Modifying Outcome After MIBG Therapy in Children With Neuroblastoma-A National Retrospective Study

Background

Neuroblastoma is the most common pediatric extracranial tumor with varied prognoses, but the survival of treated refractory or relapsing patients remains poor.

Objective

This analysis presents the outcomes of children with neuroblastoma undergoing MIBG therapy in Poland in 2006-2019.

Study Design

A retrospective cohort of 55 patients with refractory or relapsed neuroblastoma treated with I-131 MIBG in Poland in 2006-2019 was analyzed. The endpoints were overall survival (OS), event-free survival (EFS), cumulative incidence (CI) of second cancers and CI of hypothyroidism. Survival curves were estimated using the Kaplan-Meier method and compared between the cohorts by the log-rank test. Cox modeling was adopted to estimate hazard ratios for OS and EFS, considering factors with P < 0.2.

Results

Fifty-five patients with a median age of 78.4 months (range 18-193) with neuroblastoma underwent one or more (4 patients) courses of MIBG I-131 therapy. Fifteen patients were not administered chemotherapy, 3 children received standard-dose chemotherapy, and 37 patients were administered high-dose chemotherapy (HDCT) (busulfan-melphalan in 24 and treosulfan-based in 12 patients). Forty-six patients underwent stem cell transplantation, with autologous (35 patients), haploidentical (6), allogeneic (4), and syngeneic grafts (1). The median time from first MIBG therapy to SCT was 22 days. Children with relapsing tumors had inferior OS compared to those with primary resistant disease (21.2% vs 58.7%, p=0.0045). Survival was better in patients without MYCN gene amplification. MIBG therapy was never curative, except in patients further treated with HDCT with stem cell rescue irrespective of the donor type. 31 patients were referred for immune therapy after MIBG therapy, and the 5-year OS in this group was superior to the untreated children (55.2% vs 32.7%, p=0.003), but the difference in the 5-year EFS was not significant (25.6% vs 32.9%, p=ns). In 3 patients, a second malignancy was diagnosed. In 19.6% of treated children, hypothyroidism was diagnosed within 5 years after MIBG therapy.

Conclusion

MIBG therapy can be incorporated into the therapeutic strategy of relapsed or resistant neuroblastoma patients as preconditioning with HDCT rather than stand-alone therapy. Follow-up is required due to the incidence of thyroid failure and risk of second cancers.

Diagnostic Use of Post-therapy 131I-Meta-Iodobenzylguanidine Scintigraphy in Consolidation Therapy for Children with High-Risk Neuroblastoma

¹²³I-meta-iodobenzylguanidine (¹²³I-mIBG) scintigraphy is used for evaluating disease extent in children with neuroblastoma. ¹³¹I-mIBG therapy has been used for evaluation in children with high-risk neuroblastoma, and post-therapy ¹³¹I-mIBG scintigraphy may detect more lesions compared with diagnostic ¹²³I-mIBG scintigraphy. However, no studies have yet revealed the detection rate of hidden mIBG-avid lesions on post-therapy ¹³¹I-mIBG whole-body scan (WBS) and SPECT images in neuroblastoma children without mIBG-avid lesions as demonstrated by diagnostic ¹²³I-mIBG scintigraphy. We retrospectively examined the diagnostic utility of post-therapy ¹³¹I-mIBG scintigraphy in children who received ¹³¹I-mIBG as consolidation therapy. Nineteen children with complete response to primary therapy were examined. Post-therapy ¹³¹I-mIBG scintigraphy was performed four days after injection. The post-therapy ¹³¹I-mIBG scintigraphy, 4 children exhibited abnormal uptake on the WBS. Post-therapy ¹³¹I-mIBG SPECT/CT provided additional information in 2 cases. In total, 6 children exhibited abnormal uptake. The site of abnormal accumulation was on the recurrence site in one case, operation sites in five cases, and bone metastasis in one case. Post-therapy ¹³¹I-mIBG scintigraphy could detect residual disease that was not recognized using diagnostic ¹²³I-mIBG scintigraphy in 32% of children with high-risk neuroblastoma and ganglioneuroblastoma. The diagnostic use of post-therapy ¹³¹I-mIBG scintigraphy can provide valuable information for detecting residual disease.

