Follow-up of gastro-intestinal stromal tumours (GIST) during treatment with imatinib mesylate by abdominal MRI.
Typical MRI findings for gastro-intestinal stromal tumours (GIST) under treatment with imatinib were evaluated. MRI was performed in 45 patients (25 responders, 20 non-responders) with metastatic or locally advanced, unresectable GIST. Target lesions were selected and re-evaluated after 2, 4, and 6 months of therapy with imatinib. The target tumour response (TTR) was classified according to RECIST criteria. TTR, signal intensity in the centre and border of the lesion and the presence and the extension of a hypervascular rim were analysed. The mean diameter of the marker lesions decreased significantly (P<0.001) from 7.1+/-2.6 cm to 5.9+/-2.3 cm after 6 months. Accuracy of RECIST criteria was 51%, 69% and 73% on MRI 2, 4 and 6 months for response assessment. In addition, responders had higher signal-to-noise ratios on T2-w images after 2 months (P<0.05) and a decrease of vascularised areas in the lesion 4 and 6 months after treatment (each P<0.01), when compared with non-responders. Beyond the size measurement for response assessment, MRI provides additional information of tumour response using SI of T2-w images and quantification of vascularised areas of GIST manifestations.
Stroszczynski
Christian
C
Klinik und Poliklinik für Strahlenheilkunde, Campus Virchow Klinikum, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany. stros@charite.de
Jost
Dominik
D
Reichardt
Peter
P
Chmelik
Petra
P
Gaffke
Gunnar
G
Kretzschmar
Albrecht
A
Schneider
Ulrike
U
Felix
Roland
R
Hohenberger
Peter
P
D000005:Abdomen / Q000473:pathology*; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides; D005260:Female; D005500:Follow-Up Studies; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000473:pathology*; D006801:Humans; D000068877:Imatinib Mesylate; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D011379:Prognosis; D011743:Pyrimidines / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate