Radiation, Volume 5, Issue 4 (December 2025) – 6 articles

Fractal dimension (Frac) and lacunarity (Lac) are frequently proposed as biomarkers of multiscale image complexity, but their incremental value over standardized radiomics remains uncertain. We position both measures within the Image Biomarker Standardisation Initiative (IBSI) feature space by running a fully reproducible comparison in two settings. In a baseline experiment, we analyze $N=1000$ simulated $64\times 64$ textured ROIs discretized to $N_g=64$, computing 92 IBSI descriptors together with Frac (box counting) and Lac (gliding box), for 94 features per ROI. In a wavelet-augmented experiment, we analyze $N=1000$ ROIs and add level-1 wavelet descriptors by recomputing first-order and GLCM features in each sub-band (LL, LH, HL, and HH), contributing $4\times (19+19)=152$ additional features and yielding 246 features per ROI. Feature similarity is summarized by a consensus score that averages z-scored absolute Pearson and Spearman correlations, distance correlation, maximal information coefficient, and cosine similarity, and is visualized with clustered heatmaps, dendrograms, sparse networks, PCA loadings, and UMAP and t-SNE embeddings. Across both settings a stable two-block organization emerges. Frac co-locates with contrast, difference, and short-run statistics that capture high-frequency variation; when wavelets are included, detail-band terms from LH, HL, and HH join this group. Lac co-locates with measures of large, coherent structure—GLSZM zone size, GLRLM long-run, and high-gray-level emphases—and with GLCM homogeneity and correlation; LL (approximation) wavelet features align with this block. Pairwise associations are modest in the baseline but become very strong with wavelets (for example, Frac versus GLCM difference entropy, which summarizes the randomness of gray-level differences, with $\left|r\right|\approx 0.98$; and Lac versus GLCM inverse difference normalized (IDN), a homogeneity measure that weights small intensity differences more heavily, with $\left|r\right|\approx 0.96$). The multimetric consensus and geometric embeddings consistently place Frac and Lac in overlapping yet separable neighborhoods, indicating related but non-duplicative information. Practically, Frac and Lac are most useful when multiscale heterogeneity is central and they add a measurable signal beyond strong IBSI baselines (with or without wavelets); otherwise, closely related variance can be absorbed by standard texture families. Full article

Prostatic artery embolization (PAE) is increasingly used as a primary minimally invasive treatment modality for lower urinary tract symptoms associated with benign prostatic hyperplasia. As a complex, fluoroscopic-guided endovascular procedure, PAE necessitates a significant use of ionizing radiation, raising important safety considerations for both patients and medical personnel. The objective of this review is to first summarize the procedural and anatomic fundamentals of PAE, and then to provide a comprehensive overview of the current literature on radiation dosimetry, establish contemporary benchmarks for dose metrics, and present an evidence-based guide to practical dose optimization strategies. Through a thorough review of published clinical studies, this article synthesizes reported values for key radiation indices, including Dose Area Product (DAP), Cumulative Air Kerma (CAK), and Fluoroscopy Time (FT). Furthermore, we will critically examine factors influencing dose variability—including patient complexity, procedural technique, and imaging technology—and will provide a practical, clinically oriented guide to implementing dose-saving measures. Ultimately, this review concludes that while PAE involves a non-trivial radiation burden, a thorough understanding and application of optimization principles can ensure the procedure is performed safely, reinforcing its role as a valuable therapy for BPH. Full article

In large-scale radiological events, there is a need to triage affected individuals based on their biological absorbed dose. Biodosimetry measures biological responses in relation to the received dose. Radiation-responsive protein biomarkers in peripheral blood lymphocytes, especially intracellular proteins, have been validated for biodosimetry with immunochemical-based measurement methods. However, these antibody-based assays can suffer from stability and batch-to-batch variations. Aptamers are single-stranded oligonucleotide alternatives to antibodies that are stable and much smaller in size, making them ideal probes for intracellular targets. However, few aptamers have been developed against intracellular targets, and these efforts are especially hampered due to the time-consuming nature of the conventional aptamer selection method. An efficient method for isolating aptamers against intracellular radiation-responsive proteins is not available yet. Herein, we used a microfluidic aptamer isolation method to develop an aptamer against the intracellular radiation biomarker BAX in blood lymphocytes. The isolated aptamer has a dissociation constant of 6.95 nM against human BAX protein and a bright detail similarity score of 1.9 when colocalizing with anti-BAX aptamer intracellularly. The in situ labeling of the intracellular BAX protein also shows the aptamer can be used to differentiate 2.5 Gy or 3 Gy of radiation in ex vivo human and in vivo mouse peripheral blood samples exposed to X-rays. In conclusion, this proof-of-concept study indicates that the microfluidic-enabled aptamer isolation method could be used for the development of a panel of targeted intracellular proteins for radiation biodosimetry applications. Full article

