Trial results evaluating a novel high-performance Cone-Beam CT (CBCT) for guiding precision radiotherapy were posted on ClinicalTrials.gov on 2026-05-06. The study found that the novel CBCT, particularly with a breath-hold technique, achieved a median artifact index of 20.2 HU, significantly lower than the 59.2 HU observed with conventional CBCT.
Background
Radiotherapy is a critical treatment modality for various cancers, including breast, lung, and liver cancers. Precise targeting of tumors while sparing healthy tissue is paramount for treatment efficacy and minimizing side effects. Cone-Beam CT (CBCT) systems are commonly used during radiotherapy to provide on-couch imaging for patient positioning and treatment adaptation. However, conventional CBCT images can suffer from artifacts and lower image quality compared to diagnostic CT scans, which can limit their utility for detailed anatomical assessment and dose recalculations. Improving CBCT image quality is therefore important for enhancing the accuracy and safety of precision radiotherapy.
Trial design
This completed feasibility study, which did not specify a phase (Phase NA), enrolled 31 participants. The study investigated the image quality of a new, high-performance CBCT system for on-couch imaging during radiotherapy treatments. Conditions evaluated included Lung Cancer, Liver Cancer, Breast Cancer, and Other Cancer. While specific primary outcomes were not explicitly listed, the trial's brief summary indicated an investigation into image quality. The study compared the novel high-performance CBCT under both breath-hold and free-breathing conditions against conventional CBCT and CT simulation.
Key results
The study collected several key measurements related to CBCT image quality:
- CBCT Image Quality - Artifact Index:
- Breath Hold High Performance CBCT: Median of 20.2 HU
- Free Breathing High Performance CBCT: Median of 32.9 HU
- Conventional CBCT: Median of 59.2 HU
- CT Simulation: Median of 17.3 HU
- CBCT Image Quality - Image Nonuniformity:
- Breath Hold High Performance CBCT: Median of 0.1 ratio
- Free Breathing High Performance CBCT: Median of 0.25 ratio
- Conventional CBCT: Median of 0.25 ratio
- CT Simulation: Median of 0.05 ratio
- CBCT Image Quality - Contrast:
- Breath Hold High Performance CBCT: Median of 134.1 HU
- Free Breathing High Performance CBCT: Median of 129.7 HU
- Conventional CBCT: Median of 126.8 HU
- CT Simulation: Median of 142.3 HU
What this means
The results indicate that the novel high-performance CBCT system significantly improves image quality compared to conventional CBCT, particularly when patients perform a breath hold. The median artifact index of 20.2 HU for the breath-hold high-performance CBCT approaches the quality of a CT simulation (17.3 HU), suggesting a substantial reduction in imaging artifacts. Similarly, image nonuniformity was lower for the breath-hold high-performance CBCT (0.1 ratio) compared to conventional CBCT (0.25 ratio). While contrast values were generally comparable across CBCT types, the overall improvements in artifact reduction and uniformity could lead to more accurate tumor localization and better assessment of anatomical changes during radiotherapy for patients with conditions such as breast, lung, and liver cancers. This enhanced image quality could facilitate more precise treatment delivery and adaptation, potentially improving therapeutic outcomes.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT05176860, titled "Evaluation of Novel Cone-Beam CT for Guidance and Adaptation of Precision Radiotherapy", were posted on 2026-05-06 on clinicaltrials.gov.