Practical Approach to CT-Guided Online Adaptive Radiotherapy for Abdominopelvic Tumors.

Abstract

Adaptive radiation therapy (ART) represents an evolution in the field of radiation oncology, addressing the complexities of tumor motion and anatomical variability that often challenge conventional treatment techniques. In abdominopelvic cancers, where the proximity of organs at risk (OARs) and variability in patient anatomy necessitate precise dose delivery, online adaptive radiation therapy (OART) has emerged as a technique to limit dose to OARs while optimizing dose delivery to target volumes. Computed tomography-guided OART is a time-efficient modality utilizes high-resolution cone beam computed tomography (CBCT) and artificial intelligence (AI) to enable real-time plan adaptation to daily anatomical changes, improving target coverage and minimizing exposure to healthy tissues. Herein, we describe the CT-based OART framework, evaluating the multidisciplinary approach and the critical role of template generation in ensuring treatment accuracy and workflow efficiency. The discussion progresses to site-specific applications, exploring the dosimetric and clinical implications of OART in gastrointestinal, genitourinary, and gynecologic cancers. Finally, the paper highlights future directions, including emerging technologies and the integration of adaptive techniques into routine clinical practice, paving the way for broader implementation of OART across various cancer types.