Childhood scalp irradiation for tinea capitis (TC) increases the long-term risk of intracranial meningiomas. It remains unclear whether prior TC irradiation affects meningiomas' response to stereotactic radiosurgery (SRS). We compared TC-irradiated and sporadic meningiomas treated with SRS. Among 539 meningioma patients treated with SRS from 2010-2023, 204 met criteria for volumetric analysis (median follow-up 64.6 months, IQR 32.8-107.8). Of these, 61 (29.9%) had childhood scalp irradiation for TC, while 143 (70.1%) had no prior cranial irradiation. Tumor volumes were measured on T1-weighted gadolinium-enhanced MRI baseline and at last follow-up, or prior to surgery. Treatment response was assessed as percent volume change, as a binary study-defined "good response" (≥29% reduction), and RANO-aligned categories. Predictors of response and surgical intervention were evaluated using multivariable regression. TC-irradiated patients were older (median 67.6 vs. 62.8 years, P < .001) and more commonly had multiple meningiomas (73.8% vs. 11.9%, P < .001) than non-irradiated patients. Baseline tumor volume was similar between groups (P = .516), as was the need for surgical resection (P = .535). Multivariable analysis showed that TC irradiation independently predicted poorer volumetric response (a + 38.7% relative volume change, P = .026) and a lower likelihood of achieving the study-defined "good response," although this was not statistically significant. TC irradiation was not associated with progression-free survival. Childhood TC irradiation-related meningiomas are a distinct subgroup characterized by multifocality and reduced volumetric response to SRS. These findings suggest a potentially treatment-resistant phenotype, supporting the need for individualized management. Childhood radiation therapy for tinea capitis was once widely used and is now known to increase the long-term risk of developing brain tumors, specifically meningiomas. Many patients later present with multiple tumors requiring treatment. Stereotactic radiosurgery (SRS) is a noninvasive treatment that delivers highly focused radiation to the tumor. However, its specific effectiveness for radiation-induced tumors remains unclear. In this study, we compared radiation-induced and sporadic meningiomas treated with SRS. We found that radiation-induced tumors were more often multiple and showed less shrinkage after treatment, although overall disease control was similar, suggesting the need for closer monitoring and individualized care.
Radiation-induced renal injury (RIN) is a major clinical concern, particularly in cancer patients undergoing radiotherapy, where radiation triggers oxidative stress, inflammatory cascades, apoptosis and endothelial dysfunction, leading to progressive renal damage. Oleuropein (OLE), a polyphenolic compound derived from olive leaves, has demonstrated potent antioxidant, anti-inflammatory and anti-apoptotic properties in various preclinical models. However, its radioprotective potential against renal toxicity remains poorly understood. This study aimed to investigate the protective effects of OLE in a radiation-induced acute renal injury model by evaluating apoptotic regulation, endothelial-associated marker expression and renal function. Forty-eight male Wistar Albino rats were randomly assigned to four groups: Control, OLE (50 mg/kg/day for 4 weeks), Radiation (6 Gy single dose total-body gamma irradiation) and OLE+Radiation (OLE treatment 1 week before and 3 weeks after irradiation). Renal function was assessed via serum urea, BUN and creatinine levels. Histopathological, PAS and immunohistochemical (Cyclin D1, CD31) analyses were performed. Gene expression of apoptotic markers BAX and BCL2 was quantified by RT-qPCR. Data were analyzed using ANOVA and nonparametric tests where appropriate (p < .05). Radiation significantly increased serum BUN, creatinine and urea levels (p < .001), disrupted renal histoarchitecture and elevated Cyclin D1 and CD31 expression. RT-qPCR showed an increased pro-apoptotic BAX/BCL2 ratio in the RAD group. OLE treatment attenuated radiation-associated biochemical alterations and reduced the severity of histopathological changes based on semi-quantitative scoring, accompanied by decreased Cyclin D1 and CD31 expression. Importantly, OLE restored the apoptotic balance by downregulating BAX and upregulating BCL2, thereby significantly reducing the BAX/BCL2 ratio. These findings indicate that OLE exerts radioprotective effects in a radiation-induced acute renal injury model by modulating apoptotic signaling, influencing endothelial-associated marker expression and improving renal biochemical parameters. Further mechanistic and long-term studies are warranted to clarify its potential therapeutic relevance in radiation-associated renal injury.
