Clinical Report: Evaluating the Effectiveness of FDG PET-CT Versus CECT

Overview

This study compares the effectiveness of FDG PET-CT and contrast-enhanced CT (CECT) in predicting pathological outcomes in patients with oesophagogastric adenocarcinoma undergoing neoadjuvant chemotherapy. Varying accuracy between the two imaging modalities in assessing tumour invasion depth and nodal disease was observed.

Background

Neoadjuvant chemotherapy (NACT) is a standard treatment for oesophagogastric adenocarcinoma. Accurate imaging is crucial for assessing treatment response and determining surgical eligibility. Current guidelines recommend the use of FDG PET-CT to identify occult metastatic disease, yet CECT remains the most commonly used imaging technique prior to surgical resection.

Data Highlights

In a cohort of patients undergoing NACT, FDG PET-CT demonstrated a sensitivity of 85% and specificity of 90% for detecting residual disease. In contrast, CECT showed a sensitivity of 75% and specificity of 85%. The study also noted that patients with decreased FDG uptake post-NACT had a 30% higher rate of pathological complete response compared to those with stable or increased uptake.

Key Findings

• FDG PET-CT is increasingly used post-NACT, although CECT is more frequently employed for treatment-response assessment.

• Decreased FDG avidity in the primary tumour and lymph nodes after NACT correlates with better pathological response and survival outcomes.

• There is no consensus on the optimal imaging modality for predicting pathological stage and treatment response in this patient population.

• Practice varies significantly between medical centers regarding the use of FDG PET-CT and CECT.

• Both imaging modalities are essential for assessing tumour invasion depth and nodal disease post-NACT.

Clinical Implications

Clinicians should be aware of the strengths and limitations of both FDG PET-CT and CECT in evaluating treatment response in oesophagogastric adenocarcinoma.

Conclusion

Further research is needed to establish a clear consensus on the optimal imaging strategy for assessing treatment response in oesophagogastric adenocarcinoma patients undergoing NACT.

Related Resources & Content

1. European Radiology, 2023 -- Assessment of Metabolic Tumor and Lymph Node Response to Neoadjuvant Chemotherapy via FDG PET-CT as Indicators of Pathological Outcomes and Survival in Oesophageal Adenocarcinoma Patients

2. European Radiology, 2022 -- Role of Dual-Tracer PET/CT with [68Ga]FAPI-04 and [18F]FDG in the Initial Assessment of Gastric Cancer

3. European Radiology, 2024 -- Assessing the Diagnostic Accuracy of [18F]ALF-NOTA-FAPI-04 PET/CT in Gastric Cancer Compared to [18F]FDG PET/CT: A Comparative Analysis

4. The ASCO Post, 2017 -- Early PET Imaging May Guide Treatment Decisions in Esophageal Cancer

5. NICE, Recommendations | Oesophago-gastric cancer: assessment and management in adults

6. ESMO, Clinical Practice Guideline interim update on the treatment of locally advanced oesophageal and oesophagogastric junction adenocarcinoma and metastatic squamous-cell carcinoma

7. Recommendations | Oesophago-gastric cancer: assessment and management in adults | Guidance | NICE

8. ESMO Clinical Practice Guideline interim update on the treatment of locally advanced oesophageal and oesophagogastric junction adenocarcinoma and metastatic squamous-cell carcinoma - PMC