131I-MIBG followed by consolidation with busulfan, melphalan and autologous stem cell transplantation for refractory neuroblastoma

Diagnosing and Grading of Sinusoidal Obstructive Syndrome after Hematopoietic Stem Cell Transplant of Children, Adolescent and Young Adults treated in a Pediatric Institution with Pediatric Protocols

Sinusoidal obstructive syndrome (SOS), or veno-occlusive disease, of the liver has been recognized as a complex, life-threatening complication in the posthematopoietic stem cell transplant (HSCT) setting. The diagnostic criteria for SOS have evolved over the last several decades with a greater understanding of the underlying pathophysiology, with 2 recent diagnostic criteria introduced in 2018 (European Society of Bone Marrow Transplant [EBMT] criteria) and 2020 (Cairo criteria). We sought out to evaluate the performance characteristics in diagnosing and grading SOS in pediatric patients of the 4 different diagnostic criteria (Baltimore, Modified Seattle, EBMT, and Cairo) and severity grading systems (defined by the EBMT and Cairo criteria). Retrospective chart review of children, adolescent, and young adults who underwent conditioned autologous and allogeneic HSCT between 2017 and 2021 at a single pediatric institution. A total of 250 consecutive patients underwent at least 1 HSCT at UCSF Benioff Children's Hospital San Francisco for a total of 307 HSCT. The day 100 cumulative incidence of SOS was 12.1%, 21.1%, 28.4%, and 28.4% per the Baltimore, Modified Seattle, EBMT, and Cairo criteria, respectively (P < .001). We found that patients diagnosed with grade ≥4 SOS per the Cairo criteria were more likely to be admitted to the Pediatric Intensive Care Unit (92% versus 58%, P = .035) and intubated (85% versus 32%, P = .002) than those diagnosed with grade ≥4 per EBMT criteria. Age <3 years-old (HR 1.76, 95% [1.04 to 2.98], P = .036), an abnormal body mass index (HR 1.69, 95% [1.06 to 2.68], P = .027), and high-risk patients per our institutional guidelines (HR 1.68, 95% [1.02 to 2.76], P = .041) were significantly associated with SOS per the Cairo criteria. We demonstrate that age <3 years, abnormal body mass index, and other high-risk criteria associate strongly with subsequent SOS development. Patients with moderate to severe SOS based on Cairo severity grading system may correlate better with clinical course based on ICU admissions and intubations when compared to the EBMT severity grading system.

The Impact of 131I-Metaiodobenzylguanidine as a Conditioning Regimen of Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for High-Risk Neuroblastoma

BACKGROUND

The optimal conditioning regimen of tandem high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) for high-risk neuroblastoma (HR-NBL) has not been established. The efficacy of 131I-MIBG therapy is under exploration in newly diagnosed HR-NBL patients. Here, we compared the outcomes of tandem HDC/ASCT between the 131I-MIBG combination and non-MIBG groups.

METHODS

We retrospectively analyzed the clinical data of 33 HR-NBL patients who underwent tandem HDC/ASCT between 2007 and 2021 at the Seoul National University Children's Hospital.

RESULTS

The median age at diagnosis was 3.6 years. 131I-MIBG was administered to 13 (39.4%) of the patients. Thirty patients (90.9%) received maintenance therapy after tandem HDC/ASCT, twenty-two were treated with isotretinoin ± interleukin-2, and eight received salvage chemotherapy. The five-year overall survival (OS) and event-free survival (EFS) rates of all patients were 80.4% and 69.4%, respectively. Comparing the 131I-MIBG combined group and other groups, the five-year OS rates were 82.1% and 79.7% (p = 0.655), and the five-year EFS rates were 69.2% and 69.6% (p = 0.922), respectively. Among the adverse effects of grade 3 or 4, the incidence of liver enzyme elevation was significantly higher in the non-131I-MIBG group.

CONCLUSIONS

Although tandem HDC/ASCT showed promising outcomes, the 131I-MIBG combination did not improve survival rates.

Phase II study of 131 I-metaiodobenzylguanidine with 5 days of topotecan for refractory or relapsed neuroblastoma: Results of the French study MIITOP

PURPOSE

We report the results of the French multicentric phase II study MIITOP (NCT00960739), which evaluated tandem infusions of 131 I-metaiodobenzylguanidine (mIBG) and topotecan in children with relapsed/refractory metastatic neuroblastoma (NBL).

METHODS

Patients received 131 I-mIBG on day 1, with intravenous topotecan daily on days 1-5. A second activity of 131 I-mIBG was given on day 21 to deliver a whole-body radiation dose of 4 Gy, combined with a second course of topotecan on days 21-25. Peripheral blood stem cells were infused on day 31.

RESULTS

Thirty patients were enrolled from November 2008 to June 2015. Median age at diagnosis was 5.5 years (2-20). Twenty-one had very high-risk NBL (VHR-NBL), that is, stage 4 NBL at diagnosis or at relapse, with insufficient response (i.e., less than a partial response of metastases and more than three mIBG spots) after induction chemotherapy; nine had progressive metastatic relapse. Median Curie score at inclusion was 6 (1-26). Median number of prior lines of treatment was 3 (1-7). Objective response rate was 13% (95% confidence interval [CI]: 4-31) for the whole population, 19% for VHR-NBL, and 0% for progressive relapses. Immediate tolerance was good, with nonhematologic toxicity limited to grade-2 nausea/vomiting in eight patients. Two-year event-free survival was 17% (95% CI: 6-32). Among the 16 patients with VHR-NBL who had not received prior myeloablative busulfan-melphalan consolidation, 13 had at least stable disease after MIITOP; 11 subsequently received busulfan-melphalan; four of them were alive (median follow-up: 7 years).

CONCLUSION

MIITOP showed acceptable tolerability in this heavily pretreated population and encouraging survival rates in VHR-NBL when followed by busulfan-melphalan.

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.