Radiation-induced reactions (RIR), including radiation osteitis (RO), insufficiency fractures (IF), and radionecrosis (RN), are potential complications after pelvic radiotherapy (RT) for rectal cancer (RCa). This study aimed to evaluate the incidence, anatomical distribution, and timing of RIR, and to explore the relationship between bone density and RIR development. We retrospectively analyzed 133 patients with RCa who underwent pelvic MRI following neoadjuvant RT between 2015 and 2024. RIR were assessed by location (sacrum, iliac, pubic), laterality, and classified using the Radiation-Induced Sacral Changes (RISC) system. The presence of IF and RN was documented. The interval from RT to RIR detection was recorded. For patients with abdominal CT within three months before RT, bone density was measured in Hounsfield units (HU) at the L1 vertebra. Comparisons between patients with and without RIR were performed, and correlations with HU were assessed. RIR were detected in 37 patients (27.8%). All 37 patients (100% of the RIR group) had radiation osteitis (RO), most commonly in the sacrum (54.1%). Among these, only one IF (2.7%) was identified, and no RN was observed. Median detection time was 93 days post-RT. Among patients with follow-up MRI, regression of RIR was observed in 75% of cases. Mean HU values did not differ significantly between the RIR group (145.3 ± 41.1) and controls (154.3 ± 40.7) (p = .325). No correlation was found between HU and RIR grade or stage. RIR occurred in approximately one-quarter of patients with rectal cancer after neoadjuvant RT, with the sacrum most frequently affected. Only one IF and no RN were detected during the relatively early imaging interval; however, delayed complications could not be adequately assessed. No significant association was observed between L1 vertebral attenuation and RIR. Radiation-induced reactions detected in 27.8% of rectal cancer patients.Sacrum was the most common site, affected in over half of cases.Median detection time of reactions was 93 days after radiotherapy.No link found between bone density (HU values) and radiation reactions.Restaging pelvic MRI demonstrated early radiation-induced bone marrow changes after neoadjuvant RT.
Relativistic magnetized shocks are natural sources of coherent radiation, representing a promising framework for fast radio bursts (FRBs). This Letter explores how the radiation reaction (RR) effect, triggered by high-energy photon emissions during shock radiation, significantly alters particle dynamics and coherent radiation properties. Using kinetic particle simulations, we demonstrate that RR severely suppresses electron energies from shock acceleration, resulting in multiple coherent gyration cycles at the shock front. It amplifies the intensity of coherent radiation and boosts energy efficiency by several fold, as compared to the single gyration cycle in the standard model of relativistic magnetized shocks. We further find that the coherent radiation spectrum from RR-mediated shocks is characterized by upshift peak frequency, broaden bandwidth, and narrow spectral peak. These RR-induced radiation changes may be related to several observed FRB phenomena, including the statistically positive correlation between luminosity and bandwidth in repeating and one-off FRBs, the narrow spectra seen in some FRB events, and the bimodal energy distribution reported in FRB 20121102A.
This study evaluated the short-term effects of acute low-dose gamma radiation on the induction of the radio-adaptive response (RAR) and its associated hematological and biophysical blood alterations. The limited understanding of early blood biophysical changes following low-dose exposure provides the rationale for this investigation. Male rats were exposed to single low gamma doses (0.25, 0.5, or 0.75 Gy), a single challenge dose (2 Gy), or a priming dose followed by 2 Gy. Blood conductivity and conductance were measured to assess membrane electrical properties. Hematological parameters, including hemoglobin, mean corpuscular volume (MCV), and red cell distribution width (RDW), were determined. Lipid peroxidation was evaluated by malondialdehyde (MDA) levels, while electron paramagnetic resonance (EPR) spectroscopy was used to quantify radiation-induced free radicals. Blood conductivity increased following exposure to 0.25, 0.5, and 0.75 Gy, as well as after 2 Gy and 0.75 Gy + 2 Gy, indicating increased red blood cell membrane permeability. Animals receiving a 0.5 Gy priming dose before the 2 Gy challenge exhibited a clear adaptive response, demonstrated by reduced membrane damage and improved MCV, RDW, and conductivity compared with the challenge-dose group. EPR analysis confirmed radiation-induced free radical generation, whereas MDA measurements supported the involvement of oxidative stress in radiation-associated membrane alterations. Among all priming doses, 0.5 Gy produced the most pronounced radio-adaptive response. The observed hematological and electrical changes appear to be associated with oxidative stress-mediated alterations in red blood cell membrane structure and function. These findings provide additional evidence for low-dose radiation-induced adaptation, contribute to understanding early blood biophysical responses, and may improve radiation risk assessment, radiation protection strategies, and approaches to reducing the biological effects of subsequent higher-dose exposures.
