Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 928
Filtrar
1.
Mol Ther Nucleic Acids ; 35(3): 102229, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38952440

RESUMO

p47 phox -deficient chronic granulomatous disease (p47-CGD) is a primary immunodeficiency caused by mutations in the neutrophil cytosolic factor 1 (NCF1) gene, resulting in defective NADPH oxidase function in phagocytes. Due to its complex genomic context, the NCF1 locus is not suited for safe gene editing with current genome editing technologies. Therefore, we developed a targeted NCF1 coding sequence knock-in by CRISPR-Cas9 ribonucleoprotein and viral vector template delivery, to restore p47 phox expression under the control of the endogenous NCF2 locus. NCF2 encodes for p67 phox , an NADPH oxidase subunit that closely interacts with p47 phox and is predominantly expressed in myeloid cells. This approach restored p47 phox expression and NADPH oxidase function in p47-CGD patient hematopoietic stem and progenitor cells (HSPCs) and in p47 phox -deficient mouse HSPCs, with the transgene expression following a myeloid differentiation pattern. Adeno-associated viral vectors performed favorably over integration-deficient lentiviral vectors for template delivery, with fewer off-target integrations and higher correction efficacy in HSPCs. Such myeloid-directed gene editing is promising for clinical CGD gene therapy, as it leads to the co-expression of p47 phox and p67 phox , ensuring spatiotemporal and near-physiological transgene expression in myeloid cells.

2.
Cureus ; 16(6): e61544, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38962615

RESUMO

Locally advanced cervical cancers are often treated with palliative intent due to concerns that the tumor is too far advanced or too large to be treated curatively. Also, patients greater than 65 years of age with cervical cancer are sometimes regarded as being too old or too frail to be cured with combined radiation and chemotherapy. These patients are often treated with radiation alone or with palliative therapy. Understanding the treatment modalities for cervical cancer is essential, as they can be complex and unique to each patient's specific diagnosis. This case report aims to describe the dramatic response to treatment with combined radiation and chemotherapy for a patient greater than 65 years of age with pelvis-filling cervical cancer with right-sided hydronephrosis. After a five-week course of concurrent chemoradiation, the cervical mass radiographically completely disappeared, with no evidence of disease noted on pelvic MRI.

3.
Radiother Oncol ; 199: 110426, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38997094

RESUMO

BACKGROUND: Single-dose high-dose-rate brachytherapy (SD-HDR-BT) was compared to two or three fraction HDR BT in intermediate and high-risk localized prostate cancer with median follow-up of 10 years. MATERIALS AND METHODS: 293 patients received 1 × 19Gy or 1 × 20Gy (Group A = 49), 2 × 13Gy (Group B = 138), or 3 × 10.5 Gy (Group C = 106) HDR BT. The primary endpoint was biochemical relapse-free interval (bRFI). Late genitourinary (GU) and gastrointestinal (GI) morbidity used RTOG scales and the International Prostate Symptom Score (IPSS). Freedom from biochemical relapse (bRFI), overall survival (OS) and GU, GI and IPSS morbidity were calculated using Kaplan-Meier (K-M) method and log-rank test. Univariate and multivariate hazard ratios (HR) were obtained using Cox's proportional hazard. RESULTS: At 10 years, K-M estimates of bRFI were 64 % (Group A), 72 % (Group B), and 76 % (Group C) (p = 0.2). No statistically significant difference was seen in OS. In multivariate analysis risk-category and ADT administration, but not dose, were significant predictors of relapse (p = 0.0003 and 0.03, respectively). At ten years, GU grade 3 events were 8 % (A), 2 % (B) and 13 % (C); (p = 0.01). IPSS ≥ 20 was 31 % (A), 20 % (B) and 23 % (C); (p = 0.6) and grade 3 GI was 0 % in groups A and B and 2 % in C; (p = 0.3). No GU or GI grade-4 events were observed. Pre-treatment IPSS was a highly significant predictor of failure in multivariate analysis. CONCLUSIONS: Long-term outcome data show reduced but not statistically significant difference in PSA control, and no difference in overall survival, between SD-HDR-BT and 2 or 3 fractions of HDR-BT.

