Positron emission tomography for assessment of the response to induction radiochemotherapy in locally advanced oesophageal cancer.
OBJECTIVE
This prospective study was designed to determine the utility of 18F-labelled deoxyglucose (FDG) in positron emission tomography (PET) (FDG-PET) for assessing the response to neoadjuvant chemoradiation therapy (CRT) in locally advanced oesophageal tumours.


METHODS
Thirty-six patients with locally advanced oesophageal cancer (clinical T4 stage) without organ metastases, underwent FDG-PET before and 1 month after CRT. Patients were classified as major responders by serial FDG-PET when the post-CRT PET demonstrated a strong reduction of FDG uptake at the primary tumour site (>80% reduction of tumour-to-liver uptake ratio) without any abnormal FDG uptake elsewhere in the body. PET response was compared with histology obtained during post-induction transthoracic oesophagectomy.


RESULTS
A strong correlation was found between the extent of lymph node (LN) involvement as shown by the pre-CRT PET and the major response rate (P = 0.001): such response occurred in nine of 11 N0M0 patients (82%), in three of nine N(1-2)M0 patients (33%) and in two of 16 patients (13%) with distant lymphatic spread. Such a correlation was not found for computed tomography or endoscopic ultrasonography. The sensitivity of serial FDG-PET for a major CRT response was 10 of 14 (71%), its specificity 18 of 22 (82%). The concordance between the response assessment by PET and histopathology was 78%. The median survival time after CRT of PET major responders compared with PET non-major responders was 16.3 months and 6.4 months, respectively. The metabolic response as measured by serial FDG-PET is a stronger prognostic factor for overall survival (P = 0.002) than the extent of LN involvement seen on the pretreatment FDG-PET (P = 0.087).


CONCLUSIONS
These data indicate that CRT response as assessed by serial FDG-PET is strongly correlated with pathological response and survival.
Flamen
P
P
Department of Nuclear Medicine, University Hospital Gasthuisberg, Leuven, Belgium. Patrick.Flamen@uz.kuleuven.ac.be
Van Cutsem
E
E
Lerut
A
A
Cambier
J P
JP
Haustermans
K
K
Bormans
G
G
De Leyn
P
P
Van Raemdonck
D
D
De Wever
W
W
Ectors
N
N
Maes
A
A
Mortelmans
L
L
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012074:Remission Induction; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18