To evaluate the acute skin toxicity and treatment-related factors in patients undergoing breast re-irradiation in a tertiary cancer centre. A retrospective review was conducted of patients who received a repeat course of breast or chest wall radiation for ipsilateral breast cancer recurrence between April 20, 2011, and December 31, 2023. Patient characteristics, treatment parameters, and clinician-graded acute toxicity were recorded. Associations between toxicity and treatment factors were analyzed. Seventy patients met inclusion criteria. Acute skin toxicity was lower during retreatment than initial treatment with 22.9% of patients (n = 16) developing moderate/severe reactions during re-irradiation compared with 51.4% (n = 36) during the initial course. Severe toxicity at retreatment was not common, including moist desquamation in 10 patients (14.3%). Toxicity during the initial course did not predict toxicity during re-irradiation (P = .75). Across all fractionation schedules, no significant associations were observed between dose regimen and symptoms such as pruritus, pain, erythema, discoloration, edema, burning, dry desquamation or moist desquamation. Breast re-irradiation was well tolerated in the acute setting, with toxicity patterns influenced primarily by radiation dose and delivery. The findings emphasize the need for ongoing prospective work to assess long-term outcomes.
This paper updates radiation risk models for leukaemia and lymphoma incidence that can be applied to a variety of adult exposure scenarios and ages of onset of leukaemia and lymphoma, derived from the Life Span Study of atomic bomb survivors of Hiroshima and Nagasaki. Models were developed for four groups of haematological malignancies: acute lymphoblastic leukaemia (ALL), acute myeloblastic leukaemia (AML), chronic myeloid leukaemia (CML), and Hodgkin and non-Hodgkin lymphoma (LYM). Multi-model inference methodology was applied for all groups to construct flexible radiation risk models. The models revealed complex radiation risk patterns with strong dependencies on dose, age, and sex. The ALL group showed high radio-sensitivity with risk decreasing strongly with attained age. The AML group demonstrated a strong non-linear dose response requiring special considerations for fractionated or protracted exposures. The CML model showed a strong dependence on time since exposure. Excess relative risk for the lymphoma group was smaller than other groups and displayed significant sex differences. The developed models for leukaemia and lymphoma provide robust risk predictions for a large variety of adult exposure scenarios with ionising radiation. Multi-model inference proved to be an important tool in the construction of such flexible risk models. The models can be safely used in risk assessment tools or for lifetime risk evaluations.
The lens of the eye has been recognized as one of the most radiosensitive tissues in the human body. Radiation-induced cataractogenesis is believed to arise through a complex interplay of molecular processes, including crystallin protein oxidation and aggregation, impaired antioxidant defenses, apoptosis of lens epithelial cells, and epithelial-mesenchymal transition. Nonetheless, the precise mechanisms responsible for these changes remain to be fully elucidated. Organoid model systems are an emerging tool that provide a novel approach for investigating disease processes. In this study, we examined transcriptional changes in lentoid bodies, an organoid-like model of the ocular lens, following exposure to ionizing radiation. Lentoid bodies were generated from human pluripotent stem cells through a three-step differentiation protocol. Mature lentoid bodies were then subjected to an x-ray dose of 0.25 or 2 Gy and RNA was isolated 12, 24, and 48 hours post exposure for whole transcriptome RNA-sequencing. Genes were considered differentially expressed if they exhibited a fold change < -2.0 or >2.0, false discovery rate-corrected p-value <0.05, and a minimum average read count of 30 transcripts per million. Significant changes in gene expression profiles were observed post-irradiation with both dose and time post-exposure playing critical roles in the extent and nature of gene dysregulation. Differentially expressed genes were identified within key biological pathways implicated in cataract formation, including cell survival and proliferation, differentiation, migration, and epithelial-mesenchymal transition. These results advance our understanding of the molecular mechanisms underlying radiation-induced cataracts and demonstrate the value of lens organoid models as a physiologically relevant platform, offering insights beyond those achievable with conventional lens cell lines.
