Japanese
Title131I大量投与時の過剰被曝回避についての考察 : 特に排尿頻度の意義について
Subtitle寄稿
Authors小山田日吉丸*, 内田勲**, 小泉満**, 久保敦司***, 橋本順***
Authors(kana)
Organization*日本赤十字社 東京都東赤十字血液センター, **癌研究会附属病院アイソトープ部, ***慶應義塾大学医学部放射線科学教室
Journal核医学
Volume35
Number4
Page239-244
Year/Month1998/4
Article報告
Publisher日本核医学会
Abstract「要旨」転移性甲状腺癌の131I治療では1回に3.7GBq(100mCi)あるいはそれ以上が投与され, 複数回繰り返し行われるのが一般的である. したがって不必要な被曝は可能な限り低く抑える努力が要求される. 投与された131Iの主たる排泄経路は尿路系であり, 一時的にせよ高濃度の131I含有尿が膀胱に貯溜する. そこでまず最初にわれわれは, 131I大量投与後の血中の残留放射能の推移についてひとつのモデルを考え, ふたつの排尿様式(様式A: 2時間ごと排尿6回につづいて6時間ごと排尿2回と, 様式B: 6時間ごと排尿4回)での膀胱内貯溜尿からの膀胱壁, 子宮, 卵巣, 精巣, および全身の被曝線量の違いを検討した. 結果は, 様式Bの場合はいずれの臓器でもまた全身でも, 様式Aのほぼ倍の線量が膀胱内の尿からかかることが判明した. 本研究は, 従来の排尿の必要性についての漠然とした概念に数値的な裏付けを与えるものである.
Practice臨床医学:一般
KeywordsThyroid cancer, Radioiodine-131 treatment, Excess exposure, Urination
English
TitleSome Considerations on the Avoidance of Excess Body Burden in Case of High Dose 131I Treatment : With Special Reference to the Urination Frequency
SubtitleCommentary
AuthorsHiyoshimaru OYAMADA*, Isao UCHIDA**, Mitsuru KOIZUMI**, Atsushi KUBO***, Jun HASHIMOTO***
Authors(kana)
Organization*Tokyo Eastern Blood Center, Japanese Red Cross Society, **Radioisotope Division, Cancer Institute Hospital, ***Department of Radiology, Keio University School of Medicine
JournalThe Japanese Journal of nuclear medicine
Volume35
Number4
Page239-244
Year/Month1998/4
ArticleReport
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
AbstractIn case of the treatment of metastatic thyroid cancer with radioiodine (131I), 3.7 GBq (100 mCi) or more is often repeatedly administered to the patient. Therefore, we must be aware of avoiding unnecessary exposure to the radioiodine except for the lesions to be treated. The administered radioiodine is excreted mainly through urinary system, resulting in an accumulation of the urine in the bladder for a certain period, which is highly concentrated with it. Based on this fact, we set one case having a particular pattern of the whole body retention curve. Then, two different modes of urination were considered; mode A indicates every 2 hour-urination×6 times followed by every 6 hour-urination×2 times, and mode B indicates every 6 hour-urination×4 times. Focusing on the different amounts of urine in the bladder upon the different modes of urination, the radiation exposures from the urine to the neighboring organs, such as bladder wall, uterus, ovary and testis, and also to the whole body were calculated. As the results, it was found that the urination mode B would cause radiation exposure from the urine in the bladder twice as much as the urination mode A to the neighboring organs as well as to the whole body. This study will supply arguments for the necessity of frequent urination in the cases receiving radioiodine treatment for metastatic thyroid cancer.
PracticeClinical medicine
KeywordsThyroid cancer, Radioiodine-131 treatment, Excess exposure, Urination

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