Aurora Kinase A inhibition enhances DNA damage and tumor cell death with 131I-MIBG therapy in high-risk neuroblastoma

Background

Neuroblastoma is the most common extra-cranial pediatric solid tumor. 131I-metaiodobenzylguanidine (MIBG) is a targeted radiopharmaceutical highly specific for neuroblastoma tumors, providing potent radiotherapy to widely metastatic disease. Aurora kinase A (AURKA) plays a role in mitosis and stabilization of the MYCN protein in neuroblastoma. Here we explore whether AURKA inhibition potentiates a response to MIBG therapy.

Results

Using an in vivo model of high-risk neuroblastoma, we demonstrated a marked combinatorial effect of 131I-MIBG and alisertib on tumor growth. In MYCN amplified cell lines, the combination of radiation and an AURKA A inhibitor increased DNA damage and apoptosis and decreased MYCN protein levels.

Conclusion

The combination of AURKA inhibition with 131I-MIBG treatment is active in resistant neuroblastoma models and is a promising clinical approach in high-risk neuroblastoma.

Norepinephrine transporter and vesicular monoamine transporter 2 tumor expression as a predictor of response to 131 I-MIBG in patients with relapsed/refractory neuroblastoma

BACKGROUND

Prior studies suggest that norepinephrine transporter (NET) and vesicular monoamine transporter 2 (VMAT2) mediate meta-iodobenzylguanidine (MIBG) uptake and retention in neuroblastoma tumors. We evaluated the relationship between NET and VMAT2 tumor expression and clinical response to 131 I-MIBG therapy in patients with neuroblastoma.

METHODS

Immunohistochemistry (IHC) was used to evaluate NET and VMAT2 protein expression levels on archival tumor samples (obtained at diagnosis or relapse) from patients with relapsed or refractory neuroblastoma treated with 131 I-MIBG. A composite protein expression H-score was determined by multiplying a semi-quantitative intensity value (0-3+) by the percentage of tumor cells expressing the protein.

RESULTS

Tumor samples and clinical data were available for 106 patients, of whom 28.3% had partial response (PR) or higher. NET H-score was not significantly associated with response (≥PR), though the percentage of tumor cells expressing NET was lower among responders (median 80% for ≥PR vs. 90% for

CONCLUSIONS

Markers of lower NET and VMAT2 protein expression are associated with higher likelihood of response to 131 I-MIBG therapy in patients with relapsed/refractory neuroblastoma. Increased VMAT2 protein expression is associated with a more differentiated disease phenotype.

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Key Words

• 131I-MIBG
• biomarker
• neuroblastoma
• norepinephrine transporter
• vesicular monoamine transporter 2

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MESH Headings

• Humans
• 3-Iodobenzylguanidine/therapeutic use
• Norepinephrine Plasma Membrane Transport Proteins/metabolism
• Vesicular Monoamine Transport Proteins/metabolism
• Radiopharmaceuticals
• N-Myc Proto-Oncogene Protein
• Neoplasm Recurrence, Local/drug therapy
• Neuroblastoma/drug therapy
• Chronic Disease

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Grants

• R01 CA172067 NCI NIH HHS
• R35 CA220500 NCI NIH HHS
• R01 CA172067 NIH HHS
• R35 CA220500 NIH HHS

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Affiliation(s)

Vandana Batra Children’s Hospital of Philadelphia and Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA
Ajami Gikandi Harvard Medical School, Boston, MA
Bruce Pawel Department of Pathology, Children’s Hospital Los Angeles and USC Keck School of Medicine, Los Angeles, CA
Daniel Martinez Children’s Hospital of Philadelphia and Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA
M. Meaghan Granger Department of Pediatrics, Cook Children’s Hospital, Fort Worth, TX
Araz Marachelian Department of Pediatrics, Children’s Hospital Los Angeles and USC Keck School of Medicine, Los Angeles, CA
Julie R. Park Department of Pediatrics, Seattle Children’s Hospital and University of Washington School of Medicine, Seattle, WA
John M. Maris Children’s Hospital of Philadelphia and Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA
Kieuhoa T. Vo Department of Pediatrics, UCSF Benioff Children’s Hospital and UCSF School of Medicine, San Francisco, CA
Katherine K. Matthay Department of Pediatrics, UCSF Benioff Children’s Hospital and UCSF School of Medicine, San Francisco, CA
Steven G. DuBois Dana-Farber/Boston Children’s Cancer and Blood Disorders Center, Harvard Medical School, Boston, MA

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[A Report on Health Resource Use of Internal Radiation Therapy with 131I-MIBG (2nd Survey)]

Internal radiation therapy using Iodine-131 metaiodobenzylguanidine (¹³¹I-MIBG) for neuroblastoma has been discussed whether a special application scheme for off-labeled drugs called "Kouchi-Shinsei" could be applied to neuroblastoma or not by the Evaluation Committee on Unapproved or Off-labeled Drug with High Medical Needs (the Committee); if the Committee determines that Kouchi-Shinsei is applicable, neuroblastoma indication is expected to be regulatory approved within a year. Since a NHI medical technical fee is not yet set for neuroblastoma, the Japanese Society of Nuclear Medicine surveyed health resource use via a questionnaire survey of medical institution that has conducted a Japanese Advanced Medical Care B clinical study in neuroblastoma. Results showed that the necessary total cost per patient is 1,847,451 JPY when calculated based on the Draft Proposal for Medical Examination Value (Ver. 7.3) of the Japanese Health Insurance Federation for Surgery. Because follow-up is necessary for 3 months after administration, it was considered that an appropriate fee per patient is 1,847,451 JPY and an appropriate NHI medical technical fee per patient is 46,186 points which can be claimed up to once a month for 4 times including the initial month of the treatment.

Comparative Role of 18F-DOPA PET/CT and 131I-MIBG Scintigraphy in Neuroblastoma and Application of Curie and SIOPEN Scoring Systems in 18F-DOPA PET/CT

Purpose

Neuroblastoma (NB) is childhood's most common extracranial solid malignancy. We have compared two imaging modalities, 131I-MIBG and 18F-DOPA PET/CT, to evaluate NB. Also, feasibility of the application of standardised scoring systems, SIOPEN and Curie scoring systems, in 18F-DOPA PET/CT was explored.

Methods

Patients with histopathology-proven NB underwent 131I-MIBG (planar and SPECT/CT) and 18F-DOPA PET/CT scans, as per standard imaging protocols. Duration between scans ranged from 1 to 30 days (median = 8 days). Number of lesions in Curie and SIOPEN scoring systems applied on both modalities was compared.

Results

Forty-six patients were included (M:F = 29:17) with a median age of 36 months. Both 131I-MIBG and 18F-DOPA scans were positive in 39 patients and negative in four patients. 18F-DOPA PET/CT was positive in additional three patients, in which 131I-MIBG was negative (p = 0.25). Overall, 18F-DOPA identified significantly greater number of lesions than 131I-MIBG, especially metastatic skeletal lesions (p < 0.05). Significant difference was observed between Curie scores in the two modalities, unlike SIOPEN scores. However, when the cut-off age of 18 months was taken, no significant difference was seen in either of the scoring systems in both the scans (p > 0.05). CS and SIOPEN scores were significantly higher in bone marrow-positive patients.

Conclusion

18F-DOPA PET/CT detected more lesions than 131I-MIBG but had little impact on staging of the disease. For evaluation of NB, both scans can be used interchangeably as per the availability. Furthermore, both SIOPEN and Curie scoring systems, standardised for MIBG, can also be used to semi-quantify disease extent in 18F-DOPA PET/CT.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13139-022-00762-6.

The efficacy and safety of Iodine-131-metaiodobenzylguanidine therapy in patients with neuroblastoma: a meta-analysis

Objective

Neuroblastoma is a common extracranial solid tumor of childhood. Recently, multiple treatments have been practiced including Iodine-131-metaiodobenzylguanidine radiation (¹³¹I-MIBG) therapy. However, the outcomes of efficacy and safety vary greatly among different studies. The aim of this meta-analysis is to evaluate the efficacy and safety of ¹³¹I-MIBG in the treatment of neuroblastoma and to provide evidence and hints for clinical decision-making.

Methods

Medline, EMBASE database and the Cochrane Library were searched for relevant studies. Eligible studies utilizing ¹³¹I-MIBG in the treatment of neuroblastoma were included. The pooled outcomes (response rates, adverse events rates, survival rates) were calculated using either a random-effects model or a fixed-effects model considering of the heterogeneity.

