What are the symptoms, detection methods, and treatment options for liver metastasis?

Liver Metastasis: Symptoms and Detection

CT abdomen with IV contrast is the preferred initial imaging test for detecting liver metastases, with MRI abdomen without and with IV contrast being the optimal choice for presurgical assessment and for detecting small lesions (<1 cm) that may be missed by CT. 1

Symptoms of Liver Metastasis

Liver metastases often remain asymptomatic until they reach a significant size or number. When symptoms do occur, they may include:

• Right upper quadrant pain or discomfort
• Hepatomegaly (enlarged liver)
• Jaundice (yellowing of skin and eyes)
• Unexplained weight loss
• Early satiety
• Fatigue
• Ascites (in advanced cases)
• Fever (in some cases)

Detection Methods

Imaging Modalities

1. CT Abdomen with IV Contrast

   • Rated 9/9 (usually appropriate) for initial detection following primary tumor diagnosis 1
   • Provides excellent overview of primary tumor, nodal spread, peritoneal cavity, liver, and lungs
   • Sensitivity of 74.8% and specificity of 95.6% on a per-patient basis 2
   • Optimal technique requires:
     • Arterial phase and portal venous phase imaging
     • 3-5 mL/s injection rate
     • 2.5-5 mm slice thickness

2. MRI Abdomen without and with IV Contrast

   • Rated 8/9 for initial detection and 9/9 for presurgical assessment 1
   • Superior for detecting small lesions (<1 cm) with sensitivity of 81.1% and specificity of 97.2% 2
   • Particularly valuable when:
     • CT findings are indeterminate
     • Evaluating patients after chemotherapy
     • Assessing patients with fatty liver
     • Planning surgical resection
   • Hepatobiliary contrast agents (gadoxetic acid) improve detection of small metastases 3

3. Ultrasound (US)

   • Rated 4/9 (may be appropriate) for initial detection 1
   • Limited sensitivity (53-77%) for liver metastases 1
   • As low as 20% sensitivity for lesions <1 cm 1
   • Contrast-enhanced US can improve detection (sensitivity 87%, specificity 88%) 1
   • Intraoperative US is highly accurate during surgery (rated 8/9) 1

4. PET/CT

   • Rated 5/9 (may be appropriate) for initial detection 1
   • Useful when there is clinical suspicion of metastasis that cannot be confirmed by other imaging 1
   • Not recommended as routine test for diagnosis 1
   • Can help exclude other sites of disease beyond the liver 3

Algorithmic Approach to Imaging Selection

1. Initial Detection Following Primary Tumor Diagnosis:

   • First choice: CT abdomen with IV contrast 1
   • If CT findings are indeterminate or small lesions are suspected: MRI abdomen without and with IV contrast 1, 3
   • For neuroendocrine tumors: Consider In-111 somatostatin receptor scintigraphy 1

2. Surveillance Following Treatment of Primary Tumor:

   • First choice: CT abdomen with IV contrast (rated 8/9) 1
   • For patients with fatty liver: MRI is preferred over CT 4

3. Presurgical Assessment:

   • First choice: MRI abdomen without and with IV contrast (rated 9/9) 1
   • Complementary: Intraoperative US (rated 8/9) 1
   • Alternative: CT abdomen with IV contrast (rated 8/9) 1

Important Considerations

• Metastasis vs. Benign Lesions: 51-80% of small (<1-1.5 cm) lesions in patients with underlying malignancy are actually benign 1

• Hallmarks of Liver Metastases on Imaging:

  • Peripheral ring enhancement
  • Diffusion restriction on MRI
  • Hypointensity on hepatobiliary phase images 4

• Common Pitfalls:

  • Fatty liver can reduce CT accuracy for detecting metastases 3
  • Focal nodular hyperplasia-like nodules in patients who received platinum-based chemotherapy can mimic metastases 4
  • Avoid percutaneous biopsy of liver lesions without discussion with hepatobiliary unit as it may lead to extrahepatic tumor dissemination 3

• Primary Cancers with High Liver Metastasis Risk:

  • Colorectal, breast, lung, gastric, and pancreaticobiliary malignancies are the most common carcinomas to develop liver metastasis 1
  • Approximately 14.5% of colorectal cancer patients present with synchronous liver involvement 3

By following this evidence-based approach to detection, patients with liver metastases can receive appropriate and timely treatment, potentially improving morbidity, mortality, and quality of life outcomes.