Ultrasound in Oncology

What It Shows

• Liver lesions — size, number, vascularity (CEUS distinguishes HCC from metastases from haemangioma)
• Abdominal lymph node enlargement
• Ascites — small volumes detected and guided for drainage
• Thyroid nodules — characterised by TIRADS scoring (shape, margins, echogenicity, calcifications)
• Scrotal masses — differentiating testicular tumour from epididymo-orchitis
• Soft-tissue masses and superficial lymph nodes
• Pleural effusions — guided drainage
• Ultrasound-guided biopsy — precise needle positioning in real time

How It Works

A handheld transducer emitting ultrasound waves is placed on the skin (with gel for acoustic coupling). Sound waves reflect differently at tissue boundaries — the pattern of reflections creates the image. For CEUS (Contrast-Enhanced Ultrasound), microbubble contrast agents (SonoVue, Lumason) are injected IV. Microbubbles enhance vascularity assessment — cancer lesions show characteristic enhancement and washout patterns. Elastography measures tissue stiffness — liver fibrosis and solid tumours are stiffer than surrounding tissue.

• First-line investigation for right upper quadrant pain or abnormal liver function
• Liver cirrhosis surveillance for HCC (6-monthly ultrasound + AFP)
• Thyroid nodule assessment after palpable or incidental finding
• Guided biopsy for any accessible lesion (liver, lymph node, soft tissue, thyroid)
• Guided drainage of pleural effusion or ascites
• Scrotal lump assessment in young men
• Post-treatment surveillance for superficial lesions

Ultrasound has strong evidence across many oncology indications. HCC surveillance ultrasound every 6 months in cirrhosis is the international guideline standard (AASLD, EASL), with sensitivity 58–84% for HCC. CEUS for liver lesion characterisation has meta-analytic sensitivity 89%, specificity 88% — comparable to MRI in experienced centres. Thyroid TIRADS scoring has reduced unnecessary biopsies by 40–50% while maintaining sensitivity for malignancy. Ultrasound-guided core needle biopsy has >95% diagnostic yield for accessible lesions with complication rates <1%. Testicular ultrasound sensitivity for testicular cancer approaches 100% in symptomatic patients.

Preparation & What to Expect

Abdominal ultrasound: fast for 4–6 hours (reduces bowel gas). Pelvic ultrasound: full bladder required. Thyroid / breast / scrotal ultrasound: no preparation. CEUS: no fasting unless combined with abdominal ultrasound. Scan performed in real-time by a sonographer or radiologist.

• Limited by bowel gas, obesity, and patient body habitus — poor image quality in some patients
• Operator-dependent — image quality and interpretation varies with sonographer/radiologist experience
• Cannot image through bone or air — limited for lung and bone assessment
• Deep structures (retroperitoneum, pancreas) poorly visualised in obese patients
• CEUS not universally available and requires specific equipment and training

• No radiation — generally safe in pregnancy
• CEUS microbubble agents: rare anaphylactic reactions possible (1:10,000); contraindicated in right-to-left cardiac shunts
• Ultrasound biopsy: infection and bleeding risk (usually low — <1%); discuss anticoagulants before procedure