A non-Hermitian point gap (NHPG) is a unique phenomenon in non-Hermitian systems and induces a non-Hermitian skin effect (NHSE). In photonic crystals, NHPG and NHSE have previously been explored mainly through material loss, where the typically low Q factors make direct observation of complex frequencies challenging. Here, we demonstrate the direct experimental observation of an NHPG by using a radiation-loss-based non-Hermitian photonic crystal. Radiation loss can be engineered through structural design, enabling control of the imaginary part of the complex frequency and allowing relatively high Q factors. This approach is compatible with widely used absorption-free silicon-slab photonic crystals. We developed a measurement system that can measure photonic bands along arbitrary lines in k space. Our measurements showed complex-frequency loops of the NHPG in photonic crystals, and the reversal of non-Hermitian topology through the flip of the loop rotation in a complex plane. These results establish radiation-loss engineering as a practical route to directly measuring and controlling complex photonic band structures and bulk point-gap topology in nanophotonic systems without gain media or nonreciprocity.
We observe for the first time in silico the transition to a linear regime in the primary damage production in tungsten. As the critical plasma-facing material in fusion reactors, radiation damage in tungsten has been studied extensively in experiments and simulations. Irradiation experiments routinely produce recoils in the MeV range, while full atomistic modeling has been limited to a few hundred keV. Here we bridge these scales with extremely large-scale and accurate machine-learning-driven molecular dynamics simulations with recoil energies up to 2 MeV in systems up to 1×10^{9} atoms. We reveal four regimes of primary damage as a function of damage energy, with a transition to a high-energy regime that deviates from all previous models. Curiously, the start of the high-energy regime coincides with the highest possible recoil energy to tungsten atoms from fusion-emitted neutrons (300 keV).
Understanding dissipation in topological insulators is key to both fundamental physics and applications in spintronics, quantum computing, and low-power devices. Contrary to conventional expectations, dissipation in topological insulators need not rely on backscattering or dephasing: we show that finite-frequency local shot noise couples to the electromagnetic environment and generates near-field radiation, creating a nonlocal loss channel even at quantized conductance with vanishing global shot noise. Using a nonequilibrium Green's-function framework, we link the local noise tensor to the spectral Poynting vector and compute persistent local noise in realistic two- and three-probe quantum Hall/quantum anomalous Hall interfaces where inequivalent edge modes overlap. This produces near-field "hot spots" measurable by scanning microscopy. We also give a design criterion: enforce spin-sector orthogonality to eliminate edge-mode overlap, thereby suppressing this loss channel. Our results provide a microscopic mechanism for hidden dissipation and a practical blueprint for diagnosing and reducing energy loss in topological electronics.
This study presents a radioprotection assessment for an ultra-high dose rate accelerator installation in one of the animal housing of the Centre for Advanced Preclinical in vivo Research. The main problem concerns the absence of a bunker while limiting exposure in nearby work areas. The geometry of the accelerator, the building layouts and the distribution of the environmental dose equivalent were simulated with FLUKA.CERN 4-4.1, modeling a 9 MeV electron beam. The results confirmed compliance with the limit of 0.250 mSv/year for unrestricted areas during daytime operation. Night-time operating zone restrictions apply when no staff are present, allowing beam on for quality controls. The effective doses to the population, researchers and workers are less than 1 mSv/year, in accordance with Legislative Decree 101/2020; the accelerator operators are classified as exposed. For small animals, precautionary dose limit of 1 mSv/year was adopted. The use of lead shielding and site-specific safety measures ensure radiological compliance.
