High-dose Radiation Research Articles

Abstract 4205: Investigating micro-environmental changes in a syngeneic radio-recurrent prostate cancer model

Abstract Approximately 1 in 8 men in Canada will be diagnosed with prostate cancer (PCa) in their lifetime, with ~20% presenting with high-risk disease. A standard treatment is radiotherapy (RT) and while many patients respond well to RT, up to 40% of men with high-risk disease can recur, often within the prostate. It can be challenging to salvage prostate relapses due to the morbidity of re-irradiation and the high rate of subsequent progression. The tumor micro-environment (TME) is altered after radiotherapy with increased immune-suppressor and immune-stimulatory effects occurring concurrently. Therapies capitalizing on these changes in the TME might provide an advantage to tackling radiation-recurrent cancer. Identifying TME changes in radio-recurrent PCa is the first step; however, existing PCa animal models do not accurately model the TME. Our collaborator’s lab has created the DVL3 mouse model with a clinically relevant TME. It forms tumors with distinct glandular morphology and displays micro-environmental responses to RT like what is seen in high-risk PCa patients, making this model an innovative tool for investigating radio-recurrence. The objective of this study is to create a radio-recurrent DVL3 PCa cell line to explore changes in the TME both in vitro and in vivo via orthotopic injection. To generate the radio-recurrent model, the DVL3 Parental cells (DVL3-Par) underwent a conventionally fractionated RT schedule (78Gy/39fx), herein referred to as DVL3-CF cells. The first part of the project involves in vitro characterization. Radiation resistance was evaluated via clonogenic assay which demonstrated a significant increase in clonogenic survival in the DVL3-CF cells relative to DVL3-Par. Characterization of DVL3-CF cells demonstrates that they are more proliferative at baseline, they recover quicker following G2/M blocks, they have decreased senescence following high dose radiation, and they are more invasive in vitro. The second part of the project evaluates the radio-recurrent model in vivo using an orthotopic mouse model as this best emulates the TME and clinical tumor progression. Parental and CF cells will be injected orthotopically into the prostate of C57/BL-6 mice and monitored for growth by MRI which will provide information on tumor volume as well as vasculature. At the time of sacrifice, the prostate and draining lymph nodes will be cryo-preserved and formalin fixed for downstream histological analysis. Transcriptional analyses, MRI data, and histological analysis of the tumors and draining lymph nodes will be compared across the radio-recurrent model and its parental cell line to evaluate environmental changes and potentially implicated mechanisms. This study will elucidate some of the complex interactions that are occurring within the TME of radio-recurrent PCa, increasing our understanding of mechanisms of radio-recurrence. Citation Format: Stephanie D. White, Xiaoyong Huang, Ian Mills, Stanley K. Liu. Investigating micro-environmental changes in a syngeneic radio-recurrent prostate cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4205.

Abstract 7057: Validation of OXPHOS gene amplification as a driver of treatment resistance in non-small cell lung cancer

