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OBJECTIVE: Clinical radiographic imaging is seated upon the principle of differential keV photon transmission through an object. At clinical x-ray energies the scattering of photons causes signal noise and is utilized solely for transmission measurements. However, scatter - particularly Compton scatter, is characterizable. In this work we hypothesized that modern radiation sources and detectors paired with deep learning techniques can use scattered photon information constructively to resolve superimposed attenuators in planar x-ray imaging.
METHODS: We simulated a monoenergetic x-ray imaging system consisting of a pencil beam x-ray source directed at an imaging target positioned in front of a high spatial- and energy-resolution detector array. The setup maximizes information capture of transmitted photons by measuring off-axis scatter location and energy. The signal was analyzed by a convolutional neural network, and a description of scattering material along the axis of the beam was derived. The system was virtually designed/tested using Monte Carlo processing of simple phantoms consisting of 10 pseudo-randomly stacked air/bone/water materials, and the network was trained by solving a classification problem.
RESULTS: From our simulations we were able to resolve traversed material depth information to a high degree, within our simple imaging task. The average accuracy of the material identification along the beam was 0.91±0.01, with slightly higher accuracy towards the entrance/exit peripheral surfaces of the object. The average sensitivity and specificity was 0.91 and 0.95, respectively.
CONCLUSIONS: Our work provides proof of principle that deep learning techniques can be used to analyze scattered photon patterns which can constructively contribute to the information content in radiography, here used to infer depth information in a traditional 2D planar setup. This principle, and our results, demonstrate that the information in Compton scattered photons may provide a basis for further development. The work was limited by simple testing scenarios and without yet integrating complexities or optimizations. The ability to scale performance to the clinic remains unexplored and requires further study.

We propose a sitting position that achieves both high image quality and a reduced radiation dose in elbow joint imaging by area detector computed tomography (ADCT), and we compared it with the \'superman\' and supine positions. The volumetric CT dose index (CTDIvol) for the sitting, superman, and supine positions were 2.7, 8.0, and 20.0 mGy and the dose length products (DLPs) were 43.4, 204.7, and 584.8 mGy • cm, respectively. In the task-based transfer function (TTF), the highest value was obtained for the sitting position in both bone and soft tissue images. The noise power spectrum (NPS) of bone images showed that the superman position had the lowest value up to approx. 1.1 cycles/mm or lower, whereas the sitting position had the lowest value when the NPS was greater than approx. 1.1 cycles/mm. The overall image quality in an observer study resulted in the following median Likert scores for Readers 1 and 2: 5.0 and 5.0 for the sitting position, 4.0 and 3.5 for the superman position, and 4.0 and 2.0 for the supine position. These results indicate that our proposed sitting position with ADCT of the elbow joint can provide superior image quality and allow lower radiation doses compared to the superman and supine positions.

OBJECTIVE: Target positions should be acquired during beam delivery for accurate lung stereotactic body radiotherapy. We aimed to perform kilovoltage (kV) imaging during beam irradiation (intra-irradiation imaging) under phase-gated conditions and evaluate its performance.
METHODS: Catphan 504 and QUASAR respiratory motion phantoms were used to evaluate image quality and target detectability, respectively. TrueBeam STx linac and the Developer Mode was used. The imaging parameters were 125 kVp and 1.2 mAs/projection. Flattened megavoltage (MV) X-ray beam energies 6, 10 and 15 MV and un-flattened beam energies 6 and 10 MV were used with field sizes of 5 × 5 and 15 × 15 cm2 and various frame rates for intra-irradiation imaging. In addition, using a QUASAR phantom, intra-irradiation imaging was performed during intensity-modulated plan delivery. The root-mean-square error (RMSE) of the CT-number for the inserted rods, image noise, visual assessment, and contrast-to-noise ratio (CNR) were evaluated.
RESULTS: The RMSEs of intra-irradiation cone-beam computed tomography (CBCT) images under gated conditions were 50-230 Hounsfield Unit (HU) (static < 30 HU). The noise of the intra-irradiation CBCT images under gated conditions was 15-35 HU, whereas that of the standard CBCT images was 8.8-27.2 HU. Lower frame rates exhibited large RMSEs and noise; however, the iterative reconstruction algorithm (IR) was effective at improving these values. Approximately 7 fps with the IR showed an equivalent CNR of 15 fps without the IR. The target was visible on all the gated intra-irradiation CBCT images.
CONCLUSIONS: Several image quality improvements are required; however, intra-irradiated CBCT images showed good visual target detection.

