Radiation, Volume 5, Issue 2 (June 2025) – 4 articles

This article explores the implementation of Cesium-131 brachytherapy in veterinary academia, challenging the prevailing use of external beam therapy for small animal brain tumors. The authors report on the first ever canine patient treated with Cesium-131. While recent advances like intensity-modulated and stereotactic radiation therapies gain ground, brachytherapy remains underutilized in veterinary practice, primarily due to regulatory hurdles. In contrast, Cesium-131 brachytherapy, widely adopted in human medicine for neoplasia within the brain, presents advantages such as a short half-life, low kilovolt emission, and enhanced safety. Motivated by the need to eliminate post-surgery radiation delays, our academic center undertakes Cesium-131 brachytherapy for small animals, aiming to gather preliminary clinical data on disease-free intervals and survival rates. Comparative analyses against historical external beam therapy data may offer insights applicable to the human neuro-radiation community. Additionally, the technique’s implementation could initiate preclinical platform for combined intracavitary treatments, particularly immunotherapy, leveraging brachytherapy’s spatial dose distribution heterogeneity to influence the tumor microenvironment and enhance the immune response. The authors outline the adaptation of the technique on a canine glioma patient to provide preliminary feasibility results, describe the principal indications and outcomes of Cesium-131 for human brain tumors, and discuss prospects for advancing veterinary neuro-brachytherapy. Full article

Background: Patients with advanced breast cancer (BC) may be treated with stereotactic ablative radiotherapy (SABR) for tumor control. Variable treatment responses are a clinical challenge and there is a need to predict tumor radiosensitivity a priori. There is evidence showing that tumor infiltrating lymphocytes (TILs) are markers for chemotherapy response; however, this association has not yet been validated in breast radiation therapy. This pilot study investigates the computational analysis of TILs to predict SABR response in patients with inoperable BC. Methods: Patients with inoperable breast cancer (n = 22) were included for analysis and classified into partial response (n = 12) and stable disease (n = 10) groups. Pre-treatment tumor biopsies (n = 104) were prepared, digitally imaged, and underwent computational analysis. Whole slide images (WSIs) were pre-processed, and then a pre-trained convolutional neural network model (CNN) was employed to identify the regions of interest. The TILs were annotated, and spatial graph features were extracted. The clinical and spatial features were collected and analyzed using machine learning (ML) classifiers, including K-nearest neighbor (KNN), support vector machines (SVMs), and Gaussian Naïve Bayes (GNB), to predict the SABR response. The models were evaluated using receiver operator characteristics (ROCs) and area under the curve (AUC) analysis. Results: The KNN, SVM, and GNB models were implemented using clinical and graph features. Among the generated prediction models, the graph features showed higher predictive performances compared to the models containing clinical features alone. The highest-performing model, using computationally derived graph features, showed an AUC of 0.92, while the highest clinical model showed an AUC of 0.62 within unseen test sets. Conclusions: Spatial TIL models demonstrate strong potential for predicting SABR response in inoperable breast cancer. TILs indicate a higher independent predictive performance than clinical-level features alone. Full article

Humans are constantly exposed to low doses and low-dose rates of ionizing radiation from both natural and man-made sources. For this reason, there is a growing interest in studies on the biological effects of low-dose radiation. Vibrational spectroscopies, such as Fourier transform infrared and Raman micro-spectroscopies, have been fruitfully employed for studying the effects of high doses of ionizing radiation on biosystems. Aiming at clarifying the potential of the above-mentioned spectroscopic techniques to monitor the changes induced in cells, tissues, and other biological samples by low doses of ionizing radiations, we report a review of the literature in this research field. The analysis of published results suggests that vibrational spectroscopies make a valuable contribution. Additional and more systematic investigations could help to fully exploit the capabilities of these spectroscopic techniques. Full article