title: Standardized Index of Shape (DCE-MRI) and Standardized Uptake Value (PET/CT): Two quantitative approaches to discriminate chemo-radiotherapy locally advanced rectal cancer responders under a functional profile.
abstract: OBJECTIVE
  To investigate dynamic contrast enhanced-MRI (DCE-MRI) in the preoperative chemo-radiotherapy (CRT) assessment for locally advanced rectal cancer (LARC) compared to18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT).
  
  
  METHODS
  75 consecutive patients with LARC were enrolled in a prospective study. DCE-MRI analysis was performed measuring SIS: linear combination of percentage change (Δ) of maximum signal difference (MSD) and wash-out slope (WOS). 18F-FDG PET/CT analysis was performed using SUV maximum (SUVmax). Tumor regression grade (TRG) were estimated after surgery. Non-parametric tests, receiver operating characteristic were evaluated.
  
  
  RESULTS
  55 patients (TRG1-2) were classified as responders while 20 subjects as non responders. ΔSIS reached sensitivity of 93%, specificity of 80% and accuracy of 89% (cut-off 6%) to differentiate responders by non responders, sensitivity of 93%, specificity of 69% and accuracy of 79% (cut-off 30%) to identify pathological complete response (pCR). Therapy assessment via ΔSUVmax reached sensitivity of 67%, specificity of 75% and accuracy of 70% (cut-off 60%) to differentiate responders by non responders and sensitivity of 80%, specificity of 31% and accuracy of 51% (cut-off 44%) to identify pCR.
  
  
  CONCLUSIONS
  CRT response assessment by DCE-MRI analysis shows a higher predictive ability than 18F-FDG PET/CT in LARC patients allowing to better discriminate significant and pCR.
authors.affiliation: Radiology Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Petrillo
authors.affiliation: Radiology Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Fusco
authors.affiliation: Radiology Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Petrillo
authors.affiliation: Radiology Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Granata
authors.affiliation: Gastrointestinal Surgical Oncology Unit, Department of Abdominal Oncology, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Delrio
authors.affiliation: Gastrointestinal Surgical Oncology Unit, Department of Abdominal Oncology, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bianco
authors.affiliation: Radiotherapy Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Biagio
authors.initials: B
authors.lastname: Pecori
authors.affiliation: Scientific Director, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Botti
authors.affiliation: Diagnostic Pathology Unit, Department of Diagnostic and Laboratory Pathology "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Tatangelo
authors.affiliation: Nuclear Medicine Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Corradina
authors.initials: C
authors.lastname: Caracò
authors.affiliation: Nuclear Medicine Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Aloj
authors.affiliation: Gastrointestinal Medical Oncology Unit, Department of Abdominal Oncology, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Avallone
authors.affiliation: Nuclear Medicine Unit, Department of Diagnostic Imaging, Radiant and Metabolic Therapy, "Istituto Nazionale Tumori Fondazione Giovanni Pascale - IRCCS", 80131, Naples, Italy.
authors.forename: Secondo
authors.initials: S
authors.lastname: Lastoria
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D059186:Chemoradiotherapy, Adjuvant; D003287:Contrast Media / Q000008:administration & dosage; D013505:Digestive System Surgical Procedures; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D006801:Humans; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D055420:Perfusion Imaging / Q000379:methods; D000072078:Positron Emission Tomography Computed Tomography; D011237:Predictive Value of Tests; D012372:ROC Curve; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012004:Rectal Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D012039:Regional Blood Flow; D012074:Remission Induction; D015203:Reproducibility of Results; D012833:Siloxanes / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D058185:Magnetite Nanoparticles; D019275:Radiopharmaceuticals; D012833:Siloxanes; D019788:Fluorodeoxyglucose F18; C088769:ferumoxsil
keywords: DCE-MRI and FDG-PET/CT; neoadjuvant chemo-radiotherapy; rectal cancer; treatment response assessment