title: Evaluation of Soft Tissue Sarcoma Response to Preoperative Chemoradiotherapy Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging.
abstract: This study aims to assess the utility of quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters in comparison with imaging tumor size for early prediction and evaluation of soft tissue sarcoma response to preoperative chemoradiotherapy. In total, 20 patients with intermediate- to high-grade soft tissue sarcomas received either a phase I trial regimen of sorafenib + chemoradiotherapy (n = 8) or chemoradiotherapy only (n = 12), and underwent DCE-MRI at baseline, after 2 weeks of treatment with sorafenib or after the first chemotherapy cycle, and after therapy completion. MRI tumor size in the longest diameter (LD) was measured according to the RECIST (Response Evaluation Criteria In Solid Tumors) guidelines. Pharmacokinetic analyses of DCE-MRI data were performed using the Shutter-Speed model. After only 2 weeks of treatment with sorafenib or after 1 chemotherapy cycle, Ktrans(rate constant for plasma/interstitium contrast agent transfer) and its percent change were good early predictors of optimal versus suboptimal pathological response with univariate logistic regression C statistics values of 0.90 and 0.80, respectively, whereas RECIST LD percent change was only a fair predictor (C = 0.72). Post-therapy Ktrans, ve(extravascular and extracellular volume fraction), and kep(intravasation rate constant), not RECIST LD, were excellent (C > 0.90) markers of therapy response. Several DCE-MRI parameters before, during, and after therapy showed significant (P< .05) correlations with percent necrosis of resected tumor specimens. In conclusion, absolute values and percent changes of quantitative DCE-MRI parameters provide better early prediction and evaluation of the pathological response of soft tissue sarcoma to preoperative chemoradiotherapy than the conventional measurement of imaging tumor size change.
authors.affiliation: Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon; Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.affiliation: Department of Diagnostic Radiology, Oregon Health & Science University, Portland, Oregon.
authors.forename: Brooke R
authors.initials: BR
authors.lastname: Beckett
authors.affiliation: Department of Diagnostic Radiology, Oregon Health & Science University, Portland, Oregon.
authors.forename: Alina
authors.initials: A
authors.lastname: Tudorica
authors.affiliation: Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, Oregon.
authors.forename: Janelle M
authors.initials: JM
authors.lastname: Meyer
authors.affiliation: Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon.
authors.forename: Aneela
authors.initials: A
authors.lastname: Afzal
authors.affiliation: Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon; Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Pathology, Oregon Health & Science University, Portland, Oregon.
authors.forename: Atiya
authors.initials: A
authors.lastname: Mansoor
authors.affiliation: Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland, Oregon.
authors.forename: James B
authors.initials: JB
authors.lastname: Hayden
authors.affiliation: Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland, Oregon.
authors.forename: Yee-Cheen
authors.initials: YC
authors.lastname: Doung
authors.affiliation: Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon.
authors.forename: Arthur Y
authors.initials: AY
authors.lastname: Hung
authors.affiliation: Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Holtorf
authors.affiliation: Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Torrie J
authors.initials: TJ
authors.lastname: Aston
authors.affiliation: Knight Cancer Institute, Oregon Health & Science University, Portland, Oregon; Division of Hematology and Medical Oncology, Oregon Health & Science University, Portland, Oregon.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Ryan
keywords: DCE-MRI; Shutter-Speed model; pharmacokinetic modeling; soft tissue sarcoma; therapy response