title: Apparent diffusion coefficient (ADC) change on repeated diffusion-weighted magnetic resonance imaging during radiochemotherapy for non-small cell lung cancer: A pilot study.
abstract: Serial diffusion-weighted magnetic resonance imaging (DW-MRI) during radiochemotherapy of non-small cell lung cancer (NSCLC) is analyzed to investigate the apparent diffusion coefficient (ADC) as a potential biomarker for tumor response.
  
  
  
  Ten patients underwent DW-MRI prior to and at three and six weeks during radiochemotherapy. Three methods of contouring primary tumors (PT) were performed to evaluate the impact of tumor heterogeneity on ADC values: PTT: whole tumor volume; PTT-N: PTT-necrosis; PTL: small volume of presumed active tumor with low ADC value. Pretreatment and during-treatment absolute ADC values and ADC value changes were analyzed for PT and involved lymph nodes (LN).
  
  
  
  ADC values for PTT, PTT-N, PTL and LN increased by 8-14% (PT) and 15% (LN) at three weeks, and 19-26% and 23% at 6 weeks post initial treatment (p=0.04-0.002). Average percent ADC value increase was smaller than tumor volume regression (p=0.06-0.0005). Patients with overall survival <12 months had a lower increase of ADC values compared to longer surviving patients (p=0.008 for PTT).
  
  
  
  Significant ADC value increases during radiochemotherapy for non-small cell lung cancer were observed. ADC value change during treatment appears to be an independent marker of patient outcome and warrants further investigation.
authors.affiliation: Department of Radiation Oncology, Virginia Commonwealth University, 401 College Street, Richmond, VA 23298, USA. Electronic address: elisabeth.weiss@vcuhealth.org.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Weiss
authors.affiliation: Department of Radiation Oncology, Virginia Commonwealth University, 401 College Street, Richmond, VA 23298, USA; Department of Radiation Oncology, University of Miami, 1475 NW 12th Ave, Miami, FL 33136, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Ford
authors.affiliation: Department of Radiology, Virginia Commonwealth University, 1101 East Marshall Street, Richmond, VA 23298, USA; Department of Radiology, University of Colorado, 1380 Lawrence Street, Denver, CO 80204, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Olsen
authors.affiliation: Department of Radiation Oncology, Virginia Commonwealth University, 401 College Street, Richmond, VA 23298, USA.
authors.forename: Kishor
authors.initials: K
authors.lastname: Karki
authors.affiliation: Department of Radiation Oncology, Virginia Commonwealth University, 401 College Street, Richmond, VA 23298, USA.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Saraiya
authors.affiliation: Department of Radiology, Virginia Commonwealth University, 1101 East Marshall Street, Richmond, VA 23298, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Groves
authors.affiliation: Department of Radiation Oncology, Virginia Commonwealth University, 401 College Street, Richmond, VA 23298, USA.
authors.forename: Geoffrey D
authors.initials: GD
authors.lastname: Hugo
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010865:Pilot Projects; D015203:Reproducibility of Results; D047368:Tumor Burden / Q000187:drug effects
keywords: Diffusion-weighted MRI; Non small cell lung cancer; Radiotherapy; Response assessment