Clinical Advances and Perspectives in Targeted Radionuclide Therapy

Targeted radionuclide therapy has become increasingly prominent as a nuclear medicine subspecialty. For many decades, treatment with radionuclides has been mainly restricted to the use of iodine-131 in thyroid disorders. Currently, radiopharmaceuticals, consisting of a radionuclide coupled to a vector that binds to a desired biological target with high specificity, are being developed. The objective is to be as selective as possible at the tumor level, while limiting the dose received at the healthy tissue level. In recent years, a better understanding of molecular mechanisms of cancer, as well as the appearance of innovative targeting agents (antibodies, peptides, and small molecules) and the availability of new radioisotopes, have enabled considerable advances in the field of vectorized internal radiotherapy with a better therapeutic efficacy, radiation safety and personalized treatments. For instance, targeting the tumor microenvironment, instead of the cancer cells, now appears particularly attractive. Several radiopharmaceuticals for therapeutic targeting have shown clinical value in several types of tumors and have been or will soon be approved and authorized for clinical use. Following their clinical and commercial success, research in that domain is particularly growing, with the clinical pipeline appearing as a promising target. This review aims to provide an overview of current research on targeting radionuclide therapy.

Current and upcoming radionuclide therapies in the direction of precision oncology: A narrative review

As new molecular tracers are identified to target specific receptors, tissue, and tumor types, opportunities arise for the development of both diagnostic tracers and their therapeutic counterparts, termed "theranostics." While diagnostic tracers utilize positron emitters or gamma-emitting radionuclides, their theranostic counterparts are typically bound to beta and alpha emitters, which can deliver specific and localized radiation to targets with minimal collateral damage to uninvolved surrounding structures. This is an exciting time in molecular imaging and therapy and a step towards personalized and precise medicine in which patients who were either without treatment options or not candidates for other therapies now have expanded options, with tangible data showing improved outcomes. This manuscript explores the current state of theranostics, providing background, treatment specifics, and toxicities, and discusses future potential trends.

Personalized dosimetry for a deeper understanding of metastatic response to high activity 131I-mIBG therapy in high risk relapsed refractory neuroblastoma

Background

Dosimetry in molecular radiotherapy for personalized treatment is assuming a central role in clinical management of aggressive/relapsed tumors. Relapsed/refractory metastatic high-risk neuroblastoma (rrmHR-NBL) has a poor prognosis and high-activity ¹³¹I-mIBG therapy could represent a promising strategy. The primary aim of this case series study was to report the absorbed doses to whole-body (D_WB ), red marrow (D_RM ) and lesions (D_Lesion ). A secondary aim was to correlate D_Lesion values to clinical outcome.

Methods

Fourteen patients affected by rrmHR-NBL were treated with high-activity ¹³¹I-mIBG therapy (two administrations separated by 15 days). The first administration was weight-based whereas the second one was dosimetry-based (achieving D_WB equals to 4 Gy). In all patients D_WB and D_RM was assessed; 9/14 patients were selected for D_Lesion evaluation using planar dosimetric approach (13 lesions evaluated). Treatment response was classified as progressive and stable disease (PD and SD), partial and complete response (PR and CR) according to the International Neuroblastoma Response Criteria. Patients were divided into two groups: Responder (CR, PR, SD) and Non-Responder (PD), correlating treatment response to D_Lesion value.

Results

The cumulative D_WB , D_RM and D_Lesion ranged from (1.5; 4.5), (1.0; 2.6) and (44.2; 585.8) Gy. A linear correlation between D_WB and D_RM and a power law correlation between the absorbed dose to WB normalized for administered activity and the mass of the patient were observed. After treatment 3, 2, 4 and 5 patients showed CR, PR, SD and PD respectively, showing a correlation between D_Lesion and the two response group.

Conclusions

Our experience demonstrated feasibility of high activity therapy of ¹³¹I-mIBG in rrmHR-NBL children as two administration intensive strategy. Dosimetric approach allowed a tailored high dose treatment maximizing the benefits of radionuclide therapy for pediatric patients while maintaining a safety profile. The assesment of D_Lesion contributed to have a deeper understaning of metabolic treatment effects.

Tandem high-dose 131I-MIBG therapy supported by dosimetry in pediatric patients with relapsed-refractory high-risk neuroblastoma: the Bambino Gesu' Children's Hospital experience

OBJECTIVE

131I-meta-iodobenzylguanidine (131I-MIBG) combined with myeloablative chemotherapy represents an effective treatment in children affected by relapsed/refractory neuroblastoma (NBL) for disease palliation and in improving progression-free survival. The aim of our study is to evaluate the feasibility, safety and efficacy of tandem 131I-MIBG followed by high-dose chemotherapy with Melphalan.

METHODS

Thirteen patients (age range: 3-17 years) affected by relapsed/refractory NB, previously treated according to standard procedures, were included in the study. Each treatment cycle included two administrations of 131I-MIBG (with a dosimetric approach) followed by a single dose of Melphalan with peripheral blood stem cell rescue.

RESULTS

At the end of the treatment, ten patients experienced grade 4 neutropenia, two grade 3 and one patient grade 2, three patients presented febrile neutropenia and all needed RBC and platelets transfusions; one patient presented grade 4 mucositis, four grade 3 and one patient grade 2 mucositis. One patient showed progressive disease, eight patients showed stable disease and four patients showed partial response.

CONCLUSION

High-dose 131I-MIBG therapy combined with chemotherapy represent a well-tolerated and effective modality of treatment in heavily pretreated patients affected by relapsed/refractory NBL. However, further studies, including a wider cohort of patients, are needed.

Phase I/II clinical trial of high-dose [131I] meta-iodobenzylguanidine therapy for high-risk neuroblastoma preceding single myeloablative chemotherapy and haematopoietic stem cell transplantation

PURPOSE

Paediatric high-risk neuroblastoma has poor prognosis despite modern multimodality therapy. This phase I/II study aimed to determine the safety, dose-limiting toxicity (DLT), and efficacy of high-dose ¹³¹I-meta-iodobenzylguanidine (¹³¹I-mIBG) therapy combined with single high-dose chemotherapy (HDC) and haematopoietic stem cell transplantation (HSCT) in high-risk neuroblastoma in Japan.

METHODS

Patients received 666 MBq/kg of ¹³¹I-mIBG and single HDC and HSCT from autologous or allogeneic stem cell sources. The primary endpoint was DLT defined as adverse events associated with ¹³¹I-mIBG treatment posing a significant obstacle to subsequent HDC. The secondary endpoints were adverse events/reactions, haematopoietic stem cell engraftment and responses according to the Response Evaluation Criteria in Solid Tumours version 1.1 (RECIST 1.1) and ¹²³I-mIBG scintigraphy. Response was evaluated after engraftment.

