Hypertension complicating 131I-meta-iodobenzylguanidine therapy for neuroblastoma

High-Risk Neuroblastoma: Poor Outcomes Despite Aggressive Multimodal Therapy

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Neuroblastoma (NBL) is a highly malignant embryonal tumor that originates from the primordial neural crest cells. NBL is the most common tumor in infants and the most common extracranial solid tumor in children. The tumor is more commonly diagnosed in children of 1-4 years of age. NBL is characterized by enigmatic clinical behavior that ranges from spontaneous regression to an aggressive clinical course leading to frequent relapses and death. Based on the likelihood of progression and relapse, the International Neuroblastoma Risk Group classification system categorized NBL into very low risk, low risk, intermediate risk, and high risk (HR) groups. HR NBL is defined based on the patient's age (> 18 months), disease metastasis, tumor histology, and MYCN gene amplification. HR NBL is diagnosed in nearly 40% of patients, mainly those > 18 months of age, and is associated with aggressive clinical behavior. Treatment strategies involve the use of intensive chemotherapy (CTR), surgical resection, high dose CTR with hematopoietic stem cell support, radiotherapy, biotherapy, and immunotherapy with Anti-ganglioside 2 monoclonal antibodies. Although HR NBL is now better characterized and aggressive multimodal therapy is applied, the outcomes of treatment are still poor, with overall survival and event-free survival of approximately 40% and 30% at 3-years, respectively. The short and long-term side effects of therapy are tremendous. HR NBL carries a high mortality rate accounting for nearly 15% of pediatric cancer deaths. However, most mortalities are attributed to the high frequency of disease relapse (50%) and disease reactiveness to therapy (20%). Newer treatment strategies are therefore urgently needed. Recent discoveries in the field of biology and molecular genetics of NBL have led to the identification of several targets that can improve the treatment results. In this review, we discuss the different aspects of the epidemiology, biology, clinical presentations, diagnosis, and treatment of HR NBL, in addition to the recent developments in the management of the disease.

Iodine-131-meta-iodobenzylguanidine therapy for patients with newly diagnosed high-risk neuroblastoma

BACKGROUND

Patients with newly diagnosed high-risk (HR) neuroblastoma (NBL) still have a poor outcome, despite multi-modality intensive therapy. This poor outcome necessitates the search for new therapies, such as treatment with 131I-meta-iodobenzylguanidine (131I-MIBG).

OBJECTIVES

To assess the efficacy and adverse effects of 131I-MIBG therapy in patients with newly diagnosed HR NBL.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 3), MEDLINE (PubMed) (1945 to 25 April 2016) and Embase (Ovid) (1980 to 25 April 2016). In addition, we handsearched reference lists of relevant articles and reviews. We also assessed the conference proceedings of the International Society for Paediatric Oncology, Advances in Neuroblastoma Research and the American Society of Clinical Oncology; all from 2010 up to and including 2015. We scanned the International Standard Randomized Controlled Trial Number (ISRCTN) Register (www.isrctn.com) and the National Institutes of Health Register for ongoing trials (www.clinicaltrials.gov) on 13 April 2016.

