Evaluation of early response to concomitant chemoradiotherapy by interim 18F-FDG PET/CT imaging in patients with locally advanced oesophageal carcinomas.
OBJECTIVE
The best way to assess the response to chemoradiotherapy of locally advanced oesophageal carcinomas is not known. We used (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT to evaluate the metabolic response during chemoradiotherapy and tried to correlate this response to survival.


METHODS
Patients with biopsy-proven oesophageal carcinoma underwent FDG PET/CT with evaluation of the standardized uptake value (SUV) before any treatment (SUV1) and during chemoradiotherapy after two cycles of 5-fluorouracil (FU)/cisplatin and 20 Gy (SUV2). Metabolic response was defined as 1-(SUV2/SUV1). Surgery was discussed after 40 Gy and three cycles of chemotherapy. Results of interim PET were not considered for the therapeutic decision.


RESULTS
Among 72 patients who underwent a first FDG PET/CT before any treatment, 59 (82 %) could receive the second FDG PET/CT examination. Median survival was 22.2 months with 1-year and 2-year survivals of 70 and 46 %, respectively. Nineteen patients (32 %) underwent surgery. Mean SUV1 and SUV2 were 12.3 ± 6.2 and 6 ± 4.1, respectively (p < 0.001). Using a cut-off for metabolic response of 50 %, sensitivity and specificity for survival were 0.7 and 0.58. The 2-year overall survival of good responders was 62 % as compared to 27 % for poor metabolic responders. A multivariate analysis was performed, including T and N stages, surgery, histology and metabolic response: only metabolic response was significantly (p = 0.009) associated with 2-year survival.


CONCLUSIONS
Early evaluation of metabolic response had a great prognostic value and could help identify good responders to chemoradiotherapy.
Department of Radiation Oncology, Saint Louis Hospital, AP-HP, Paris, France.
Xavier
X
Cuenca
Christophe
C
Hennequin
Elif
E
Hindié
Sofia
S
Rivera
Laetitia
L
Vercellino
Valérie
V
Baruch-Hennequin
Jean-Marc
JM
Gornet
Pierre
P
Cattan
Mircea
M
Chirica
Laurent
L
Quéro
D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000628:therapy; D059248:Chemoradiotherapy; D002945:Cisplatin / Q000627:therapeutic use; D018572:Disease-Free Survival; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002945:Cisplatin