Radiotherapy employs high-energy X-rays to precisely target tumor tissues while minimizing damage to the surrounding healthy structures. Although its clinical efficacy is well established, the immunomodulatory effects of ionizing radiation remain complex and context-dependent. This study investigated the biological effects of radiotherapeutic doses on immune cells by evaluating lymphocyte viability, phenotypic profiles, and cytokine expression levels. Peripheral blood mononuclear cells (PBMCs) were isolated from six healthy donors and irradiated with 0, 2, or 6 Gy using a 6 MV linear accelerator (LINAC). Dose validation with an ionization chamber demonstrated strong agreement between estimated and measured values (intraclass correlation coefficient = 1, 95% CI). Immune subsets, including T cells (CD3+), helper T cells (CD3+CD4+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+CD4+Foxp3+), and natural killer (CD3-CD56+) cells, along with intracellular cytokines interleukin-12 (IL-12) and interferon-gamma (IFN-γ), were analyzed via flow cytometry at multiple time points. The results showed a significant, dose-dependent decline in overall lymphocyte viability (p < 0.01) compared to control. Cytotoxic T cells were the most radiosensitive, followed by helper and regulatory T cells, while NK cells were the most radioresistant. IL-12 expression initially increased post-irradiation, while IFN-γ levels remained variable. These findings demonstrate that radiation induces distinct alterations in immune phenotypes and cytokine profiles, which may shape the immune response. Immune profiling following irradiation may therefore provide valuable insights for optimizing combination strategies that integrate radiotherapy and immunotherapy in cancer treatment. Full article

Chronic pelvic neuropathies involving the pudendal, ilioinguinal, and genitofemoral nerves are a major source of refractory pain and disability, yet conventional steroid injections typically provide only short-lived benefit. We retrospectively analyzed 78 patients: 49 with pudendal neuralgia treated by pulsed radiofrequency and 29 with ilioinguinal (n = 15) or genitofemoral (n = 14) neuropathies treated by continuous radiofrequency ablation. For pudendal neuropathy, pRF provided a mean pain relief of 9.48 ± 9.52 weeks versus 3.98 ± 3.56 weeks after the first steroid injection and 3.32 ± 3.21 weeks after the most recent (p < 0.0001 for both). Quality-of-life scores improved significantly through 3 months, and analgesic use declined during this period. No correlation was found between symptom duration and treatment response. For ilioinguinal and genitofemoral neuropathies, cRFA extended pain relief to 21.76 and 17.68 weeks, respectively. Mean VAS scores improved from 6.87 to 1.73 for ilioinguinal (p < 0.0001) and from 6.36 to 2.36 for genitofemoral (p = 0.0007) neuropathies. Quality-of-life scores improved through 3 months, with trends toward baseline by 6 months, while analgesic use decreased initially before returning to baseline. Across all nerves, no major complications occurred. Radiofrequency treatment offers safe, longer-lasting relief than steroid injections for refractory pelvic neuropathies. Full article

Exposure to ionising radiation may be hazardous to living beings, including humans. Ionising radiation exposure has been shown to cause hepatic dysfunction or even liver cancer in persons receiving radiation therapy who do not have liver disease. Changes in hepatic enzyme values may suggest radiation-induced stress on liver cells. Then this experimental study examined the effect of different doses of radiation on the liver enzymes aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase (ALT). Methods: Six equal groups of thirty-six New Zealand white rabbits weighing 3 and 5 kg each were formed. The rabbits received total body radiation doses of 0 Gy (Control group), 0.053 Gy, 0.11 Gy, 0.21 Gy, 0.42 Gy, and 0.84 Gy on days, 1, 3, and 5 and week 1, week 2, week 3, and week 4. Generalised Linear Mixed Models (GLMMs) were used to compare the data statistically. Results: There was a significant rise in the serum liver enzyme levels; aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) all showed a statistically significant time effect after the application of different radiation doses. Based on the group effect of radiation, AST and ALP, but not ALT, showed statistically significant findings. Full article