Guidelines for Staging and Restaging in Oncology Using FDG-PET/CT

Overview

The European Society for Hybrid, Molecular, and Translational Imaging provides recommendations for the selective use of [18F]FDG-PET/CT in oncology. This imaging modality offers superior diagnostic accuracy in staging, treatment planning, and response monitoring for several common cancers, including lung cancer and lymphoma.

Background

Positron emission tomography (PET) combined with computed tomography (CT) using [18F]fluorodeoxyglucose ([18F]FDG) is a molecular imaging technique that visualizes metabolic activity in tumors. Unlike conventional anatomical imaging, PET provides functional information at the cellular level, though with lower spatial resolution. [18F]FDG-PET/CT is widely used for detecting various cancers due to the increased glucose metabolism characteristic of malignant cells. This review focuses on its application in prevalent cancers such as lung cancer, lymphoma, head and neck cancer, breast cancer, and colorectal cancer.

Data Highlights

Key Findings

• [18F]FDG-PET/CT should be used selectively when it offers superior sensitivity, specificity, and clinical impact compared to conventional imaging (moderate evidence).
• It is highly useful in treatment planning and monitoring response to chemotherapy, immunotherapy, and radiotherapy, enabling early detection of non-responding tumors (high evidence).
• Combining [18F]FDG-PET/CT with other modalities like MRI enhances diagnostic accuracy, especially for evaluating liver metastases (high evidence).
• In lung cancer, [18F]FDG-PET/CT shows high sensitivity (96%) and accuracy (92%) for characterizing solitary pulmonary nodules larger than 8–10 mm, though specificity is low due to false positives from inflammation.
• False negatives may occur in subcentimeter nodules (<8–10 mm) due to PET’s spatial resolution limitations.
• Hybrid imaging with diagnostic CT and PET provides complementary anatomical and functional information, improving staging and treatment response assessment using criteria such as PERCIST.

Clinical Implications

[18F]FDG-PET/CT should be integrated thoughtfully into oncology workflows to optimize patient selection and maximize diagnostic yield. Its ability to detect metabolic changes before anatomical alterations supports early intervention and tailored treatment adjustments. Combining PET/CT with other imaging modalities and structured reporting enhances clinical decision-making and patient management.

Conclusion

[18F]FDG-PET/CT is a valuable tool in oncology for accurate staging, restaging, and treatment monitoring. Its selective use based on clinical criteria improves diagnostic accuracy and impacts therapeutic strategies across multiple cancer types.

References

1. European Society for Hybrid, Molecular, and Translational Imaging -- Guidelines for Staging and Restaging in Oncology Using FDG-PET/CT