A systematic review on the role of FDG-PET/CT in tumour delineation and radiotherapy planning in patients with esophageal cancer

• Published in: Radiotherapy and oncology Vol. 97; no. 2; pp. 165 - 171
• Main Authors: Muijs, Christina T, Beukema, Jannet C, Pruim, Jan, Mul, Veronique E, Groen, Henk, Plukker, John Th, Langendijk, Johannes A
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.11.2010
• Subjects: Esophageal cancer; Esophageal Neoplasms - diagnosis; Esophageal Neoplasms - radiotherapy; FDG-PET/CT; Fluorodeoxyglucose F18; Hematology, Oncology and Palliative Medicine; Humans; Neoplasm Staging; Positron-Emission Tomography; Radiotherapy planning; Radiotherapy Planning, Computer-Assisted; Tomography, X-Ray Computed; Treatment Outcome; FDG-PET/CT; Radiotherapy planning; Esophageal cancer
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2010.04.024

Abstract Purpose: FDG-PET/CT has proven to be useful in the staging process of esophageal tumours. This review analysed the role of FDG-PET/CT in tumour delineation and radiotherapy planning in comparison with CT alone among patients with esophageal cancer. Thereby we focused on the detection of the primary tumour and lymph nodes by FDG-PET/CT, changes in target volume (TV) delineation based on FDG-PET/CT and its validity, changes in inter- and intra-observer variability in TV delineation, consequences for radiotherapy treatment planning with regard to either target volumes or organs at risk and finally on the validation of FDG-PET/CT-based TVs in terms of treatment outcome. Methods: A literature search was performed in MEDLINE and Cochrane library databases for studies concerning the current value of FDG-PET/CT in tumour detection and delineation and radiotherapy-planning procedures among patients with esophageal cancer. Both prospective and retrospective studies were included. Results: Fifty publications met the eligibility criteria, of which 19 were review papers and one was a case report. The remaining 30 publications reported on the results of original studies. FDG-PET was able to identify most primary tumours, with a sensitivity and specificity for the detection of metastatic lymph nodes of 30–93% and 79–100%. The use of FDG-PET/CT resulted in changes of target volumes, and consequently in changes in treatment planning. However, evidence supporting the validity of the use of FDG-PET/CT in the tumour delineation process is very limited. Only three studies reported a significant positive correlation between FDG-PET-based tumour lengths and pathological findings. There were two studies that tested the influence of FDG-PET/CT to the inter- and intra-observer variability. One of them found a significant decrease in inter- and intra-observer variability, while the others did not. Furthermore, there are no studies demonstrating the use of PET/CT in terms of improved locoregional control or survival. Conclusion: Since the literature is very limited standard implementation of FDG-PET/CT into the tumour delineation process for radiation treatment seems unjustified and needs further clinical validation first.