SELECTION CRITERIA

Randomised controlled trials (RCTs), controlled clinical trials (CCTs), non-randomised single-arm trials with historical controls and cohort studies examining the efficacy of 131I-MIBG therapy in 10 or more patients with newly diagnosed HR NBL.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We identified two eligible cohort studies including 60 children with newly diagnosed HR NBL. All studies had methodological limitations, with regard to both internal (risk of bias) and external validity. As the studies were not comparable with regard to prognostic factors and treatment (and often used different outcome definitions), pooling of results was not possible. In one study, the objective response rate (ORR) was 73% after surgery; the median overall survival was 15 months (95% confidence interval (CI) 7 to 23); five-year overall survival was 14.6%; median event-free survival was 10 months (95% CI 7 to 13); and five-year event-free survival was 12.2%. In the other study, the ORR was 56% after myeloablative therapy and autologous stem cell transplantation; 10-year overall survival was 6.25%; and event-free survival was not reported. With regard to short-term adverse effects, one study showed a prevalence of 2% (95% CI 0% to 13%; best-case scenario) for death due to myelosuppression. After the first cycle of 131I-MIBG therapy in one study, platelet toxicity occurred in 38% (95% CI 18% to 61%), neutrophil toxicity in 50% (95% CI 28% to 72%) and haemoglobin toxicity in 69% (95% CI 44% to 86%); after the second cycle this was 60% (95% CI 36% to 80%) for platelets and neutrophils and 53% (95% CI 30% to 75%) for haemoglobin. In one study, the prevalence of hepatic toxicity during or within four weeks after last the MIBG treatment was 0% (95% CI 0% to 9%; best-case scenario). Neither study reported cardiovascular toxicity and sialoadenitis. One study assessed long-term adverse events in some of the children: there was elevated plasma thyroid-stimulating hormone in 45% (95% CI 27% to 65%) of children; in all children, free T4 was within the age-related normal range (0%, 95% CI 0% to 15%). There were no secondary malignancies observed (0%, 95% CI 0% to 9%), but only five children survived more than four years.

AUTHORS' CONCLUSIONS

We identified no RCTs or CCTs comparing the effectiveness of treatment including 131I-MIBG therapy versus treatment not including 131I-MIBG therapy in patients with newly diagnosed HR NBL. We found two small observational studies including chilren. They had high risk of bias, and not all relevant outcome results were available. Based on the currently available evidence, we cannot make recommendations for the use of 131I-MIBG therapy in patients with newly diagnosed HR NBL in clinical practice. More high-quality research is needed.

Impact of Whole-Body Radiation Dose on Response and Toxicity in Patients With Neuroblastoma After Therapy With 131 I-Metaiodobenzylguanidine (MIBG)

BACKGROUND

(131) I-metaiodobenzylguanidine ((131) I-MIBG) is a targeted radiopharmaceutical for patients with neuroblastoma. Despite its tumor-specific uptake, the treatment with (131) I-MIBG results in whole-body radiation exposure. Our aim was to correlate whole-body radiation dose (WBD) from (131) I-MIBG with tumor response, toxicities, and other clinical factors.

METHODS

This retrospective cohort analysis included 213 patients with high-risk neuroblastoma treated with (131) I-MIBG at UCSF Benioff Children's Hospital between 1996 and 2015. WBD was determined from radiation exposure rate measurements. The relationship between WBD ordered tertiles and variables were analyzed using Cochran-Mantel-Haenszel test of trend, Kruskal-Wallis test, and one-way analysis of variance. Correlation between WBD and continuous variables was analyzed using Pearson correlation and Spearman rank correlation.

RESULTS

WBD correlated with (131) I-MIBG administered activity, particularly with (131) I-MIBG per kilogram (P < 0.001). Overall response rate did not differ significantly among the three tertiles of WBD. Correlation between response by relative Curie score and WBD was of borderline significance, with patients receiving a lower WBD showing greater reduction in osteomedullary metastases by Curie score (rs = 0.16, P = 0.049). There were no significant ordered trends among tertiles in any toxicity measures (grade 4 neutropenia, thrombocytopenia < 20,000/μl, and grade > 1 hypothyroidism).

CONCLUSIONS

This study showed that (131) I-MIBG activity per kilogram correlates with WBD and suggests that activity per kilogram will predict WBD in most patients. Within the range of activities prescribed, there was no correlation between WBD and either response or toxicity. Future studies should evaluate tumor dosimetry, rather than just WBD, as a tool for predicting response following therapy with (131) I-MIBG.