RESULTS

We enrolled eight patients with high-risk neuroblastoma (six females; six newly diagnosed and two relapsed high-risk neuroblastoma; median age, 4 years; range, 1-10 years). Although all patients had adverse events/reactions after high-dose ¹³¹I-mIBG therapy, we found no DLT. Adverse events and reactions were observed in 100% and 25% patients during single HDC and 100% and 12.5% patients during HSCT, respectively. No Grade 4 complications except myelosuppression occurred during single HDC and HSCT. The response rate according to RECIST 1.1 was observed in 87.5% (7/8) in stable disease and 12.5% (1/8) were not evaluated. Scintigraphic response occurred in 62.5% (5/8) and 37.5% (3/8) patients in complete response and stable disease, respectively.

CONCLUSION

¹³¹I-mIBG therapy with 666 MBq/kg followed by single HDC and autologous or allogeneic SCT is safe and efficacious in patients with high-risk neuroblastoma and has no DLT.

TRIAL REGISTRATION NUMBER

jRCTs041180030.

NAME OF REGISTRY

Feasibility of high-dose iodine-131-meta-iodobenzylguanidine therapy for high-risk neuroblastoma preceding myeloablative chemotherapy and haematopoietic stem cell transplantation (High-dose iodine-131-meta-iodobenzylguanidine therapy for high-risk neuroblastoma). URL OF REGISTRY: https://jrct.niph.go.jp/en-latest-detail/jRCTs041180030 .

DATE OF ENROLMENT OF THE FIRST PARTICIPANT TO THE TRIAL

12/01/2018.

A safety and feasibility trial of 131 I-MIBG in newly diagnosed high-risk neuroblastoma: A Children's Oncology Group study

INTRODUCTION

¹³¹ I-meta-iodobenzylguanidine (¹³¹ I-MIBG) is effective in relapsed neuroblastoma. The Children's Oncology Group (COG) conducted a pilot study (NCT01175356) to assess tolerability and feasibility of induction chemotherapy followed by ¹³¹ I^- MIBG therapy and myeloablative busulfan/melphalan (Bu/Mel) in patients with newly diagnosed high-risk neuroblastoma.

METHODS

Patients with MIBG-avid high-risk neuroblastoma were eligible. After the first two patients to receive protocol therapy developed severe sinusoidal obstruction syndrome (SOS), the trial was re-designed to include an ¹³¹ I-MIBG dose escalation (12, 15, and 18 mCi/kg), with a required 10-week gap before Bu/Mel administration. Patients who completed induction chemotherapy were evaluable for assessment of ¹³¹ I-MIBG feasibility; those who completed ¹³¹ I-MIBG therapy were evaluable for assessment of ¹³¹ I-MIBG + Bu/Mel feasibility.

RESULTS

Fifty-nine of 68 patients (86.8%) who completed induction chemotherapy received ¹³¹ I-MIBG. Thirty-seven of 45 patients (82.2%) evaluable for ¹³¹ I-MIBG + Bu/Mel received this combination. Among those who received ¹³¹ I-MIBG after revision of the study design, one patient per dose level developed severe SOS. Rates of moderate to severe SOS at 12, 15, and 18 mCi/kg were 33.3%, 23.5%, and 25.0%, respectively. There was one toxic death. The ¹³¹ I-MIBG and ¹³¹ I-MIBG+Bu/Mel feasibility rates at the 15 mCi/kg dose level designated for further study were 96.7% (95% CI: 83.3%-99.4%) and 81.0% (95% CI: 60.0%-92.3%).

CONCLUSION

This pilot trial demonstrated feasibility and tolerability of administering ¹³¹ I-MIBG followed by myeloablative therapy with Bu/Mel to newly diagnosed children with high-risk neuroblastoma in a cooperative group setting, laying the groundwork for a cooperative randomized trial (NCT03126916) testing the addition of ¹³¹ I-MIBG during induction therapy.

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.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Management of Metastatic and/or Unresectable Pheochromocytoma and Paraganglioma

ABSTRACT

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management and surveillance of metastatic and unresectable pheochromocytoma and paraganglioma held on October 2 and 3, 2019. The panelists consisted of endocrinologists, medical oncologists, surgeons, radiologists/nuclear medicine physicians, nephrologists, pathologists, and radiation oncologists. The panelists performed a literature review on a series of questions regarding the medical management of metastatic and unresectable pheochromocytoma and paraganglioma as well as questions regarding surveillance after resection. The panelists voted on controversial topics, and final recommendations were sent to all panel members for final approval.

131 I-Meta-iodobenzylguanidine followed by busulfan and melphalan and autologous stem cell rescue in high-risk neuroblastoma

INTRODUCTION

Despite the progress in current treatments, the event-free survival of high-risk neuroblastoma (HR-NB) patients does not exceed 40%-50%, and the prognosis of refractory or relapsed patients is poor, still representing a challenge for pediatric oncologist. Therapeutic Iodine-131 meta-iodobenzylguanidine (Th-¹³¹ I-MIBG) is a recognized safe and potentially effective treatment for NB.

MATERIALS

This retrospective study reports the outcomes of 28 MIBG-avid NB patients with advanced disease either refractory or relapsed, which was undertaken from 1996 to 2014. Th-¹³¹ I-MIBG was administered shortly before (median: 17 days) high-dose chemotherapy with busulfan and melphalan (HD-BuMel) and autologous stem cell rescue (ASCR) at the Gaslini Institute in Genoa, with the aim of analyzing the feasibility, safety, and efficacy of this approach.

RESULTS

Engraftment occurred in all patients after a median of 14 (11-29) and 30 days (13-80) from ASCR for neutrophils and platelets, respectively. No treatment-related deaths were observed. The main high-grade (3-4) toxicity observed was oral and gastrointestinal mucositis in 78.6% and 7.1% of patients, respectively, whereas high-grade hepatic toxicity was observed in 10.7%. Two patients developed veno-occlusive-disease (7.1%), completely responsive to defibrotide. Hypothyroidism was the main late complication that occurred in nine patients (31.1%). After Th-¹³¹ MIBG and HD-BuMel, 19 patients (67.8%) showed an improvement in disease status. Over a median follow-up of 15.9 years, the three-year and five-year overall survival (OS) probabilities were 53% (CI 0.33-0.69) and 41% (CI 0.22-0.59), and the three-year and five-year rates of cumulative risk of progression/relapse were 64% (CI 0.47-0.81) and 73% (CI 0.55-0.88), respectively. MYCN amplification emerged as the only risk factor significantly associated with OS (HR, 3.58;P = 0.041).

CONCLUSION

Th-¹³¹ I-MIBG administered shortly before HD-BuMel is a safe and effective regimen for patients with advanced MIBG-avid NB. These patients should be managed in centers with proven expertise.

Iodine-131 metaiodobenzylguanidine (131I-mIBG) treatment in relapsed/refractory neuroblastoma

BACKGROUND

I-meta-iodo-benzylguanidine (I-mIBG) therapy has been used in treatment of for advanced neuroblastoma for many years with promising results. There are several studies regarding predictors and outcomes of I-mIBG therapies in relapsed/refractory neuroblastoma patients.

OBJECTIVE

To identify the predictors and outcomes of I-mIBG treatment in relapsed/refractory neuroblastoma.

METHODS

This study was a retrospective review of 22 patients with high risk stage IV relapsed/refractory neuroblastoma who received at least one cycle of I-mIBG therapy. Patient' characteristics, hematologic toxicity, scintigraphic semi-quantitative scoring, and overall survival were recorded. Factors predicting survival were analyzed.

RESULTS

Twenty-two patients (50% male) with mean age of 3.7 years (4.8 months to 8.3 years) received I-mIBG therapies at an average of 3.8 and mean dose of 136 mCi (5032 MBq) per treatment. Most common acute hematologic toxicity was thrombocytopenia. Overall 5-year survival rate was 37% (95% confidence interval: 16.3-58.0) and median survival time was 2.8 year (95% confidence interval: 1.38-6.34). Patients with rising Curie score of ≥25% upon the second therapy were major determinants of overall survival with poorer response to treatment. At least three treatments of I-mIBG were needed to identify some degrees of survival prolongation (crude hazard ratio: P-value = 0.003). Age, sex, metastatic status, and baseline Curie scoring system were good predictors associated with survival. Seven patients (32%) demonstrated objective responses.

CONCLUSION

Despite multimodality therapy, high risk neuroblastoma had a propensity of treatment failure in terms of relapsed or refractory, with some objective responses after I-mIBG treatments. The declined or non-rising Curie score upon second post-treatment total body scan was an important predictor of survival and aided a decision whether or not to proceed with bone marrow transplantation.

Upfront consolidation treatment with 131I-mIbG followed by myeloablative chemotherapy and hematopoietic stem cell transplantation in high-risk neuroblastoma

Importance

¹³¹I‐metaiodobenzylguanidine (¹³¹I‐mIBG) has a significant targeted antitumor effect for neuroblastoma. However, currently there is a paucity of data for the use of ¹³¹I‐mIBG as a “front‐line” therapeutic agent in those patients with newly diagnosed high‐risk neuroblastoma as part of the conditioning regimen for myeloablative chemotherapy (MAC).

Objective

To evaluate the feasibility of upfront consolidation treatment with ¹³¹I‐mIBG plus MAC and hematopoietic stem cell transplantation (HSCT) in high‐risk neuroblastoma patients.

Methods

A retrospective, single‐center study was conducted from 2003–2019 on newly diagnosed high‐risk neuroblastoma patients without progressive disease (PD) after the completion of induction therapy. They received ¹³¹I‐mIBG infusion and MAC followed by HSCT.

Results

A total of 24 high‐risk neuroblastoma patients were enrolled with a median age of 3.0 years at diagnosis. After receiving this sequential consolidation treatment, 3 of 13 patients who were in partial response (PR) before ¹³¹I‐mIBG treatment achieved either complete response (CR) (n = 1) or very good partial response (VGPR) (n = 2) after HSCT. With a median follow‐up duration of 13.0 months after ¹³¹I‐mIBG therapy, the 5‐year event‐free survival and overall survival rates estimated were 29% and 38% for the entire cohort, and 53% and 67% for the patients who were in CR/VGPR at the time of ¹³¹I‐mIBG treatment.

Interpretation

Upfront consolidation treatment with ¹³¹I‐mIBG plus MAC and HSCT is feasible and tolerable in high‐risk neuroblastoma patients, however the survival benefit of this ¹³¹I‐mIBG regimen is only observed in the patients who were in CR/VGPR at the time of ¹³¹I‐mIBG treatment.

Neutron-activated theranostic radionuclides for nuclear medicine

Theranostics in nuclear medicine refers to personalized patient management that involves targeted therapy and diagnostic imaging using a single or combination of radionuclide (s). The radionuclides emit both alpha (α) or beta (β-) particles and gamma (γ) rays which possess therapeutic and diagnostic capabilities, respectively. However, the production of these radionuclides often faces difficulties due to high cost, complexity of preparation methods and that the products are often sourced far from the healthcare facilities, hence losing activity due to radioactive decay during transportation. Subject to the availability of a nuclear reactor within an accessible distance from healthcare facilities, neutron activation is the most practical and cost-effective route to produce radionuclides suitable for theranostic purposes. Holmium-166 (166Ho), Lutetium-177 (177Lu), Rhenium-186 (186Re), Rhenium-188 (188Re) and Samarium-153 (153Sm) are some of the most promising neutron-activated radionuclides that are currently in clinical practice and undergoing clinical research for theranostic applications. The aim of this paper is to review the physical characteristics, current clinical applications and future prospects of these neutron activated radionuclides in theranostics. The production, physical properties, validated clinical applications and clinical studies for each neutron-activated radionuclide suitable for theranostic use in nuclear medicine are reviewed in this paper.

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

This study was performed to evaluate the safety and effectiveness of tandem HDCT/ASCT combined with targeted radiotherapy using ¹³¹ I-MIBG for high-risk neuroblastoma. Patients with high-risk neuroblastoma were treated with 8 to 10 cycles of induction chemotherapy before tandem HDCT/ASCT. Patients received ¹³¹ I-MIBG treatment before the second HDCT/ASCT. Local radiotherapy and maintenance therapy were performed after tandem HDCT/ASCT. Between 2012 and 2016, 19 patients were diagnosed with high-risk neuroblastoma in our institution and 18 of them received tandem HDCT/ASCT combined with ¹³¹ I-MIBG therapy. For the first HDCT/ASCT regimen, 12 patients received busulfan/melphalan and six patients received melphalan/etoposide/carboplatin. The second HDCT included ThioCy. The median dose of ¹³¹ I-MIBG was 17.2 mCi/kg for the first eight patients, while 12 patients in the latter period of the study received reduced dose of 10.7 mCi/kg. The 5-year OS and EFS rates were 79% and 61%, respectively, for all 19 patients with high-risk neuroblastoma, and 83% and 64%, respectively, for 18 patients who completed tandem HDCT/ASCT combined with ¹³¹ I-MIBG therapy. Six patients experienced disease relapse and five patients died. Treatment-related mortality was not observed. Among 15 evaluable patients, 11 patients (73%) developed hypothyroidism, six patients (40%) had CKD, and six patients (40%) had growth failure. Hypothyroidism and growth failure were less frequent in patients who received reduced doses of ¹³¹ I-MIBG therapy. Tandem HDCT/ASCT combined with HD ¹³¹ I-MIBG therapy could be feasible for patients with high-risk neuroblastoma with acceptable toxicity profiles and favorable outcomes.