4.
Clin Genet ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940299

RESUMO

HDR syndrome is a rare disease characterized by hypoparathyroidism, deafness, and renal dysplasia. An autosomal dominant disease caused by heterozygous pathogenic GATA3 variants, the penetrance of each associated condition is variable. Literature reviews have provided some answers, but many questions remain, in particular what the relationship is between genotype and phenotype. The current study examines 28 patients with HDR syndrome combined with an exhaustive review of the literature. Some conditions such as hearing loss are almost always present, while others described as rare initially, do not seem to be so rare after all (genital malformations and basal ganglia calcifications). By modeling pathogenic GATA3 variants found in HDR syndrome, we found that missense variations appear to always be located in the same area (close to the two Zinc Finger domain). We describe new pathogenic GATA3 variants, of which some seem to always be associated with certain conditions. Many audiograms were studied to establish a typical audiometric profile associated with a phenotype in HDR. As mentioned in the literature, hearing function should always be assessed as early as possible and follow up of patients with HDR syndrome should include monitoring of parathyroid function and vesicoureteral reflux in order to prevent complications.

5.
J Appl Clin Med Phys ; : e14392, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38742858

RESUMO

PURPOSE: The purpose of this study was to validate the use of a model-based dose calculation algorithm (MBDCA), Acuros BV, for high dose rate brachytherapy treatment planning for a community-based hospital with a Bravos afterloader. Based on published AAPM recommendations, this work details a practical approach for community-based clinics to complete initial validation of Acuros BV, in order to add a MBDCA to a TG-43 based brachytherapy treatment planning program. METHODS: Source dimensions and materials used in Acuros BV and TG-43 source models were compared to the physical source. TG-186 testing was completed with standardized test cases externally calculated with Monte Carlo compared to locally calculated with Acuros BV. Point doses calculated using TG-43 were compared to those calculated with Acuros BV in water at various dose grid settings. Secondary dose check software was used to evaluate dose distributions resembling clinical patient plans, both in water and on CT datasets representative of patient anatomy. RESULTS: The major source of discrepancy of source models was the length of modeled steel cable. TG-186 testing showed that the largest differences between Monte Carlo and Acuros BV dose distributions were located along the source axis for cases calculated in water, as well as located in regions of high dose gradients and within the applicator for the case calculated with a generic shielded applicator. An audit of point doses calculated with both TG-43 and Acuros BV in water found that dose grid settings significantly affected agreement. Secondary dose check software indicated that Acuros BV functioned satisfactorily, and a 5% threshold was adopted for secondary dose checks on gynecologic plans. CONCLUSION: This validation process indicated that Acuros BV met expected standards and affirmed its suitability for integration into this clinical practice's brachytherapy treatment planning.

6.
Cureus ; 16(4): e58254, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38745812

RESUMO

Intraductal papillary neoplasm of the bile duct (IPNB) represents a relatively nascent pathological entity, recognized as a precancerous condition within the spectrum of cholangiocarcinoma. Surgical intervention is advocated for all patients with IPNB due to their susceptibility toward obstructive jaundice, cholangitis, and the heightened likelihood of malignant transformation. Nonetheless, the efficacy of radiation therapy for IPNB cases that are either inoperable or refractory remains inadequately substantiated. Herein, we present a case study of an IPNB patient who declined surgery, and a commendable local control was accomplished solely through the implementation of brachytherapy utilizing Ir-192. A septuagenarian Japanese man presented at our medical institution with the chief complaint of jaundice and was subsequently diagnosed with IPNB. The IPNB lesion extensively spanned from the lower intrapancreatic bile duct to the right (extending to B5/B8) and left bile ducts (up to just before B4). The patient underwent weekly endoscopic retrograde cholangiopancreatography (ERCP) sessions. The prescribed treatment regimen encompassed 36 Gy/6 Fr high-dose-rate brachytherapy (HDR-BT) administered once per week during ERCP, with each treatment session adhering to a timeframe not exceeding two hours. Two months following the initiation of treatment, a biliary endoscopy demonstrated complete resolution of the tumor lesion and amelioration of jaundice. The only observed acute adverse event was grade 2 hepatic dysfunctions. To the best of our knowledge, this represents the first documented instance of HDR-BT employed in IPNB management, suggesting its potential as a viable alternative for inoperable or refractory IPNB cases.

