title: Basal renal function reserve and mean kidney dose predict future radiation-induced kidney injury in stomach cancer patients.
abstract: BACKGROUND
  Adjuvant chemoradiotherapy (CRT) improves the survival in patients with locally advanced stomach cancer. The kidneys are the major dose-limiting organs for radiotherapy (RT) in upper abdominal cancers. We aimed to evaluate the impact of adjuvant CRT on renal function of patients with stomach cancer.
  
  
  METHODS
  Fifty-nine stomach cancer patients who underwent postoperative CRT were included. Demographic parameters (age, gender), and basal and 12th-month biochemical parameters were recorded. Mean kidney dose (MKD) administered was determined. Estimated glomerular filtration rate (eGFR) was calculated by modification of diet in renal disease formula.
  
  
  RESULTS
  Fifty-nine patients were recruited (age 60.8 ± 11.9 years; female/male 25/34; follow-up duration 15.6 ± 9.8 months). Twenty-one patients (35.6 %) had basal eGFR <90 ml/min/1.73 m(2). When the basal and 12th-month eGFR was compared, eGFR decreased in 27 patients (45.8 %), whereas eGFR remained stable in 32 (54.2 %) patients. Cox regression analyses revealed that a MKD ≥1,500 cGy and basal eGFR <90 ml/min/1.73 m(2) significantly increased the risk of a decreased eGFR at 12th month (HR = 2.288, 95 % CI 1.009-5.188, p = 0.048 and HR = 2.854, 95 % CI 1.121-7.262, p = 0.028, respectively).
  
  
  CONCLUSIONS
  MKD ≥1,500 cGy and a basal eGFR <90 ml/min/1.73 m(2) significantly increased the risk of a decreased eGFR at 12th month. We suggest that patients with stomach cancer be evaluated for their basal renal reserve prior to RT, and it may be more convenient to further minimize the dose to the kidneys with more sophisticated RT techniques in patients with stomach cancer, more specifically in patients with decreased renal reserve.
authors.affiliation: Department of Radiation Oncology, Selcuk University, Konya, Turkey, guler.aydinyavas@gmail.com.
authors.forename: Guler
authors.initials: G
authors.lastname: Yavas
authors.forename: Rengin
authors.initials: R
authors.lastname: Elsurer
authors.forename: Cagdas
authors.initials: C
authors.lastname: Yavas
authors.forename: Ozlem
authors.initials: O
authors.lastname: Ata
mesh_terms: D000328:Adult; D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005919:Glomerular Filtration Rate / Q000528:radiation effects; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000503:physiopathology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011182:Postoperative Care / Q000379:methods; D011832:Radiation Injuries / Q000209:etiology* / Q000503:physiopathology*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery