Comparative Analysis of Whole-Body Diffusion-Weighted Imaging and PET/CT in Metastasis Detection: A Prospective Study

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Accurate cancer staging and metastasis detection are crucial for treatment planning and prognosis.
• Whole-body diffusion-weighted imaging (WB-DWI) is an emerging MRI technique for whole-body staging.
• Positron emission tomography/computed tomography (PET/CT) is a standard imaging modality for metastasis detection.

Purpose of the Study:

• To prospectively compare the sensitivity of WB-DWI with PET/CT in detecting metastatic lesions across various anatomical sites.
• To evaluate the agreement between WB-DWI and PET/CT in identifying different types of metastases.

Main Methods:

• Twenty-one patients with confirmed metastatic cancer underwent both PET/CT (using 18F-FDG) and WB-DWI.
• Metastatic lesions were assessed and localized across 18 predefined sites, including skeletal, visceral, and lymph node regions.
• Quantitative and qualitative comparisons of lesion detection and localization between the two imaging modalities were performed.

Main Results:

• PET/CT detected 68 metastases, while WB-DWI detected 64 metastases across 378 examined regions.
• WB-DWI showed substantial agreement with PET/CT for liver (κ=0.77) and lung metastases (κ=0.74).
• Perfect agreement (κ=1) was observed for adrenal gland, soft tissue, and lymph node metastases detected by WB-DWI compared to PET/CT.

Conclusions:

• WB-DWI demonstrates high sensitivity and excellent agreement with PET/CT for detecting various types of metastases, particularly lymph nodes and soft tissue lesions.
• WB-DWI offers significant advantages, including reduced imaging time, no radiation exposure, and lower costs compared to PET/CT.
• WB-DWI shows potential as a cost-effective and safer alternative to PET/CT for metastasis screening, warranting further research into optimized DWI parameters and MRI technology.