Update on neuroblastoma

Neuroblastoma is an embryonic cancer arising from neural crest stem cells. This cancer is the most common malignancy in infants and the most common extracranial solid tumor in children. The clinical course may be highly variable with the possibility of spontaneous regression in the youngest patients and increased risk of aggressive disease in older children. Clinical heterogeneity is a consequence of the diverse biologic characteristics that determine patient risk and survival. This review will focus on current progress in neuroblastoma staging, risk stratification, and treatment strategies based on advancing knowledge in tumor biology and genetic characterization. TYPE OF STUDY: Review article. LEVEL OF EVIDENCE: Level II.

Feasibility of Busulfan Melphalan and Stem Cell Rescue After 131I-MIBG and Topotecan Therapy for Refractory or Relapsed Metastatic Neuroblastoma: The French Experience

High-risk neuroblastoma is characterized by poor long-term survival, especially for very high-risk (VHR) patients (poor response of metastases after induction therapy). The benefits of a tandem high-dose therapy and hematologic stem cell reinfusion (HSCR) have been shown in these patients. Further dose escalation will be limited by toxicity. It is thus important to evaluate the efficacy and tolerability of the addition of new agents such as I-MIBG (131Iode metaiodobenzylguanidine) to be combined with high-dose therapy in the consolidation phase. We report the feasibility of busulfan/melphalan (BuMel) after I-MIBG therapy with HSCR in patients with refractory or relapsed metastatic neuroblastoma. From November 2008 to March 2015, 9 patients received BuMel after I-MIBG therapy and topotecan. The main toxicity was digestive with only 1 patient developing grade 4 sinusoidal obstructive syndrome. Seven patients are alive at a median follow-up of 25 months. Among them, 2 are in ongoing complete remission and 1 in ongoing stable disease. These results suggest that BuMel with HSCR can be administered safely 2 months after I-MIBG therapy associated with topotecan for VHR patients. This strategy will be compared with tandem high-dose chemotherapy (thiotepa and busulfan-melphalan), followed by HSCR in the upcoming SIOPEN VHR Neuroblastoma Protocol.

Current Consensus on I-131 MIBG Therapy

Metaiodobenzylguanidine (MIBG) is structurally similar to the neurotransmitter norepinephrine and specifically targets neuroendocrine cells including some neuroendocrine tumors. Iodine-131 (I-131)-labeled MIBG (I-131 MIBG) therapy for neuroendocrine tumors has been performed for more than a quarter-century. The indications of I-131 MIBG therapy include treatment-resistant neuroblastoma (NB), unresectable or metastatic pheochromocytoma (PC) and paraganglioma (PG), unresectable or metastatic carcinoid tumors, and unresectable or metastatic medullary thyroid cancer (MTC). I-131 MIBG therapy is one of the considerable effective treatments in patients with advanced NB, PC, and PG. On the other hand, I-131 MIBG therapy is an alternative method after more effective novel therapies are used such as radiolabeled somatostatin analogs and tyrosine kinase inhibitors in patients with advanced carcinoid tumors and MTC. No-carrier-aided (NCA) I-131 MIBG has more favorable potential compared to the conventional I-131 MIBG. Astatine-211-labeled meta-astatobenzylguanidine (At-211 MABG) has massive potential in patients with neuroendocrine tumors. Further studies about the therapeutic protocols of I-131 MIBG including NCA I-131 MIBG in the clinical setting and At-211 MABG in both the preclinical and clinical settings are needed.

Theranostics in nuclear medicine practice

The importance of personalized medicine has been growing, mainly due to a more urgent need to avoid unnecessary and expensive treatments. In nuclear medicine, the theranostic approach is an established tool for specific molecular targeting, both for diagnostics and therapy. The visualization of potential targets can help predict if a patient will benefit from a particular treatment. Thanks to the quick development of radiopharmaceuticals and diagnostic techniques, the use of theranostic agents has been continually increasing. In this article, important milestones of nuclear therapies and diagnostics in the context of theranostics are highlighted. It begins with a well-known radioiodine therapy in patients with thyroid cancer and then progresses through various approaches for the treatment of advanced cancer with targeted therapies. The aim of this review was to provide a summary of background knowledge and current applications, and to identify the advantages of targeted therapies and imaging in nuclear medicine practices.

Norepinephrine Transporter as a Target for Imaging and Therapy

The norepinephrine transporter (NET) is essential for norepinephrine uptake at the synaptic terminals and adrenal chromaffin cells. In neuroendocrine tumors, NET can be targeted for imaging as well as therapy. One of the most widely used theranostic agents targeting NET is metaiodobenzylguanidine (MIBG), a guanethidine analog of norepinephrine. ¹²³I/¹³¹I-MIBG theranostics have been applied in the clinical evaluation and management of neuroendocrine tumors, especially in neuroblastoma, paraganglioma, and pheochromocytoma. ¹²³I-MIBG imaging is a mainstay in the evaluation of neuroblastoma, and ¹³¹I-MIBG has been used for the treatment of relapsed high-risk neuroblastoma for several years, however, the outcome remains suboptimal. ¹³¹I-MIBG has essentially been only palliative in paraganglioma/pheochromocytoma patients. Various techniques of improving therapeutic outcomes, such as dosimetric estimations, high-dose therapies, multiple fractionated administration and combination therapy with radiation sensitizers, chemotherapy, and other radionuclide therapies, are being evaluated. PET tracers targeting NET appear promising and may be more convenient options for the imaging and assessment after treatment. Here, we present an overview of NET as a target for theranostics; review its current role in some neuroendocrine tumors, such as neuroblastoma, paraganglioma/pheochromocytoma, and carcinoids; and discuss approaches to improving targeting and theranostic outcomes.