Abstract Lung cancer is the leading cause of cancer deaths in the U.S. and worldwide. Up to 90% of all lung cancers are non-small cell lung cancer (NSCLC). NSCLC is a complex and highly aggressive disease typical for poor prognosis and high rates of treatment resistance. Clinical management of NSCLC varies according to the stage. High-dose stereotactic body radiation therapy (SBRT) is the standard of care for localized non-resectable NSCLC. However, tumor hypoxia is a significant barrier to effective radiation therapy. In the last decade, first line NSCLC treatment has been substantially reinforced with the introduction of immunotherapy targeting immune checkpoints such as programmed cell death 1 (PD-1), yet long-term disease control occurs in less than 25% of NSCLC patients. Therefore, understanding the mechanisms of treatment resistance is essential to address the dire need of introducing novel synergistic therapies to enhance anti-cancer treatment response in refractory NSCLC tumors. The basis of tumor hypoxia has traditionally been attributed to the oxygen supply deficit as malformed tumor vasculature fails to meet the high demand of the rapidly proliferating tumor mass. However, our preliminary analysis of NSCLC patient datasets in the Cancer Genome Atlas (TCGA) PanCancer dataset revealed a significant correlation between high-level expression of nuclear genes encoding mitochondrial subunits essential for oxidative phosphorylation (OXPHOS), and high-level expression of hypoxia-regulated genes (Buffa hypoxia score). Furthermore, we have observed a direct correlation between copy number amplification (CNA) of several OXPHOS genes and hypoxia levels in patient samples. Because mitochondrial function consumes up to 90% of available cellular oxygen, its activity may be indirectly regulating oxygen availability in the tumor microenvironment by rapidly consuming oxygen upon its delivery to the tumor. Moreover, we have identified that almost 40% of NSCLC patients harbor CNA of these essential OXPHOS genes. To provide mechanistic insight into these clinical observations, we have generated mouse syngeneic NSCLC cell lines with modified mRNA expression levels of OXPHOS genes (representing deletion, diploid and amplified number of copies) identified in our screen and observed a direct effect on the rates of mitochondrial oxygen consumption in these cells. Our study investigates the previously unknown role of OXPHOS gene copy number in driving mitochondrial oxygen demand and thus contributing to tumor hypoxia and treatment resistance in NSCLC. Citation Format: Martin Benej, Katarina Benejova, Rebecca Hoyd, Caroline Wheeler, Daniel Spakowicz, Nicholas C. Denko. Validation of OXPHOS gene amplification as a driver of treatment resistance in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7057.

Local Diagnostic Reference Levels for Adult Computed Tomography Urography Exams.

A Computed Tomography Urography (CTU) scan is a medical imaging test that examines the urinary tract, including the bladder, kidneys, and ureters. It helps diagnose various urinary tract diseases with precision. However, patients undergoing CTU imaging receive a relatively high dose of radiation, which can be a concern. In our research paper, we analyzed the Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP) for 203 adult patients who underwent CTU at one of the most important regional centers in Bosnia and Herzegovina that sees a large number of patients. Our study included the distribution of age and sex, the number of phases within one examination, and different clinical indications. We compared our findings with the results available in the scientific literature, particularly the recently published results from 20 European countries. Furthermore, we established the local diagnostic reference levels (LDRLs) that can help set the national diagnostic reference levels (NDRLs). We believe our research is a significant step towards optimizing the protocols used in different hospitals in our country.

A study of the effect of γ-radiation on the current-carrying mechanism in the P-CuTlS2 single crystal

The electrical conductivity and volt–ampere characteristics (VAC) of the p-CuTlS2 single crystal with specific resistance [Formula: see text] and irradiated by [Formula: see text]-quantum were studied in the range of 100–300[Formula: see text]K temperature and 10–104[Formula: see text]V/cm. It was determined that the cause of the conduction disorder observed in the CuTlS2 single crystal at low electric fields and high radiation doses is the formation of defect clusters dominated by cation vacancies. A sharp increase in current at high electric fields and temperatures occurs as a result of thermo-field ionization of the acceptor level with activation energy [Formula: see text][Formula: see text]eV and the ionization voltage decreases with increasing radiation dose. Based on the determination of the parameters ([Formula: see text]) that determine the mechanism of current flow, the dependence of the shape of the potential hole on the radiation dose was determined.

MnO2 nanozyme with lanthanide-based radiosensitization for advanced radiotherapy by tumor microenvironment triggering STING pathway activation

Radiotherapy, being a primary approach for cancer treatment, is plagued by systemic toxicity resulting from high-dose radiation, as well as radioresistance due to the unique characteristics of tumor microenvironment (TME), including hypoxia, high expression of reducing substances and immunosuppression. The collaboration between radiosensitization and manipulation of the TME has the potential to surmount the challenges associated with advanced radiotherapy. Here, we propose a radiosensitization approach that involves enhancing X-ray deposition through physical means, while simultaneously reducing radioresistance and activating the stimulator of interferon genes (STING) pathway using a nanozyme that mimics natural enzymatic activity. This is achieved by fabricating a lanthanide ion radiosensitizer-based multifunctional enzyme activity nanoplatform, MnO2@NaGdF4:5%Nd@NaYbF4:20%Nd(MN). In the TME, the NaGdF4:5%Nd@NaYbF4:20%Nd radiosensitizer sensitizes cancer cells to X-ray. The MnO2 exhibits catalase-like (CAT) activity, enabling it to catalyze the conversion of H2O2 into O2, thereby alleviating tumor hypoxia. Additionally, MnO2 reacts with overexpressed glutathione (GSH) by glutathione oxidase-like (GSHOx) activity to generate Mn2+ ions. This reaction optimizes the function of ·OH, which can also be produced by the released Mn2+ through a Fenton-like reaction. The DNA damage caused by ·OH can be detected by cyclic GMP-AMP synthase (cGAS) to activate STING pathway, which also can be activated by the released Mn2+ ion. Through a two-pronged strategy with radical oxygen species overproduction and STING pathway activation, the lanthanide doped radiosensitizer-based MN can be relied upon to deliver highly effective radiotherapy.

The LHCb VELO Upgrade II: Design and development of the readout electronics

In 2032–2034, the LHCb will be upgraded to efficiently explore the new HL-LHC conditions. The increased number of interactions per event and radiation level brings several challenges including high non-uniform radiation doses (up to 6×1016MeVneq/cm2), operation under vacuum (power dissipation below 1.5 W/cm2), high data rates (up to order of 100 Gbps/ASIC) and ASIC timing resolution (30 ps or better). This proceedings describes the requirements for two different upgrade scenarios (different pixel pitch, radiation doses and material budget while keeping the same scattering terms), application specific integrated circuit status to readout the sensor pixels (PicoPix and IGNITE), electronic integration (Anisotropic Conductive Bonding) and data transmission (FALAPHEL). In summary, the open challenges mentioned before are being addressed in the current R&D phase and the most suitable candidate solutions will be consolidated in the technical design report in the coming years.

A potential novel technique for measurement of pulp volume on periapical radiography: A pilot study.

Pulp volume can be assessed during dental treatment. Three-dimensional imaging techniques are not routinely used for this purpose because of high radiation doses. This study aimed to develop a novel method to measure pulp volume using periapical radiography. In this study, cone-beam computed tomography (CBCT) was used as a reference method. Periapical radiography and CBCTs obtained from the same patients (n = 32) were recorded. Pulp volume was determined by observing the density differences between the pulp and peripheral structures using ImageJ. A method of graph and volume calculation was developed for each tooth. The Shapiro-Wilk test and Mann-Whitney U test were used to show normality and non-normal distributions. The Bland-Altman plot was used to show the scattering of the mean versus difference values of the measurements of the two methods used to calculate the pulp volume. Normality was evaluated using the Shapiro-Wilk test. CBCT measurements are normally distributed (p = 0.307), while ImageJ is not normally distributed (p = 0.027). Therefore, the mean difference between the two groups was analyzed using the nonparametric Mann-Whitney U test. There was a statistically significant difference between the CBCT and ImageJ measurements (p = 0.01). According to Spearman's correlation analysis, the results obtained from the novel method were moderately correlated with those obtained from the reference method (r = 0.444). The results of this study indicated that a novel method-based Java software can be used to calculate pulp volume using low-dose radiation containing periapical radiography.

RADIOPROTECTIVE PROTEIN OF TARDIGRADE DSUP (DAMAGE SUPPRESSOR) IS RESISTANT TO HIGH DOSES OF IONIZING RADIATION

The unique Dsup protein of the tardigrade Ramazzottiusvarieornatus increases resistance to radiation and oxidative stress in various species of organisms and in human cell culture. According to modeling data,Dsup forms a complex with DNA with an intermolecular distance of ∼4˚A, as a result of which DNA is lessdamaged by reactive oxygen species formed during exposure to radiation.However, the stability of the Dsupprotein itself under the in uence of ionizing radiation remains unclear, which is important for assessing its radioprotective potential and understanding the molecular mechanisms of the action of this protein under conditions of high doses of radiation. In this work, the radiation degradation of the Dsup protein after γ-ray irradiation by small-angle X-ray scattering (SAXS) and protein electrophoresis in polyacrylamide gel under denaturing conditions (SDS-PAGE) was studied for the rst time.It has been shown that, in contrast to the control bovine serum albumin, the spatial and structural characteristics of the Dsup protein remain almost unchanged even when exposed to high doses of radiation (5 and 10 kGy), which suggests its high radiation stability.

