Adaptive Radiotherapy

In this prospective, multi-center cohort study, the tolerability and quality of life during ultrahypofractionated radiotherapy (RT) of early stage prostate cancer is surveyed at several institutions in Germany. Radiotherapy is delivered by an online-adaptive RT device (Varian Ethos), which is able to correct daily variations in anatomy and to adjust the irradiation plan accordingly. A digital patient questionnaire is used to asses quality of life longitudinally. Quality of life (QoL) and toxicity profiles will be correlated with planning parameters and compared to retrospective cohorts of patients who underwent normofractionated RT or moderately hypofractionated RT, respectively.

To evaluate the Efficacy and Safety of the Combination of Sintilimab With Platinum-doublet Chemotherapy and Adaptive Radiotherapy Strategy in the Treatment of Stage III Non-small Cell Lung Cancer Patients

1. To investigate the tolerability of MR-linac based stereotactic ablative radiotherapy (MRL-SBRT)for patients with localized prostate cancer 2. To assess the acute and late toxicities, efficacy and quality of life for patients treated by MRL-SBRT 3. To simulate the dose planning and assess the feasibility of simultaneous-boost for MR-prominent foci 4. To investigate the relationship between the changes of blood and tissue biomarkers and manifestations on mp-MRI pre-/post-MRL-SBRT, to further ascertain the predictive factors of local persisting and/or relapse disease

Locally advanced non-small cell lung cancer (LA-NSCLC) patients could benefit in overall and progression-free survival from regular dosimetric treatment plan adaptations during radiotherapy. This is known as adaptive radiotherapy (ART). However, implementing an adaptive radiotherapy workflow presents a highly cumbersome process. First, repeated planning-CT imaging during treatment is required, which results in additional radiation dose for patients. Second, an ART workflow includes the repetition of various manual and semi-automated tasks such as target and organ-at-risk contouring on the images and dosimetric treatment planning. These obstacles hinder widespread ART implementation. To avoid repeated planning-CT imaging, position-verification imaging can be utilized. Modern cone-beam CT (CBCT) imaging, integrated into the treatment unit, assists radiation therapists (RTTs) in administering the dose. Recent improvements in CBCT imaging sources and detectors have enhanced image quality. Moreover, it may be possible to calculate radiation dose directly on these CBCTs. Utilizing CBCT imaging for plan adaptation could also eliminate the need for an additional CT procedure, thereby increasing patient comfort. To address the labor-intensive contouring and treatment planning steps, CE-marked and validated commercial AI applications are already being used to support organ contouring and accelerate the treatment-planning process. These tools are currently applied to pre-treatment planning CTs. The time efficiency of these contemporary tools in a prospective ART workflow has yet to be studied, as has the feasibility of applying these applications within a CBCT-based ART workflow.

This study aims to explore the safety and efficacy of eliminating the PTV (planning target volume) margins based on online adaptive stereotactic radiotherapy for patients with early-stage non-small cell lung cancer (NSCLC) or pulmonary oligometastases.

Gliomas are common primary brain tumors in adults. Gliomas can be classified into different types based on tumor grade, histopathological features, and molecular characteristics. The common types of diffuse gliomas include glioblastoma, astrocytoma, and oligodendroglioma. The standard treatment for diffuse gliomas includes surgery followed by radiation and chemotherapy. As per standard institutional practice, a uniform dose of radiation is delivered to the disease area and MRI is done before and after the treatment. In this study, MRI and PET scan will be done before starting the treatment and standard dose of radiation will be delivered. The interval imaging will be done twice during the course of treatment with MRI and PET, followed by dose modifications. The CT, MRI, and PET will be combined. Based on PET imaging, specific dose will be altered and delivered to specific areas. Dose modification will be done with the help of artificial intelligence. Participant's assessment will be done at regular intervals. Modifications in radiation plans are done based on the changes in disease seen in scans is likely to improve the accuracy of RT treatments. Dose modifications based on imaging to resistant areas will help achieve better tumor control, reduce treatment-related toxicities, precise delivery of the RT and adjusting doses to the organs at risk (OAR) and changes in disease leading to better treatment compliance. Creating an artificial intelligence framework in radiation oncology promises to improve quality of workflow, treatment planning and RT delivery. The aim of the study is to develop an artificial intelligence workflow for treatment of glioma with adaptive radiotherapy. This study will be conducted in Tata Memorial Centre on a population of 60 patients for a duration of 2 years. The total study duration is 4 years.

Based on preliminary findings on the motion error of the clinical target volume (CTV) in MR-guided adaptive radiotherapy (MRgART) for locally advanced rectal cancer (LARC), this study aims to reduce CTV-to-PTV margins and evaluate the complete response (CR) rate following MRgART in LARC patients. Additionally, it will investigate the safety and tolerability of MRgART, as well as its impact on: 3-year organ preservation rate Local recurrence rate in patients under a "watch-and-wait" approach 3-year overall survival (OS), disease-free survival (DFS), and local progression-free survival (LPFS). Furthermore, by analyzing ADC maps of the gross tumor volume (GTV), this study will characterize treatment responses and spatial deformation in metabolically active tumor subregions. These insights may inform future dose-escalation strategies for LARC radiotherapy, with the ultimate goal of improving prognosis and quality of life in this patient population.

The most common external beam radiotherapy fractionation scheme for cervical cancer is 45-50.4 Gy delivered in 25-28 fractions. However, prolonged treatment duration can lead to insufficient availability of medical resources. We hope to assess the safety and efficacy of moderated hypofractionated online adaptive radiotherapy in combination with brachytherapy in patients with cervical cancer in a multicenter study.

Most newly diagnosed oropharyngeal and hypopharyngeal cancers are treated with radiochemotherapy with curative intent. If the field-set UP margins are broad, the consequence may be that quality of life is impaired. The study group of Nutting et al. (2023) investigated this year whether dysphagia-optimized intensity-modulated radiotherapy can reduce the radiation dose to structures associated with dysphagia and aspiration and improve swallowing function compared to standard IMRT (Nutting C, Finneran L, Roe J, Petkar I, Rooney K, Hall E; DARS Triallist Group. Dysphagia-optimized intensity-modulated radiotherapy versus standard radiotherapy in patients with pharyngeal cancer - Authors' reply. Lancet Oncol. 2023 Oct;24(10):e398. doi: 10.1016/S1470-2045(23)00457-6. PMID: 37797636.) The study group concluded that the results suggest that dysphagia-optimized IMRT improves patient-reported swallowing function compared to standard IMRT. DO-IMRT should be considered the new standard of care for patients receiving radiotherapy for pharyngeal cancer, and ART could further improve outcomes.

Adaptive radiotherapy (ART) includes image-guided radiotherapy (IGRT) and also offers further possibilities for plan adaptation. A particularly high benefit can be expected for patients in whom the clinical target volume (CTV) can show a significant change in shape from fraction to fraction due to anatomical deviations. The shape and position constancy of the CTV during the course of the series is examined in this trial. Dosimetric disadvantages of this type have not been reported so far. The aim of this study is to identify patients who benefit from ART at an early stage and to select them for this method, and then to continue to offer ART to this patient group. If a relevant reduction in the minimum planning target volume (PTV) margins with ART compared to IGRT is demonstrated in this study, patients could be treated with ART.

Prospective randomized evaluation of adaptive radiotherapy in the definitive radiotherapy of locally advanced gynecologic carcinoma (e.g. cervical carcinoma, endometrial carcinoma, vaginal carcinoma), in the postoperative situation or first series of external beam radiotherapy and in patients in whom radical surgery or HDR brachytherapy as dose boost is not an option.