7.
Materials (Basel) ; 17(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38730793

RESUMO

This paper examines the corrosion behavior of the welding heat-affected zone (HAZ) of HDR (high chromium, duplex, corrosion-resistant) duplex stainless steel, which currently faces corrosion-related challenges in marine seawater systems. The corrosion behavior of the HAZ was studied using microstructure analysis, polarization curve experiments, and double-loop potentiodynamic reactivation experiments. The results show that (1) the covering welding current can promote the formation of austenite in the HAZ, and that the covering welding current has no strict correspondence with the formation of austenite; (2) increasing the welding gap properly can facilitate the formation of austenite; (3) increasing the covering welding current enhances the material's pitting resistance, and a covering welding current of 70 A, coupled with a covering welding current of 100 A, represents a reasonable choice in terms of achieving a stronger pitting resistance; (4) in terms of intergranular corrosion resistance, increasing the covering welding current is not conducive to the intergranular corrosion resistance of the material, as the covering current will promote the precipitation of the secondary phase at the grain boundary, thus reducing its intergranular corrosion resistance; and (5) reducing the welding current appropriately contributes to improving the stability of the grain boundary.

8.
Med Eng Phys ; 128: 104177, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38789214

RESUMO

Prostate cancer patients with an enlarged prostate and/or excessive pubic arch interference (PAI) are generally considered non-eligible for high-dose-rate (HDR) brachytherapy (BT). Steerable needles have been developed to make these patients eligible again. This study aims to validate the dosimetric impact and performance of steerable needles within the conventional clinical setting. HDR BT treatment plans were generated, needle implantations were performed in a prostate phantom, with prostate volume > 55 cm3 and excessive PAI of 10 mm, and pre- and post-implant dosimetry were compared considering the dosimetric constraints: prostate V100 > 95 % (13.50 Gy), urethra D0.1cm3 < 115 % (15.53 Gy) and rectum D1cm3 < 75 % (10.13 Gy). The inclusion of steerable needles resulted in a notable enhancement of the dose distribution and prostate V100 compared to treatment plans exclusively employing rigid needles to address PAI. Furthermore, the steerable needle plan demonstrated better agreement between pre- and post-implant dosimetry (prostate V100: 96.24 % vs. 93.74 %) compared to the rigid needle plans (79.13 % vs. 72.86 % and 87.70 % vs. 81.76 %), with no major changes in the clinical workflow and no changes in the clinical set-up. The steerable needle approach allows for more flexibility in needle positioning, ensuring a highly conformal dose distribution, and hence, HDR BT is a feasible treatment option again for prostate cancer patients with an enlarged prostate and/or excessive PAI.


Assuntos
Braquiterapia , Agulhas , Neoplasias da Próstata , Radiometria , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Masculino , Braquiterapia/instrumentação , Humanos , Neoplasias da Próstata/radioterapia , Imagens de Fantasmas , Próstata/efeitos da radiação
9.
Genesis ; 62(3): e23598, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38727638

RESUMO

Nowadays, a significant part of the investigations carried out in the medical field belong to cancer treatment. Generally, conventional cancer treatments, including chemotherapy, radiotherapy, and surgery, which have been used for a long time, are not sufficient, especially in malignant cancers. Because genetic mutations cause cancers, researchers are trying to treat these diseases using genetic engineering tools. One of them is clustered regularly interspaced short palindromic repeats (CRISPR), a powerful tool in genetic engineering in the last decade. CRISPR, which forms the CRISPR-Cas structure with its endonuclease protein, Cas, is known as a part of the immune system (adaptive immunity) in bacteria and archaea. Among the types of Cas proteins, Cas9 endonuclease has been used in many scientific studies due to its high accuracy and efficiency. This review reviews the CRISPR system, focusing on the history, classification, delivery methods, applications, new generations, and challenges of CRISPR-Cas9 technology.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Humanos , Edição de Genes/métodos , Neoplasias/genética , Neoplasias/terapia , Animais , Terapia Genética/métodos , Técnicas de Transferência de Genes
10.
J Contemp Brachytherapy ; 16(2): 128-131, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38808206