Ultrathin and Biodegradable Bismuth Oxycarbonate Nanosheets with Massive Oxygen Vacancies for Highly Efficient Tumor Therapy.

Nanomaterials doped with high atom number elements can improve the efficacy of cancer radiotherapy, but their clinical application faces obstacles, such as being difficult to degrade in vivo, or still requiring relatively high radiation dose. In this work, a bismuth oxycarbonate-based ultrathin nanosheet with the thickness of 2.8nm for safe and efficient tumor radiotherapy under low dose of X-ray irradiation is proposed. The high oxygen content (62.5% at%) and selective exposure of the facets of ultrathin 2D nanostrusctures facilitate the escape of large amounts of oxygen atoms on bismuth nanosheets from surface, forming massive oxygen vacancies and generating reactive oxygen species that explode under the action of X-rays. Moreover, the exposure of almost all atoms to environmental factors and the nature of oxycarbonates makes the nanosheets easily degrade into biocompatible species. In vivo studies demonstrate that nanosheets could induce apoptosis in cancer cells after low dose of X-ray irradiation without causing any damage to the liver or kidney. The tumor growth inhibition effect of radiotherapy increases from 49.88% to 90.76% with the help of bismuth oxycarbonate nanosheets. This work offers a promising future for nanosheet-based clinical radiotherapies of malignant cancers.

Proapoptotic effects of ceranib-2 in combination with radiation therapy on human breast cancer cells.

Strategies for cancer therapy involve radiation therapy (RT), which accounts for about 40% of all cancer treatment types. As to current chemotherapeutics, cancer cells also develop resistance that remains a clinical problem, such as disease recurrence. Recent studies focused on understanding the molecular mechanisms of radiation-induced cell death. Conventional RT aims at treatment with a single fraction per day of 8-30 Gy per fraction. Radiotherapy increases intracellular ceramide levels that trigger cell death. Additionally, increasing intracellular ceramide by radiation may restore therapeutic sensitivity to cancer treatments. Drugs that inhibit ceramide-metabolizing enzymes like ceramidases are expected to be radiotherapy sensitizers. In this research, we investigated the proapoptotic effects of SRS alone and in combination with ceranib-2, a ceramidase inhibitor in human breast adenocarcinoma cells. The molecular mechanism of action of RT and ceranib-2 was investigated on MCF-7 cells exposed to 13 µM ceranib-2 for 24 hours following 20 Gy radiation using MTT, radiotherapy, and annexin-V analyses. Results indicated that the dose of 20 Gy radiation induces apoptosis on human breast cancer cells with and without co-treatment with ceranib-2 by causing cytotoxicity in the cells. Based on the results of ceranib-2 exposure, it can be concluded that the mechanism of action may rely on an increase of intracellular ceramides, also called apoptotic lipids. The study results suggest that co-treatment of human breast adenocarcinoma cells with a ceramidase inhibitor, ceranib-2, and a high dose of radiation of 20 Gy exerted cytotoxicity and apoptosis and might be a solid, potent alternative to current therapy strategies.

Proteomic changes in the hippocampus of large mammals after total-body low dose radiation.

There is a growing interest in low dose radiation (LDR) to counteract neurodegeneration. However, LDR effects on normal brain have not been completely explored yet. Recent analyses showed that LDR exposure to normal brain tissue causes expression level changes of different proteins including neurodegeneration-associated proteins. We assessed the proteomic changes occurring in radiated vs. sham normal swine brains. Due to its involvement in various neurodegenerative processes, including those associated with cognitive changes after high dose radiation exposure, we focused on the hippocampus first. We observed significant proteomic changes in the hippocampus of radiated vs. sham swine after LDR (1.79Gy). Mass spectrometry results showed 190 up-regulated and 120 down-regulated proteins after LDR. Western blotting analyses confirmed increased levels of TPM1, TPM4, PCP4 and NPY (all proteins decreased in various neurodegenerative processes, with NPY and PCP4 known to be neuroprotective) in radiated vs. sham swine. These data support the use of LDR as a potential beneficial tool to interfere with neurodegenerative processes and perhaps other brain-related disorders, including behavioral disorders.