Retinoic acid postconsolidation therapy for high-risk neuroblastoma patients treated with autologous haematopoietic stem cell transplantation

BACKGROUND

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumours mainly develop in the adrenal medullary tissue, with an abdominal mass as the most common presentation. About 50% of patients have metastatic disease at diagnosis. The high-risk group is characterised by metastasis and other features that increase the risk of an adverse outcome. High-risk patients have a five-year event-free survival of less than 50%. Retinoic acid has been shown to inhibit growth of human neuroblastoma cells and has been considered as a potential candidate for improving the outcome of patients with high-risk neuroblastoma. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate the efficacy and safety of additional retinoic acid as part of a postconsolidation therapy after high-dose chemotherapy (HDCT) followed by autologous haematopoietic stem cell transplantation (HSCT), compared to placebo retinoic acid or to no additional retinoic acid in people with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (2016, Issue 11), MEDLINE in PubMed (1946 to 24 November 2016), and Embase in Ovid (1947 to 24 November 2016). Further searches included trial registries (on 22 December 2016), conference proceedings (on 23 March 2017) and reference lists of recent reviews and relevant studies. We did not apply limits by publication year or languages.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating additional retinoic acid after HDCT followed by HSCT for people with high-risk neuroblastoma compared to placebo retinoic acid or to no additional retinoic acid. Primary outcomes were overall survival and treatment-related mortality. Secondary outcomes were progression-free survival, event-free survival, early toxicity, late toxicity, and health-related quality of life.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

The update search did not identify any additional studies. We identified one RCT that included people with high-risk neuroblastoma who received HDCT followed by autologous HSCT (N = 98) after a first random allocation and who received retinoic acid (13-cis-retinoic acid; N = 50) or no further therapy (N = 48) after a second random allocation. These 98 participants had no progressive disease after HDCT followed by autologous HSCT. There was no clear evidence of difference between the treatment groups either in overall survival (hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.46 to 1.63; one trial; P = 0.66) or in event-free survival (HR 0.86, 95% CI 0.50 to 1.49; one trial; P = 0.59). We calculated the HR values using the complete follow-up period of the trial. The study also reported overall survival estimates at a fixed point in time. At the time point of five years, the survival estimate was reported to be 59% for the retinoic acid group and 41% for the no-further-therapy group (P value not reported). We did not identify results for treatment-related mortality, progression-free survival, early or late toxicity, or health-related quality of life. We could not rule out the possible presence of selection bias, performance bias, attrition bias, and other bias. We judged the evidence to be of low quality for overall survival and event-free survival, downgraded because of study limitations and imprecision.

AUTHORS' CONCLUSIONS

We identified one RCT that evaluated additional retinoic acid as part of a postconsolidation therapy after HDCT followed by autologous HSCT versus no further therapy in people with high-risk neuroblastoma. There was no clear evidence of a difference in overall survival and event-free survival between the treatment alternatives. This could be the result of low power. Information on other outcomes was not available. This trial was performed in the 1990s, since when many changes in treatment and risk classification have occurred. Based on the currently available evidence, we are therefore uncertain about the effects of retinoic acid in people with high-risk neuroblastoma. More research is needed for a definitive conclusion.

Incorporation of high-dose 131I-metaiodobenzylguanidine treatment into tandem high-dose chemotherapy and autologous stem cell transplantation for high-risk neuroblastoma: results of the SMC NB-2009 study

Background

In our previous SMC NB-2004 study of patients with high-risk neuroblastomas, which incorporated total-body irradiation (TBI) with second high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT), the survival rate was encouraging; however, short- and long-term toxicities were significant. In the present SMC NB-2009 study, only TBI was replaced with ¹³¹I-meta-iodobenzylguanidine (MIBG) treatment in order to reduce toxicities.

Methods

From January 2009 to December 2013, 54 consecutive patients were assigned to receive tandem HDCT/auto-SCT after nine cycles of induction chemotherapy. The CEC (carboplatin + etoposide + cyclophosphamide) regimen and the TM (thiotepa + melphalan) regimen with (for metastatic MIBG avid tumors) or without (for localized or MIBG non-avid tumors) ¹³¹I-MIBG treatment (18 or 12 mCi/kg) were used for tandem HDCT/auto-SCT. Local radiotherapy, differentiation therapy with 13-cis-retinoic acid, and immunotherapy with interleukin-2 were administered after tandem HDCT/auto-SCT.

Results

Fifty-two patients underwent the first HDCT/auto-SCT and 47 patients completed tandem HDCT/auto-SCT. There was no significant immediate toxicity during the ¹³¹I-MIBG infusion. Acute toxicities during the tandem HDCT/auto-SCT were less severe in the NB-2009 study than in the NB-2004 study. Late effects such as growth hormone deficiency, cataracts, and glomerulopathy evaluated at 3 years after the second HDCT/auto-SCT were also less significant in the NB-2009 study than in NB-2004 study. There was no difference in the 5-year event-free survival (EFS) between the two studies (67.5 ± 6.7% versus 58.3 ± 6.9%, P = 0.340).

Conclusions

Incorporation of high-dose ¹³¹I-MIBG treatment into tandem HDCT/auto-SCT could reduce short- and long-term toxicities associated with TBI, without jeopardizing the survival rate.

Trial registration

ClinicalTrials.gov NCT03061656

Neuroblastoma: A Tough Nut to Crack

Neuroblastoma, an embryonal tumor arising from neural crest-derived progenitor cells, is the most common solid tumor in childhood, with more than 700 cases diagnosed per year in the United States. In the past several decades, significant advances have been made in the treatment of neuroblastoma. Treatment advances reflect improved understanding of the biology of neuroblastoma. Although amplification of MYCN was discovered in the early 1980s, our understanding of neuroblastoma oncogenesis has advanced in the last decade as a result of high-throughput genomic analysis, exome and whole-genome sequencing, genome-wide association studies, and synthetic lethal drug screens. Our refined understanding of neuroblastoma biology and genetics is reflected in improved prognostic stratification and appropriate tailoring of therapy in recent clinical trials. Moreover, for high-risk neuroblastoma, a disease that was uniformly fatal 3 decades ago, recent clinical trials incorporating autologous hematopoietic transplant and immunotherapy utilizing anti-GD2 antibody plus cytokines have shown improved event-free and overall survival. These advances have resulted in a growing population of long-term survivors of neuroblastoma. Examination of the late effects and second malignant neoplasms (SMNs) in both older generations of survivors and more recently treated survivors will inform both design of future trials and surveillance guidelines for long-term follow-up. As a consequence of advances in understanding of the biology of neuroblastoma, successful clinical trials, and refined understanding of the late effects and SMNs of survivors, the promise of precision medicine is becoming a reality for patients with neuroblastoma.

Clinical research on rare diseases of children: neuroblastoma

PURPOSE

Early access to new treatment options should not preclude accurate research planning, especially for rare diseases and fragile populations. Taking neuroblastoma as a model case, we analyzed the rationale supporting the search for future therapeutic strategies in the light of preclinical and clinical evidence.

METHODS

We reviewed ongoing randomized trials of pharmacological interventions for the treatment of neuroblastoma retrieved by searching ClinicalTrials.gov and the European Union Clinical Trials Registry (last update March 2016).

RESULTS

Our search identified four randomized clinical trial reports. We found poor evidence from preclinical and early clinical research supporting their rationale. Their methodology was questionable too.

CONCLUSIONS

The urgency to cover unmet needs in difficult clinical settings like rare diseases, particularly those involving fragile populations, cannot justify disorderly research approaches. Under these circumstances, clinical questions should be properly identified and addressed to protect patients and avoid wasteful research.

MIBG in Neuroblastoma Diagnostic Imaging and Therapy

Neuroblastoma is a common malignancy observed in infants and young children. It has a varied prognosis, ranging from spontaneous regression to aggressive metastatic tumors with fatal outcomes despite multimodality therapy. Patients are divided into risk groups on the basis of age, stage, and biologic tumor factors. Multiple clinical and imaging tests are needed for accurate patient assessment. Iodine 123 ((123)I) metaiodobenzylguanidine (MIBG) is the first-line functional imaging agent used in neuroblastoma imaging. MIBG uptake is seen in 90% of neuroblastomas, identifying both the primary tumor and sites of metastatic disease. The addition of single photon emission computed tomography (SPECT) and SPECT/computed tomography to (123)I-MIBG planar images can improve identification and characterization of sites of uptake. During scan interpretation, use of MIBG semiquantitative scoring systems improves description of disease extent and distribution and may be helpful in defining prognosis. Therapeutic use of MIBG labeled with iodine 131 ((131)I) is being investigated as part of research trials, both as a single agent and in conjunction with other therapies. (131)I-MIBG therapy has been studied in patients with newly diagnosed neuroblastoma and those with relapsed disease. Development and implementation of an institutional (131)I-MIBG therapy research program requires extensive preparation with a focus on radiation protection.

Individualized 131I-mIBG therapy in the management of refractory and relapsed neuroblastoma

OBJECTIVE

Iodine-131-labelled meta-iodobenzylguanidine (I-mIBG) therapy is an established treatment modality for relapsed/refractory neuroblastoma, most frequently administered according to fixed or weight-based criteria. We evaluate response and toxicity following a dosimetry-based, individualized approach.

MATERIALS AND METHODS

A review of 44 treatments in 25 patients treated with I-mIBG therapy was performed. Patients received I-mIBG therapy following relapse (n=9), in refractory disease (n=12), or with surgically unresectable disease despite conventional treatment (n=4). Treatment schedule (including mIBG dose and number of administrations) was individualized according to the clinical status of the patient and dosimetry data from either a tracer study or previous administrations. Three-dimensional tumour dosimetry was also performed for eight patients.

RESULTS

The mean administered activity was 11089±7222 MBq and the mean whole-body dose for a single administration was 1.79±0.57 Gy. Tumour-absorbed doses varied considerably (3.70±3.37 mGy/MBq). CTCAE grade 3/4 neutropenia was documented following 82% treatments and grade 3/4 thrombocytopenia following 71% treatments. Further acute toxicity was found in 49% of patients. All acute toxicities resolved with appropriate therapy. The overall response rate was 58% (complete or partial response), with a further 29% of patients having stable disease.

CONCLUSION

A highly personalized approach combining patient-specific dosimetry and clinical judgement enables delivery of high activities that can be tolerated by patients, particularly with stem cell support. We report excellent response rates and acceptable toxicity following individualized I-mIBG therapy.

Arsenic Trioxide as a Radiation Sensitizer for 131I-Metaiodobenzylguanidine Therapy: Results of a Phase II Study

Arsenic trioxide has in vitro and in vivo radiosensitizing properties. We hypothesized that arsenic trioxide would enhance the efficacy of the targeted radiotherapeutic agent (131)I-metaiodobenzylguanidine ((131)I-MIBG) and tested the combination in a phase II clinical trial.

METHODS

Patients with recurrent or refractory stage 4 neuroblastoma or metastatic paraganglioma/pheochromocytoma (MP) were treated using an institutional review board-approved protocol (Clinicaltrials.gov identifier NCT00107289). The planned treatment was (131)I-MIBG (444 or 666 MBq/kg) intravenously on day 1 plus arsenic trioxide (0.15 or 0.25 mg/m(2)) intravenously on days 6-10 and 13-17. Toxicity was evaluated using National Cancer Institute Common Toxicity Criteria, version 3.0. Response was assessed by International Neuroblastoma Response Criteria or (for MP) by changes in (123)I-MIBG or PET scans.

RESULTS

Twenty-one patients were treated: 19 with neuroblastoma and 2 with MP. Fourteen patients received (131)I-MIBG and arsenic trioxide, both at maximal dosages; 2 patients received a 444 MBq/kg dose of (131)I-MIBG plus a 0.15 mg/kg dose of arsenic trioxide; and 3 patients received a 666 MBq/kg dose of (131)I-MIBG plus a 0.15 mg/kg dose of arsenic trioxide. One did not receive arsenic trioxide because of transient central line-induced cardiac arrhythmia, and another received only 6 of 10 planned doses of arsenic trioxide because of grade 3 diarrhea and vomiting with concurrent grade 3 hypokalemia and hyponatremia. Nineteen patients experienced myelosuppression higher than grade 2, most frequently thrombocytopenia (n = 18), though none required autologous stem cell rescue. Twelve of 13 evaluable patients experienced hyperamylasemia higher than grade 2 from transient sialoadenitis. By International Neuroblastoma Response Criteria, 12 neuroblastoma patients had no response and 7 had progressive disease, including 6 of 8 entering the study with progressive disease. Objective improvements in semiquantitative (131)I-MIBG scores were observed in 6 patients. No response was seen in MP. Seventeen of 19 neuroblastoma patients continued on further chemotherapy or immunotherapy. Mean 5-year overall survival (±SD) for neuroblastoma was 37% ± 11%. Mean absorbed dose of (131)I-MIBG to blood was 0.134 cGy/MBq, well below myeloablative levels in all patients.

