Definition
- CT Angiogram is a computed tomography scan performed with intravenous contrast to visualize blood vessels (arteries and veins).
- Provides high-resolution 3D images to detect vascular abnormalities.
Indications in Oncology
- Pre-surgical planning: assess vascular anatomy before tumor resection (e.g., liver, pancreas, head & neck cancers).
- Evaluation of tumor vascularity: differentiates hypervascular tumors (e.g., hepatocellular carcinoma, renal cell carcinoma) from surrounding tissue.
- Detection of tumor thrombus or vascular invasion: e.g., renal vein or portal vein thrombus.
- Assessment of pulmonary embolism in cancer patients (cancer increases VTE risk).
- Interventional planning: for embolization or intra-arterial chemotherapy.
Procedure
- Patient receives IV iodinated contrast.
- Timing of scan is crucial: arterial phase vs venous phase depending on vessels of interest.
- Patient may need to hold certain medications (e.g., metformin) around the time of contrast administration.
Contraindications / Precautions
- Severe iodine allergy → premedication or alternative imaging.
- Renal impairment → risk of contrast-induced nephropathy; monitor creatinine/eGFR.
- Pregnancy → use caution; minimize fetal radiation.
Pharmacist Considerations
- Contrast–drug interactions: hold or adjust nephrotoxic drugs (cisplatin, aminoglycosides) and metformin.
- Hydration: encourage adequate IV/oral fluids to reduce contrast nephropathy.
- Allergy prophylaxis: premedicate with steroids/antihistamines if history of contrast reaction.
- Patient education: explain the need for contrast, possible warmth sensation, and post-scan hydration.
Key Takeaways for Oncology Pharmacists
- CTA is primarily a diagnostic tool for vascular structures and tumor vascular involvement.
- Know renal function, allergy history, and drug interactions before contrast administration.
- Often used in surgical planning, interventional radiology, or PE evaluation in cancer patients.