What is the utility of Computed Tomography Angiography (CTA) for post-radiation therapy hematemesis (vomiting blood)?

From the Guidelines

Computed Tomography Angiography (CTA) is highly recommended for evaluating post-radiation hematemesis (vomiting blood) due to its high sensitivity and specificity in detecting active gastrointestinal bleeding (GIB). The utility of CTA in this context is supported by a recent study published in the Journal of the American College of Radiology in 2024 1, which highlights the effectiveness of CTA in detecting bleeding rates as slow as 0.3 mL/min.

Key Benefits of CTA

• High sensitivity and specificity of 85% and 92%, respectively, in detecting active GIB 1
• Ability to detect intraluminal high-attenuation material that may mimic intraluminal blood on contrast-enhanced images
• Faster acquisition and greater availability compared to conventional angiography and Tc-99m–labeled red blood cell (RBC) scintigraphy
• Non-invasive nature makes it an excellent first-line imaging choice before more invasive procedures

Optimal CTA Protocol

• Noncontrast images for CTA performed on single-energy CT, which can be replaced by virtual noncontrast reconstructions with dual-energy CT 1
• Multiphase acquisition, including a portal venous or a delayed phase, in addition to the angiographic phase
• No oral contrast is usually given for GIB studies to avoid rendering the examination nondiagnostic

Clinical Implications

• CTA can effectively identify radiation-induced vascular abnormalities such as telangiectasias, pseudoaneurysms, and fistulas that may cause bleeding
• Findings from CTA can direct appropriate management, which may include endovascular embolization, surgical intervention, or conservative management depending on the bleeding severity and source identified
• CTA may still be underused for the diagnosis of GIB, and its use as the first test can lead to faster triage of patients toward definitive treatment 1

From the Research

Computed Tomography Angiography (CTA) for Post-Radiation Therapy Hematemesis

• CTA has become a mainstay for the imaging of vascular diseases due to its high accuracy, availability, and rapid turnaround time 2.
• The utility of CTA in managing gastrointestinal bleeding, including hematemesis, has been explored in several studies, with some suggesting its high sensitivity and specificity for diagnosis and treatment 3.
• However, the diagnostic utility of CTA compared to endoscopy in patients with acute GI hemorrhage has been found to be limited, with a sensitivity of 20% for detecting the source of GI bleeding 4.
• CTA principles and technical updates have been reviewed, highlighting the importance of understanding contrast medium enhancement and adapting to evolving CT technology 5.
• The role of CTA in intracranial hemorrhage has also been evaluated, with benefits justifying the known risks in everyday practice, particularly in detecting abnormalities related to the hemorrhage in 42% of patients 6.

Limitations and Considerations

• The use of CTA in post-radiation therapy hematemesis may be limited by its sensitivity and specificity, as well as the risks associated with radiation exposure and intravenous contrast administration.
• Clinical judgment should be exercised when considering CTA as a diagnostic tool, taking into account the potential benefits and risks, as well as alternative diagnostic modalities such as endoscopy.
• Further studies are needed to fully evaluate the utility of CTA in post-radiation therapy hematemesis and to determine its optimal role in the management of this condition 3, 4.