Is apparent diffusion coefficient reliable and accurate for monitoring effects of antiangiogenic treatment in a longitudinal study?
OBJECTIVE
To evaluate the reliability and accuracy of the apparent diffusion coefficient (ADC) for monitoring antiangiogenic treatment in a longitudinal study.


METHODS
Tumor volume and ADC were monitored by T2-weighted magnetic resonance imaging (MRI) and diffusion-weighted MRI, respectively, in 18 mice with angiogenesis-dependent tumors (U118MG) before (day 0) and after 2, 7, 14, and 21 days of administration of the antiangiogenic agent sunitinib maleate (n = 12) or vehicle (n = 6). Percent changes in tumor volume and ADC were calculated and correlations between tumor volume and ADC were evaluated.


RESULTS
Tumor volume and ADC showed a negative correlation at 69 of the 72 (96%) follow-up measurements. In the 13 mice with tumor regrowth, ADC started to decrease before (27%) or at the same time (73%) as tumor regrowth. Pretreatment ADC and percent change in ADC change on days 0-2 were similar in mice with positive and negative responses to treatment (0.851 vs. 0.999, 24% vs. 16%). Percent change of ADC showed significant negative correlation with percent change in tumor volume in both the control (r = -0.69) and treated (r = -0.65) groups.


CONCLUSIONS
Percent change in ADC is a reliable and accurate marker for monitoring the effects of antiangiogenic treatment, whereas pretreatment ADC and early changes in ADC (ie, days 0-2) are limited in predicting treatment outcome.
Division of Magnetic Resonance, Korea Basic Science Institute, Cheongwon, Chungbuk, Korea.
Ji-Yeon
JY
Suh
Gyunggoo
G
Cho
Youngkyu
Y
Song
Chang Kyung
CK
Lee
Jong Soon
JS
Kang
Moo Rim
MR
Kang
Sung Bin
SB
Park
Young Ro
YR
Kim
Jeong Kon
JK
Kim
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy* / Q000473:pathology*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007211:Indoles / Q000627:therapeutic use*; D008137:Longitudinal Studies; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000473:pathology*; D011758:Pyrroles / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000077210:Sunitinib; D016896:Treatment Outcome
D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib