Browsing by Author "Simonds, Hannah"

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    Automated radiation treatment planning for cervical cancer
    (Elsevier, 2020-10) Rhee, Dong Joo; Jhingran, Anuja; Kisling, Kelly; Cardenas, Carlos; Simonds, Hannah; Court, Laurence
    The radiation treatment-planning process includes contouring, planning, and reviewing the final plan, and each component requires substantial time and effort from multiple experts. Automation of treatment planning can save time and reduce the cost of radiation treatment, and potentially provides more consistent and better quality plans. With the recent breakthroughs in computer hardware and artificial intelligence technology, automation methods for radiation treatment planning have achieved a clinically acceptable level of performance in general. At the same time, the automation process should be developed and evaluated independently for different disease sites and treatment techniques as they are unique from each other. In this article, we will discuss the current status of automated radiation treatment planning for cervical cancer for simple and complex plans and corresponding automated quality assurance methods. Furthermore, we will introduce Radiation Planning Assistant, a web-based system designed to fully automate treatment planning for cervical cancer and other treatment sites.
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    Automated treatment planning of postmastectomy radiotherapy
    (American Association of Physicists in Medicine, 2019-05-11) Kisling, Kelly; Zhang, Lifei; Shaitelman, Simona F.; Anderson, David; Thebe, Tselane; Yang, Jinzhong; Balter, Peter A.; Howell, Rebecca M.; Jhingran, Anuja; Schmeler, Kathleen; Simonds, Hannah; Du Toit, Monique; Trauernicht, Christoph; Burger, Hester; Botha, Kobus; Joubert, Nanette; Beadle, Beth M.; Court, Laurence
    Purpose: Breast cancer is the most common cancer in women globally and radiation therapy is a cornerstone of its treatment. However, there is an enormous shortage of radiotherapy staff, especially in low- and middle-income countries. This shortage could be ameliorated through increased automation in the radiation treatment planning process, which may reduce the workload on radiotherapy staff and improve efficiency in preparing radiotherapy treatments for patients. To this end, we sought to create an automated treatment planning tool for postmastectomy radiotherapy (PMRT). Methods: Algorithms to automate every step of PMRT planning were developed and integrated into a commercial treatment planning system. The only required inputs for automated PMRT planning are a planning computed tomography scan, a plan directive, and selection of the inferior border of the tangential fields. With no other human input, the planning tool automatically creates a treatment plan and presents it for review. The major automated steps are (a) segmentation of relevant structures (targets, normal tissues, and other planning structures), (b) setup of the beams (tangential fields matched with a supraclavicular field), and (c) optimization of the dose distribution by using a mix of high- and low-energy photon beams and field-in-field modulation for the tangential fields. This automated PMRT planning tool was tested with ten computed tomography scans of patients with breast cancer who had received irradiation of the left chest wall. These plans were assessed quantitatively using their dose distributions and were reviewed by two physicians who rated them on a three-tiered scale: use as is, minor changes, or major changes. The accuracy of the automated segmentation of the heart and ipsilateral lung was also assessed. Finally, a plan quality verification tool was tested to alert the user to any possible deviations in the quality of the automatically created treatment plans. Results: The automatically created PMRT plans met the acceptable dose objectives, including target coverage, maximum plan dose, and dose to organs at risk, for all but one patient for whom the heart objectives were exceeded. Physicians accepted 50% of the treatment plans as is and required only minor changes for the remaining 50%, which included the one patient whose plan had a high heart dose. Furthermore, the automatically segmented contours of the heart and ipsilateral lung agreed well with manually edited contours. Finally, the automated plan quality verification tool detected 92% of the changes requested by physicians in this review. Conclusions: We developed a new tool for automatically planning PMRT for breast cancer, including irradiation of the chest wall and ipsilateral lymph nodes (supraclavicular and level III axillary). In this initial testing, we found that the plans created by this tool are clinically viable, and the tool can alert the user to possible deviations in plan quality. The next step is to subject this tool to prospective testing, in which automatically planned treatments will be compared with manually planned treatments.
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    The impact of HIV status on staging, treatment and outcomes in locally advanced cervical carcinoma
    (Stellenbosch : Stellenbosch University, 2019-12) Simonds, Hannah; Botha, Matthys Hendrik; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Obstetrics and Gynaecology.