Boron neutron capture therapy (BNCT) has emerged as a promising cell-selective clinical treatment for recurrent glioblastoma as well as head and neck cancers. In recent years, BNCT has been implemented in several hospitals using accelerator-based neutron sources. However, direct online measurement of the incident neutron beam intensity during clinical BNCT remains a major challenge. Neutron dosimetry is typically inferred from the accumulated electric charge of the incident proton beam delivered to the beryllium neutron-production target. To improve the reliability of neutron beam control, it is essential to implement an online neutron-monitoring system that complements proton beam current measurements. Such a system enables precise real-time regulation of the neutron dose delivered to patients. In this study, we developed a new online neutron-beam monitoring technique capable of measuring the neutron beam intensity in real time. Reliable monitoring of neutron intensity at the patient position was achieved by detecting fast neutrons. The fast-neutron detector consisted of a silicon diode coupled with a high-density polyethylene neutron converter. The spatial distribution of neutrons was evaluated using Monte Carlo simulations to determine the optimal placement of the neutron beam monitor. The proposed method was validated through gold-activation analysis, cell irradiation experiments, and accelerator tuning. Online neutron-beam monitoring was successfully achieved by detecting fast neutrons at the end of the vacuum beam duct, where neutrons propagate directly without traversing radiation shielding. The neutron counting rate increased immediately at the onset of proton-beam irradiation and decreased upon its termination, exhibiting periodic fluctuations throughout the irradiation period. These fluctuations did not significantly affect the integrated neutron counts, as they were averaged over a typical BNCT irradiation time of approximately 30 min. The fast-neutron detector produced a mean counting rate of 124.6 counts per mC of incident proton-beam charge, with a relative standard deviation of 1.2%, and yielded a neutron-calibration factor of 4.9 × 10 6 cm - 2 per monitor unit. The neutron counting rates remained consistent even when different irradiation phantoms were placed at the patient position. The online neutron-beam monitoring technique using a fast-neutron detector demonstrated high reproducibility, as the neutron counting rates remained stable regardless of the irradiation phantom placed downstream.
To evaluate the feasibility, reproducibility, and operational impact of a structured, dose-aware 5-star CT image quality (IQ) rating system across multiple institutions and clinical indications. This retrospective, multinational, IAEA study included 2737 adult (1247 chest, 1490 abdomen) CT examinations across six hospitals in five countries of Europe. Three radiologists per hospital scored CT images using a standardized 5-star system designed to evaluate diagnostic IQ with consideration of radiation dose. Data collected included CT scanner type, clinical indication, patient characteristics, CTDIvol, and DLP. Inter-reader agreement, concordance of star ratings, and dose metrics were evaluated per hospital and clinical indication. The rating framework demonstrated robust reproducibility, with three-reader concordance reaching up to 93% in highly standardized centers and complete discordance remaining exceptionally rare (1.6% cases overall). A compelling inverse correlation between CTDIvol and star ratings was observed, especially for larger patients. Analysis by clinical indication revealed that some intrinsically noise-tolerant exams (for pulmonary nodules and kidney stones) showed high radiation exposure, highlighting an opportunity for optimization. Certain centers used higher-dose protocols, heavily skewing toward 2-star ratings. The 5-star CT IQ rating system is reproducible and supports dose-aware CT optimization. Noise-tolerant examinations should maintain diagnostic quality at lower radiation dose, supporting wider use of low-dose protocols. The method highlights opportunities for multinational and manufacturer-level protocol harmonization and may guide optimization strategies, including the number of series and reconstruction approaches.