Emerging therapeutic targets for neuroblastoma

INTRODUCTION

Neuroblastoma (NB) is the prime cancer of infancy, and accounts for 9% of pediatric cancer deaths. While children diagnosed with clinically stable NB experience a complete cure, those with high-risk disease (HR-NB) do not recover, despite intensive therapeutic strategies. Development of novel and effective targeted therapies is needed to counter disease progression, and to benefit long-term survival of children with HR-NB.

AREAS COVERED

Recent studies (2017-2020) pertinent to NB evolution are selectively reviewed to recognize novel and effective therapeutic targets. The prospective and promising therapeutic targets/strategies for HR-NB are categorized into (a) targeting oncogene-like and/or reinforcing tumor suppressor (TS)-like lncRNAs; (b) targeting oncogene-like microRNAs (miRs) and/or mimicking TS-miRs; (c) targets for immunotherapy; (d) targeting epithelial-to-mesenchymal transition and cancer stem cells; (e) novel and beneficial combination approaches; and (f) repurposing drugs and other strategies in development.

EXPERT OPINION

It is highly unlikely that agents targeting a single candidate or signaling will be beneficial for an HR-NB cure. We must develop efficient drug deliverables for functional targets, which could be integrated and advance clinical therapy. Fittingly, the looming evidence indicated an aggressive evolution of promising novel and integrative targets, development of efficient drugs, and improvised strategies for HR-NB treatment.

High-dose 131I-mIBG as consolidation therapy in pediatric patients with relapsed neuroblastoma and ganglioneuroblastoma: the Japanese experience

OBJECTIVE

Children with relapsed neuroblastoma have a poor prognosis despite modern multimodality therapy. Novel and more effective therapeutic strategies are required for relapsed neuroblastoma. We retrospectively examined the utility of consolidation therapy with high-dose ¹³¹I-meta-iodo-benzyl-guanidine (¹³¹I-mIBG) in relapsed neuroblastoma or ganglioneuroblastoma patients with complete response (CR) to induction therapy as demonstrated by diagnostic ¹²³I-mIBG scintigraphy.

METHODS

Between December 2009 and 2014, five patients with relapsed neuroblastoma and one with relapsed ganglioneuroblastoma received high-dose ¹³¹I-mIBG therapy. Overall and progression-free survival rates at five years after ¹³¹I-mIBG therapy were analyzed by the Kaplan-Meier method.

RESULTS

During follow-up, three children showed no signs of disease relapse, whereas three died. One child without a relapse died from post-transplant side effects, and two children with a relapse died owing to tumor progression. The 5-year progression-free and overall survival rates after ¹³¹I-mIBG therapy were 44% and 67%, respectively.

CONCLUSIONS

Consolidation therapy with high-dose ¹³¹I-mIBG for patients with 2^nd CR showed good overall and progression-free survival. While the risks of radiation exposure must be considered, high-dose ¹³¹I-mIBG therapy as consolidation therapy needs to be further investigated.

Theragnostic Aspects and Radioimmunotherapy in Pediatric Tumors

The use of theragnostic radiopharmaceuticals in nuclear medicine has grown rapidly over the years to combine the diagnosis and therapy of tumors. In this review, we performed web-based and desktop literature research to investigate and explain the potential role of theragnostic imaging in pediatric oncology. We focused primarily on patients with aggressive malignancies such as neuroblastoma and brain tumors, to select patients with the highest chance of benefit from personalized therapy. Moreover, the most critical and groundbreaking applications of radioimmunotherapy in children’s oncology were examined in this peculiar context. Preliminary results showed the potential feasibility of theragnostic imaging and radioimmunotherapy in pediatric oncology. They revealed advantages in the management of the disease, thereby allowing an intra-personal approach and adding new weapons to conventional therapies.