Deep learning CT reconstruction (DLR) has become increasingly popular as a method for improving image quality and reducing radiation exposure. Due to their nonlinear nature, these algorithms result in resolution and noise performance which are object-dependent. Therefore, traditional CT phantoms, which lack realistic tissue morphology, have become inadequate for assessing clinical imaging performance. We propose to utilize 3D-printed PixelPrint phantoms, which exhibit lifelike attenuation profiles, textures, and structures, as a better tool for evaluating DLR performance. In this study, we evaluate a DLR algorithm (Precise Image (PI), Philips Healthcare) using a custom PixelPrint lung phantom and perform head-to-head comparisons between DLR, iterative reconstruction, and filtered back projection (FBP) with scans acquired at a broad range of radiation exposures (CTDIvol: 0.5, 1, 2, 4, 6, 9, 12, 15, 19, and 20 mGy). We compared the performance of each resultant image using noise, peak signal to noise ratio (PSNR), structural similarity index (SSIM), feature-based similarity index (FSIM), information theoretic-based statistic similarity measure (ISSM) and universal image quality index (UIQ). Iterative reconstruction at 9 mGy matches the image quality of FBP at 12 mGy (diagnostic reference level) for all metrics, demonstrating a dose reduction capability of 25%. Meanwhile, DLR matches the image quality of diagnostic reference level FBP images at doses between 4 - 9 mGy, demonstrating dose reduction capabilities between 25% and 67%. This study shows that DLR allows for reduced radiation dose compared to both FBP and iterative reconstruction without compromising image quality. Furthermore, PixelPrint phantoms offer more realistic testing conditions compared to traditional phantoms in the evaluation of novel CT technologies. This, in turn, promotes the translation of new technologies, such as DLR, into clinical practice.