Results

A total of 26 clinical trials including 883 patients were analyzed. The pooled rates of objective response, stable disease, progressive disease, and minor response of ¹³¹I-MIBG monotherapy were 39%, 31%, 22% and 15%, respectively. The pooled objective response rate of ¹³¹I-MIBG in combination with other therapies was 28%. The pooled 1-year survival and 5-year survival rates were 64% and 32%. The pooled occurrence rates of thrombocytopenia and neutropenia in MIBG monotherapy studies were 53% and 58%. In the studies of ¹³¹I-MIBG combined with other therapies, the pooled occurrence rates of thrombocytopenia and neutropenia were 79% and 78%.

Conclusion

¹³¹I-MIBG treatment alone or in combination of other therapies is effective on clinical outcomes in the treatment of neuroblastoma, individualized ¹³¹I-MIBG is recommended on a clinical basis.

Inhibition of glycolysis and mitochondrial respiration promotes radiosensitisation of neuroblastoma and glioma cells

BACKGROUND

Neuroblastoma accounts for 7% of paediatric malignancies but is responsible for 15% of all childhood cancer deaths. Despite rigorous treatment involving chemotherapy, surgery, radiotherapy and immunotherapy, the 5-year overall survival rate of high-risk disease remains < 40%, highlighting the need for improved therapy. Since neuroblastoma cells exhibit aberrant metabolism, we determined whether their sensitivity to radiotherapy could be enhanced by drugs affecting cancer cell metabolism.

METHODS

Using a panel of neuroblastoma and glioma cells, we determined the radiosensitising effects of inhibitors of glycolysis (2-DG) and mitochondrial function (metformin). Mechanisms underlying radiosensitisation were determined by metabolomic and bioenergetic profiling, flow cytometry and live cell imaging and by evaluating different treatment schedules.

RESULTS

The radiosensitising effects of 2-DG were greatly enhanced by combination with the antidiabetic biguanide, metformin. Metabolomic analysis and cellular bioenergetic profiling revealed this combination to elicit severe disruption of key glycolytic and mitochondrial metabolites, causing significant reductions in ATP generation and enhancing radiosensitivity. Combination treatment induced G2/M arrest that persisted for at least 24 h post-irradiation, promoting apoptotic cell death in a large proportion of cells.

CONCLUSION

Our findings demonstrate that the radiosensitising effect of 2-DG was significantly enhanced by its combination with metformin. This clearly demonstrates that dual metabolic targeting has potential to improve clinical outcomes in children with high-risk neuroblastoma by overcoming radioresistance.

Low-Dose, Low-Specific Activity 131I-metaiodobenzyl Guanidine Therapy in Metastatic Pheochromocytoma/Sympathetic Paraganglioma: Single-Center Experience from Western India

INTRODUCTION

Radionuclide therapy is a promising treatment modality in metastatic pheochromocytoma/paraganglioma (PPGL). There is scarce data on ¹³¹I-metaiodobenzyl guanidine (¹³¹I-MIBG) therapy from the Indian subcontinent. Hence, we aim to study the safety and effectiveness of low-dose, low-specific activity (LSA) ¹³¹I-MIBG therapy in patients with symptomatic, metastatic PPGL.

METHODS

Clinical, hormonal, and radiological response parameters and side effects of LSA ¹³¹I-MIBG therapy in patients with symptomatic, metastatic PPGL were retrospectively reviewed. World health organizations' (WHO) symptomatic, hormonal, and tumor response, and response evaluation criteria in solid tumors (RECIST1.1) criteria were used to assess the response.

RESULTS

Seventeen (PCC: 11, sympathetic PGL: 06) patients (15 with disease progression) received low-dose LSA ¹³¹I-MIBG therapy. Complete remission (CR), partial remission (PR), stable disease (SD), and progressive disease (PD) were 18% (3/17), 24% (4/17), 18% (3/17), and 41% (7/17), respectively, for WHO symptomatic response; 20% (2/10), 10% (1/10), 30% (3/10), and 40% (4/10), respectively, for WHO hormonal response; and 19% (3/16), 6% (1/16), 31% (5/16), and 44% (7/16), respectively for tumor response based on RECIST1.1. All patients with symptomatic PD and 50% (2/4) with hormonal PD had progression as per RECIST1.1 criteria. Side effects included thrombocytopenia, acute myeloid leukemia, mucoepidermoid carcinoma, and azoospermia in 6% (1/17) each.

CONCLUSIONS

Our study reaffirms the modest efficacy and safety of low-dose, LSA ¹³¹I-MIBG therapy in patients with symptomatic, metastatic PPGL. Symptomatic, but not hormonal, progression after ¹³¹I-MIBG therapy correlates well with tumor progression and should be further evaluated with imaging. In resource-limited settings, anatomic imaging alone may be used to assess tumor response to ¹³¹I-MIBG therapy.

Effects of Repeated 131I-Meta-Iodobenzylguanidine Radiotherapy on Tumor Size and Tumor Metabolic Activity in Patients with Metastatic Neuroendocrine Tumors

¹³¹I-meta-iodobenzylguanidine (¹³¹I-MIBG) radiotherapy has shown some survival benefits in metastatic neuroendocrine tumors (NETs). European Association of Nuclear Medicine clinical guidelines for ¹³¹I-MIBG radiotherapy suggest a repeated treatment protocol, although none currently exists. The existing single-high-dose ¹³¹I-MIBG radiotherapy (444 MBq/kg) has been shown to have some benefits for patients with metastatic NETs. However, this protocol increases adverse effects and requires alternative therapeutic approaches. Therefore, the aim of this study was to evaluate the effects of repeated ¹³¹I-MIBG therapy on tumor size and tumor metabolic response in patients with metastatic NETs. Methods: Eleven patients with metastatic NETs (aged 49.2 ± 16.3 y) prospectively received repeated 5,550-MBq doses of ¹³¹I-MIBG therapy at 6-mo intervals. In total, 31 treatments were performed. The mean number of treatments was 2.8 ± 0.4, and the cumulative ¹³¹I-MIBG dose was 15,640.9 ± 2,245.1 MBq (286.01 MBq/kg). Tumor response was observed by CT and ¹⁸F-FDG PET or by ¹⁸F-FDG PET/CT before and 3-6 mo after the final ¹³¹I-MIBG treatment. Results: On the basis of the CT findings with RECIST, 3 patients showed a partial response and 6 patients showed stable disease. The remaining 2 patients showed progressive disease. Although there were 2 progressive-disease patients, analysis of all patients showed no increase in summed length diameter (median, 228.7 mm [interquartile range (IQR), 37.0-336.0 mm] to 171.0 mm [IQR, 38.0-270.0 mm]; P = 0.563). In tumor region-based analysis with partial-response and stable-disease patients (n = 9), ¹³¹I-MIBG therapy significantly reduced tumor diameter (79 lesions; median, 16 mm [IQR, 12-22 mm] to 11 mm [IQR, 6-16 mm]; P < 0.001). Among 5 patients with hypertension, there was a strong trend toward systolic blood pressure reduction (P = 0.058), and diastolic blood pressure was significantly reduced (P = 0.006). Conclusion: Eighty-two percent of metastatic NET patients effectively achieved inhibition of disease progression, with reduced tumor size and reduced metabolic activity, through repeated ¹³¹I-MIBG therapy. Therefore, this relatively short-term repeated ¹³¹I-MIBG treatment may have potential as one option in the therapeutic protocol for metastatic NETs. Larger prospective studies with control groups are warranted.

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.

68Ga-DOTATATE PET/CT Compared with 131I-MIBG SPECT/CT in the Evaluation of Neural Crest Tumors

Objective(s):

⁶⁸Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) has shown promising results in imaging of neural crest tumors (NCT). Herein, we compared the performance of ⁶⁸Ga-DOTATATE PET/CT and ¹³¹I-MIBG single photon emission computed tomography (SPECT)/CT in the initial diagnosis, staging and follow-up of patients with NCTs.

Methods:

Twenty-five patients (males:females=8:17; age range=2–71 years) with clinically proven or suspicious neuroblastoma, pheochromocytoma (PCC) or paraganglioma (PGL) were enrolled in this prospective study and underwent both ⁶⁸Ga-DOTATATE PET/CT and ¹³¹I-MIBG SPECT/CT. A composite reference standard derived from histopathological information, together with anatomical and functional imaging findings, was used to validate the results. Imaging findings were assessed on a per-patient and on a per-lesion basis. Sensitivity and accuracy were assessed using McNemar’s test.

Results:

Referring to radiological imaging and histopathological findings as reference standard, ⁶⁸Ga-DOTATATE and ¹³¹I-MIBG scans showed a sensitivity and accuracy of (100%, 96%) and (86.7%, 88%), respectively, on a per-patient basis. In PCC/PGL patients, on a per-patient basis, the sensitivity of ⁶⁸Ga-DOTATATE was 100% and that of ¹³¹I-MIBG was 77.8%. In neuroblastoma patients, on a per-patient basis, the sensitivities of both ⁶⁸Ga-DOTATATE and ¹³¹I-MIBG were 100%. Overall, in this patient cohort, ⁶⁸Ga-DOTATATE PET/CT identified 52 lesions and ¹³¹I-MIBG SPECT/CT identified only 30 lesions. On a per-lesion analysis, ⁶⁸Ga-DOTATATE was found to be superior to ¹³¹I-MIBG in detecting lesions in all anatomical locations, particularly osseous lesions. According to the McNemar test results, differences were not statistically significant.

Conclusion:

This relatively small patient cohort suggests ⁶⁸Ga-DOTATATE PET/CT be superior to ¹³¹I-MIBG SPECT/CT in providing particularly valuable information for both primary staging and follow-up in patients with NCT.

Molecular imaging and radionuclide therapy of pheochromocytoma and paraganglioma in the era of genomic characterization of disease subgroups

In recent years, advancement in genetics has profoundly helped to gain a more comprehensive molecular, pathogenic, and prognostic picture of pheochromocytomas and paragangliomas (PPGLs). Newly discovered molecular targets, particularly those that target cell membranes or signaling pathways have helped move nuclear medicine in the forefront of PPGL precision medicine. This is mainly based on the introduction and increasing experience of various PET radiopharmaceuticals across PPGL genotypes quickly followed by implementation of novel radiotherapies and revised imaging algorithms. Particularly, 68Ga-labeled-SSAs have shown excellent results in the diagnosis and staging of PPGLs and in selecting patients for PRRT as a potential alternative to 123/131I-MIBG theranostics. PRRT using 90Y/177Lu-DOTA-SSAs has shown promise for treatment of PPGLs with improvement of clinical symptoms and/or disease control. However, more well-designed prospective studies are required to confirm these findings, in order to fully exploit PRRT's antitumoral properties to obtain the final FDA approval. Such an approval has recently been obtained for high-specific-activity 131I-MIBG for inoperable/metastatic PPGL. The increasing experience and encouraging preliminary results of these radiotherapeutic approaches in PPGLs now raises an important question of how to further integrate them into PPGL management (e.g. monotherapy or in combination with other systemic therapies), carefully taking into account the PPGLs locations, genotypes, and growth rate. Thus, targeted radionuclide therapy (TRT) should preferably be performed at specialized centers with an experienced interdisciplinary team. Future perspectives include the introduction of dosimetry and biomarkers for therapeutic responses for more individualized treatment plans, α-emitting isotopes, and the combination of TRT with other systemic therapies.

Feasibility of High-dose Iodine-131-metaiodobenzylguanidine Therapy for High-risk Neuroblastoma Preceding Myeloablative Chemotherapy and Hematopoietic Stem Cell Transplantation: a Study Protocol

Objective(s):

High-risk neuroblastoma is a childhood cancer with poor prognosis despite modern multimodality therapy. Internal radiotherapy using ¹³¹I-metaiodobenzylguanidine (MIBG) is effective for treating the disease even if it is resistant to chemotherapy. The aim of this study is to evaluate the safety and efficacy of ¹³¹I-MIBG radiotherapy combined with myeloablative high-dose chemotherapy and hematopoietic stem cell transplantation.

Methods:

Patients with high-risk neuroblastoma will be enrolled in this study. A total of 8 patients will be registered. Patients will receive 666 MBq/kg of ¹³¹I-MIBG and after safety evaluation will undergo high-dose chemotherapy and hematopoietic stem cell transplantation. Autologous and allogeneic stem cell sources will be accepted. After engraftment or 28 days after hematopoietic stem cell transplantation, the safety and response will be evaluated.

Conclusion:

This is the first prospective study of ¹³¹I-MIBG with high-dose chemotherapy and hematopoietic stem cell transplantation in Japan. The results will be the basis of a future nationwide clinical trial.

