Saudi Cultural Missions Theses & Dissertations
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Item Restricted Assessing artificial intelligence MRI autocontouring in Raystation and the AutoConfidence uncertainty model for brain radiotherapy(The University of Leeds, 2024-10) Alzahrani, Nouf; Henry, Ann; Nix, Michael; Murray, Louise; Al-qaisieh, BasharAbstract: Background: In radiotherapy, deep learning autosegmentation (DL-AS) and automation of quality assurance (QA) have the potential to efficiently standardize and enhance the quality of contours. Aim: To assess the performance of DL-AS in delineating organs-at-risk (OARs) in brain RT using the RayStation Treatment Planning System. Secondly, to build and test a novel artificial intelligence QA model called AutoConfidence (ACo). Methods: Retrospective MRI and CT cases were randomly selected for training and testing. DL-AS models were evaluated from geometric and dosimetric perspectives, focusing on the impact of pre-training editing. The ACo model was evaluated using two sources of autosegmentation: internal autosegmentations (IAS) produced from the ACo generator and two external DL-AS with different qualities (high and low quality) produced from RayStation models. Results: The edited DL-AS models generated more segmentations than the unedited models. Editing pituitary, orbits, optic nerves, lenses, and optic chiasm on MRI before training significantly improved at least one geometry metric. MRI-based DL-AS performed worse than CT-based in delineating the lacrimal gland, whereas the CT-based performed worse in delineating the optic chiasm. Except for the right orbit, when delineated using MRI models, the dosimetric statistical analysis revealed no superior model in terms of the dosimetric accuracy between the MR and CT DL-AS models. The number of patients where the clinical significance threshold was exceeded was higher for the optic chiasm D1% than for other OARs, for all models. ACo had excellent performance on both internal and external segmentations across all OARs (except lenses). Mathews Correlation Coefficient was higher on IAS and low-quality external segmentations than high-quality ones. Conclusion: MRI DL-AS in RT may improve consistency, quality, and efficiency but requires careful editing of training contours. ACo was a reliable predictor of uncertainty and errors on DL-AS, demonstrating its potential as an independent, reference-free QA tool.9 0Item Restricted Orofacial Development Changes in Children Following Cancer Treatment: A Comprehensive Review of Literature and Analysis of Current Data in Leeds Dental Institute.(University of Leeds, 2024) Alghamdi, Talal; Drummond, BernadetteIntroduction: Childhood cancer survivors often experience various side effects after treatment, including dental and orofacial developmental conditions. According to the literature, the treatment for cancer in children can affect the development of teeth, the function of salivary glands, the development of facial structures, and the operation of the temporomandibular joint [TMJ]. Leeds Dental Institute [LDI] has accumulated a wealth of data while providing dental healthcare for cancer survivors. This extensive data has not been thoroughly explored or published. Thus, this study aims to investigate the long-term effects of cancer treatment on dental and orofacial structures from the literature and the available records in children at Leeds Dental Institute. Methods: This research is structured into two sections. The first is a comprehensive literature review of existing studies on the adverse effects of cancer treatments on oral and facial structures in children by searching six databases to establish a foundation for understanding the broader context of the issue. The second section is a retrospective data collection and analysis of paediatric patient data from the electronic records in LDI using a list of appointments attended by cancer patients in LDI. Results: Fifty-one articles were included in the comprehensive literature review following the database search and the inclusion criteria. Numerous studies concluded that chemotherapy and other anticancer treatments in children are linked to increased dental anomalies like microdontia and enamel defects, especially when treatment occurs at a young age. The findings have been summarised in tables. Of the 806 registered appointments identified, the clinical records of 85 childhood cancer survivors who met the inclusion criteria were included. The post-treatment identified conditions included microdontia, hypodontia and enamel hypoplasia. Demographics, cancer diagnosis and type of treatment, in addition to dental findings, were summarised in tables. The data were also categorised according to age at the cancer treatment time and type of treatment provided. Conclusions: The literature review and LDI patient data revealed that childhood cancer survivors commonly face serious long-term dental issues due to their treatments. These findings highlight the importance of a better understanding of cancer therapy's impact on orofacial development, requiring