RESUMO

Purpose: Approximately 20% of women worldwide have a retroverted uterus. A retroverted uterus is closer to the rectum and may cause toxicity during brachytherapy. Upon manipulation, a small percentage turn anteverted. Conventional brachytherapy applicators are designed for an anteverted uterus and can pose issues during insertion. Modified Fletcher suit and ring applicators have major differences in their geometry to achieve similar target coverage, and were analyzed in this study with respect to immediate adverse events and dosimetry. Material and methods: Three hundred seventy-four consecutive applications performed over a 20-month period were studied retrospectively to identify intra-cavitary applications (ICAs) in retroverted uteri. Cases were divided into 2 groups: modified Fletcher suit applicator with hemi-ovoids (group A) and ring applicator (group B). D2cc for bladder and rectum were noted, and acute adverse events were recorded. Results: Seventy-five applications were identified, out of which 47 cases used Fletcher suit applicator, and 28 cases used ring applicator. The median bladder D2cc for group A and B were 5.98 Gy and 6.3 Gy, respectively, and the median rectum D2cc was 5.27 Gy and 3.68 Gy, respectively; the median dose prescribed to point A was 6 Gy (range, 5.5-9.0 Gy). All patients had a point A coverage between 97% and 102%. Eighteen cases in both groups complained of pain requiring analgesics. Twenty-five cases (53.2%) and 20 cases (71.4%) in group A and B, respectively, required dose optimization, which was statistically insignificant (p > 0.11). A significant difference was identified (p < 0.00001) in rectal doses. A higher reported pain was noted in ring applicator group (p < 0.03). No patient experienced a profuse bleeding. Conclusions: In most parameters, the two applicators demonstrated comparable results. The control of rectal dosage is superior in the ring applicator at the cost of higher pain incidence. Patient's comfort and rectal dose in EBRT should be taken into consideration, with preference given to the ring applicator.

11.
J Contemp Brachytherapy ; 16(2): 111-120, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38808210

RESUMO

Purpose: Isolated intra-prostatic recurrence of prostate adenocarcinoma after definitive radiotherapy presents a challenging clinical scenario. Salvage options require specialized expertise and pose risks of harm. This study aimed to present the acute toxicity results from using salvage high-dose-rate brachytherapy (sHDR-BT) as treatment in locally recurrent prostate cancer cases. Material and methods: Seventeen consecutive patients treated with sHDR-BT between 2019 and 2022 were evaluated retrospectively. Eligible patients had to have received curative intent prostate radiotherapy previously, and showed evidence of new biochemical failure. Evaluation with American Urological Association (AUA) and Common Terminology Criteria for Adverse Events (CTCAE) symptom assessments were performed for each case. Results: The median (inter-quartile range) age prior to salvage treatment was 68 (66-74) years. The median post-sHDR-BT follow-up time was 20 (13-24) months. At baseline prior to sHDR-BT, 8 (47%) patients had significant lower urinary tract symptoms. The median AUA score prior to sHDR-BT was 7 (3-18). Three (18%) patients reported irregular bowel function and 2 (12%) reported hematochezia prior to sHDR-BT. One-month post-treatment, the median AUA score was 13 (8-21, p = 0.21). Using CTCAE scoring, there were no cases of grade 2+ bowel or rectal toxicity, and no cases of grade 3+ urinary toxicity. Reported grade 2 urinary toxicities included 10 (59%) cases of bladder spasms, 2 (12%) cases of incontinence, 1 (6%) urinary obstruction, and 4 (24%) reports of urinary urgency. All these adverse events were temporary. Conclusions: This study adds to the existing literature by demonstrating that the acute toxicity profile of sHDR-BT is acceptable even without intra-operative magnetic resonance (MR) guidance or image registration. Further study is ongoing to determine long-term efficacy and toxicity of treatment.

