title: IMRT limits nephrotoxicity after chemoradiotherapy for gastric cancer.
abstract: OBJECTIVE
  This observational study compares the effect of different radiotherapy techniques on late nephrotoxicity after postoperative chemoradiotherapy for gastric cancer.
  
  
  METHODS
  Dosimetric parameters were compared between AP-PA, 3D-conformal and IMRT techniques. Renal function was measured by (99m)Tc-MAG-3 renography, glomerular filtration rate (GFR) and the development of hypertension. Mixed effects models were used to compare renal function over time.
  
  
  RESULTS
  Eighty-seven patients treated between 2002 and 2010 were included, AP-PA (n=31), 3D-conformal (n=25) and IMRT (n=31), all 45 Gy in 25 fractions. Concurrent chemotherapy: 5FU/leucovorin (n=4), capecitabine (n=37), and capecitabine/cisplatin (n=46). Median follow-up time was 4.7 years (range 0.2-8). With IMRT, the mean dose to the left kidney was significantly lower. Left kidney function decreased progressively in the total study population, however with IMRT this occurred at a lower rate. A dose-effect relationship was present between mean dose to the left kidney and the left kidney function. GFR decreased only moderately in time, which was not different between techniques. Six patients developed hypertension, of whom none in the IMRT group.
  
  
  CONCLUSIONS
  This study confirms progressive late nephrotoxicity in patients treated with postoperative chemoradiotherapy by different techniques for gastric cancer. Nephrotoxicity was less severe with IMRT and should be considered the preferred technique.
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Anouk Kirsten
authors.initials: AK
authors.lastname: Trip
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Jasper
authors.initials: J
authors.lastname: Nijkamp
authors.affiliation: Department of Biometrics, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Harm
authors.initials: H
authors.lastname: van Tinteren
authors.affiliation: Department of Gastroenterology and Hepatology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Annemieke
authors.initials: A
authors.lastname: Cats
authors.affiliation: Department of Gastroenterology and Hepatology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: Boot
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Edwin Petrus Marianus
authors.initials: EP
authors.lastname: Jansen
authors.affiliation: Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. Electronic address: m.verheij@nki.nl.
authors.forename: Marcel
authors.initials: M
authors.lastname: Verheij
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D000069287:Capecitabine; D059248:Chemoradiotherapy / Q000009:adverse effects / Q000379:methods; D002945:Cisplatin / Q000008:administration & dosage; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000528:radiation effects; D007674:Kidney Diseases / Q000139:chemically induced / Q000209:etiology* / Q000517:prevention & control; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology* / Q000517:prevention & control; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*
chemical_list: D003841:Deoxycytidine; D000069287:Capecitabine; D002945:Cisplatin; D002955:Leucovorin; D005472:Fluorouracil
keywords: 3D-conformal; AP–PA; Gastric cancer; IMRT; Nephrotoxicity; Postoperative chemoradiotherapy