BACKGROUND: Clinical guidelines for the treatment of rheumatoid arthritis (RA) recommend reducing the use of glucocorticoids (GCs) due to the high risk of associated complications.
OBJECTIVE: To determine the frequency of GC cancellations and dose reductions in real clinical practice, while taking into account active RA therapy.
METHODS: The study group consisted of 303 patients with RA reliable according to ACR/EULAR criteria (women 79.9%, age 52.8±13.3, disease duration 9 [4; 16] years, DAS-28-CRP 4.9±1.0, RF seropositivity 77.4%, ACPA seropositivity 70.3%), who were prescribed or changed therapy with disease-modifying antirheumatic drugs (DMARDs), biologic disease-modifying antirheumatic drugs (bDMARDs) or Janus kinase inhibitors (iJAK) due to disease exacerbation and ineffectiveness of previous treatment. All patients initially received GC (7.7±3.8 mg/day equivalent of prednisolone). After adjustment of therapy, 42.9% of patients received methotrexate, 27.6% leflunomide, 2.5% sulfasalazine, hydroxychloroquine, or a combination with an Non-steroidal anti-inflammatory drugs, 63.7% bDMARDs, and 7.2% iJAK. The need for GC intake was assessed by a telephone survey conducted 6 months after the start of follow-up.
RESULTS: Telephone survey was possible in 274 (90.4%) persons. There was a significant decrease in pain intensity (numerical rating scale, NRS 0-10) from 6.3±1.4 to 4.3±2.4 (p<0.001), fatigue (NRS) from 6.7±2.3 to 5.2±2.1 (p<0.001), and functional impairment (NRS) from 5.4±2.1 to 3.9±2.0 (p<0.001). A positive PASS index (symptom status acceptable to patients) was noted in 139 (50.7%) patients. GC cancellation was noted in 19.7%, dose reduction in 25.9%, maintaining the same dose in 42.7%, and dose increase in 11.7%.
CONCLUSIONS: Against the background of intensive RA therapy, including combination of DMARDs with bDMARDs or iJAK, complete withdrawal or reduction of GC dose was achieved in less than half (45.6%) of patients after 6 months.
Обоснование. Актуальные клинические рекомендации по лечению ревматоидного артрита (РА) указывают на необходимость снижения использования глюкокортикоидов (ГК) в связи с высоким риском осложнений на фоне приема этих препаратов. Цель. Определить частоту отмен и снижения дозы ГК на фоне активной терапии РА в реальной клинической практике. Материалы и методы. Исследуемую группу составили 303 пациента с РА, достоверным по критериям ACR/EULAR (женщины – 79,9%, возраст – 52,8±13,3 года, длительность болезни – 9 [4; 16] лет, DAS-28-СРБ – 4,9±1,0, серопозитивность по ревматоидному фактору – 77,4%, по антителам к циклическому цитруллиновому пептиду – 70,3%), которым в связи с обострением заболевания и неэффективностью предшествующего лечения назначена или изменена терапия синтетическими базисными противовоспалительными препаратами (сБПВП), генно-инженерными биологическими препаратами (ГИБП) или ингибиторами янус-киназ (иJAK). Все пациенты исходно получали ГК (7,7±3,8 мг/сут в эквиваленте преднизолона). После коррекции терапии 42,9% пациентов получали метотрексат, 27,6% – лефлуномид, 29,5% – сульфасалазин, гидроксихлорохин или комбинацию сБПВП, 63,7% – ГИБП, 7,2% – иJAK. Оценивалась потребность в приеме ГК по данным телефонного опроса, проведенного через 6 мес после начала наблюдения. Результаты. Телефонный опрос удалось провести у 274 (90,4%) лиц. Отмечено достоверное снижение интенсивности боли (числовая рейтинговая шкала – ЧРШ 0–10) с 6,3±1,4 до 4,3±2,4 (p<0,001), усталости (ЧРШ) – с 6,7±2,3 до 5,2±2,1 (p<0,001), функциональных нарушений (ЧРШ) – с 5,4±2,1 до 3,9±2,0 (p<0,001). Положительный индекс PASS (состояние симптомов, приемлемое для пациентов) отмечен у 139 (50,7%) пациентов. Отмена ГК наблюдалась у 19,7%, снижение дозы – у 25,9%, сохранение прежней дозы – у 42,7%, повышение дозы – у 11,7%. Заключение. На фоне активной терапии РА, включающей комбинацию сБПВП с ГИБП или иJAK, через 6 мес удалось добиться полной отмены или снижения дозы ГК менее чем у 1/2 (45,6%) пациентов.

Background: Brentuximab Vedotin (BV) has revolutionized the treatment landscape for Hodgkin\'s lymphoma, yet its effects on pre-existing autoimmune disorders remain elusive. Methods: Here, we present four cases of patients with concurrent autoimmune conditions-Crohn\'s disease, vitiligo, type I diabetes, and minimal change disease-undergoing BV therapy for Hodgkin\'s lymphoma. The patients were treated with A-AVD instead of ABVD due to advanced-stage disease with high IPI scores. Results: Our findings reveal the surprising and complex interplay between BV exposure and autoimmune manifestations, highlighting the need for multidisciplinary collaboration in patient management. Notably, the exacerbation of autoimmune symptoms was observed in the first three cases where T-cell-mediated autoimmunity predominated. Additionally, BV exposure precipitated autoimmune thrombocytopenia in the vitiligo patient, underscoring the profound disruptions in immune regulation. Conversely, in the minimal change disease case, a disease characterized by a blend of B- and T-cell-mediated immunity, the outcome was favorable. Conclusions: This paper underscores the critical importance of vigilance toward autoimmune flare-ups induced by BV in patients with concurrent autoimmune conditions, offering insights for tailored patient care.