12.
J Appl Clin Med Phys ; 25(7): e14371, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38682540

RESUMO

PURPOSE: To create and evaluate a three-dimensional (3D) Prompt-nnUnet module that utilizes the prompts-based model combined with 3D nnUnet for producing the rapid and consistent autosegmentation of high-risk clinical target volume (HR CTV) and organ at risk (OAR) in high-dose-rate brachytherapy (HDR BT) for patients with postoperative endometrial carcinoma (EC). METHODS AND MATERIALS: On two experimental batches, a total of 321 computed tomography (CT) scans were obtained for HR CTV segmentation from 321 patients with EC, and 125 CT scans for OARs segmentation from 125 patients. The numbers of training/validation/test were 257/32/32 and 87/13/25 for HR CTV and OARs respectively. A novel comparison of the deep learning neural network 3D Prompt-nnUnet and 3D nnUnet was applied for HR CTV and OARs segmentation. Three-fold cross validation and several quantitative metrics were employed, including Dice similarity coefficient (DSC), Hausdorff distance (HD), 95th percentile of Hausdorff distance (HD95%), and intersection over union (IoU). RESULTS: The Prompt-nnUnet included two forms of parameters Predict-Prompt (PP) and Label-Prompt (LP), with the LP performing most similarly to the experienced radiation oncologist and outperforming the less experienced ones. During the testing phase, the mean DSC values for the LP were 0.96 ± 0.02, 0.91 ± 0.02, and 0.83 ± 0.07 for HR CTV, rectum and urethra, respectively. The mean HD values (mm) were 2.73 ± 0.95, 8.18 ± 4.84, and 2.11 ± 0.50, respectively. The mean HD95% values (mm) were 1.66 ± 1.11, 3.07 ± 0.94, and 1.35 ± 0.55, respectively. The mean IoUs were 0.92 ± 0.04, 0.84 ± 0.03, and 0.71 ± 0.09, respectively. A delineation time < 2.35 s per structure in the new model was observed, which was available to save clinician time. CONCLUSION: The Prompt-nnUnet architecture, particularly the LP, was highly consistent with ground truth (GT) in HR CTV or OAR autosegmentation, reducing interobserver variability and shortening treatment time.


Assuntos
Braquiterapia , Aprendizado Profundo , Neoplasias do Endométrio , Órgãos em Risco , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Tomografia Computadorizada por Raios X , Humanos , Feminino , Neoplasias do Endométrio/radioterapia , Neoplasias do Endométrio/cirurgia , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/patologia , Braquiterapia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Órgãos em Risco/efeitos da radiação , Tomografia Computadorizada por Raios X/métodos , Imageamento Tridimensional/métodos , Radioterapia de Intensidade Modulada/métodos , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Prognóstico
13.
Brachytherapy ; 23(4): 407-415, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38641455

RESUMO

PURPOSE: To evaluate clinical outcomes of CT-based adaptive intracavitary and interstitial brachytherapy (IC followed by IC-ISBT) in locally advanced cervical cancer (LACC) in resource-constrained settings. METHODS AND MATERIALS: LACC patients treated with adaptive brachytherapy techniques were analyzed to evaluate treatment characteristics and clinical outcomes. The Kaplan-Meier method was used for survival analysis, and the log-rank test for univariate analysis. RESULTS: Out of 141 eligible patients with LACC, 87 (61.7%) patients received external beam radiotherapy (EBRT) in referral hospitals, while 54 (38.3%) were treated at our center. We divided our cohort into two groups: poor EBRT responder group (n = 70 [49.6%]) where IC-ISBT was adapted to achieve optimum tumor doses and OAR optimization group 71 (50.4%) where IC-ISBT was performed to reduce OAR doses. Median HRCTV-D90 dose was 88 Gy (range 70-109 Gy) with median HRCTV volume 33cc (range 15-96). Median D2cc doses to OARs were 90 Gy (range 70-107), 71 Gy (range 55-105) and 70 Gy (range 47-90) to bladder, rectum and sigmoid, respectively. At median follow-up of 32 months, 3-year local control (LC), locoregional control (LRC), disease-free survival (DFS) and overall survival (OS) were 83%, 75%, 64% and 72%, respectively. Subgroup analysis revealed significantly better outcomes for OAR optimization compared to poor EBRT responders, with 3-year LC (95% vs. 70.1%, p < 0.001), LRC (87.3% vs. 62.7%, p < 0.001), DFS (79.2% vs. 49.4%, p < 0.001), and OS (86.2% vs. 57.4%, p < 0.001) CONCLUSION: In resource-constrained settings, implementation of Adaptive IC-ISBT is a viable alternative for optimizing OAR doses in LACC. However proactive approach employing IC-ISBT for tumor dose-escalation from first fraction of BT is warranted for improving LC in poor EBRT responders.