Cotransfecting norepinephrine transporter and vesicular monoamine transporter 2 genes for increased retention of metaiodobenzylguanidine labeled with iodine 131 in malignant hepatocarcinoma cells

Norepinephrine transporter (NET) transfection leads to significant uptake of iodine-131-labeled metaiodobenzylguanidine (¹³¹I-MIBG) in non-neuroendocrine tumors. However, the use of ¹³¹I-MIBG is limited by its short retention time in target cells. To prolong the retention of ¹³¹I-MIBG in target cells, we infected hepatocarcinoma (HepG2) cells with Lentivirus-encoding human NET and vesicular monoamine transporter 2 (VMAT2) genes to obtain NET-expressing, NET-VMAT2-coexpressing, and negative-control cell lines. We evaluated the uptake and efflux of ¹³¹I-MIBG both in vitro and in vivo in mice bearing transfected tumors. NET-expressing and NET-VMAT2-coexpressing cells respectively showed 2.24 and 2.22 times higher ¹³¹I-MIBG uptake than controls. Two hours after removal of ¹³¹I-MIBG-containing medium, 25.4% efflux was observed in NET-VMAT2-coexpressing cells and 38.6% in NET-expressing cells. In vivo experiments were performed in nude mice bearing transfected tumors; results revealed that NET-VMAT2-coexpressing tumors had longer ¹³¹I-MIBG retention time than NET-expressing tumors. Meanwhile, NET-VMAT2-coexpressing and NET-expressing tumors displayed 0.54% and 0.19%, respectively, of the injected dose per gram of tissue 24 h after ¹³¹I-MIBG administration. Cotransfection of HepG2 cells with NET and VMAT2 resulted in increased ¹³¹I-MIBG uptake and retention. However, the degree of increase was insufficient to be therapeutically effective in target cells.

An evaluation in vitro of PARP-1 inhibitors, rucaparib and olaparib, as radiosensitisers for the treatment of neuroblastoma

BACKGROUND

The radiopharmaceutical (131)I-meta-iodobenzylguanidine ((131)I-MIBG) is an effective treatment for neuroblastoma. However, maximal therapeutic benefit from (131)I-MIBG is likely to be obtained by its combination with chemotherapy. We previously reported enhanced antitumour efficacy of (131)I-MIBG by inhibition of the poly(ADP-ribose) polymerase-1 (PARP-1) DNA repair pathway using the phenanthridinone derivative PJ34. Recently developed alternative PARP-1 inhibitors have greater target specificity and are expected to be associated with reduced toxicity to normal tissue. Therefore, our purpose was to determine whether the more specific PARP-1 inhibitors rucaparib and olaparib enhanced the efficacy of X-radiation or (131)I-MIBG.

METHODS

Radiosensitisation of SK-N-BE(2c) neuroblastoma cells or noradrenaline transporter gene-transfected glioma cells (UVW/NAT) was investigated using clonogenic assay. Propidium iodide staining and flow cytometry was used to analyse cell cycle progression. DNA damage was quantified by the phosphorylation of H2AX (γH2AX).

RESULTS

By combining PARP-1 inhibition with radiation treatment, it was possible to reduce the X-radiation dose or (131)I-MIBG activity concentration required to achieve 50 % cell kill by approximately 50 %. Rucaparib and olaparib were equally effective inhibitors of PARP-1 activity. X-radiation-induced DNA damage was significantly increased 2 h after irradiation by combination with PARP-1 inhibitors (10-fold greater DNA damage compared to untreated controls; p < 0.01). Moreover, combination treatment (i) prevented the restitution of DNA, exemplified by the persistence of 3-fold greater DNA damage after 24 h, compared to untreated controls (p < 0.01) and (ii) induced greater G2/M arrest (p < 0.05) than either single agent alone.

CONCLUSION

Rucaparib and olaparib sensitise cancer cells to X-radiation or (131)I-MIBG treatment. It is likely that the mechanism of radiosensitisation entails the accumulation of unrepaired radiation-induced DNA damage. Our findings suggest that the administration of PARP-1 inhibitors and (131)I-MIBG to high risk neuroblastoma patients may be beneficial.

Use of radioactive substances in diagnosis and treatment of neuroendocrine tumors

Radionuclides are needed both for nuclear medicine imaging as well as for peptide-receptor radionuclide therapy (PRRT) of neuroendocrine tumors (NET). Imaging is important in the initial diagnostic work-up and for staging NETs. In therapy planning, somatostatin receptor imaging (SRI) is used when treatment is targeted at the somatostatin receptors as with the use of somatostatin analogues or PRRT. SRI with gamma camera technique using the tracer (111)In-DTPA-octreotide has for many years been the backbone of nuclear imaging of NETs. However, increasingly PET tracers for SRI are now used. (68)Ga-DOTATATE, (68)Ga-DOTATOC and (68)Ga-DOTANOC are the three most often used PET tracers. They perform better than SPECT tracers and should be preferred. FDG-PET is well suited for visualization of most of the somatostatin receptor-negative tumors prognostic in NET patients. Also (11)C-5-HTP, (18)F-DOPA and (123)I-MIBG may be used in NET. However, with FDG-PET and somatostatin receptor PET at hand we see limited necessity of other tracers. PRRT is an important tool in the treatment of advanced NETs causing complete or partial response in 20% and minor response or tumor stabilization in 60% with response duration of up to 3 years. Grade 3-4 kidney or bone marrow toxicity is seen in 1.5% and 9.5%, respectively, but are completely or partly reversible in most patients. (177)Lu-DOTATATE seems to have less toxicity than (90)Y-DOTATOC. However, until now only retrospective, non-randomized studies have been performed and the role of PRRT in treatment of NETs remains to be established.

Diagnostic Performance of (68)Ga-DOTATATE PET/CT, (18)F-FDG PET/CT and (131)I-MIBG Scintigraphy in Mapping Metastatic Pheochromocytoma and Paraganglioma

PURPOSE

To evaluate the diagnostic performance of (68)Ga-DOTATATE (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT), (18)F-FDG PET/CT and (131)I-MIBG scintigraphy in the mapping of metastatic pheochromocytoma and paraganglioma.

MATERIALS AND METHODS

Seventeen patients (male = 8, female = 9; age range, 13-68 years) with clinically proven or suspicious metastatic pheochromocytoma or paraganglioma were included in this prospective study. Twelve patients underwent all three modalities, whereas five patients underwent (68)Ga-DOTATATE and (131)I-MIBG without (18)F-FDG. A composite reference standard derived from anatomical and functional imaging findings, along with histopathological information, was used to validate the findings. Results were analysed on a per-patient and on per-lesion basis. Sensitivity and accuracy were assessed using McNemar's test.

RESULTS

On a per-patient basis, 14/17 patients were detected in (68)Ga-DOTATATE, 7/17 patients in (131)I-MIBG, and 10/12 patients in (18)F-FDG. The sensitivity and accuracy of (68)Ga-DOTATATE, (131)I-MIBG and (18)F-FDG were (93.3 %, 94.1 %), (46.7 %, 52.9 %) and (90.9 %, 91.7 %) respectively. On a per-lesion basis, an overall of 472 positive lesions were detected; of which 432/472 were identified by (68)Ga-DOTATATE, 74/472 by (131)I-MIBG, and 154/300 (patient, n = 12) by (18)F-FDG. The sensitivity and accuracy of (68)Ga-DOTATATE, (131)I-MIBG and (18)F-FDG were (91.5 %, 92.6 % p < 0.0001), (15.7 %, 26.0 % p < 0.0001) and (51.3 %, 57.8 % p < 0.0001) respectively. Discordant lesions were demonstrated on (68)Ga-DOTATATE, (131)I-MIBG and (18)F-FDG.

CONCLUSIONS

Ga-DOTATATE PET/CT shows high diagnostic accuracy than (131)I-MIBG scintigraphy and (18)F-FDG PET/ CT in mapping metastatic pheochromocytoma and paraganglioma.

Recurrent malignant pheochromocytoma with unusual omental metastasis: (68)Ga-DOTANOC PET/CT and (131)I-MIBG SPECT/CT scintigraphy findings

Pheochromocytomas are rare catecholamine-secreting tumors derived from the sympathetic nervous system. The most common sites of metastasis for pheochromocytoma or extra-adrenal paraganglioma are lymph nodes, bones, lungs, and liver. Patients with known or suspected malignancy should undergo staging with computed tomography (CT) or magnetic resonance imaging as well as functional imaging (e.g. with (123)I/(131)I-MIBG ((131)I-metaiodobenzylguanidine) and (68)Ga-DOTANOC ((68)Ga-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI3-octreotide) positron emission tomography (PET)/CT) to determine the extent and location of disease. We present a case of recurrent malignant pheochromocytoma with unusual site of metastasis in omentum, which was positive on (68)Ga-DOTANOC PET/CT and (131)I-MIBG single-photon emission computed tomography (SPECT/)/CT scintigraphy.

Administration of ¹³¹I-Metaiodobenzylguanidine Using the Peristaltic Infusion Pump Method

Syringe pumps are commonly used to administer therapeutic (131)I-metaiodobenzylguanidine. Here we describe our recent experience with a peristaltic infusion pump system in a pediatric setting. This method can easily accommodate infusions from several vials simultaneously and is adaptable to various types of peristaltic pump.

