International Atomic Energy Agency

New developments have been brought to our energy-, spin-, and parity-dependent nuclear level densities based on the microscopic combinatorial method. Our new calculation is based on the BSkG3 mean-field model [Grams et al., Skyrme-Hartree-Fock-Bogoliubov mass models on a 3D mesh: III. From atomic nuclei to neutron stars, Eur. Phys. J. A 59, 270 (2023)] which relies on a three-dimensional coordinate-space representation of the nucleus, allowing for the spontaneous breaking of ground-state rotational, axial, and reflection symmetry. In particular, we now account for the impact of possible triaxial deformation of nuclear ground states on the level density. This has two effects on our calculations: the additional freedom of the single-particle levels affects the intrinsic level density while the absence of a rotational symmetry axis results in a larger collective correction. The present model reproduces the experimental s- and p-wave neutron resonance spacings with a degree of accuracy comparable to that of the best global models available. It is also shown that the model gives a reliable extrapolation at low energies where experimental data on the cumulative number of levels can be extracted. The predictions are also in good agreement with the experimental data extracted from the Oslo method. Total level densities for more than 8500 nuclei are made available in a table format for practical applications. For the nuclei for which experimental s-wave spacings and enough low-lying states exist, renormalization factors are provided to reproduce simultaneously both observables. The same combinatorial method is used to estimate the nuclear level densities at the fission saddle points of actinides and at the shape isomer deformation. Finally, the new nuclear-level densities are applied to the calculation of radiative neutron capture cross sections and compared with those obtained with our previous combinatorial model.

PURPOSE:Based on bioeffect modeling of published outcomes after radiation therapy for head and neck squamous cell carcinoma with various time-dose-fractionation, we hypothesized that a 20-fraction hypofractionated (HFX) schedule delivering 55 Gy in 20 fractions, 5 fractions per week, over 4 weeks would be noninferior to a 33-fraction accelerated, normofractionated (NFX) 2 Gy per fraction schedule, delivering 66 Gy in 2-Gy fractions, 6 fractions per week over 5.5 weeks with respect to both local tumor control and late adverse events. METHODS AND MATERIALS:The HYPNO (HYPo-fractionated vs NOrmo-fractionated radiation therapy for head and neck squamous cell carcinoma) trial was designed as a multicenter, pragmatic, embedded, 2-arm, unblinded, randomized controlled noninferiority trial with dual primary endpoints, loco-regional tumor control, and grade 3 or higher late adverse events with a 10% noninferiority margin for both endpoints. The trial was open for enrollment in 12 centers, each adhering to their standard of care to the extent that it was consistent with the requirements of the trial protocol. Concurrent chemoradiation therapy with 35 mg/m2 cisplatin weekly was permitted. RESULTS:Between March 2014 and February 2020, 792 patients were centrally randomized: 395 to HFX and 397 to NFX. Accrual closed, with all outcome data still blinded, with 792 of a planned 836 patients (94.7%) enrolled, in part due to the emerging COVID-19 pandemic. The HYPNO test arm passed the separate noninferiority tests for both loco-regional tumor control (P = .04) and grade 3+ late adverse events (P = .004). At 3 years, the absolute difference in outcome between the 2 arms was ≤1.4 percentage points for overall survival, progression-free survival, loco-regional control, and grade 3+ late adverse events. The planned subgroup analyses showed no statistically significant heterogeneity of effect estimates for loco-regional control between the 2 trial arms. CONCLUSIONS:The HYPNO test arm schedule was shown to be noninferior with respect to both loco-regional tumor control and grade 3+ late adverse events.