Assuntos
Braquiterapia , Dosagem Radioterapêutica , Neoplasias do Colo do Útero , Humanos , Braquiterapia/métodos , Feminino , Neoplasias do Colo do Útero/radioterapia , Neoplasias do Colo do Útero/diagnóstico por imagem , Pessoa de Meia-Idade , Idoso , Adulto , Resultado do Tratamento , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Órgãos em Risco/efeitos da radiação
14.
Front Physiol ; 15: 1302301, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38590693

RESUMO

Introduction: The aim of this study was to demonstrate the potential of an in vivo four-dimensional (4D) tracking system to accurately localize the radiation source, Iridium-192 (Ir-192) in high-dose rate brachytherapy. Methods: To achieve time-dependent 3D positioning of the Ir-192 source, we devised a 4D tracking system employing multiple compact detectors. During the system's design phase, we conducted comprehensive optimization and analytical evaluations of the diverging collimator employed for detection purposes. Subsequently, we executed 3D reconstruction and positioning procedures based on the 2D images obtained by six detectors, each equipped with an optimized diverging collimator. All simulations for designing and evaluating the 4D tracking system were performed using the open-source GATE (v9.1) Monte Carlo platform based on the GEANT4 (v10.7) toolkit. In addition, to evaluate the accuracy of the proposed 4D tracking system, we conducted simulations and 3D positioning using a solid phantom and patient data. Finally, the error between the reconstructed position coordinates determined by the tracking system and the original coordinates of the Ir-192 radiation source was analyzed. Results: The parameters for the optimized diverging collimator were a septal thickness of 0.3 mm and a collimator height of 30 mm. A tracking system comprising 6 compact detectors was designed and implemented utilizing this collimator. Analysis of the accuracy of the proposed Ir-192 source tracking system found that the average of the absolute values of the error between the 3D reconstructed and original positions for the simulation with the solid phantom were 0.440 mm for the x coordinate, 0.423 mm for the y coordinate, and 0.764 mm for the z coordinate, and the average Euclidean distance was 1.146 mm. Finally, in a simulation based on data from a patient who underwent brachytherapy, the average Euclidean distance between the original and reconstructed source position was 0.586 mm. Discussion: These results indicated that the newly designed in vivo 4D tracking system for monitoring the Ir-192 source during brachytherapy could determine the 3D position of the radiation source in real time during treatment. We conclude that the proposed positioning system has the potential to make brachytherapy more accurate and reliable.

15.
J Imaging ; 10(4)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38667990

RESUMO

This study considers a method for reconstructing a high dynamic range (HDR) original image from a single saturated low dynamic range (LDR) image of metallic objects. A deep neural network approach was adopted for the direct mapping of an 8-bit LDR image to HDR. An HDR image database was first constructed using a large number of various metallic objects with different shapes. Each captured HDR image was clipped to create a set of 8-bit LDR images. All pairs of HDR and LDR images were used to train and test the network. Subsequently, a convolutional neural network (CNN) was designed in the form of a deep U-Net-like architecture. The network consisted of an encoder, a decoder, and a skip connection to maintain high image resolution. The CNN algorithm was constructed using the learning functions in MATLAB. The entire network consisted of 32 layers and 85,900 learnable parameters. The performance of the proposed method was examined in experiments using a test image set. The proposed method was also compared with other methods and confirmed to be significantly superior in terms of reconstruction accuracy, histogram fitting, and psychological evaluation.

