title: Induced radioactivity in the blood of cancer patients following Boron Neutron Capture Therapy.
abstract: Since 1990, Boron Neutron Capture Therapy (BNCT) has been used for over 400 cancer patients at the Kyoto University Research Reactor Institute (KURRI). After BNCT, the patients are radioactive and their (24)Na and (38)Cl levels can be detected via a Na-I scintillation counter. This activity is predominantly due to (24)Na, which has a half-life of 14.96 h and thus remains in the body for extended time periods. Radioactive (24)Na is mainly generated from (23)Na in the target tissue that is exposed to the neutron beam in BNCT. The purpose of this study is to evaluate the relationship between the radioactivity of blood (24)Na following BNCT and the absorbed gamma ray dose in the irradiated field. To assess blood (24)Na, 1 ml of peripheral blood was collected from 30 patients immediately after the exposure, and the radioactivity of blood (24)Na was determined using a germanium counter. The activity of (24)Na in the blood correlated with the absorbed gamma ray doses in the irradiated field. For the same absorbed gamma ray dose in the irradiated field, the activity of blood (24)Na was higher in patients with neck or lung tumors than in patients with brain or skin tumors. The reasons for these findings are not readily apparent, but the difference in the blood volume and the ratio of bone to soft tissue in the irradiated field, as well as the dose that leaked through the clinical collimator, may be responsible.
authors: Radiation Safety and Control Department of Research Reactor Institute, Kyoto University, Kumatori-cho, Sennann-gun, Osaka 590-0494, Japan.
authors: Keiko
authors: K
authors: Fujiwara
authors: Yuko
authors: Y
authors: Kinashi
authors: Tomoyuki
authors: T
authors: Takahashi
authors: Hiroshi
authors: H
authors: Yashima
authors: Kouta
authors: K
authors: Kurihara
authors: Yoshinori
authors: Y
authors: Sakurai
authors: Hiroki
authors: H
authors: Tanaka
authors: Koji
authors: K
authors: Ono
authors: Sentaro
authors: S
authors: Takahashi
mesh_terms: D001769:Blood / Q000528:radiation effects; D001894:Borohydrides / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D016754:Boron Neutron Capture Therapy / Q000379:methods*; D001921:Brain / Q000528:radiation effects; D017666:Deuterium Oxide; D004867:Equipment Design; D005720:Gamma Rays; D005857:Germanium / Q000737:chemistry; D006801:Humans; D008168:Lung / Q000528:radiation effects; D009333:Neck / Q000528:radiation effects; D009369:Neoplasms / Q000097:blood* / Q000532:radiotherapy*; D009502:Neutrons; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D012044:Regression Analysis; D012867:Skin / Q000528:radiation effects; D012975:Sodium Isotopes; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D001894:Borohydrides; D001896:Boron Compounds; D012975:Sodium Isotopes; D013438:Sulfhydryl Compounds; D005857:Germanium; C014651:mercaptoundecahydrododecaborate; D010649:Phenylalanine; D017666:Deuterium Oxide; C033685:4-boronophenylalanine
keywords: 24Na; Boron Neutron Capture Therapy; germanium detector; neutron irradiation; radioactivity of blood
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