A Palmisano1, A Di Chiara2, A Esposito2, P M V Rancoita3, C Fiorino4, P Passoni5, L Albarello6, R Rosati7, A Del Maschio2, F De Cobelli2. 1. Unit of Clinical Research in Radiology, Experimental Imaging Center, IRCCS Ospedale San Raffaele, Milano, Italy. Electronic address: palmisano.anna@hsr.it. 2. Unit of Clinical Research in Radiology, Experimental Imaging Center, IRCCS Ospedale San Raffaele, Milano, Italy; Vita-Salute San Raffaele University, Milano, Italy. 3. University Centre of Statistics in the Biomedical Sciences, Vita-Salute San Raffaele University, Milan, Italy. 4. Medical Physics, San Raffaele Hospital, Milano, Italy. 5. Unit of Radiotherapy, IRCCS Ospedale San Raffaele, Milano, Italy. 6. Department of Pathology, IRCCS Ospedale San Raffaele, Milano, Italy. 7. Vita-Salute San Raffaele University, Milano, Italy; Department of Gastrointestinal Surgery, San Raffaele Hospital, Milano, Italy.
Abstract
AIM: To investigate the role of diffusion-weighted imaging (DWI), T2-weighted (W) imaging, and apparent diffusion coefficient (ADC) histogram analysis before, during, and after neoadjuvant chemoradiotherapy (CRT) in the prediction of pathological response in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Magnetic resonance imaging (MRI) at 1.5 T was performed in 43 patients with LARC before, during, and after CRT. Tumour volume was measured on both T2-weighted (VT2W) and on DWI at b=1,000 images (Vb,1,000) at each time point, hence the tumour volume reduction rate (ΔVT2W and ΔVb,1,000) was calculated. Whole-lesion (three-dimensional [3D]) first-order texture analysis of the ADC map was performed. Imaging parameters were compared to the pathological tumour regression grade (TRG). The diagnostic performance of each parameter in the identification of complete responders (CR; TRG4), partial responders (PR; TRG3) and non-responders (NR; TRG0-2) was evaluated by multinomial regression analysis and receiver operating characteristics curves. RESULTS: After surgery, 11 patients were CR, 22 PR, and 10 NR. Before CRT, predictions of CR resulted in an ADC value of the 75th percentile and median, with good accuracy (74% and 86%, respectively) and sensitivity (73% and 82%, respectively). During CRT, the best predictor of CR was ΔVT2W (-58.3%) with good accuracy (81%) and excellent sensitivity (91%). After CRT, the best predictors of CR were ΔVT2W (-82.8%) and ΔVb, 1,000 (-86.8%), with 84% accuracy in both cases and 82% and 91% sensitivity, respectively. CONCLUSIONS: The median ADC value at pre-treatment MRI and ΔVT2W (from pre-to-during CRT MRI) may have a role in early and accurate prediction of response to treatment. Both ΔVT2W and ΔVb,1,000 (from pre-to-post CRT) can help in the identification of CR after CRT.
AIM: To investigate the role of diffusion-weighted imaging (DWI), T2-weighted (W) imaging, and apparent diffusion coefficient (ADC) histogram analysis before, during, and after neoadjuvant chemoradiotherapy (CRT) in the prediction of pathological response in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Magnetic resonance imaging (MRI) at 1.5 T was performed in 43 patients with LARC before, during, and after CRT. Tumour volume was measured on both T2-weighted (VT2W) and on DWI at b=1,000 images (Vb,1,000) at each time point, hence the tumour volume reduction rate (ΔVT2W and ΔVb,1,000) was calculated. Whole-lesion (three-dimensional [3D]) first-order texture analysis of the ADC map was performed. Imaging parameters were compared to the pathological tumour regression grade (TRG). The diagnostic performance of each parameter in the identification of complete responders (CR; TRG4), partial responders (PR; TRG3) and non-responders (NR; TRG0-2) was evaluated by multinomial regression analysis and receiver operating characteristics curves. RESULTS: After surgery, 11 patients were CR, 22 PR, and 10 NR. Before CRT, predictions of CR resulted in an ADC value of the 75th percentile and median, with good accuracy (74% and 86%, respectively) and sensitivity (73% and 82%, respectively). During CRT, the best predictor of CR was ΔVT2W (-58.3%) with good accuracy (81%) and excellent sensitivity (91%). After CRT, the best predictors of CR were ΔVT2W (-82.8%) and ΔVb, 1,000 (-86.8%), with 84% accuracy in both cases and 82% and 91% sensitivity, respectively. CONCLUSIONS: The median ADC value at pre-treatment MRI and ΔVT2W (from pre-to-during CRT MRI) may have a role in early and accurate prediction of response to treatment. Both ΔVT2W and ΔVb,1,000 (from pre-to-post CRT) can help in the identification of CR after CRT.
Authors: Joao Miranda; Gary Xia Vern Tan; Maria Clara Fernandes; Onur Yildirim; John A Sims; Jose de Arimateia Batista Araujo-Filho; Felipe Augusto de M Machado; Antonildes N Assuncao-Jr; Cesar Higa Nomura; Natally Horvat Journal: Clin Imaging Date: 2021-11-16 Impact factor: 2.420