Prediction of early response to radiotherapy of uterine carcinoma with dynamic contrast-enhanced MR imaging using pixel analysis of MR perfusion imaging

Abstract Purpose To assess the predictability of the response to radiotherapy of uterine carcinoma, this study retrospectively analyzed dynamic contrast-enhanced magnetic resonance images (DCE-MRI) taken before radiotherapy. Materials and Methods Forty-two patients with uterine carcinoma were studied, of whom 22 had adenocarcinoma and 20 had squamous cell carcinoma (SCC). In DCE-MRI analysis, two parameters, SIe and R down , were measured. SIe is a median value for the degree of signal intensity change in all selected pixels in the tumor at 1–2 min after contrast agent injection. R down is the ratio of the number of down-sloped pixels to that of all selected pixels 3–7 min after injection. The tumor volume reduction rate (TVRR) was measured by MRI-based volumetry in pre- and post-radiotherapy transverse T2-weighted images. Results Overall, TVRR was significantly correlated to both SIe ( r =0.37, P =.015) and R down ( r =0.73, P R down was significantly different between the adenocarcinoma and SCC patients ( t =3.64, P R down in adenocarcinoma patients ( r =0.78, P Conclusion SIe may reflect differences in histological characteristics. R down may be useful for predicting the response to radiotherapy of uterine carcinoma.