title: Assessment of serial multi-parametric functional MRI (diffusion-weighted imaging and R2*) with (18)F-FDG-PET in patients with head and neck cancer treated with radiation therapy.
abstract: OBJECTIVE
  To evaluate the serial changes and correlations between readout-segmented technique with navigated phase correction diffusion-weighted MRI (DWI), R2*-MRI and (18)F-FDG positron emission tomography (PET) CT performed before and during radiation therapy (RT) in patients with mucosal primary head and neck cancer.
  
  
  METHODS
  The mean apparent diffusion coefficient (ADCmean) from DWI (at b = 50 and 800 s mm(-2)), the mean R2* values derived from T2(*)-MRI, and PET metabolic parameters, including maximum standardized uptake value (SUVmax), metabolic tumour volume (MTV) and total lesional glycolysis (TLG) were measured for the primary tumour. Spearman correlation coefficients were calculated to evaluate correlations between ADCmean, R2*, SUVmax, MTV and TLG. A paired t-test was performed to assess the MRI changes and the slope of serial MRI changes during RT.
  
  
  RESULTS
  Pre-treatment scans were performed in 28 patients and mid-treatment scans in 20 patients. No significant correlation was found between ADCmean and either R2* values or PET parameters. There were significant negative correlations of R2* values with pre-treatment PET parameters but not with mid-RT PET parameters: pre-SUVmax (p = 0.008), pre-MTV (p = 0.006) and pre-TLG (p = 0.008). A significant rise in ADCmean was found during the first half (p < 0.001) of RT but not in the second half (p = 0.215) of the treatment. There was an increase of the ADCmean values of 279.4 [95% confidence interval (95% CI): 210-348] in the first half of the treatment (Weeks 0-3). However, during the second-half period of treatment, the mean ADC value (Weeks 3-6) was 24.0 and the 95% CI (-40 to 88) included zero. This suggests that there was no significant change in ADC values during the second half of the treatment.
  
  
  CONCLUSIONS
  A significant negative correlation was found between pre-treatment R2*-MRI and PET parameters. DWI appeared to demonstrate potentially predictable changes during RT.
  
  
  CONCLUSIONS
  Understanding the correlation and changes that occur with time between potential imaging biomarkers may help us establish the most appropriate biomarkers to consider in future research.
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.|2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.|3 Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia.
authors.forename: Myo
authors.initials: M
authors.lastname: Min
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.|2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Lee
authors.affiliation: 2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.|4 Department of Nuclear Medicine and PET, Liverpool Hospital, Liverpool, NSW, Australia.|5 School of Science and Health, Western Sydney University, NSW, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Lin
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.|2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.|3 Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia.
authors.forename: Lois
authors.initials: L
authors.lastname: Holloway
authors.affiliation: 3 Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia.|5 School of Science and Health, Western Sydney University, NSW, Australia.
authors.forename: Dj
authors.initials: Dj
authors.lastname: Wijesekera
authors.affiliation: 2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.|6 Department of Radiology, Liverpool Hospital, Liverpool, NSW, Australia.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Gooneratne
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.
authors.forename: Robba
authors.initials: R
authors.lastname: Rai
authors.affiliation: 3 Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia.
authors.forename: Wei
authors.initials: W
authors.lastname: Xuan
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.
authors.forename: Allan
authors.initials: A
authors.lastname: Fowler
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.|2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.|3 Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia.
authors.forename: Dion
authors.initials: D
authors.lastname: Forstner
authors.affiliation: 1 Department of Radiation Oncology, Cancer Therapy Centre, Liverpool Hospital, Liverpool, NSW, Australia.|2 South Western Clinical School, School of Medicine, University of New South Wales, NSW, Australia.|3 Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia.|7 Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Liney
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D038524:Diffusion Magnetic Resonance Imaging; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D050397:Radiotherapy, Intensity-Modulated; D047368:Tumor Burden
chemical_list: D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18