Chemotherapy response evaluation in metastatic colorectal cancer with FDG PET/CT and CT scans.
BACKGROUND
[18F]-fluorodeoxyglucose with positron-emission tomography (PET) and computed tomography (CT) scans were used to assess morphological and metabolic tumour response after chemotherapy in metastatic colorectal cancer.


METHODS
Twenty-five patients were evaluated after 4 courses of chemotherapy (+/-target therapy), and among them 20 patients after 2 courses. Response Evaluation Criteria In Solid Tumors (RECIST) and European Organisazion for Research and Treatment of Cancer (EORTC) criteria were used to evaluate CT and PET respectively.


RESULTS
Discrepancies between the two procedures were noted after 4 courses of chemotherapy in patient-based analysis. Two morphologically complete responses (CR) were correlated with metabolic response. Seven morphological partial responses (PR) were evaluated as 3 metabolic PR, 2 CR and 1 progressive disease (PD). Seventeen cases of morphologically stable disease (SD) were evaluated as 3 metabolic CR, 13 PR and 1 PD. These discrepancies were confirmed in lesion-based analysis. Perfect concordance was noted between metabolic responses obtained after 2 and 4 cycles.


CONCLUSIONS
Morphological and metabolic imaging does not permit concordant therapeutic assessment in metastatic colorectal cancer.
Monteil
J
J
Department of Nuclear Medicine, University Hospital of Limoges, France.
Mahmoudi
N
N
Leobon
S
S
Roudaut
P Y
PY
El Badaoui
A
A
Verbeke
S
S
Venat-Bouvet
L
L
Martin
J
J
Le Brun-Ly
V
V
Lavau-Denes
S
S
Maubon
A
A
Bouillet
P
P
Pouquet
M
M
Vandroux
J C
JC
Tubiana-Mathieu
N
N
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed
D000970:Antineoplastic Agents; D019788:Fluorodeoxyglucose F18