Introduction After primary CRT, a non-invasive evaluation of the tumour response could help in the treatment decision to identify patients who may benefit from surgery. Whether FDG-PET provides clinically relevant information remains questionable. The objective of this prospective trial was to evaluate the role of 18F-Fluorodeoxyglucose-positron emission tomography (FDG-PET) in the assessment of tumour response after the completion of neoadjuvant chemoradiation (CRT) in patients with locally advanced resectable oesophageal cancer.
Methods Operable patients with locally advanced oesophageal cancer (clinically staged T3 N0-1 M0) were enrolled. The complete treatment plan included neoadjuvant CRT (cisplatin + 5-Fluorouracil/45 Gy) followed 6–8 weeks later by a transthoracic en bloc oesophagectomy. Morphological evaluations combined with FDG-PET results were performed 2 weeks before and 4–6 weeks after the completion of CRT. Intratumoural pre- and post-treatment FDG-standardised uptake values were assessed (SUV1, SUV2, percentage change). These variables were correlated with pathologic and morphologic responses and survival. Investigators were blinded to the FDG-PET results unless metastatic disease was suspected.
Results Out of 60 total patients, 46 underwent the complete treatment plan (median age: 60.1 years; adenocarcinoma: 25 patients; squamous cell cancer: 21 patients). A major pathological response occurred in 19.6% of patients and was associated with a favourable outcome (p=0.057). Neoadjuvant CRT led to a significant reduction in intratumoral FDG-uptake (p<0.001). No significant association was seen between a pathologic response (either complete or major) and the FDG-PET results (p>0.280). The SUV2 value was correlated with a morphological response and the possibility to perform an R0 resection (p<0.018; ROC analysis: SUV2 threshold = 5.5). No significant association was found between metabolic imaging and recurrence or survival.
Conclusion FDG-PET does not effectively correlate with pathologic response and long-term survival in patients with locally advanced oesophageal cancer undergoing neoadjuvant CRT followed by surgery (registered on http://www.e-cancer.fr website, RECF0350, 2002-1936R).
Funding Funded by the French ministry of Health – Programme Hospitalier de Recherche Clinique 2002.
Competing interests None declared.