Hypothyroidism after 131I-monoclonal antibody treatment of neuroblastoma

GD2-targeted theranostics of neuroblastoma with [64Cu]Cu/[177Lu]Lu-hu3F8

PURPOSE

Neuroblastoma (NB) is a malignant embryonic tumour with poor prognosis and high mortality rate. The antigen gisialoganglioside (GD2), which is highly expressed on the surface of NB cells, is an effective target for therapy. This study aims to evaluate the GD2 expression with [64Cu]Cu-NOTA-hu3F8 positron emission tomography (PET) imaging and explore the radioimmunotherapy (RIT) effect of [177Lu]Lu-DOTA-hu3F8 in NB tumour models.

METHODS

The in vitro validation of the binding ability of anti-GD2 humanised monoclonal antibody (hu3F8) to GD2 was achieved via flow cytometry, cell immunofluorescence, and cell uptake test. Hu3F8 were conjugated with p-SCN-Bn-NOTA (NOTA) and p-SCN-Bn-DOTA (DOTA) for 64Cu- and 177Lu- radiolabelling. PET imaging and RIT studies were conducted using [64Cu]Cu-NOTA-hu3F8 and [177Lu]Lu-DOTA-hu3F8 in subcutaneous NB tumour models.

RESULTS

The Institute for Medical Research-32 (IMR32) cell line exhibited a specific binding ability of hu3F8. PET imaging demonstrated a specific accumulation of [64Cu]Cu-NOTA-hu3F8 in IMR32 tumour models, with a maximum tumour uptake of 23.73 ± 2.29%ID/g (n = 3) at 72 h post-injection (p.i.), outperforming other groups significantly (P < 0.001). The high dose [177Lu]Lu-DOTA-hu3F8 group (11.1MBq) showed the most potent tumour suppression, with a standardised tumour volume of about 20.47 ± 6.32% at 30 days p.i., significantly smaller than other groups (n = 5, P < 0.05).

CONCLUSION

This study demonstrated that 64Cu-/177Lu- labelled hu3F8 could noninvasively evaluate the GD2 expression and effectively inhibit tumour growth in NB tumour models. The excellent therapeutic efficacy of [177Lu]Lu-DOTA-hu3F8 may be helpful for the clinical translation of this GD2-targeted theranostics approach in GD2-positive tumours.

Pharmacological protection of the thyroid gland against radiation damage from radioactive iodine labeled compounds in children: a systematic review

Purpose

There is currently no consensus on which protective strategy is most effective to prevent I-131 uptake in the thyroid during medical interventions in children. We aimed to collect the best available evidence to determine which pharmacological intervention is most effective in protecting the thyroid gland from damage by radioactive iodine (RAI).

Methods

Literature searches were performed using PubMed, Embase, OLDMEDLINE, and the Cochrane Central Register of Controlled Trials. Only original studies were included (1950–2022). Studies comparing pharmacological prevention of the thyroid against RAI uptake or occurrence of hypothyroidism, thyroid nodule or thyroid cancer were included. Included studies were graded according to the Grading of Recommendations Assessment, Development and Evaluation considerations. Pharmacological interventions were compared for effectiveness on reduction of thyroidal intake or relevant clinical thyroidal outcomes.

Results

Forty studies were included. Quality of included studies was low and many different outcome variables were used, making meta-analysis impossible. In 81% of studies, the pharmacological intervention could not prevent RAI uptake or thyroid damage. The administration of potassium iodide (KI) 1 h before exposure to RAI seemed most effective to reduce thyroidal uptake, however, hypothyroidism was reported in up to 64% as well as several cases of thyroid carcinoma. The combination of KI, thyroxine and thiamazole reduced RAI uptake and occurrence of hypothyroidism; yet, after follow-up of 9 years, still 50% of patients developed hypothyroidism. KI with potassium perchlorate showed hypothyroidism to occur in up to 12% of patients after short follow-up time.

Conclusions

The lack of well-designed studies impairs making strong recommendations on the optimal way to prevent thyroid damage when using radioactive coupled ligands for medical interventions. To improve the protection of the thyroid against radiation damage by I-131, well-designed randomized clinical trials with sufficient follow-up time, comparing new protective strategies’ effects on valid and well-defined thyroid outcomes are needed.

Approaches to reduce the long-term burden of treatment-related complications in survivors of childhood cancer

Advances in diagnostics, treatment strategies, and supportive care have contributed to a marked improvement in outcomes for children with cancer. This has resulted in a growing number of long-term childhood cancer survivors. Currently there are over 360,000 individuals who are survivors of childhood cancer in the United States. However, treatment for patients with childhood cancer with chemotherapy, radiation, and/or hematopoietic stem cell transplantation can result in health-related complications that may not become evident until years after completion of treatment. As a result, several initiatives have been established to help standardize the surveillance for treatment-related late effects in childhood cancer survivors. This review highlights emerging concepts related to commonly reported late effects, such as subsequent malignant neoplasms, cardiovascular disease, and endocrinopathies. It also discusses relevant population-based screening strategies to mitigate the long-term health-related burden in vulnerable populations of survivors.

Long-term follow-up of the thyroid gland after treatment with 131I-Metaiodobenzylguanidine in children with neuroblastoma: importance of continuous surveillance

BACKGROUND

Thyroid dysfunction has been reported in up to 52% of patients 1.4 years after treatment with (131) I-Metaiodobenzylguanidine (MIBG) in children with neuroblastoma (NBL), despite the use of potassium-iodide (KI). Our aim was to investigate if the incidence and severity of thyroid damage increases in time.

MATERIALS AND METHODS

All long-term survivors of childhood NBL treated with (131) I-MIBG in the period 1989-1999 in our center (n = 16 of 43) were evaluated. During exposure to (131) I-MIBG, patients received 100 mg KI per day as thyroid protection. All MIBG images were evaluated for thyroid uptake of radio-iodine. Thyroid dysfunction was defined as a plasma thyrotropin concentration above the institutional age-related reference ranges (thyrotropin elevation, TE) or using thyroxine at last moment of follow-up. In all, ultrasound investigation of the thyroid was performed.

RESULTS

Fifteen years after treatment with (131) I-MIBG, in 81% (n = 13) thyroid disorders were diagnosed. Eight survivors (50%) were treated with thyroxine. Thyroid nodules were found in nine survivors, of which two were diagnosed with papillary thyroid carcinoma. In 28% of (131) I-MIBG-images radio-iodine uptake in the thyroid gland was seen, but no correlation was found between thyroidal radio-iodine uptake and thyroid disorders.

CONCLUSIONS

Despite protection with KI during exposure to (131) I-MIBG in childhood, the occurrence of thyroid disorders is high and increases in time. Continuous screening for thyroid dysfunction and nodules in these survivors is recommended. Other ways to protect the thyroid gland should be further evaluated.