Treatment response monitoring in patients with gastrointestinal stromal tumor using diffusion‐weighted imaging: preliminary results in comparison with positron emission tomography/computed tomography

Abstract

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.

Combination of 18F-FDG PET/CT and Diffusion-Weighted MR Imaging as a Predictor of Histologic Response to Neoadjuvant Chemotherapy: Preliminary Results in Osteosarcoma

“…Consistent with our data, previous studies in breast cancer and gastrointestinal stromal tumors have shown a significant negative correlation between ΔSUV and ΔADC (24,25). In osteosarcoma with good histologic response after neoadjuvant chemotherapy, at least 90% of cancer tissue is necrotic and less than 10% of primary viable cancer cells remain (20).…”

The Therapeutic Response of Gastrointestinal Stromal Tumors to Imatinib Treatment Assessed by Intravoxel Incoherent Motion Diffusion-Weighted Magnetic Resonance Imaging with Histopathological Correlation

“…In previous clinical studies, ADC values derived from conventional DWMRI have been used to predict responders versus non-responders among GIST patients within one month after Imatinib treatment[8, 15, 16], where increasing ADC values correlated well with the standardized uptake value (SUV) in 18 F-FDG PET/CT[15, 16]. Higher ADC values of responders compared to non-responders may correlate to the extensive cystic or myxoid degeneration of GIST[8, 27, 28].…”

“…Diffusion-weighted magnetic resonance imaging (DWMRI) is a non-invasive and nonionizing radiation imaging method that can measure tissue water mobility changes in order to evaluate GIST response to Imatinib[8, 15, 16]. In conventional DWMRI, tissue water mobility can be quantified with the apparent diffusion coefficient (ADC), which is calculated as the slope of the logarithm signal decay on diffusion-weighted images acquired at two or three diffusion weightings (e.g.…”

Potential Role of Positron Emission Tomography/Magnetic Resonance Imaging in Gastrointestinal and Abdominal Malignancies: Preliminary Experience

“…103 The conclusions of a recent systematic review confirm that [ 18 F]-FDG-PET and PET/CT have a significant role in assessing treatment response to drugs including tyrosine kinase inhibitors. 104 For MRI, promising results have shown that DWI is comparable to PET/CT in detecting the GIST lesions 105,106 and correlates with the response of [ 18 F]-FDG-PET to drug therapy. 106,107 Therefore, MRI with DWI may be an alternative for tumor characterization and follow-up.…”

“…104 For MRI, promising results have shown that DWI is comparable to PET/CT in detecting the GIST lesions 105,106 and correlates with the response of [ 18 F]-FDG-PET to drug therapy. 106,107 Therefore, MRI with DWI may be an alternative for tumor characterization and follow-up. Combined PET-MR may be of valuable importance in the management of patients; however, no data are available at current times on PET-MR in these tumors.…”