16.
J Contemp Brachytherapy ; 16(1): 67-71, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38584882

RESUMO

Purpose: Brachytherapy plays a crucial role in the standard of care for locally advanced gynecological malignancies. In this report, we present the experience from a tertiary teaching hospital, which is a referral center for image-guided brachytherapy (IGBT) in the management of locally advanced gynecological malignancies. Material and methods: This was a retrospective study of 130 patients referred to our hospital for IGBT after receiving initial external beam radiotherapy in their primary healthcare facilities, from January 2021 till January 2023. CT-based planning was done to delineate high-risk clinical target volume (HR-CTV). Dose of 6-7.5 Gy in 3-4 fractions was prescribed. Overall treatment time (OTT) was calculated, and patients were assessed for clinical response and toxicity after three months. Results: All patients received IGBT using an intra-cavitary or interstitial technique. The D90 HR-CTV mean EQD2 dose was 28.34 ±2.78 Gy. The mean EQD2 dose to 2 cc of the bladder, rectum, and sigmoid was 18.31 ±5.19 Gy, 14.14 ±5.76 Gy, and 17.43 ±4.75 Gy, respectively. The median interval time between the last fraction of external beam radiation therapy (EBRT) and first evaluation in the hospital was 19 (range, 13-28) days (interquartile range [IQR]). The median time between the completion of chemoradiation and brachytherapy procedure was 25 (range, 19-33) days (IQR). The mean overall treatment time (OTT) was 63.5 ±14.7 days. Conclusions: This study highlights the established advantages of image-guided interstitial brachytherapy and associated challenges. To optimize the overall treatment duration, it is imperative to prioritize and update the referral processes for brachytherapy centers.

17.
J Contemp Brachytherapy ; 16(1): 35-47, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38584884

RESUMO

Purpose: To use failure modes and effects analysis (FMEA) to identify failure modes for gynecological high-dose-rate (HDR) brachytherapy pathway and score with severity, occurrence, and detectability. Material and methods: A research team was organized to observe gynecological HDR brachytherapy pathway, and draw detailed process map to identify all potential failure modes (FMs). The whole team scored FMs based on three parameters, including occurrence (O), detectability (D), and severity (S), and then multiplied three scores to obtain risk priority number (RPN). All FMs were ranked according to RPNs and/or severity scores, and FMs with the highest RPN scores (> 100) and severity scores (> 8) were selected for in-depth analysis. Fault tree analysis (FTA) was applied to find progenitor causes of high-risk FMs and their propagation path, and determine which steps in the process need to be changed and optimized. Efficiency of each existing preventive methods to detect and stop FMs was analyzed, and proposals to improve quality management (QM) and ensure patient safety were suggested. Results: The whole gynecological HDR brachytherapy pathway consisted of 5 sub-processes and 30 specific steps, in which 57 FMs were identified. Twelve high-risk FMs were found, including 7 FMs with RPNs > 100 and 5 FMs with severity scores > 8. For these FMs, 2 were in the insertion stage, 1 in the imaging stage, 4 in the treatment planning stage, and 5 in the final stage of treatment delivery. The most serious of these FMs was the change in organ at risk (OAR) during treatment delivery (RPN = 245.7). The FM that occurred most frequently was the applicator shift during patient transfer. Conclusions: Failure modes and effects analysis is a prospective risk-based tool that can identity high-risk steps before failures occur, provide preventive measures to stop their occurrence, and improve quality management system.