Light therapies, such as photobiomodulation and photodynamic therapy, have demonstrated effective therapeutical response. However, external irradiation and targeting internal organs is challenging due to high light attenuation and the interindividual anatomical variability, strongly affecting light dosimetry. When considering lung diseases, such as pneumonia and inflammatory conditions, light dosimetry using transcutaneous delivery must consider the total light path from skin coupling through thoracic tissues to the fluence rate reaching the lungs. We here present a computational model based on Monte Carlo simulation developed in house to determine the light dosimetry in the lungs for different wavelengths in normal and diseased lungs. The simulation uses the actual anatomical models derived from human CT scans to generate 3D representations of the thoracic cavity, including 12 distinct tissue types. The lungs were segmented into normal, collapsed regions, infiltrate, and blood vessels. Wavelength-dependent absorption and scattering coefficients for each tissue type were estimated by the reported data in the literature. Our analysis focused on normalized energy deposition profiles defined as µa*fluence rate and fluence rate distributions within each lobe from normal, focal, and diffuse pneumonia, and COVID-19 conditions, under different irradiation positions. The results reveal significant variations in energy deposition and fluence rate distribution across different lung conditions and irradiation parameters, highlighting the need for individualized light dosimetry planning.
Despite advancements in breast cancer adjuvant therapies, some patients with indications may not receive treatment. We examined the association of self-reported racial/ethnic discrimination in patient-provider interactions and the receipt of clinically indicated therapies. The Pathways Study is a prospective cohort of women diagnosed with invasive breast cancer from 2005 to 2013 at Kaiser Permanente Northern California. Racial/ethnic discrimination in patient-provider interactions was assessed from the Interpersonal Processes of Care survey at baseline, 6 months, and 24 months post-diagnosis. Logistic regression compared women who did not initiate clinically-indicated adjuvant therapy with those who did overall, and by race and ethnicity. Covariates included race and ethnicity, age at diagnosis, country of birth, education level, income, marital status, and American Joint Committee on Cancer staging. Overall, 3,610 women had indication for hormonal therapy, 2,450 for chemotherapy, and 3,258 for radiation therapy. In multivariable analyses, women reporting discrimination were at increased odds of not initiating hormonal therapy (adjusted odds ratio [aOR] = 1.43, 95% CI = 1.05-1.93) than those who did not self-report discrimination, regardless of their race/ethnicity. An increased odds of non-initiation for reported discrimination was found for radiation therapy (aOR = 1.26, 95% CI = 0.99-1.61), although it was not statistically significant. There was no association for chemotherapy initiation (aOR = 0.96, 95% CI = 0.69-1.33). Self-reported racial/ethnic discrimination in patient-provider interactions was associated with the non-initiation of hormonal therapy in women with breast cancer. Further studies are needed to explore the impact of this association on breast cancer prognosis. Not applicable.
Robotic magnetic navigation (RMN) allows for catheter ablation in the presence of complex cardiac anatomy, such as that seen in congenital heart disease (CHD). The objective of this study was to evaluate the feasibility, efficacy and safety of this procedure in a wide range of CHD conditions. Patients with CHD who underwent catheter ablation for cardiac arrhythmias using RMN were included in this single-centre observational study. Patients' baseline characteristics, procedural data, periprocedural complications and acute success rates were obtained. The efficacy of the ablation was evaluated during follow-up in the outpatient clinic using 24-h Holter monitoring. The study population consisted of 38 patients (26 males) with a median age of 36.8 (IQR 30.8-39.6) years. Surgically corrected transposition of the great arteries was the most common CHD, observed in 14 patients (36.8%). Nineteen patients (50.0%) had more than one congenital defect. Intra-atrial re-entrant tachycardia was the most common arrhythmia ablated, accounting for 21 procedures (55.3%).Median procedural time was 232.5 min (IQR 186.3-281.3); the median radiation dose and radiation time were 2.4 mGy m2 (IQR 1.3-4.4) and 14.0 min (IQR 9.5-30.4), respectively. Acute arrhythmia cessation was observed in 81.6% of procedures. Major complications were noted in 2 cases (5.3%). The median time from the ablation to follow-up was 5.4 months (IQR 3.4-9.3). Arrhythmia recurrence was observed in 7 cases (18.4%). RMN is a valuable tool for catheter ablation of arrhythmias in patients with congenital heart disease and complex anatomy.
