title: Advanced pancreatic cancer: the use of the apparent diffusion coefficient to predict response to chemotherapy.
abstract: The purpose of this study was to determine if the apparent diffusion coefficient (ADC) on diffusion-weighted MRI could predict the response of patients with advanced pancreatic cancer to chemotherapy. Diffusion-weighted MRI was performed in 63 consecutive patients with advanced pancreatic cancer who were subsequently treated with chemotherapy. The ADC values of the primary tumour with a middle b-value (400 s mm(-2)) and a high b-value (1000 s mm(-2)) were determined; cystic or necrotic components were avoided. The patients were classified into two groups: (i) those with progressive disease and (ii) those who were stable 3 months and 6 months after initial treatment. The groups were compared with respect to the ADC and clinical factors, including gender, age, Union International Contre le Cancer (UICC ) stage, initial tumour size and chemotherapy agents used. Local tumour progression rates were evaluated using the Kaplan-Meier method. The middle b-value ADC of the pancreatic cancers ranged from 0.93-2.42 x10(-3) mm(2) s(-1) (mean, 1.50 x10(-3) mm(2) s(-1)), and the high b-value ADC ranged from 0.72-1.88 x10(-3) mm(2) s(-1) (mean, 1.20 x10(-3) mm(2) s(-1)). The high b-value ADC was significantly different between the progressive and stable groups at 3 months' and 6 months' follow-up (p = 0.03 and p = 0.04, respectively). The rate of tumour progression was significantly higher in those with a lower high b-value ADC than in those with a higher b-value ADC (median progression time, 140 days vs 182 days; p = 0.01). In conclusion, a lower high b-value ADC in patients with advanced pancreatic cancer may be predictive of early progression in chemotherapy-treated patients.
authors.affiliation: Department of Radiology, Kanagawa Cancer Centre, Asahi-ku, Yokohama, Japan. tniwa@kcmc.jp
authors.forename: T
authors.initials: T
authors.lastname: Niwa
authors.forename: M
authors.initials: M
authors.lastname: Ueno
authors.forename: S
authors.initials: S
authors.lastname: Ohkawa
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Doiuchi
authors.forename: K
authors.initials: K
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D003841:Deoxycytidine; D000093542:Gemcitabine