Gastrointestinal stromal tumors treated with imatinib: monitoring response with contrast-enhanced sonography.
OBJECTIVE
The purpose of this study was to evaluate contrast-enhanced Doppler sonography with perfusion software as a predictor of early tumor response to imatinib (Glivec) in c-kit-positive gastrointestinal stromal tumors (GISTs).


METHODS
Thirty patients (59 tumors) with metastases or a recurrence from a GIST were prospectively included in a single-center imaging trial. Contrast-enhanced Doppler sonography was performed with an Aplio scanner the day before (day-1) starting oral treatment (400 mg) and at days 1, 7, 14, 60, 90, and 6 months, 9 months, and 1 year. The percentage of contrast uptake (Levovist or Sonovue) before treatment and at the different stages of follow-up was evaluated by two radiologists. Digitized quantification was performed using Photoshop software. To define the benchmark standard, all patients were rated as responders or nonresponders at 2 and 6 months by a board consisting of oncologists and radiologists who had all clinical and imaging data at their disposal. Changes in the percentage of contrast uptake at each sonographic examination were compared statistically.


RESULTS
A total of 185 examinations were performed. Forty-four lesions in 24 patients were completely evaluated at 2 months, and 29 lesions in 15 patients were completely evaluated at 6 months. Initial contrast uptake at day 1 was predictive of the future response. A strong correlation was found between the decline in tumor contrast uptake at days 7 and 14 and tumor response (p < 10(-4)).


CONCLUSIONS
Contrast-enhanced Doppler sonography is a noninvasive imaging technique that allows the early prediction of tumor response in c-kit-positive GIST treated with Glivec.
Lassau
Nathalie
N
Department of Medical Imaging, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif, France. lassau@igr.fr
Lamuraglia
Michele
M
Chami
Linda
L
Leclère
Jerome
J
Bonvalot
Sylvie
S
Terrier
Philippe
P
Roche
Alain
A
Le Cesne
Axel
A
D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D003287:Contrast Media; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D010743:Phospholipids; D010879:Piperazines / Q000627:therapeutic use*; D011134:Polysaccharides; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D011743:Pyrimidines / Q000627:therapeutic use*; D013459:Sulfur Hexafluoride; D018608:Ultrasonography, Doppler
D000970:Antineoplastic Agents; D001549:Benzamides; D003287:Contrast Media; D010743:Phospholipids; D010879:Piperazines; D011134:Polysaccharides; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; C420843:contrast agent BR1; C059891:SHU 508; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit; D013459:Sulfur Hexafluoride