Cone-beam CT-based synthetic CT generation for adaptive radiotherapy: methodological paradigms, clinical reliability assessment, and translation.
Authors
Affiliations (5)
Affiliations (5)
- First Affiliated Hospital of Yangtze University, Yangtze University, Jingzhou, Hubei, China.
- Yangtze University Health Science Center, Yangtze University, Jingzhou, Hubei, China.
- Beijing Jishuitan Hospital, Capital Medical University, Beijing, China.
- School of Biomedical Engineering, Capital Medical University, Beijing, China.
- Laboratory for Clinical Medicine, Capital Medical University, Beijing, China.
Abstract
Synthetic computed tomography (sCT) generated from cone-beam computed tomography (CBCT) has important applications in quantitative imaging, dose recalculation, and adaptive radiotherapy. Deep learning has improved image quality and Hounsfield unit accuracy, but its reliability for patient-specific dosimetry and routine clinical use remains uncertain. This narrative review examines deep learning methods for generating sCT from treatment CBCT in photon and proton radiotherapy, with emphasis on data requirements, generalizability, structural fidelity, dosimetric accuracy, and clinical feasibility. The literature search was last updated on 30 July 2026. Current methods mainly include supervised regression, adversarial networks, registrationguided approaches, and diffusion models. Available evidence demonstrates encouraging image and dosimetric performance, although no method consistently performs best across anatomical sites, imaging systems, and treatment modalities. Most studies are based on proof of concept or single-center validation and show considerable heterogeneity in datasets, acquisition protocols, reference images, registration methods, and evaluation criteria. External validation, prospective assessment, failure detection, and quality assurance remain limited. Future studies should emphasize multicenter validation, standardized and modality-specific evaluation criteria, uncertainty assessment, and prospective workflow testing. More rigorous and clinically relevant evidence is needed to support the reliable use of sCT in patient-specific adaptive radiotherapy.