Publication Date:
2016-12-17
Description:
Purpose To assess stretched-exponential, mono-exponential and intravoxel incoherent motion (IVIM) models of diffusion-weighted MRI(DWI) in predicting pathological complete response (pCR) to neoadjuvant chemoradiotherapy (CRT) in rectal cancer patients. Materials and Methods This prospective study recruited 98 consecutive patients with locally advanced rectal cancer who underwent 3 Tesla MR examination before, during and after CRT. The apparent diffusion coefficient (ADC), IVIM-derived parameters (D, f, and D*), and stretched-exponential model-derived parameters (DDC and α) were measured. The parameters and their corresponding changes during and after CRT were compared between pCR and non-pCR. Receiver-operating characteristic curve analysis was performed to evaluate the diagnostic performance. Coefficient of variations and intraclass correlation coefficient were calculated to assess reliability and agreement. Results Nineteen patients achieved pCR while 79 did not. The pCR group had higher ADC and α (ADC 2 and α 2 ), and their changes (ΔADC 2 , and Δα 2 ) at the endpoint than non-pCR group. α 2 and ADC 2 yielded similar AUCs ( P = 0.339), Δα 2 and ΔADC 2 yielded similar AUCs ( P = 0.263) ADC and α presented substantial agreement, and α presented the minimum CV (5.0–7.0%). Conclusion ADC and α were useful for assessing pCR after CRT. α might be more useful because it demonstrated better diagnostic performance than IVIM-derived parameters and better reliability than ADC. Level of Evidence:1 J. Magn. Reson. Imaging 2016
Print ISSN:
1053-1807
Electronic ISSN:
1522-2586
Topics:
Medicine
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