title: Investigation of volumetric apparent diffusion coefficient histogram analysis for assessing complete response and clinical outcomes following pre-operative chemoradiation treatment for rectal carcinoma.
abstract: To investigate the relationship of pre-treatment volumetric apparent diffusion coefficient (ADC) histogram parameters with post-operative histopathologic treatment response and clinical outcomes following pre-operative chemoradiation treatment (CRT) in rectal cancer.
  
  
  
  In a Health Insurance Portability and Accountability Act compliant retrospective study, 78 rectal cancer patients treated with pre-operative CRT and rectal MRI were included. MR imaging analysis was performed using OncoTREAT (software tool). Multiple volumetric ADC histogram parameters (voxel distribution across ADC ranges, kurtosis, and skewness) were assessed. Correlation was made to post-operative pathological complete response, clinical, or radiological evidence of disease progression using the Mann-Whitney test.
  
  
  
  Post CRT, 8 patients showed pathologic complete response and 13 patients showed distant disease progression. Pre-treatment mean ADC was 1.2 × 10-3mm2/s (range 0.3-1.99 × 10-3mm2/s). Mean kurtosis measured was 0.56 (range -1 to 6; SD 1.36). Mean skewness was 0.3 (range -1 to 2; SD 0.69). Skewness had significant correlation (p value = 0.006) with disease progression. The mean rectal tumor volume was 24cc (range 1cc-134cc). Pre-treatment MRI tumor volume showed significant correlation (p value = 0.013) with pathologic complete response. Mean ADC and percentage voxels distribution against ADC ranges had no significant correlation with treatment response or disease outcomes.
  
  
  
  Volumetric ADC histogram analysis of pre-CRT rectal cancer MRI appears promising for prediction of post-CRT complete response and disease progression.
authors.affiliation: Royal Liverpool and Broadgreen University Hospitals, NHS Trust, Prescot Street, Liverpool, L7 8XP, UK.
authors.forename: Vijay
authors.initials: V
authors.lastname: Chidambaram
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre, Princess Margaret Hospital, University of Toronto, 610 University Avenue, Toronto, ON, M5G 2M9, Canada.
authors.forename: James D
authors.initials: JD
authors.lastname: Brierley
authors.affiliation: Department of Radiation Oncology, Princess Margaret Cancer Centre, Princess Margaret Hospital, University of Toronto, 610 University Avenue, Toronto, ON, M5G 2M9, Canada.
authors.forename: Bernard
authors.initials: B
authors.lastname: Cummings
authors.affiliation: Department of Medical Imaging, JDMI Research, University of Toronto, 2nd Floor, North Side, 700 University Avenue, Toronto, ON, M5G 1X6, Canada.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Bhayana
authors.affiliation: Joint Department of Medical Imaging, JDMI Research, University Health Network, 2nd Floor, North Side, 700 University Avenue, Toronto, ON, M5G 1X6, Canada.
authors.forename: Ravi J
authors.initials: RJ
authors.lastname: Menezes
authors.affiliation: Division of General Surgery, Mount Sinai Hospital, University of Toronto, 600 University Avenue, Toronto, ON, M5G 1X5, Canada.
authors.forename: Erin D
authors.initials: ED
authors.lastname: Kennedy
authors.affiliation: Pathology & Lab Medicine Department, Mount Sinai Hospital, University of Toronto, 600 University Ave. Rm 6-500-10, Toronto, ON, M5G 1X5, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Kirsch
authors.affiliation: Joint Department of Medical Imaging, University Health Network, Mount Sinai Hospital and Women's College Hospital, University of Toronto, 610 University Ave, 3-957, Toronto, ON, M5G 2M9, Canada. Kartik.jhaveri@uhn.ca.|Department of Radiology, Princess Margaret Hospital, University of Toronto, 610 University Ave, 3-957, Toronto, ON, M5G 2M9, Canada. Kartik.jhaveri@uhn.ca.
authors.forename: Kartik S
authors.initials: KS
authors.lastname: Jhaveri
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D012189:Retrospective Studies; D012984:Software; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: Apparent diffusion coefficient (ADC); Chemoradiation treatment (CRT); Diffusion-weighted MRI; Rectal carcinoma