Work

Blood and bone marrow dosimetry for thyroid cancer patients prepared with rhTSH injection

Year: 2025

Type: article

Abstract: Purpose Radioiodine ( 131 I) dosimetry is used to maximise tumour dose while reducing the chances of toxicity. High thyroid-stimulating-hormone (TSH) levels are required for 131 I treatment, achieved through hormone withdrawal or intramuscular injection of recombinant human TSH (rhTSH). Both approaches have shown equivalent results, with the rhTSH approach reported to reduce morbidity and avoid hypothyroidism. There are established differences in 131 I biokinetics using each method . This clinical cohort study investigated if pretherapy iodine biokinetics as measured using a dosimetry protocol without a dose of rhTSH are predictive of post therapy biokinetics in patients prepared with rhTSH injection. Methods Thirteen patients with differentiated thyroid cancer (DTC) were recruited. An adaptation of the European Association of Nuclear Medicine (EANM) dosimetry protocol was conducted at St James’s Hospital, Ireland. The maximum tolerable activity (MTA) was calculated using the EANM, Association of Physics in Medicine (AIFM) and Traino models, after administering 131 I, and subsequent whole-body (WB) dose-rate measurements and blood-sampling were carried out. The MTA estimated from pre-therapeutic (PT) 131 I tracer administration (6.07 ± 2.46 MBq) was compared to during therapy (DT) administration (3.88 ± 0.16 GBq). Results The PT WB residence-time overestimated the DT with a difference of − 7.72 ± 8.13% ( p = 0.007), while no significant difference is reported between the blood residence-time (1.13 ± 6.49%, p = 0.559). The EANM model reported the lowest difference of 1.73 ± 4.83% ( p = 0.241) in MTA. Conclusion This study validated the feasibility of using dosimetry in euthyroid patients to predict therapeutic 131 I biokinetics in DTC patients prepared with rhTSH.

Source: Annals of Nuclear Medicine

DOI: 10.1007/s12149-025-02042-7

Authors: Amna Juma Al Jabri, Jennie Cooke, Seán Cournane, Marie-Louise Healy

Institutions: Trinity College Dublin, Sultan Qaboos University, Children's Health Ireland at Crumlin, St. Vincent's University Hospital, St. James's Hospital

Language: English

Topic: Thyroid Cancer Diagnosis and Treatment

Subfield: Endocrinology, Diabetes and Metabolism

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,390