CONCLUSION

(131)I-MIBG plus arsenic trioxide was well tolerated, with an adverse event profile similar to that of (131)I-MIBG therapy alone. The addition of arsenic trioxide to (131)I-MIBG did not significantly improve response rates when compared with historical data with (131)I-MIBG alone.

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.

Retinoic acid post consolidation therapy for high-risk neuroblastoma patients treated with autologous hematopoietic stem cell transplantation

BACKGROUND

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumors mainly develop in the adrenal medullary tissue and an abdominal mass is the most common presentation. About 50% of patients have metastatic disease at diagnosis. The high-risk group is characterized by metastasis and other characteristics that increase the risk for an adverse outcome. High-risk patients have a five-year event-free survival of less than 50%. Retinoic acid has been shown to inhibit growth of human neuroblastoma cells and has been considered as a potential candidate for improving the outcome of patients with high-risk neuroblastoma.

OBJECTIVES

To evaluate efficacy and adverse events of retinoic acid after consolidation with high-dose chemotherapy followed by bone marrow transplantation as compared to placebo or no therapy in patients with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system). Our outcomes of interest were overall survival and treatment-related mortality as primary outcomes; and progression- and event-free survival, early and late toxicity, and health-related quality of life as secondary outcomes.

SEARCH METHODS

We searched the electronic databases CENTRAL (2014, Issue 8) on The Cochrane Library, MEDLINE (1946 to October 2014), and EMBASE (1947 to October 2014). Further searches included trial registries, conference proceedings, and reference lists of recent reviews and relevant articles. We did not apply limits on publication year or languages.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating retinoic acid post consolidation therapy for high-risk neuroblastoma patients treated with autologous hematopoietic stem cell transplantation (HSCT) compared to placebo or no further treatment.

DATA COLLECTION AND ANALYSIS

Two review authors performed the study selection, extracted the data on study and patient characteristics and assessed the risk of bias independently. We resolved differences by discussion or by appeal to a third review author. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. The authors of the included study did not report the results specifically for the treatment groups relevant to this Cochrane Review. Therefore, we deduced the appropriate survival data from the published survival curves and calculated a hazard ratio (HR) based on the deduced data.

MAIN RESULTS

We identified one RCT (CCG-3891) that included patients with high-risk neuroblastoma who received high-dose chemotherapy followed by autologous HSCT (N = 98) after a first random allocation and who received retinoic acid (13-cis-retinoic acid; N = 50) or no further therapy (N = 48) after a subsequent second random allocation. These patients had no progressive disease after consolidation therapy. There was no clear evidence of difference between the treatment groups in both overall survival (HR 0.87, 95% CI 0.46 to 1.63; one trial; P = 0.66, low quality of evidence) and event-free survival (HR 0.86, 95% CI 0.50 to 1.49; one trial; P = 0.59, low quality of evidence). We calculated these HR values using the complete follow-up period of the trial. The study also reported five-year overall survival rates: 59% for the retinoic acid group and 41% for the no further therapy group (P value not reported). We did not identify results for treatment-related mortality, progression-free survival, early or late toxicity, or health-related quality of life. Also, we could not rule out the possible presence of selection bias, performance bias, attrition bias, and other bias.

AUTHORS' CONCLUSIONS

We identified one RCT that evaluated retinoic acid as a consolidation therapy versus no further therapy after high-dose chemotherapy followed by bone-marrow transplantation in patients with high-risk neuroblastoma. The difference in overall survival and event-free survival between both treatment alternatives was not statistically significantly different. This could be the result of low power. Information on other outcomes was not available. This trial was performed in the 1990s, since then many changes in for example treatment and risk classification have occurred. Therefore, based on the currently available evidence, we are uncertain about the effects of retinoic acid in patients with high-risk neuroblastoma. More research is needed for a definitive conclusion.

[Childhood cancer: progress but prognosis still very unequal. Example of Retinoblastoma and high-risk Neuroblastoma]

Children suffering with cancer have a higher probability of cure than adult. Since the 1950's, high cure rates have been achieved following remarkable progress in the overall care of these children. Not only children are more often "cured" than during the past century but they are probably "better cured" with the hope of experiencing less late effects. Nevertheless, there are still large disparities related to tumor diagnosis and regional area on the globe. If retinoblastoma is now cured in about 100% of the cases in industrialized countries, a different figure is seen unfortunately in economically disadvantaged countries. Not only is access to primary care lower, but also ophthalmologic techniques and available cancer treatments are less effective. Nowadays, such high cure rates observed for children with retinoblastoma are not the rule for all children with cancer. For example, despite considerable progress with new innovative treatments, the cure rate of children with metastatic neuroblastoma does not exceed 40%.

Proton versus photon radiation therapy for patients with high-risk neuroblastoma: the need for a customized approach

BACKGROUND

Proton therapy for treatment for high-risk neuroblastoma may offer sparing of organs at risk (OAR) when compared to intensity-modulated X-ray therapy (IMXT).

PROCEDURE

Double-scattered proton plans and IMXT plans delivering 2,160 cGy to the primary tumor site and other residual disease were developed for 13 consecutive HR-NBL patients. Radiation doses to target volumes and OAR were calculated to determine the optimal modality for each.

RESULTS

All patients received radiation (5/13 ≥ 2 sites). No patient has experienced local recurrence or clinical organ toxicity. Coverage was excellent using both protons and IMXT: median % dose delivered to 95% clinical target volume was 99% and 100%, respectively. For nine patients with lateralized disease, proton therapy offered sparing of the contralateral kidney both with regard to median dose and dose to 20% (median <1 cGy vs. 362 cGy, P = 0.01; median 100 cGy vs. 634 cGy, P = 0.02, respectively). Proton therapy did not reduce ipsilateral kidney dose, and for 2 select patients with lateralized disease IMXT improved overall bilateral renal sparing. Proton therapy improved median bowel (median 33 cGy vs. 590 cGy, P = 0.01), total body (median <1 cGy vs. 30 cGy, P = 0.15), and liver dose (median <1 cGy vs. 529, P < 0.001). When chest RT was required, proton therapy decreased median heart dose and mean lung dose.

CONCLUSIONS

For most patients (11/13), proton therapy offered the optimal combination of target coverage and organ sparing, and is a feasible treatment for HR-NBL. We recommend a customized approach with careful evaluation of renal dosimetry; IMXT may be preferred for select patients.