UNASSIGNED: The KRAS G12C inhibitor sotorasib was approved for treating advanced NSCLC in the second line or later on the basis of the CodeBreaK100 trial. Nevertheless, data on the real-world efficacy and safety of sotorasib, and to its optimal dose, remain limited.
UNASSIGNED: Patients treated with sotorasib for NSCLC through the Veterans Health Administration were retrospectively identified from the Corporate Data Warehouse. Survival, response, and toxicity data were obtained from chart review.
UNASSIGNED: Among the 128 patients treated with sotorasib through the Veterans Health Administration, objective response rate was 34%, progression-free survival (PFS) six months, and overall survival 12 months. Similar PFS was observed among the 16 patients who received frontline sotorasib without any prior systemic therapy for NSCLC. Toxicity leading to sotorasib interruption or dose reduction occurred in 37% of patients, whereas sotorasib discontinuation for toxicity occurred in 25%. Notably, sotorasib dose reduction was associated with substantially improved PFS and OS.
UNASSIGNED: In this real-world study, the observed efficacy of sotorasib was similar to the results of CodeBreaK100. Patients who received frontline sotorasib had similar PFS to our overall cohort, suggesting that first-line sotorasib monotherapy may benefit patients who are not eligible for chemotherapy. Toxicities leading to sotorasib interruption, dose reduction, or discontinuation were common. Sotorasib dose reduction was associated with improved survival, suggesting that sotorasib dose reduction may not compromise efficacy.

OBJECTIVE: The aims of this study were to investigate the prevalence of dose reduction in patients with SLE treated with belimumab (BEL) in Spain, analyze treatment modalities, and determine impact on control of disease activity.
METHODS: Retrospective longitudinal and multicentre study of SLE patients treated with BEL. Data on disease activity, treatments and outcomes were recorded before and after reduction (6-12 months), and they were compared.
RESULTS: A total of 324 patients were included. The dose was reduced in 29 patients (8.9%). The dosing interval was increased in 9 patients receiving subcutaneous BEL and in 6 patients receiving intravenous BEL. The dose per administration was reduced in 16 patients.Pre-reduction status was remission (2021 DORIS) in 15/26 patients (57.7%) and LLDAS in 23/26 patients (88.5%). After reduction, 2/24 patients (8.3%) and 3/22 patients (13.6%) lost remission at 6 months and 12 months, respectively (not statistically significant [NS]). As for LLDAS, 2/23 patients (8.7%) and 2/21 patients (9.5%) lost their status at 6 and 12 months, respectively (NS). Significantly fewer patients were taking glucocorticoids (GCs) at their 12-month visit, although the median dose of GCs was higher at the 12-month visit (5 [0.62-8.75] vs 2.5 [0-5] at baseline).
CONCLUSIONS: Doses of BEL can be reduced with no relevant changes in disease activity-at least in the short term-in a significant percentage of patients, and most maintain the reduced dose. However, increased clinical or serologic activity may be observed in some patients. Consequently, tighter post-reduction follow-up is advisable.

OBJECTIVE: The recommended dose of a rituximab course for the treatment of Rheumatoid Arthritis (RA) consists of two infusions of 1000 mg with a 2-week interval. Evidence is growing that a lower dose could be as effective. We aimed to investigate patients\' and rheumatologists\' perceptions on dose reduction of rituximab.
METHODS: Patients with RA treated with rituximab, and rheumatologists were invited for a qualitative study via individual semi-structured interviews. Participants were recruited based on purposive sampling to ensure diversity. Interviews were analysed according to the principles of grounded theory and the constant comparative method.
RESULTS: Sixteen patients and 13 rheumatologists were interviewed. Patients and rheumatologists perceived the benefits of rituximab dose reduction for reasons of safety and societal costs. Furthermore, available evidence for the effectiveness of lower doses was mentioned as an argument in favour, in addition to the possibility to tailor the dose based on the patients\' clinical manifestations. However, patients and rheumatologists had concerns about the potential loss of effectiveness and quality of life. Moreover, some rheumatologists felt uncomfortable with dose reduction due to insufficient experience with rituximab in general. Patients and rheumatologists emphasised the importance of shared decision-making, underscoring the pivotal role of physicians in this process by explaining the reasoning behind dose reduction.
CONCLUSIONS: Although some concerns on effectiveness were perceived, both patients and rheumatologists saw potential benefits of dose reduction in terms of safety, societal costs, and application of a personalised approach. As a result, most rheumatologists and patients showed a willingness to consider dose reduction strategies.