18.
J Contemp Brachytherapy ; 16(1): 1-5, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38584887

RESUMO

Introduction: Inflammatory bowel disease (IBD) is a relative contraindication to external beam radiation therapy (EBRT) for prostate cancer patients due to fear of increased risk of gastrointestinal (GI) toxicity. High-dose-rate (HDR) brachytherapy, capable of minimizing radiation dose to surrounding tissues, is a feasible alternative. Given limited data, this study examined the safety profile of HDR brachytherapy in this setting. Material and methods: We conducted a retrospective review of patients with localized prostate cancer and IBD treated with HDR brachytherapy at the University of California San Francisco (UCSF), between 2010 and 2022. Eligibility criteria included biopsy-proven prostate cancer, no distant metastases, absence of prior pelvic radiotherapy, IBD diagnosis, and at least one follow-up visit post-treatment. Results: Eleven patients were included, with a median follow-up of 28.7 months. The median dose administered was 2700 cGy (range, 1500-3150 cGy) over 2 fractions (range, 1-3 fractions). Two patients also received EBRT. Rectal spacers (SpaceOAR) were applied in seven patients. All patients experienced acute genitourinary (GU) toxicity, ten of which were grade 1 and one was grade 2. Eight patients experienced late grade 1 GU toxicity, and three patients had late grade 2 GU toxicity. GI toxicities were similarly low-grade, with six grade 1 acute toxicity, no grade 2 or higher acute toxicity, six grade 1 late toxicity, and one late grade 2 GI toxicity. No grade 3 or higher acute or late GI or GU toxicities were reported. Conclusions: HDR brachytherapy appears to be a safe and tolerable treatment modality for patients with prostate cancer and IBD, with minimal acute and late GI and GU toxicity. These findings warrant multi-institutional validation due to small sample size.

19.
Int J Mol Sci ; 25(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38473704

RESUMO

Since its discovery in 2012, the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) system has supposed a promising panorama for developing novel and highly precise genome editing-based gene therapy (GT) alternatives, leading to overcoming the challenges associated with classical GT. Classical GT aims to deliver transgenes to the cells via their random integration in the genome or episomal persistence into the nucleus through lentivirus (LV) or adeno-associated virus (AAV), respectively. Although high transgene expression efficiency is achieved by using either LV or AAV, their nature can result in severe side effects in humans. For instance, an LV (NCT03852498)- and AAV9 (NCT05514249)-based GT clinical trials for treating X-linked adrenoleukodystrophy and Duchenne Muscular Dystrophy showed the development of myelodysplastic syndrome and patient's death, respectively. In contrast with classical GT, the CRISPR/Cas9-based genome editing requires the homologous direct repair (HDR) machinery of the cells for inserting the transgene in specific regions of the genome. This sophisticated and well-regulated process is limited in the cell cycle of mammalian cells, and in turn, the nonhomologous end-joining (NHEJ) predominates. Consequently, seeking approaches to increase HDR efficiency over NHEJ is crucial. This manuscript comprehensively reviews the current alternatives for improving the HDR for CRISPR/Cas9-based GTs.


Assuntos
Sistemas CRISPR-Cas , Reparo de DNA por Recombinação , Animais , Humanos , Reparo do DNA por Junção de Extremidades , Edição de Genes , Terapia Genética , Mamíferos/genética
20.
Strahlenther Onkol ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38488901

RESUMO

BACKGROUND AND PURPOSE: Comparing oncological outcomes and toxicity after primary treatment of localized prostate cancer using HDR- or LDR-mono-brachytherapy (BT), or conventionally (CF) or moderately hypofractionated (HF) external beam radiotherapy. MATERIALS AND METHODS: Retrospectively, patients with low- (LR) or favorable intermediate-risk (IR) prostate cancer treated between 03/2000 and 09/2022 in two centers were included. Treatment was performed using either CF with total doses between 74 and 78 Gy, HF with 2.4-2.6 Gy per fraction in 30 fractions, or LDR- or HDR-BT. Biochemical control (BC) according to the Phoenix criteria, and late gastrointestinal (GI), and genitourinary (GU) toxicity according to RTOG/EORTC criteria were assessed. RESULTS: We identified 1293 patients, 697 with LR and 596 with IR prostate cancer. Of these, 470, 182, 480, and 161 were treated with CF, HF, LDR-BT, and HDR-BT, respectively. For BC, we did not find a significant difference between treatments in LR and IR (p = 0.31 and 0.72). The 5­year BC for LR was between 93 and 95% for all treatment types. For IR, BC was between 88% in the CF and 94% in the HF group. For CF and HF, maximum GI and GU toxicity grade ≥ 2 was between 22 and 27%. For LDR-BT, we observed 67% grade ≥ 2 GU toxicity. Maximum GI grade ≥ 2 toxicity was 9%. For HDR-BT, we observed 1% GI grade ≥ 2 toxicity and 19% GU grade ≥ 2 toxicity. CONCLUSION: All types of therapy were effective and well received. HDR-BT caused the least late toxicities, especially GI.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...