Acquired rectourethral fistulas (RUF) are uncommon but challenging problems in colorectal and urologic surgery. They are most commonly iatrogenic or secondary to trauma, inflammatory bowel disease, or infection. Standard management consists of colonic diversion, fistula tract division or excision, repair of defects of the structures involved (ie, urethra and rectum), and tissue interposition. Several techniques have been described for soft tissue interposition for RUF repair; however, there is a paucity of literature describing outcomes and comparing surgical options. Here, we present the posterior scrotal artery adipofascial (PSAF) flap, used to interpose healthy, vascularized soft tissue between the repaired rectum and urethra following division of RUF and to provide soft tissue coverage of other urologic defects. To our knowledge, this is the first description of this adipofascial flap in a male patient. We describe the surgical technique of the PSAF flap used as an interposition flap for iatrogenic urologic defects, most commonly RUF, by a single surgeon at a single institution. A retrospective case series is performed evaluating recurrence rates and other complications. The PSAF flap was used in 8 male patients from 2014 to 2026. Average age at time of surgery was 69.4±9.7 years. Six patients underwent PSAF flap for repair of RUF, 1 for urethrocutaneous fistula, and 1 for urethrectomy defect. Five patients reported a history of smoking, and 2 patients had prior radiation. Average follow-up was 40.0±45.8 weeks. Postoperatively, there were no fistula recurrences or other major complications in patients who underwent PSAF for RUF. One patient with a diagnosis of urethrocutaneous fistula experienced a recurrent fistula, and 1 patient reported persistent scrotal numbness. Six patients reported urinary incontinence postoperatively; 2 of these patients had reported incontinence before undergoing PSAF flap. The PSAF flap is a novel, safe option for tissue interposition in the setting of RUF repair. It can be reliably identified and dissected for coverage of iatrogenic urologic defects, even in the setting of advanced age, prior instrumentation, radiation, or prior smoking. High-powered studies with long-term follow-up are necessary to evaluate outcomes and compare the effectiveness of the PSAF flap to other reconstructive options.
Although the pressure amplitude of scattering and related nonlinear effects (e.g., the acoustic radiation force and torque) are widely studied, the modulation of spatial phase resulting from the interaction of vortex beams with scatterers has been less explored. In this paper, we investigate the lateral spatial phase of the backward scattering from an underwater elastic sphere in a Bessel vortex with the angular spectrum method. The resonance scattering is isolated by subtracting the background contribution from the total field based on the resonance scattering theory. A cross correlation method is proposed to locate the positions of singularities of spatial phase from scattering fields precisely. Our theoretical analysis shows that in a limited regime, the offset of the singularities of the spatial phase for the backscattering from a sphere is linearly proportional to the sphere's positions although, beyond this limit, the linear relation breaks. In addition, the modulation of the singularity offset versus the dimensionless frequency ka provides a possible way to evaluate the target size even though the resonance scattering is suppressed at a specific frequency. This work may facilitate an alternative method for the detection/classification of underwater targets with a new degree of freedom of the spatial phase.
In critically ill patients, postpyloric feeding via a nasojejunal (NJ) tube is essential for those at high risk of aspiration. However, traditional blind insertion techniques are associated with high failure rates and complications. This study aims to establish a standardized, bedside ultrasound-guided protocol for NJ tube placement to enhance safety and efficacy. The procedure involves real-time tracking of the NJ tube from the esophagus to the jejunum using both linear and curvilinear probes. Key technical steps include pre-procedural assessment of the gastric antral area and motility, cervical verification, and dynamic guidance through the pylorus. The protocol identifies specific sonographic markers for confirmation: the 'Double-Track Sign' serves as the static indicator of tube presence in the gastrointestinal tract, while the dynamic 'Cloud Sign' confirms tube patency and tip location. Real-time visualization enables immediate correction of complications, such as pharyngeal coiling or tracheal deviation. The method facilitates passage through the pylorus by synchronizing advancement with peristalsis. Ultrasound-guided NJ tube placement provides a bedside, radiation-free approach for visualizing tube trajectory and identifying malposition during the procedure. This protocol article presents representative sonographic findings during NJ tube progression; comparative outcomes such as first-attempt success rate, procedure time, and adverse event rates were not evaluated.