Follow-up of hepatic and peritoneal metastases of gastrointestinal tumors (GIST) under Imatinib therapy requires different criteria of radiological evaluation (size is not everything!!!).
OBJECTIVE
To define computed tomography (CT) criteria for evaluating the response of patients with gastrointestinal stromal tumors (GIST) who are receiving Imatinib (tyrosine-kinase inhibitor therapy).


METHODS
This prospective CT study evaluated 107 consecutive patients with advanced metastatic GIST treated with Imatinib.


RESULTS
Seventy patients had total or partial cystic-like transformation of hepatic and/or peritoneal metastases. These pseudocysts remained unchanged in size or stable in size on successive CT examinations (stable disease according to RECIST criteria). Forty-six patients developed metastases, 17 patients showed increasing parietal thickness and 29 patients with peripheral enhancing nodules. These CT changes represented local recurrence consistent with GIST resistance to Imatinib treatment. WHO or RECIST criteria did not provide a reliable evaluation of disease evolution or recurrence. Development of new enhancement of lesions (parietal thickness or nodule) was the only reliable criterion.


CONCLUSIONS
The development of peripheral thickening or enhancing nodules within cystic-like metastatic lesions, even without any change in size, represented progressive GIST under Imatinib, growing in a short time and should alert the clinician for the possible need for a change in therapy.
Mabille
Mylène
M
Department of Radiology, Institut Gustave-Roussy, Villejuif, France.
Vanel
Daniel
D
Albiter
Marcela
M
Le Cesne
Axel
A
Bonvalot
Sylvie
S
Le Péchoux
Cécile
C
Terrier
Philippe
P
Shapeero
Lorraine G
LG
Dromain
Clarisse
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage; D001549:Benzamides; D005260:Female; D005500:Follow-Up Studies; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000556:secondary; D006801:Humans; D000068877:Imatinib Mesylate; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000556:secondary; D008297:Male; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000556:secondary; D010879:Piperazines / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate