Selective Interarterial Radiation Therapy (SIRT) in Colorectal Liver Metastases: How Do We Monitor Response?

Area of Science:

• Oncology
• Radiotherapy
• Medical Imaging

Background:

• Radioembolisation offers targeted radiotherapy for colorectal liver metastases.
• Current treatment response assessment methods lack standardization, hindering optimal patient management.
• Encouraging results necessitate validated tools for evaluating radioembolisation efficacy.

Purpose of the Study:

• To review current experiences and methods for assessing treatment response following radioembolisation.
• To compare different staging methods, criteria, and response assessment techniques in clinical practice.
• To identify a validated modality for evaluating radioembolisation in colorectal liver metastases.

Main Methods:

• A comprehensive literature review was conducted on electronic databases from 1980 to November 2011.
• Nineteen studies, including RCTs, clinical trials, meta-analyses, and case series, were analyzed.
• Data extracted included patient numbers, treatment regimens, staging/response criteria, tumor markers, and survival outcomes.

Main Results:

• No single validated modality is currently the method of choice for assessing radioembolisation response.
• Computed Tomography (CT) at 3 months post-treatment is the most frequently used assessment tool.
• Positron Emission Tomography-Computed Tomography (PET-CT) is increasingly adopted for its functional and radiological insights; RECIST criteria are most common.

Conclusions:

• A validated modality for assessing radioembolisation response in colorectal liver metastases is critically needed.
• The study proposes using PET-CT combined with Carcinoembryonic Antigen (CEA) tumor markers.
• Recommended assessment involves pre- and post-treatment evaluation at 3 months using RECIST 1.1 criteria, incorporating PET-CT findings, cystic changes, and necrosis.