Consensus guidelines for the management of posterior fossa tumour for low- and middle-income countries.

The posterior fossa is a limited compartment therefore lesions compressing its structures can result in devastating outcomes. It can cause significant neurological deficit due to mass effect on critical structures and hydrocephalus. Due to the nature of the infratentorial region, urgent surgical intervention is often the first-line option. Surgical neuro-oncologists guide patients and caregivers through the course of this disease and to inform them about the various options for management and long-term outcome optimisation. There is currently conflicting data; however, institutional experiences can guide us towards achieving improvements in surgical outcomes and quality of life. Advances in molecular classifications coupled with highdose radiation treatment improve our capacity for improving overall survival in these patients. Common childhood tumours are ependymomas, medulloblastomas, and juvenile pilocytic astrocytomas, while adults often present with metastases, and less commonly, cerebellar haemangioblastomas and gliomas. This paper outlines management strategies with consideration for multidisciplinary care and resourcelimited settings.

Digital twins in dosimetry and radiotherapy, a survey and some applications

Digital Twins (DTs) are emerging as a powerful tool in several applications, including Dosimetry and Radiotherapy (RT). Indeed, DTs have increased their effectiveness, up to the point that can be considered as virtual replicas of physical objects, processes, or systems. Through predictive modeling, DTs can determine optimal doses in radiation therapy, assist in defining personalized treatment schedules for individual patients, and monitor treatment responses. Moreover, DTs play a pivotal role in designing radioisotope production processes in the field of nuclear medicine. This can help to ensure the most effective treatment possible while minimizing the risk of side effects.As a frontier case example, DTs can be employed in the analysis of a possible new source for flash radiotherapy worth with respect to their effectiveness parameters like Radio-Biological Effectiveness (RBE) or cell Surviving Fraction (SF). Flash techniques involve the delivery of a high dose of radiation in a short time, reducing damage to surrounding healthy tissue while possibly increasing damage to malignant cells. DTs could be used to simulate and collect data about particle interactions with the treated tissues, optimizing the treatment and leading to improved outcomes.The most powerful tools that can be applied in DTs development are the Monte Carlo (MC) codes, particularly those with the highest capability of a detailed material/geometry description through an automatized spatial discretization approach like the one based on Unstructured Mesh (UM), allowing a common mathematical domain for both particle/radiation transport and thermal, fluid-dynamics and mechanical simulations. What comes out from various kind of applications is a common ground in terms of data management, phase space identification, simulation tools, that can be easily recognized even if spanning from cell response to technological devices, making realistic the perspective of the setup of general optimization procedures.

Radiation dose during contemporary percutaneous coronary interventions for chronic total occlusion: insights from the PROGRESS-CTO registry.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with high radiation doses. In this manuscript, we examined the contemporary trends and determinants of radiation dose in the PROGRESS CTO (Prospective Global Registry for the Study of CTO Intervention; Clinicaltrials.gov identifier: NCT02061436) registry. Radiation dose during CTO PCI did not change significantly since 2020, highlighting the need for innovation and operator education to further maintain radiation safety.

Deformable 3D/3D CT-to-digital-tomosynthesis image registration in image-guided bronchoscopy interventions

Traditional navigational bronchoscopy procedures rely on preprocedural computed tomography (CT) and intraoperative chest radiography and cone-beam CT (CBCT) to biopsy peripheral lung lesions. This navigational approach is challenging due to the projective nature of radiography, and the high radiation dose, long imaging time, and large footprints of CBCT. Digital tomosynthesis (DTS) is considered an attractive alternative combining the advantages of radiography and CBCT. Only the depth resolution cannot match a full CBCT image due to the limited angle acquisition. To address this issue, preoperative CT is a good auxiliary in guiding bronchoscopy interventions. Nevertheless, CT-to-body divergence caused by anatomic changes and respiratory motion, hinders the effective use of CT imaging. To mitigate CT-to-body divergence, we propose a novel deformable 3D/3D CT-to-DTS registration algorithm employing a multistage, multiresolution approach and using affine and elastic B-spline transformation models with bone and lung mask images. A multiresolution strategy with a Gaussian image pyramid and a multigrid strategy within the B-spline model are applied. The normalized correlation coefficient is included in the cost function for the affine model and a multimetric weighted cost function is used for the B-spline model, with weights determined heuristically. Tested on simulated and real patient bronchoscopy data, the algorithm yields promising results. Assessed qualitatively by visual inspection and quantitatively by computing the Dice coefficient (DC) and the average symmetric surface distance (ASSD), the algorithm achieves mean DC of 0.82±0.05 and 0.74±0.05, and mean ASSD of 0.65±0.29mm and 0.93±0.43mm for simulated and real data, respectively. This algorithm lays the groundwork for CT-aided intraoperative DTS imaging in image-guided bronchoscopy interventions with future studies focusing on automated metric weight setting.

Synthetic interpolated DSA for radiation exposure reduction via gamma variate contrast flow modeling: a retrospective cohort study

BackgroundDigital subtraction angiography (DSA) yields high cumulative radiation dosages (RD) delivered to patients. We present a temporal interpolation of low frame rate angiograms as a method to reduce cumulative RDs.MethodsPatients undergoing interventional evaluation and treatment of cerebrovascular vasospasm following subarachnoid hemorrhage were retrospectively identified. DSAs containing pre- and post-intervention runs capturing the full arterial, capillary, and venous phases with at least 16 frames each were selected. Frame rate reduction (FRR) of the original DSAs was performed to 50%, 66%, and 75% of the original frame rate. Missing frames were regenerated by sampling a gamma variate model (GVM) fit to the contrast response curves to the reduced data. A formal reader study was performed to assess the diagnostic accuracy of the “synthetic” studies (sDSA) compared to the original DSA.ResultsThirty-eight studies met inclusion criteria (average RD 1,361.9 mGy). Seven were excluded for differing views, magnifications, or motion. GVMs fit to 50%, 66%, and 75% FRR studies demonstrated average voxel errors of 2.0 ± 2.5% (mean ± standard deviation), 6.5 ± 1.5%, and 27 ± 2%, respectively for anteroposterior projections, 2.0 ± 2.2%, 15.0 ± 3.1%, and 14.8 ± 13.0% for lateral projections, respectively. Reconstructions took 0.51 s/study. Reader studies demonstrated an average rating of 12.8 (95% CI 12.3−13.3) for 75% FRR, 12.7 (12.2−13.2) for 66% FRR and 12.0 (11.5−12.5) for 50% FRR using Subjective Image Grading Scale. Kendall’s coefficient of concordance resulted in W = 0.506.ConclusionFRR by 75% combined with GVM reconstruction does not compromise diagnostic quality for the assessment of cerebral vasculature.Relevance statementUsing this novel algorithm, it is possible to reduce the frame rate of DSA by as much as 75%, with a proportional reduction in radiation exposure, without degrading imaging quality.Key points• DSA delivers some of the highest doses of radiation to patients.• Frame rate reduction (FRR) was combined with bolus tracking to interpolate intermediate frames.• This technique provided a 75% FRR with preservation of diagnostic utility as graded by a formal reader study for cerebral angiography performed for the evaluation of cerebral vasospasm.• This approach can be applied to other types of angiography studies.Graphical

Separation surgery for metastatic spine tumors: How less became more.

Metastatic epidural spinal cord compression (MESCC) is an increasingly common clinical entity in cancer patients and is associated with significant morbidity and neurologic sequalae. Management of MESCC has undergone many significant paradigms shifts over the past 50 years and was at times managed exclusively with either surgery or radiation. Historically, aggressive surgical techniques to achieve en bloc or intralesional gross tumor resections were pursued but were associated with significant morbidity and poor tumor control rates when combined with conventional external beam radiation. However, improvements in radiation treatment delivery in the form of stereotactic body radiation therapy have allowed for the safe delivery of high-dose conformal photon beam radiation providing histology-independent ablative responses. This shifted the goals of surgery away from maximal tumor resection toward simple spinal cord decompression with reconstitution of the thecal to create a tumor target volume capable of being irradiated within the constraints of spinal cord tolerance. This new approach of creating space between the thecal sac and the tumor was termed separation surgery and when combined with postoperative SBRT, it is referred to as hybrid therapy. Herein, we will describe the evolution of the management of MESCC, the technique of separation surgery and its outcomes, and finish with an illustrative case example.

