title: Glioblastoma treated with concurrent radiation therapy and temozolomide chemotherapy: differentiation of true progression from pseudoprogression with quantitative dynamic contrast-enhanced MR imaging.
abstract: OBJECTIVE
  To explore the role of dynamic contrast material-enhanced magnetic resonance (MR) imaging in the differentiation of true progression from pseudoprogression in patients with glioblastoma on the basis of findings in entirely newly developed or enlarged enhancing lesions after concurrent radiation therapy and chemotherapy with temozolomide and to evaluate the diagnostic performance of the quantitative pharmacokinetic parameters obtained at dynamic contrast-enhanced MR imaging, such as the volume transfer constant (K(trans)), the extravascular extracellular space per unit volume of tissue(ve), and the blood plasma volume per unit volume of tissue(vp).
  
  
  METHODS
  This prospective study had institutional review board approval; written informed consent was obtained from all patients. Thirty-three patients with histopathologically proven glioblastoma who had undergone concurrent radiation therapy and chemotherapy with temozolomide were included. Dynamic contrast-enhanced MR imaging-derived pharmacokinetic parameters, including K(trans), ve, and vp, were calculated for newly developed or enlarged enhancing lesions. Pharmacokinetic parameters were compared between the true progression (n = 17) and pseudoprogression (n = 16) groups by using unpaired t tests and then multivariable analysis.
  
  
  RESULTS
  The mean K(trans) and ve were higher in the true progression group than in the pseudoprogression group (mean K(trans), 0.44 min(-1) ± 0.25 [standard deviation] and 0.23 min(-1) ± 0.10 for true progression and pseudoprogression groups, respectively, P = .004; and mean ve, 1.26 ± 0.78 and 0.75 ± 0.49 for true progression and pseudoprogression groups, respectively, P = .034). Multivariable analysis showed that mean K(trans) was the only independently differentiating variable (P = .004).
  
  
  CONCLUSIONS
  Dynamic contrast-enhanced MR imaging-derived pharmacokinetic parameters, including K(trans) and ve, in the entire newly developed or enlarged enhancing lesion may be useful objective diagnostic tools in the differentiation of true progression from pseudoprogression in patients with glioblastoma who have undergone concurrent radiation therapy and chemotherapy with temozolomide.
authors.affiliation: From the Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea (T.J.Y., J.H.K., C.H.S., S.H.C.); Department of Radiology (T.J.Y., J.H.K., C.H.S., S.H.C.), Department of Neurosurgery (C.K.P.), Department of Internal Medicine, Cancer Research Institute (T.M.K., S.H.L.), Department of Pathology (S.H.P.), and Department of Radiation Oncology, Cancer Research Institute (I.H.K.), Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Republic of Korea; Center for Nanoparticle Research, Institute for Basic Science, Seoul, Republic of Korea (S.H.C.); and School of Chemical and Biological Engineering, Seoul National University, Seoul, Republic of Korea (S.H.C.).
authors.forename: Tae Jin
authors.initials: TJ
authors.lastname: Yun
authors.forename: Chul-Kee
authors.initials: CK
authors.lastname: Park
authors.forename: Tae Min
authors.initials: TM
authors.lastname: Kim
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Sohn
authors.forename: Sung-Hye
authors.initials: SH
authors.lastname: Park
authors.forename: Il Han
authors.initials: IH
authors.lastname: Kim
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D003287:Contrast Media; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy* / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D000077204:Temozolomide; D016896:Treatment Outcome
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003287:Contrast Media; D003606:Dacarbazine; D000077204:Temozolomide