Iodine-131 metaiodobenzylguanidine therapy for neuroblastoma: reports so far and future perspective

Neuroblastoma, which derives from neural crest, is the most common extracranial solid cancer in childhood. The tumors express the norepinephrine (NE) transporters on their cell membrane and take in metaiodobenzylguanidine (MIBG) via a NE transporter. Since iodine-131 (I-131) MIBG therapy was firstly reported, many trails of MIBG therapy in patients with neuroblastoma were performed. Though monotherapy with a low dose of I-131 MIBG could achieve high-probability pain reduction, the objective response was poor. In contrast, more than 12 mCi/kg I-131 MIBG administrations with or without hematopoietic cell transplantation (HCT) obtain relatively good responses in patients with refractory or relapsed neuroblastoma. The combination therapy with I-131 MIBG and other modalities such as nonmyeloablative chemotherapy and myeloablative chemotherapy with HCT improved the therapeutic response in patients with refractory or relapsed neuroblastoma. In addition, I-131 MIBG therapy incorporated in the induction therapy was proved to be feasible in patients with newly diagnosed neuroblastoma. To expand more the use of MIBG therapy for neuroblastoma, further studies will be needed especially in the use at an earlier stage from diagnosis, in the use with other radionuclide formations of MIBG, and in combined use with other therapeutic agents.

Long-term outcome and toxicity after dose-intensified treatment with 131I-MIBG for advanced metastatic carcinoid tumors

Reported experience with systemic (131)I-metaiodobenzylguanidine ((131)I-MIBG) therapy of neuroendocrine tumors comprises different dosing schemes. The aim of this study was to assess the long-term outcome and toxicity of treatment with 11.1 GBq (300 mCi) of (131)I-MIBG per cycle.

METHODS

We performed a retrospective review of 31 patients with advanced metastatic neuroendocrine tumors (20 with carcinoid tumors and 11 with other tumors) treated with (131)I-MIBG. Treatment outcome was analyzed for patients with carcinoid tumors (the most common tumors in this study), and toxicity was analyzed for the entire patient cohort (n = 31). Treatment comprised 11.1 GBq (300 mCi) per course and minimum intervals of 3 mo. The radiographic response was classified according to modified Response Evaluation Criteria in Solid Tumors. Toxicity was determined according to Common Terminology Criteria for Adverse Events (version 3.0) for all laboratory data at regular follow-up visits and during outpatient care, including complete blood counts and hepatic and renal function tests. Survival analysis was performed with the Kaplan-Meier curve method (log rank test; P < 0.05).

RESULTS

The radiographic responses in patients with carcinoid tumors comprised a minor response in 2 patients (10%), stable disease in 16 patients (80%; median time to progression, 34 mo), and progressive disease in 2 patients (10%). The symptomatic responses in patients with functioning carcinoid tumors comprised complete resolution in 3 of the 11 evaluable symptomatic patients (27%), partial resolution in 6 patients (55%), and no significant change in 11 patients. The median overall survival in patients with carcinoid tumors was 47 mo (95% confidence interval, 32-62), and the median progression-free survival was 34 mo (95% confidence interval, 13-55). Relevant treatment toxicities were confined to transient myelosuppression of grade 3 or 4 in 15.3% (leukopenia) and 7.6% (thrombocytopenia) of applied cycles and a suspected late adverse event (3% of patients), myelodysplastic syndrome, after a cumulative administered activity of 66.6 GBq. The most frequent nonhematologic side effect was mild nausea (grade 1 or 2), which was observed in 28% of administered cycles. No hepatic or renal toxicities were noted.

CONCLUSION

Dose-intensified treatment with (131)I-MIBG at a fixed dose of 11.1 GBq (300 mCi) per cycle is safe and offers effective palliation of symptoms and disease stabilization in patients with advanced carcinoid tumors. The favorable survival and limited toxicity suggest that high cycle activities are suitable and that this modality may be used for targeted carcinoid treatment--either as an alternative or as an adjunct to other existing therapeutic options.

Acute changes in blood pressure in patients with neuroblastoma treated with ¹³¹I-metaiodobenzylguanidine (MIBG)

BACKGROUND

Iodine-131-metaiodobenzylguanidine ((131)I-MIBG) provides targeted radiotherapy for children with neuroblastoma. The aim of our study was to evaluate systematically the acute effects of (131)I-MIBG on blood pressure in patients with neuroblastoma and to identify possible predictors of hypertension.

PROCEDURE

We conducted a retrospective chart review of neuroblastoma patients who were treated with (131)I-MIBG between January 1, 1999 and June 1, 2012 at the University of California, San Francisco. Clinical data for 172 patients with neuroblastoma, receiving 218 administrations of (131)I-MIBG, were collected. The primary endpoint was development of systolic blood pressure above the 95th percentile for age. Logistic regression with generalized estimating equations to account for multiple administrations in some subjects was used to identify bivariate and multivariate predictors of hypertension.

RESULTS

Of the 218 administrations of (131)I-MIBG, 112 (51.3%) were associated with at least one episode of systolic hypertension during or after the (131)I-MIBG infusion. The majority of these acute elevations in blood pressure resolved within 48 hours of the infusion. Only six administrations in five patients required nifedipine administration to lower blood pressure. Younger age (P = 0.012), lower eGFR (P = 0.047), and elevated blood pressure measurements immediately before infusion began (P = 0.010) were all independently associated with risk of treatment-associated hypertension.

CONCLUSIONS

Acute elevations in blood pressure are common after therapeutic doses of (131) I-MIBG. Elevations in blood pressure typically occur only within the first 48 hours after (131)I-MIBG administration. Blood pressure monitoring during this period of risk is recommended.

Toxicity of upfront ¹³¹I-metaiodobenzylguanidine (¹³¹I-MIBG) therapy in newly diagnosed neuroblastoma patients: a retrospective analysis

Purpose

In the treatment of patients with high-risk neuroblastoma, different doses of ¹³¹I-metaiodobenzylguanidine (¹³¹I-MIBG) are administered at different time points during treatment. Toxicity, mainly haematological (thrombocytopenia), from ¹³¹I-MIBG therapy is known to occur in extensively chemotherapy pretreated neuroblastoma patients. Up to now, acute toxicity from ¹³¹I-MIBG as initial treatment has never been studied in a large cohort. The aim of this retrospective study was to document acute toxicity related to upfront ¹³¹I-MIBG.

Methods

All neuroblastoma patients (stages 1–4 and 4S) treated upfront with ¹³¹I-MIBG at the Emma Children’s Hospital, Academic Medical Centre (1992 – 2008) were included in this retrospective analysis. The acute toxicity (during therapy) and short-term toxicity (1st month following therapy) of the first two ¹³¹I-MIBG therapies were studied.

Results

Of 66 patients (34 boys, 32 girls; median age 2.2 years, range 0.1 – 9.4 years), 49 had stage 4 disease, 5 stage 4S, 6 stage 3, 1 stage 2 and 5 stage 1. The median first dose was 441 MBq/kg (range 157 – 804 MBq/kg). The median second dose was 328 MBq/kg (range 113 – 727 MBq/kg). The most frequently observed symptoms were nausea and vomiting (21 %, maximum grade II). The main toxicity was grade IV haematological, occurring only in stage 4 patients, after the first and second ¹³¹I-MIBG therapies: anaemia (5 % and 4 %, respectively), leucocytopenia (3 % and 4 %) and thrombocytopenia (2 % and 4 %). No stem cell rescue was needed.

Conclusion

The main acute toxicity observed was haematological followed by nausea and vomiting. One patient developed posterior reversible encephalopathy syndrome during ¹³¹I-MIBG therapy, possibly related to ¹³¹I-MIBG. We consider ¹³¹I-MIBG therapy to be a safe treatment modality.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-013-2510-z) contains supplementary material, which is available to authorized users.