title: Diffusion-weighted magnetic resonance imaging in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy.
abstract: OBJECTIVE
  To analyze diffusion-weighted magnetic resonance imaging (DW-MRI) for treatment response assessment in locally advanced rectal cancer (LARC).
  
  
  METHODS
  Patients with histologically proven rectal adenocarcinoma, stage II-III disease, were enrolled and underwent surgery following neoadjuvant chemoradiotherapy (nCRT). All patients were referred for a DW-MRI protocol on a 3 Tesla MR-system, consisting of axial T2-weighted and DWI sequences prior (I), during (II) and after (III) nCRT. Corresponding apparent diffusion coefficient (ADC) values were calculated.
  
  
  RESULTS
  Between February 2011 and June 2015, 37 patients participated in the study. All patients completed programmed treatment. Overall, 11 patients (29.7%) had pathologic complete response (pCR). No correlation between the mean pre- (ADC-I), during (ADC-II), post- (ADC-III) ADC and the reduction in tumor size after nCRT was recorded. No substantial difference in the ADC distribution was found between pCR and no-pCR patients. The ADC-II level significantly increased in the pCR cases (T = 1.675; p < 0.05).
  
  
  CONCLUSIONS
  ADC value could be useful for discriminating between the pCR patients and the no-pCR patients. Further studies are necessary to identify the optimal MRI parameters combination to predict tumor response to nCRT. It is hoped that these data will provide the basis for a more solid scientific evidence.
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy. Electronic address: fradefelice@hotmail.it.
authors.forename: F
authors.initials: F
authors.lastname: De Felice
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy.
authors.forename: A L
authors.initials: AL
authors.lastname: Magnante
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Musio
authors.affiliation: Department of Radiological Sciences, Oncology and Pathology Policlinico Umberto I "Sapienza" University of Rome - Polo Pontino, Latina, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Ciolina
authors.affiliation: Department of Radiological Sciences, Oncology and Pathology Policlinico Umberto I "Sapienza" University of Rome - Polo Pontino, Latina, Italy.
authors.forename: C N
authors.initials: CN
authors.lastname: De Cecco
authors.affiliation: Department of Radiological Sciences, Oncology and Pathology Policlinico Umberto I "Sapienza" University of Rome - Polo Pontino, Latina, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rengo
authors.affiliation: Department of Radiological Sciences, Oncology and Pathology Policlinico Umberto I "Sapienza" University of Rome - Polo Pontino, Latina, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Laghi
authors.affiliation: Department of Radiotherapy, Policlinico Umberto I "Sapienza" University of Rome, Rome, Italy; Spencer-Lorillard Foundation, Rome, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Tombolini
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059186:Chemoradiotherapy, Adjuvant; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011446:Prospective Studies; D012372:ROC Curve; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: ADC; Chemoradiotherapy; Diffusion-weighted; Magnetic resonance imaging; Neoadjuvant treatment; Rectal cancer