more attention and support from healthcare professionals, particularly dentists.37 0Item Restricted Understanding the influence of radiotherapy in HCC cell lines, alone or when in combination with BCL-2 inhibitors(Saudi Digital Library, 2023-09-18) Alqarafi, Bashaer; Bird, Thomas; May, StephanieHepatocellular carcinoma (HCC) is the predominant form of liver cancer, accounting for approximately 90% of all cases. It is the third most common cause of cancer-related mortality worldwide. The development of this disease is associated with several risk factors, including liver inflammatory diseases, such as cirrhosis. Treatment options for advanced HCC are limited as the majority of patients present with incurable disease. Stereotactic ablative radiotherapy (SBRT) has recently been approved for patients who are not eligible for curative options. SBRT is reported to provide good tumour control, but patients often succumb to recurrent or metastatic disease. This could be due to a cancer's ability to evade cell death. Therefore, there is a significant opportunity for combining SBRT and systemic therapy to improve treatment outcomes. The intrinsic apoptosis pathway plays a crucial role in programmed cell death. Disruption of this pathway can lead to uncontrolled cell division. Therefore, there is untapped potential in combining SBRT with treatments that promote cell death (termed BH3-mimetics). The aims of this study were to: 1) assess the radiosensitivity of an HCC cell line (Hep53.4) using in vitro clonogenic assays; 2) evaluate the potential synergistic effect of combination SBRT and BH3-mimetic treatment (e.g. ABT263) using in vitro cell viability assays, and 3) examine whether SBRT causes radiation-induced liver disease in vivo in murine models using immunohistochemistry. Key findings of this study indicate that Hep53.4 cells are radiosensitive and combination treatment with 6Gy irradiation and ABT263, had a synergistic killing effect. Additionally, histological analysis of collagen markers revealed that SBRT effectively spares healthy liver tissue, whilst modifying the tumour collagen deposition compared to non-irradiated tumour controls. While in vitro data displays promising outcomes regarding the synergistic potential of systemic BH3-mimetic therapy and SBRT, further pre-clinical studies are imperative to establish its applicability in the clinical setting.25 0Item Restricted Osteoradionecrosis Prophylaxis by Pentoxifylline and Tocopherol Prior to Dental Extractions: A Systematic Review(Saudi Digital Library, 2022) Alleft, Abdullah; Leeson, RachelBackground and Objectives: Osteoradionecrosis (ORN) remains one of the most abysmal complications of head and neck radiotherapy (XRT). The advantageous and welcoming news of increased survivability for head and neck cancer patients came at the expense of increased risks of complications in general, including ORN. Consequently, this positive survival outcome provides plentiful of time for dental deterioration to occur, which may lead to more dental extractions, the main propagator for ORN. Therefore, preventing ORN became a pivotal matter for head and neck cancer patients. From the numerous preventative measures for ORN, prophylactic administration of Pentoxifylline and Tocopherol (PVe) appears promising, especially since many publications have demonstrated its success in treating ORN. However, recently multiple studies investigating PVe prophylactic use to prevent ORN came to fruition. This study aims to assess reported publications by employing a systematic review to investigate whether the prophylactic administration of PVe can prevents or reduces the incidence of ORN. Methods: The systematic review was done according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. An electronic database search on Medline (Ovid), Embase (Ovid), Cochrane Library, Web of Science and Google Scholar focusing on the prophylactic use of PVe to prevent ORN was conducted. Results: Out of two thousand five hundred and thirty-six (2536) publications, five (5) were included based on the patient/population, intervention, comparison, outcomes and studies type (PICOS) design for the prophylactic use of PVe before extraction and/or oral surgical procedure. This systematic review revealed out of 440 individuals, 19 developed ORN representing an incidence rate of 4.3%. However, when control groups and studies that were deemed high risk of bias or poor design were excluded, the incidence of ORN dropped to 2.5 % (9 out of 359 individuals). Both outcomes reveal a lower incidence of ORN compared to the established benchmark without any preventive measures of 7% and lower than the controlled group incidence of 11.5 % in one of the reviewed studies. Conclusion: This systematic review shows that current literature supports the prophylactic use of PVe to prevent ORN prior to dental extraction and other oral surgical intervention. Nevertheless, additional well-designed and prospective randomised controlled trial studies are needed to further validate the efficacy of PVe prophylaxis to prevent ORN before any oral surgical intervention.21 0