Semiquantitative perfusion combined with diffusion-weighted MR imaging in pre-operative evaluation of endometrial carcinoma: results in a group of 57 patients

Abstract

Purpose: To evaluate the semiquantitative DCE and quantitative DWI parameters in endometrial cancer, in order to assess the presence of neoplastic tissue and normal myometrium and to ascertain a potential relationship with tumor grade.

Methods and materials: A total of 57 patients with biopsy-proven endometrial adenocarcinoma who underwent MR imaging examination for staging purposes were retrospectively evaluated. Imaging protocol included multiplanar T1- and T2-weighted TSE, DCE T1-weighted (THRIVE; 0, 30, 90 and 120seconds after intravenous injection of gadolinium) and DWIBS sequences (b values=0 and 1000mm(2)/s). Color perfusion and ADC maps were automatically generated on dedicated software. Relative enhancement (RE, %), maximum enhancement (ME, %), maximum relative enhancement (MRE, %), time to peak (TTP, s) and mean apparent diffusion coefficient (ADC) were calculated by manually drawing a region of interest (ROI) both on the neoplastic tissue and the normal myometrium. Histopathology was used as reference standard.

Results: Histopathological analysis confirmed the presence of endometrial carcinoma in all patients. Neoplastic tissue demonstrated significantly lower (P<0.001) values of RE (%) 63.92±35.68; ME (%) 864.91±429.54 and MRE (%) 75.97±38.26 as compared to normal myometrium (RE (%) 151.43±55.99; ME (%) 1800.73±721.32; MRE (%) 158.28±54.05). TTP was significantly higher (P<0.05) in tumor lesion (385.51±1630.27 vs 195.44±78.69). Mean ADC value of neoplastic tissue (775.09±?220.73×10(-3)mm(2)/s) was significantly lower (P<0.05) than in myometrium (1602.37±378.54×10(-3)mm(2)/s). The analysis of perfusion and diffusion parameters classified according to tumor grades, showed a statistically significant difference only for RE (P=0.043) and ME (P=0.007).

Conclusions: Perfusion parameters and mean ADC differ significantly between endometrial cancer and normal myometrium, potentially reflecting the different microscopical features of cellularity and vascularity; however a significant relationship with tumor grade was not found in our series.

Keywords: Endometrial cancer; Magnetic resonance imaging; Perfusion imaging; Staging; T1 contrast sequences.