Accurate staging of unfavorable intermediate- or high-risk prostate cancer (PCa) is essential for treatment decisions. Conventional imaging often fails to detect lymph node, bone, and visceral metastases, and for this purpose 68Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT is clinically used. This prospective, multicenter, International Atomic Energy Agency-supported trial evaluated the accuracy of 68Ga-PSMA-11 PET/CT for initial staging compared with MRI and histopathology and the impact of 68Ga-PSMA-11 PET/CT on determining surgical eligibility. Methods: In a prospective, international study supported by the International Atomic Energy Agency, 775 patients with high-risk or unfavorable intermediate-risk PCa from 12 centers across 11 countries-including low-, middle-, and high-income settings, scheduled for radical prostatectomy based on conventional imaging (including bone scanning and pelvic MRI) underwent 68Ga-PSMA-11 PET/CT before treatment. PET and MRI findings were compared with radical prostatectomy histopathology, and the impact of PET on radical prostatectomy was assessed. Results: 68Ga-PSMA-11 PET/CT detected metastatic disease (M1) in 20.4% of cases, altering management and preventing prostatectomy in 24.0%. The accuracy for seminal vesicle invasion was 90.1% for 68Ga-PSMA-11 PET/CT versus 57.3% for MRI, and for lymph node metastases it was 91.1% for 68Ga-PSMA-11 PET/CT versus 69.7% for MRI. In 13.1% of patients (78/593), there were discordant results between 68Ga-PSMA-11 PET/CT and histopathology. 68Ga-PSMA-11 PET/CT had false-negative lymph node findings in 8.6% of cases, with the most clinically significant being 4.5% of patients incorrectly staged as N0. False-positive lymph node findings at 68Ga-PSMA-11 PET/CT occurred in 4.5% of patients. Conclusion: 68Ga-PSMA-11 PET/CT significantly improves staging accuracy, reducing the indication for prostatectomy and impacting treatment decisions. These findings, from a broad international cohort including low-, middle-, and high-income countries, support the global adoption of 68Ga-PSMA-11 PET/CT into standard staging protocols for high-risk PCa.

We present the ExoAtom database, an extension of the ExoMol database to provide atomic line lists in the ExoMol format. ExoAtom is designed for detailed astrophysical, planetary, and laboratory applications. ExoAtom currently includes atomic data for 80 neutral atoms and 74 singly charged ions. These data are extracted from both the nist and Kurucz databases, with 79/71 atoms/ions sourced from nist and 38/37 atoms/ions sourced from Kurucz. ExoAtom uses the file types .all, .def, .states, .trans, and .pf as fundamental components for structuring atomic data in a consistent hierarchy. The .states file contains quantum numbers, uncertainties, lifetimes, etc. The .trans file specifies Einstein A coefficients and their associated wavenumbers. The .pf file provides partition functions over a wide grid of temperatures. Post-processing of the ExoAtom data is provided by the program PyExoCross. Future development of ExoAtom will include additional ionization stages.

We aimed to investigate the current status of nuclear medicine (NM) services across Africa, including identifying infrastructure gaps, radiopharmaceutical availability, systemic challenges, uneven growth trends, and efforts to improve access. Methods: Data on NM infrastructure, radiopharmaceutical availability, and challenges faced by NM professionals in the region were collected at regional International Atomic Energy Agency (IAEA) training courses, from IAEA databases, and by direct correspondence with NM professionals in the region between September 2024 and September 2025. Results: NM services are available in 29 countries. Seven countries have more than 1 SPECT or SPECT/CT camera per million inhabitants, and 12 countries offer PET/CT services, with no country in the region having more than 1 PET/CT camera per million inhabitants. There are 29 cyclotrons in 11 countries. There has been a 5.58% compound annual growth rate of SPECT or SPECT/CT and 32.8% growth (above global averages) in PET/CT cameras since 2022. 99mTc is available in all countries with NM services, and all, except Burkina Faso, have access to 131I. Prostate-specific membrane antigen imaging is available in 9 countries, and somatostatin receptor type 2 imaging is available in 8 countries. Targeted radiopharmaceutical therapy services are limited to 131I for benign or malignant thyroid disease in most countries. 177Lu-therapies are restricted to 7 countries, and the availability of [131I]MIBG remains limited. Clinical trials with 225Ac and 161Tb are under way. Member states face similar challenges, including high costs of medical equipment and consumables, limited health care infrastructure, low government health care expenditures, weak economies, staff shortages, and limited educational opportunities. Conclusion: Despite challenges, there is clear momentum and NM growth in Africa. Although infrastructure, radiopharmaceutical access, and workforce gaps remain, data show progress. Sustained investment in facilities, training, and regulatory frameworks is essential to achieve equitable access to care. IAEA's regional anchor centers as part of the Rays of Hope initiative exemplifies strategic capacity building, collaboration, and knowledge sharing in the region.