PT  - JOURNAL ARTICLE
AU  - Sasaki, T.
AU  - Moritani, T.
AU  - Belay, A.
AU  - Capizzano, A.A.
AU  - Sato, S.P.
AU  - Sato, Y.
AU  - Kirby, P.
AU  - Ishitoya, S.
AU  - Oya, A.
AU  - Toda, M.
AU  - Takahashi, K.
TI  - Role of the Apparent Diffusion Coefficient as a Predictor of Tumor Progression in Patients with Chordoma
AID  - 10.3174/ajnr.A5664
DP  - 2018 Jul 01
TA  - American Journal of Neuroradiology
PG  - 1316--1321
VI  - 39
IP  - 7
4099  - http://www.ajnr.org/content/39/7/1316.short
4100  - http://www.ajnr.org/content/39/7/1316.full
SO  - Am. J. Neuroradiol.2018 Jul 01; 39
AB  - BACKGROUND AND PURPOSE: Diffusion-weighted imaging may aid in distinguishing aggressive chordoma from nonaggressive chordoma. This study explores the prognostic role of the apparent diffusion coefficient in chordomas.MATERIALS AND METHODS: Sixteen patients with residual or recurrent chordoma were divided postoperatively into those with an aggressive tumor, defined as a growing tumor having a doubling time of <1 year, and those with a nonaggressive tumor on follow-up MR images. The ability of the ADC to predict an aggressive tumor phenotype was investigated by receiver operating characteristic analysis. The prognostic role of ADC was assessed using a Kaplan-Meier curve with a log-rank test.RESULTS: Seven patients died during a median follow-up of 48 months (range, 4–126 months). Five of these 7 patients were in the aggressive tumor group, and 2 were in the nonaggressive tumor group. The mean ADC was significantly lower in the aggressive tumor group than in the nonaggressive tumor group (P = .002). Receiver operating characteristic analysis showed that a cutoff ADC value of 1.494 × 10−3 × mm2/s could be used to diagnose aggressive tumors with an area under the curve of 0.983 (95% CI, 0.911–1.000), a sensitivity of 1.000 (95% CI, 0.541–1.000), and a specificity of 0.900 (95% CI, 0.555–0.998). Furthermore, a cutoff ADC of ≤1.494 × 10−3 × mm2/s was associated with a significantly worse prognosis (P = .006).CONCLUSIONS: Lower ADC values could predict tumor progression in postoperative chordomas.RTradiotherapy