title: Preliminary study of apparent diffusion coefficient assessment after ion beam therapy for hepatocellular carcinoma.
abstract: We evaluated the state of hepatocellular carcinoma (HCC) and the liver after ion beam therapy by analyzing the apparent diffusion coefficient (ADC). In this retrospective study, we evaluated 13 HCC lesions in 10 patients who underwent magnetic resonance imaging before and after therapy. Diffusion-weighted imaging was performed with use of b values of 0, 150, and 800 s/mm(2). The ADC was determined for the tumor, irradiated liver, and normal liver. The maximum size of the tumor was measured, and reduction in tumor size was determined as a ratio of the maximum size of the diameter of the tumor. We compared the ADC before and after the therapy with the reduction in tumor size ratio. The reduction in tumor size ratio was compared with the ADCs of the tumors. The ADC of the tumor and the irradiated liver were significantly higher after therapy than before therapy. The ADC of the normal liver was not significantly different before and after therapy. The reduction ratio increased significantly (R = 0.73, P = 0.006) after therapy at the second follow-up when compared with after therapy at the first follow-up. No correlation was found between the reduction ratio and the ADC of the tumor in each follow-up. Inflammation of the liver occurs after treatment as a result of radiation doses from the ion beam, and the tumor reaches a state of necrosis. ADC value analysis provides a non-invasive assessment and yields focal information regarding the tumor and liver before and after ion beam therapy.
authors.affiliation: Department of Radiology, University of Fukui Hospital, 23-3, Shimoaizuki, Matsuoka, Eiheiji-tyo, Yoshida-gun, Fukui, 910-1193, Japan. kanamo@u-fukui.ac.jp.|Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa, Ishikawa, 920-0942, Japan. kanamo@u-fukui.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanamoto
authors.affiliation: Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa, Ishikawa, 920-0942, Japan.
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.affiliation: Departments of Radiology, Hyogo Ion Beam Center, 1-2-1 Kouto, Shingutyo, Tatsuno, Hyogo, 679-5165, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Terashima
authors.affiliation: Hyogo Ion Beam Medical Support, 1-2-1 Kouto, Shingutyo, Tatsuno, Hyogo, 679-5165, Japan.
authors.forename: Daisaku
authors.initials: D
authors.lastname: Suga
authors.affiliation: Japanese Red Cross Ise Hospital, 1-471-2 Funase, Ise, Mie, 516-8512, Japan.
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Fuwa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D004058:Diffusion; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D047368:Tumor Burden
keywords: Apparent diffusion coefficient; Diffusion-weighted imaging; Hepatocellular carcinoma; Ion beam therapy; Magnetic resonance imaging