    ENGLISH ABSTRACT: Cervical carcinoma is one of the most frequently diagnosed malignancies in women in many countries in sub-Saharan Africa, including South Africa. In sub-Saharan Africa, among women without HIV the age-standardised cervical cancer incidence rate is greater than 40 per 100 000. However, women infected with both the human-immunodeficiency virus (HIV) and the human papilloma virus (HPV) have a higher risk of developing cervical carcinoma than women infected with HPV alone. Published studies of the ideal staging methods, treatment algorithms, and outcomes for women with comorbid locally advanced cervical carcinoma and HIV are scarce. The aim of this body of work is to fill some of these gaps. We conducted four cohort studies of patients with locally advanced cervical carcinoma with or without HIV, recording demographic data, staging information and treatment delivered. Additional information gathered for individual studies included treatment response and survival outcomes. We evaluated the statistical significance of differences between HIV-positive and negative patients. Logistic regression models were utilised to evaluate risk for toxicity, treatment response, and survival outcomes. In the first of three retrospective cohort studies, among 383 patients, early response to chemoradiation was found to be related to advanced stage [OR 2.39, 95% CI 1.45-3.96] and completion of brachytherapy [OR 3.14; 95% CI 1.24-7.94] but not HIV status. In the second retrospective study, among 213 patients undergoing radical radiotherapy, acute Grade 3 / 4 toxicity was associated with receiving chemotherapy [OR4.41; 95%CI 1.76- 11.1; p 0.023] and having HIV [OR 2.16; 95% CI0.98-4.8; p 0.05]. In a prospective study of 492 patients, OS at 5 years was 49.5% (95%CI; 44.6% - 54.4%) among HIV-negative patients but only 35.9% (95% CI; 23.9% - 48.0%) among HIV-positive patients (p=0.002). In our Cox models, factors affecting outcome were HIV infection, stage IIIB disease, hydronephrosis, and delivery of concurrent chemotherapy. In the fourth cohort study, among 273 patients with locally advanced cervical carcinoma who underwent a radiotherapy planning PET-CT scan, overall 235 (84.5%) were upstaged. Upstaging was not associated with HIV status (HIV-negative 83.9% vs HIV-positive 87.2%; p=0.47). Following the PET-CT scan, among the 263 patients who attended for radiotherapy treatment, intent changed for 124 patients (46.3%): 53.6% of HIV-positive patients and 42.9% of HIV-negative patients (p=0.11). This body of work demonstrated that in HIV-positive patients, integration of PET-CT into staging algorithms for cervical carcinoma is a viable option. During treatment HIV-positive patients experienced increased toxicity, but most were able to complete treatment, and their 5-year overall survival was nearly 40%. Among women with locally advanced cervical cancer, those with HIV infection should be treated with the best standard of care. Future research should focus on factors that improve outcomes for these women.
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    Long-term complications of pelvic radiotherapy
    (South African Society of Gynaecologic Oncology, 2010) Simonds, Hannah
    Complications following pelvic radiation are frequently under-reported and inadequately addressed. This overview examines the nature and the intensity of complications encountered by cancer survivors; it focuses specifically on gastrointestinal and vaginal complications, and the problems surrounding the methods of recording and assessing toxicities.
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    Radiation planning assistant - a streamlined, fully automated radiotherapy treatment planning system
    (Journal of Visualized Experiments, 2018) Court, Laurence E.; Kisling, Kelly; McCarroll, Rachel; Zhang, Lifei; Yang, Jinzhong; Simonds, Hannah; Du Toit, Monique; Trauernicht, Chris; Burger, Hester; Parkes, Jeannette; Mejia, Mike; Bojador, Maureen; Balter, Peter; Branco, Daniela; Steinmann, Angela; Baltz, Garrett; Gay, Skylar; Anderson, Brian; Cardenas, Carlos; Jhingran, Anuja; Shaitelman, Simona; Bogler, Oliver; Schmeller, Kathleen; Followill, David; Howell, Rebecca; Nelson, Christopher; Peterson, Christine; Beadle, Beth
    The Radiation Planning Assistant (RPA) is a system developed for the fully automated creation of radiotherapy treatment plans, including volume-modulated arc therapy (VMAT) plans for patients with head/neck cancer and 4-field box plans for patients with cervical cancer. It is a combination of specially developed in-house software that uses an application programming interface to communicate with a commercial radiotherapy treatment planning system. It also interfaces with a commercial secondary dose verification software. The necessary inputs to the system are a Treatment Plan Order, approved by the radiation oncologist, and a simulation computed tomography (CT) image, approved by the radiographer. The RPA then generates a complete radiotherapy treatment plan. For the cervical cancer treatment plans, no additional user intervention is necessary until the plan is complete. For head/neck treatment plans, after the normal tissue and some of the target structures are automatically delineated on the CT image, the radiation oncologist must review the contours, making edits if necessary. They also delineate the gross tumor volume. The RPA then completes the treatment planning process, creating a VMAT plan. Finally, the completed plan must be reviewed by qualified clinical staff.