title: Long-term observations of radiation-induced creatinine clearance reduction and renal parenchymal volume atrophy.
abstract: The kidney is a dose-limiting organ for upper abdominal radiotherapy. In this study, radiation-induced kidney injury represented by changes of creatinine clearance (Ccr) and renal parenchymal volume measured by computed tomography (CT) were evaluated by analysing dose-volume histograms (DVHs) in patients with primary gastric diffuse large B-cell lymphoma (PGDLBCL) treated with chemoradiotherapy.
  
  
  
  Thirty-eight PGDLBCL patients (seventy-six kidneys) treated with chemoradiotherapy were included in this study. At least 4 years of follow-up was required for eligibility. Patients underwent (immuno-) chemotherapy followed by radiotherapy with approximately 40Gy to the whole stomach and perigastric lymph nodes. Ccr and CT were obtained at least annually. Changes of Ccr and renal parenchymal volume before and 4years after radiotherapy were compared using DVH parameters.
  
  
  
  Mean Ccr decreased significantly from 82.7mL/min (range, 39-124mL/min) before radiotherapy to 70.4mL/min (range, 35-109mL/min) (p=0.01) 4years after radiotherapy. Mean reduction of bilateral renal parenchymal volume was 12% (range, -5-37%) in the same time period. Ccr and renal parenchymal volume tended to lower over time more than 4years after radiotherapy. Concerning DVH analysis, V20Gy⩾26.6% and D30%⩾19Gy had a significant risk of bilateral renal atrophy of ⩾14% and reduction of the Ccr⩾20mL/min.
  
  
  
  This study revealed that there was a definite relationship between DVH, renal atrophy and Ccr reduction. V20Gy<26.6% and D30%<19Gy appeared to be safe dose constraints for a Ccr reduction of <20mL/min 4years after radiotherapy.
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan. Electronic address: koinaba@ncc.go.jp.
authors.forename: Koji
authors.initials: K
authors.lastname: Inaba
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okamoto
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Wakita
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Tsuchida
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Tairo
authors.initials: T
authors.lastname: Kashihara
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Kazuma
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Harada
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Mayuka
authors.initials: M
authors.lastname: Kitaguchi
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Sekii
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Umezawa
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Murakami
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Igaki
authors.affiliation: Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Uno
authors.affiliation: Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Itami
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001284:Atrophy; D059248:Chemoradiotherapy / Q000009:adverse effects*; D003404:Creatinine / Q000378:metabolism*; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology / Q000528:radiation effects*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000628:therapy*; D008228:Lymphoma, Non-Hodgkin / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology*; D013274:Stomach Neoplasms / Q000628:therapy*
chemical_list: D003404:Creatinine
keywords: Creatinine clearance; Dose constraint; Renal volume change