Usefulness of specific calibration coefficients for gamma‐emitting sources measured by radionuclide calibrators in nuclear medicine

Bochud, François; Laedermann, Jean-Pascal; Baechler, Sébastien; Kosinski, Marek; Bailat, Claude

doi:10.1118/1.3596528

Cited by 8 publications

(7 citation statements)

References 20 publications

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“…Olsovcova highlighted that the effect of low-energy gamma-rays of 123 I (~ 30 keV) for plastic syringes can lead to an activity measurement error of 40% [4]. The effect of low energies (20-40 keV) for different container types were also discussed in [5]. An error of up to 25% for syringes with 111 In was observed, confirming the results from [3,4] described previously.…”

Section: Introductionsupporting

confidence: 81%

Precise activity measurements of medical radionuclides using an ionization chamber: a case study with Terbium-161

et al. 2022

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Background 161Tb draws an increasing interest in nuclear medicine for therapeutic applications. More than 99% of the emitted gamma and X-rays of 161Tb have an energy below 100 keV. Consequently, precise activity measurement of 161Tb becomes inaccurate with radionuclide dose calibrators when using inappropriate containers or calibration factors to account for the attenuation of this low energy radiation. To evaluate the ionization chamber response, the sample activity must be well known. This can be performed using standards traceable to the Système International de Référence, which is briefly described as well as the method to standardize the radionuclides. Methods In this study, the response of an ionization chamber using different container types and volumes was assessed using 161Tb. The containers were filled with a standardized activity solution of 161Tb and measured with a dedicated ionization chamber, providing an accurate response. The results were compared with standardized solutions of high-energy gamma-emitting radionuclides such as 137Cs, 60Co, 133Ba and 57Co. Results For the glass vial type with an irregular glass thickness, the 161Tb measurements gave a deviation of 4.5% between two vials of the same type. The other glass vial types have a much more regular thickness and no discrepancy was observed in the response of the ionization chamber for these type of vials. Measurements with a plastic Eppendorf tube showed stable response, with greater sensitivity than the glass vials. Conclusion Ionization chamber measurements for low-energy gamma emitters (< 100 keV), show deviation depending on the container type used. Therefore, a careful selection of the container type must be done for activity assessment of 161Tb using radionuclide dose calibrators. In conclusion, it was highlighted that appropriate calibration factors must be used for each container geometry when measuring 161Tb and, more generally, for low-energy gamma emitters.

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Section: Introductionsupporting

confidence: 81%

Precise activity measurements of medical radionuclides using an ionization chamber: a case study with Terbium-161

et al. 2022

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“…Geometry effects (same reading for the same amount of activity irrespective of the volume or the vial of the sample) can dramatically affect the activity measurements, particularly for low-energy X-ray or gamma photons. It should be, therefore, assessed for the vials used to collect the product, as well as those used for quality control and in GMP [76,77].…”

Section: Quality Control Of the Radionuclide For Preclinical Studiesmentioning

confidence: 99%

A Step-by-Step Guide for the Novel Radiometal Production for Medical Applications: Case Studies with 68Ga, 44Sc, 177Lu and 161Tb

et al. 2020

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The production of novel radionuclides is the first step towards the development of new effective radiopharmaceuticals, and the quality thereof directly affects the preclinical and clinical phases. In this review, novel radiometal production for medical applications is briefly elucidated. The production status of the imaging nuclide 44Sc and the therapeutic β--emitter nuclide 161Tb are compared to their more established counterparts, 68Ga and 177Lu according to their targetry, irradiation process, radiochemistry, and quality control aspects. The detailed discussion of these significant issues will help towards the future introduction of these promising radionuclides into drug manufacture for clinical application under Good Manufacturing Practice (GMP).

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“…Moreover, even between syringes or vials of the same type, the geometry can be different from one manufacturer to another. Therefore, when different types of syringes (for instance) are used, the ionization chamber has to be calibrated specifically for each syringe type [46,[48][49][50].…”

Section: Radioactive Source Sample Container and Source Holdermentioning

confidence: 99%

Uncertainty evaluation in activity measurements using ionization chambers

et al. 2015

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Pressurized re-entrant (or 4π) ionization chambers (ICs) connected to current-measuring electronics are used for activity measurements of photon emitting radionuclides and some beta emitters in the fields of metrology and nuclear medicine. As a secondary method, these instruments need to be calibrated with appropriate activity standards from primary or direct standardization. The use of these instruments over 50 years has been well described in numerous publications, such as the Monographie BIPM-4 and the special issue of Metrologia on radionuclide metrology (

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Usefulness of specific calibration coefficients for gamma‐emitting sources measured by radionuclide calibrators in nuclear medicine

Cited by 8 publications

References 20 publications

Precise activity measurements of medical radionuclides using an ionization chamber: a case study with Terbium-161

Precise activity measurements of medical radionuclides using an ionization chamber: a case study with Terbium-161

A Step-by-Step Guide for the Novel Radiometal Production for Medical Applications: Case Studies with 68Ga, 44Sc, 177Lu and 161Tb

Uncertainty evaluation in activity measurements using ionization chambers

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