Methodology for measuring photonuclear reaction cross sections with an electron accelerator based on Bayesian analysis.

Accurate measurements of photonuclear reaction cross sections are crucial for a number of applications, including radiation shielding design, absorbed dose calculations, reactor physics and engineering, nuclear safeguard and inspection, astrophysics, and nuclear medicine. Primarily motivated by the study of the production of selected radionuclides with high-energy photon beams (mainly Ac, Sc, and Cu), we have established a methodology for the measurement of photonuclear reaction cross sections with the microtron accelerator available at the Swiss Federal Institute of Metrology (METAS). The proposed methodology is based on the measurement of the produced activity with a High Purity Germanium (HPGe) spectrometer and on the knowledge of the photon fluence spectrum through Monte Carlo simulations.

Sc production from enriched TiO targets with a medical cyclotron.

Sc is a β-emitter which has been extensively studied for nuclear medicine applications. Its promising decay characteristics [t = 3.97 h, E [Formula: see text] = 632 keV (94.

Study of thulium-167 cyclotron production: a potential medically-relevant radionuclide.

Targeted Radionuclide Therapy is used for the treatment of tumors in nuclear medicine, while sparing healthy tissues. Its application to cancer treatment is expanding. In particular, Auger-electron emitters potentially exhibit high efficacy in treating either small metastases or single tumor cells due to their short range in tissue.

Experimental assessment of nuclear cross sections for the production of Tb radioisotopes with a medical cyclotron.

Tb is one of the most interesting radionuclides for theranostic applications. It is suitable for SPECT imaging and it can be used as a true diagnostic partner of the therapeutic Tb and Tb. Its production by proton irradiation using enriched Gd and Gd oxide targets is currently being investigated and represents a promising solution.

Cross-section measurement of thulium radioisotopes with an 18 MeV medical PET cyclotron for an optimized Er production.

Er is a pure Auger-electron emitter with promising characteristics for therapeutic applications in nuclear medicine. The short penetration path and high Linear Energy Transfer (LET) of the emitted Auger electrons make Er particularly suitable for treating small tumor metastases. Several production methods based on the irradiation with charged particles of Er and Ho targets can be found in the literature.

Optimized production of Cu based on cross section measurements of Cu and Cu using an 18 MeV medical cyclotron.

RadioNuclide Therapy (RNT) in nuclear medicine is a cancer treatment based on the administration of radioactive substances that specifically target cancer cells in the patient. These radiopharmaceuticals consist of tumor-targeting vectors labeled with β, α, or Auger electron-emitting radionuclides. In this framework, Cu is receiving increasing interest as it provides β-particles accompanied by low-energy γ radiation.

Activity Measurement of Sc and Calibration of Activity Measurement Instruments on Production Sites and Clinics.

Sc is a promising radionuclide for positron emission tomography (PET) in nuclear medicine. As a part of the implementation of a production site for Sc, precise knowledge of the activity of the product is necessary. At the Paul Scherrer Institute (PSI) and the University of Bern (UniBE), Sc is produced by enriched CaO-target irradiation with a cyclotron.

Alternative routes for Cu production using an 18 MeV medical cyclotron in view of theranostic applications.

Radiometals play a fundamental role in the development of personalized nuclear medicine. In particular, copper radioisotopes are attracting increasing interest since they offer a varying range of decay modes and half-lives and can be used for imaging (Cu, Cu, Cu and Cu) and targeted radionuclide therapy (Cu and Cu), providing two of the most promising true theranostic pairs, namely Cu/Cu and Cu/Cu. Currently, the most widely used in clinical applications is Cu, which has a unique decay scheme featuring β-, β-decay and electron capture.

Half-life measurement of Sc and Sc.

The half-lives of Sc and Sc were measured by following their decay rate using several measurement systems: two ionization chambers and three γ-spectrometry detectors with digital and/or analogue electronics. For Sc, the result was the combination of seven half-life values giving a result of 4.042(7) h, which agrees with the last reported value of 4.

Cross-section measurement for an optimized Cu production at an 18 MeV medical cyclotron from natural Zn and enriched Zn solid targets.

The availability of novel medical radionuclides is a key point in the development of personalised nuclear medicine. In particular, copper radioisotopes are attracting considerable interest as they can be used to label various molecules of medical interest, such as proteins and peptides, and offer two of the most promising true theranostic pairs, namely Cu/Cu and Cu/Cu. Although Cu (t = 12.

Sc and Sc cross-section measurement for an optimized Sc production with an 18 MeV medical PET cyclotron.

The availability of novel radionuclides plays a fundamental role in the development of personalized nuclear medicine. In particular, there is growing interest in pairs formed by two radioisotopes of the same element, the so-called true theranostic pairs, such as Cu/Cu, Sc/Sc and Tb/Tb. In this case, the two radionuclides have identical kinetics and chemical reactivity, allowing to predict whether the patient will benefit from a therapeutic treatment on the basis of nuclear imaging data.

Cross section measurement of terbium radioisotopes for an optimized Tb production with an 18 MeV medical PET cyclotron.

Tb [t = 5.32 d, E = 87 keV (32%); 105 keV (25%) (IAEA, 2021)] is a novel promising radionuclide for theranostic applications in nuclear medicine. Its physical properties make it suitable for single photon emission computed tomography (SPECT) imaging, while its chemistry allows it to be used as a diagnostic partner for therapeutic radiolanthanides or pseudo-radiolanthanides, such as Lu and Y.

Developments toward the Implementation of Sc Production at a Medical Cyclotron.

Sc has favorable properties for cancer diagnosis using Positron Emission Tomography (PET) making it a promising candidate for application in nuclear medicine. The implementation of its production with existing compact medical cyclotrons would mean the next essential milestone in the development of this radionuclide. While the production and application of Sc has been comprehensively investigated, the development of specific targetry and irradiation methods is of paramount importance.