@misc{oai:repo.qst.go.jp:00064204,
 author = {Kishimoto, Riwa and Omatsu, Tokuhiko and Hasegawa, Azusa and Kandatsu, Susumu and Mizoe, Junetsu and Kamada, Tadashi and 岸本 理和 and 尾松 徳彦 and 長谷川 安都佐 and 神立 進 and 溝江 純悦 and 鎌田 正},
 month = {Dec},
 note = {PURPOSE: Carbon ion radiotherapy often induces radiation brain injury in various degrees and differentiation of recurrent tumor from radiation injury on follow-up MR images is problematic. Recently it has been reported that assessment of apparent diffusion coefficients (ADCs) of enhancing regions was useful in differentiation between recurrent glioma and radiation injury. The purpose of this study is to assess the relationship between ADC value and prognosis of patients with malignant astrocytic tumors after carbon ion radiotherapy retrospectively and to evaluate the prognostic value of ADC
METHOD AND MATERIALS: Twenty-five patients who underwent diffusion weighted imaging (DWI) in follow-up MR examination after carbon ion radiotherapy for malignant astrocytic tumors were enrolled in this study. We evaluated the most recent MR examination in our institution. MR imaging was performed using a 1.5T MRI unit with a head coil. DWI in the axial direction was obtained by using a STIR-EPI sequence with b-values of 0 and 1,000 sec/mm2, acquired in three orthogonal directions. Region of interest (ROIs) were drawn manually onto the obtained ADC maps in the region corresponding to the enhancing area on contrast-enhanced T1-weighted images. Statistical analysis was performed with SPSS. Mean ADC values between fatality group and survival group were compared using Mann-Whitney U test.
RESULTS: One survival patient in whom local recurrence could not be denied because of short follow-up period was excluded from this study. Fatality group included 16 cases and survival group included eight cases. Fatality group included three patients who died from other cause than recurrence. All surviving patients were followed up for more than 3 years and their intracranial lesions were thought to be brain injury. Mean ADC value of fatality group (1.13+0.15[x10-3mm2/sec]) was significantly smaller than those of survival group (1.50+0.26) (p<0.01) . When we used a cutoff value of 1.3 for suspecting prognosis on mean ADC values (i.e., patient with ADC<1.3 would die from recurrence), positive predictive value was 86.7% and negative predictive value was 88.9%.
CONCLUSION: For malignant astrocytic tumors after carbon-ion radiotherapy, cases with intracranial lesions of ADC value smaller than 1.3 are suspected to have poor prognosis., 96th Scientific Assembly and Annual Meeting},
 title = {Prognostic Value of ADC: Malignant Astrocytic Tumors after Carbon Ion Radiotherapy},
 year = {2010}
}