title: Performance of diffusion-weighted imaging, perfusion imaging, and texture analysis in predicting tumoral response to neoadjuvant chemoradiotherapy in rectal cancer patients studied with 3T MR: initial experience.
abstract: To determine the performance of texture analysis (TA), diffusion-weighted imaging, and perfusion MR (pMRI) in predicting tumoral response in patients treated with neoadjuvant chemoradiotherapy (CRT).
  
  
  
  12 consecutive patients (8 females, 4 males, 63.2 ± 13.4 years) with rectal cancer were prospectively enrolled, and underwent pre-treatment 3T MRI. Treatment protocol consisted of neoadjuvant CRT with oxaliplatin and 5-fluorouracile. Unenhanced T2-weighted images TA (kurtosis), apparent diffusion coefficient (ADC), and pMRI parameters (Ktrans, Kep, Ve, IAUGC) were quantified by manually delineating a region of interest around the tumor outline. After CRT, all patients underwent complete surgical resection and the surgical specimen served as the gold standard. Receiver operating characteristic (ROC) curve analysis was performed to assess the discriminatory power of each quantitative parameter to predict complete response.
  
  
  
  Pathological complete response (pCR) was reported in six patients and partial response (PR) in three patients. Three patients were classified as non-responders (NR). Pre-treatment kurtosis was significantly lower in the pCR sub-group in comparison with PR + NR (p = .01). Among ADC and pMRI parameters, only Ve was significantly lower in the pCR sub-group compared with PR + NR (p = .01). A significant negative correlation between kurtosis and ADC (r = -0.650, p = .022) was observed. Pre-treatment area under the ROC curves (AUC), to discriminate between pCR and PR + NR, was significantly higher for kurtosis (0.861, p = .001) and Ve (0.861, p = .003) compared to all other parameters. The optimal cutoff value for pre-treatment kurtosis and Ve was ≤0.19 (100% sensitivity, 67% specificity) and ≤0.311 (83% sensitivity, 83% specificity), respectively.
  
  
  
  Pre-treatment kurtosis derived from T2w images and Ve from pMRI have the potential to act as imaging biomarkers of rectal cancer response to neoadjuvant CRT.
authors.affiliation: Diagnostic Imaging Unit, Department of Radiological Sciences, Oncology and Pathology, I.C.O.T. Hospital, University of Rome "Sapienza" - Polo Pontino, Latina, Italy.|Department of Radiology, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Carlo N
authors.initials: CN
authors.lastname: De Cecco
authors.affiliation: Diagnostic Imaging Unit, Department of Radiological Sciences, Oncology and Pathology, I.C.O.T. Hospital, University of Rome "Sapienza" - Polo Pontino, Latina, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Ciolina
authors.affiliation: Diagnostic Imaging Unit, Department of Radiological Sciences, Oncology and Pathology, I.C.O.T. Hospital, University of Rome "Sapienza" - Polo Pontino, Latina, Italy.
authors.forename: Damiano
authors.initials: D
authors.lastname: Caruso
authors.affiliation: Diagnostic Imaging Unit, Department of Radiological Sciences, Oncology and Pathology, I.C.O.T. Hospital, University of Rome "Sapienza" - Polo Pontino, Latina, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Rengo
authors.affiliation: Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Falmer, Sussex, United Kingdom.
authors.forename: Balaji
authors.initials: B
authors.lastname: Ganeshan
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Germany.
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
authors.affiliation: Department of Radiotherapy, University of Rome "Sapienza", Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Musio
authors.affiliation: Department of Radiotherapy, University of Rome "Sapienza", Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Felice
authors.affiliation: Department of Radiotherapy, University of Rome "Sapienza", Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Tombolini
authors.affiliation: Diagnostic Imaging Unit, Department of Radiological Sciences, Oncology and Pathology, I.C.O.T. Hospital, University of Rome "Sapienza" - Polo Pontino, Latina, Italy. andrea.laghi@uniroma1.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Laghi
mesh_terms: D059248:Chemoradiotherapy; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D055420:Perfusion Imaging; D012004:Rectal Neoplasms; D016896:Treatment Outcome
keywords: Diffusion-weighted imaging; Magnetic resonance imaging; Neoadjuvant chemoradiotherapy; Perfusion imaging; Rectal cancer; Texture analysis