Treatment response monitoring in patients with gastrointestinal stromal tumor using diffusion-weighted imaging: preliminary results in comparison with positron emission tomography/computed tomography.
We compared the parameters derived from diffusion-weighted imaging (DWI) and positron emission tomography/computed tomography (PET/CT) for treatment response evaluation and response prediction in patients with gastrointestinal stromal tumor (GIST). Seven patients with histologically proven metastatic disease were enrolled. DWI and PET/CT data were collected from all patients at diagnosis and from six at follow-up. All 37 lesions were identifiable in DWI with a sensitivity of 100%. To achieve higher accuracy, we used the apparent diffusion coefficient (ADC) of liver and background noise as thresholds for the measurement of the ADCs of lesions. Significant inverse correlations were found between ADC(mean_thr) (ADC(mean) with thresholds) and SUV(mean) (mean standardized uptake value) (R(2)=0.523, p<0.001 at diagnosis, and R(2)=0.916, p<0.001 at follow-up), between ADC(mean_thr) and SUV(max) (maximum SUV) (R(2)=0.529, p<0.001 at diagnosis, and R(2)=0.761, p<0.001 at follow-up), between ΔADC(mean_thr) (percentage change in ADC(mean_thr) ) and ΔSUV(mean) (percentage change in SUV(mean) ) (R(2)=0.384, p<0.001), and between ΔADC(mean_thr) and ΔSUV(max) (percentage change in SUV(max) ) (R(2)=0.500, p<0.001). In lesion-based analysis, pre-treatment ADC(mean_thr) outperformed SUV(mean) and SUV(max) in treatment response prediction, with an area under the receiver operating characteristic curve of 0.706. These results show that DWI can provide a quantitative assessment comparable with PET/CT in GIST lesion characterization, treatment response evaluation and response prediction.
Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong.
Nan-Jie
NJ
Gong
Chun-Sing
CS
Wong
Yiu-Ching
YC
Chu
Jing
J
Gu
D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides / Q000627:therapeutic use*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy*; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000188:drug therapy*; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D010865:Pilot Projects; D010879:Piperazines / Q000627:therapeutic use*; D049268:Positron-Emission Tomography; D011379:Prognosis; D011743:Pyrimidines / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate