Stereotactic radiotherapy for liver oligometastases

Area of Science:

• Oncology
• Radiotherapy
• Medical Imaging

Background:

• Liver metastases are common in colorectal, lung, and breast cancers.
• Computed tomography (CT) and magnetic resonance imaging (MRI) are standard for assessing liver lesions, with MRI offering superior soft-tissue contrast for small lesions.
• Positron emission tomography with computed tomography (PET-CT) aids in diagnosing liver metastases.

Purpose of the Study:

• To review the role of imaging in liver metastases management.
• To discuss treatment planning considerations for liver stereotactic radiotherapy (SRT).
• To evaluate the efficacy and toxicity of liver SRT.

Main Methods:

• Review of imaging techniques including contrast-enhanced CT, MRI, and PET-CT for liver lesion characterization.
• Discussion of treatment planning challenges, including respiratory motion management and precise contouring.
• Analysis of data from retrospective studies on liver SRT, focusing on dose fractionation and outcomes.

Main Results:

• High local control rates (60-90% at 1-2 years) are achievable with liver SRT.
• Biological effective doses (BED10) over 100 Gy correlate with the best local control.
• Common toxicities include elevated liver enzymes, hyperbilirubinemia, and hypoalbuminemia, with generally mild late toxicity.

Conclusions:

• Accurate imaging (contrast MRI, PET-CT) is crucial for precise target delineation in liver metastases.
• Liver SRT shows potential for effective local control, though optimal dosing and fractionation are still under investigation.
• Stereotactic radiotherapy for liver metastases is associated with manageable toxicity, even in long-term follow-up.