METHODS

Simple off-the-shelf components are used to vent the vial: a charcoal filter, a 0.22-μm syringe filter, and a 2.54-cm (1-in) needle. The vial is connected to the primary infusion set using a male/male extension line and a 19-gauge × 8.89-cm (3.5-in) aspirating needle. With aseptic technique, the extension line is attached to the Y connector closest to the primary intravenous line leading from the saline reservoir to the infusion pump. An A-clamp is attached to the primary intravenous line, immediately before the entrance to the pump. Gravity is allowed to clear the air from the extension set and the aspirating needle. After all the air has been purged, the aspirating needle is inserted into the therapy vial using aseptic technique. The pump is programmed with the desired infusion rate and volume to be infused.

RESULTS

Twenty-one consecutive infusions have been performed to date using this method. Most of the infusions involved the use of 1 vial. On 7 occasions, 2 or 3 vials connected in series were used to successfully administer the therapy. Overestimation of the volume in the vials or of the total infusion time required can cause air to be pulled into the lines. To prevent this, the volume in the vials is equalized to 30 mL, facilitating calculation of the infusion time. If the infusion is observed over the last 2 or 3 mL and the pump stops when the air-fluid mark is about halfway up the extension set, air will be kept out of the primary infusion set.

CONCLUSION

This method for infusing one or more vials of therapeutic radiopharmaceuticals is robust and easy to use. During infusion, the radiopharmaceutical remains in a shielded vial. Multiple vials can be connected in series to infuse the entire dose simultaneously.

68Ga-DOTANOC PET/CT for baseline evaluation of patients with head and neck paraganglioma

The purpose of this study was to evaluate the role of (68)Ga-labeled DOTANOC PET/CT for baseline evaluation of patients with head and neck paragangliomas (HNPs).

METHODS

The data for 26 patients (mean age ± SD, 34.3 ± 10.4 y; 50% men) with known or suspected HNPs who underwent (68)Ga-DOTANOC PET/CT for staging were retrospectively analyzed. PET/CT was performed after intravenous injection of 132-222 MBq of (68)Ga-DOTANOC. The images were evaluated by 2 experienced nuclear medicine physicians in consensus, both qualitatively and quantitatively. The PET/CT findings were grouped as HNPs, paraganglioma at other sites (non-HNPs), and metastatic disease. The size and maximum standardized uptake values (SUVmax) were measured for all lesions. All of the patients also underwent whole-body (131)I-metaiodobenzylgunanidine ((131)I-MIBG) scintigraphy and conventional imaging (CT/MR imaging) of the head and neck region. Their results were compared with those of (68)Ga-DOTANOC PET/CT.

RESULTS

(68)Ga-DOTANOC PET/CT findings were positive in all 26 patients, and 78 lesions were detected. PET/CT imaging demonstrated 45 HNPS, 10 non-HNPs, and 23 metastatic sites. Fifteen patients (57.6%) had more than one site of disease on PET/CT. Among 45 HNPs, 26 were carotid body tumors (CBTs), 15 glomus jugulare, 3 glomus tympanicum, and 1 laryngeal paraganglioma. A positive correlation was seen between size and SUVmax of HNPs (ρ = 0.323; P = 0.030). The SUVmax of the CBTs was higher than that of jugulotympanic paragangliomas (P = 0.026). No correlation was seen between size and SUVmax (ρ = 0.069; P = 0.854) of non-HNPs. The size and SUVmax of non-HNPs were significantly less than those of HNPs (P = 0.029 and 0.047, respectively). (131)I-MIBG scintigraphy showed only 30 of the 78 lesions and was inferior to PET/CT (P < 0.0001). Conventional imaging (CT/MR imaging) was positive for 42 of 49 head and neck lesions and was inferior to PET/CT on direct comparison (P = 0.015). A combination of CT/MR imaging and (131)I-MIBG scintigraphy detected only 53 of 78 (67.9%) lesions and was also inferior to PET/CT (P < 0.0001).

CONCLUSION

(68)Ga-DOTANOC PET/CT is useful for the baseline evaluation of patients with HNPs and can demonstrate synchronous paragangliomas at other sites and distant metastases. It is superior to (131)I-MIBG scintigraphy and conventional imaging (CT/MR imaging) for this purpose.