Characterizing the Early Acidic Response in Advanced Small Modular Reactors Cooled with High-Temperature, High-Pressure Water

Utilizing Monte Carlo multi-track chemistry simulations along with a cylindrical instantaneous pulse (Dirac) irradiation model, we assessed the initial acidic response in both subcritical and supercritical water under high radiation dose rates. This investigation spans a temperature range of 300 to 500 °C at a nominal pressure of 25 MPa, aligning with the operational conditions anticipated in proposed supercritical water (SCW)-cooled small modular reactors (SCW-SMRs). A pivotal finding from our study is the observation of a significant ‘acid spike’ effect, which shows a notable intensification in response to increasing radiation dose rates. Our results bring to light the potential risks posed by this acidity, which could potentially foster a corrosive environment and thereby increase the risk of accelerated material degradation in reactor components.

A Multicentric Audit to Reevaluate the Guidelines Adherence in Computed Tomography of Kidneys, Ureters, and Bladder (CT-KUB) X-ray Imaging in Jordan.

Background With the increasing use of imaging techniques involving ionizing radiation, the area of the body scanned should be restricted to what is required to answer the clinical question. Therefore, this is a retrospective audit that intends to evaluate the presence of overscanning in renal computed tomography (CT) scan images during the process of evaluation for urinary symptoms. Objective This study aims to reduce the unnecessary scan length and exposure to radiation in patients who undergo CT scans for urinary symptoms. Materials and Methods In two months duration, patients from different clinics underwent CT imaging, and the resulting radiographic images were collected and analyzed. Overscanning was defined to be more than 10% of the total scan. Subsequently, the total length of the CT scan was measured which is used to measure the unnecessary overscan above the highest kidney margin as a percentage of the total length. Results Out of the 88 patients who were evaluated, 100% did not meet the guidelines for renal CT imaging and were exposed to a high radiation dose. However, the minimum percentage of overscanned patients was 20-40%. Conclusion A significant number of scans demonstrated surplus overscanning above the highest kidney. Therefore, recognizing the suitable anatomical landmarks for scanning and establishing a follow-up audit are suggested measures to minimize the noxious effects of radiation exposure.

A Meta-Analysis and Review of Radiation Dose Escalation in Definitive Radiation Therapy between Squamous Cell Carcinoma and Adenocarcinoma of Esophageal Cancer

Esophageal cancer, ranked as the eighth most prevalent cancer globally, is characterized by a low survival rate and poor prognosis. Concurrent chemoradiation therapy (CCRT) is the standard therapy in the non-surgical treatment of localized carcinoma of the esophagus. Nevertheless, the radiation doses employed in CCRT remain notably lower compared to the curative definite chemoradiation therapy utilized in the management of other carcinomas. In order to increase the local control rates and enhance the treatment outcomes, several clinical trials have used high-dose radiation to analyze the effect of dose escalation. Despite the integration of technically advanced RT schemes such as intensity-modulated radiation therapy (IMRT), the results of these trials have failed to demonstrate a significant improvement in overall survival or local progression-free survival. In this review, we investigated previous clinical trials to determine the ineffectiveness of radiation dose escalation in the context of CCRT for esophageal cancer. We aim to clarify the factors contributing to the limited efficacy of escalated radiation doses in improving patient outcomes. Furthermore, we delve into recent research endeavors, exploring prospective radiation dose modifications being altered based on the histological characteristics of the carcinoma. The exploration of these recent studies not only sheds light on potential refinements to the existing treatment protocols but also seeks to identify novel approaches that may pave the way for more efficacious and personalized therapeutic strategies for esophageal cancer management.