title: Image-guided intensity-modulated radiotherapy for patients with locally advanced gastric cancer: a clinical feasibility study.
abstract: BACKGROUND
  The aim of this study was to determine the medical and technical feasibility of intensity-modulated radiotherapy (IMRT) in high-risk nonmetastatic gastric cancer stage II and III after primary gastrectomy and D2 lymphadenectomy.
  
  
  METHODS
  A prospective nonrandomized phase II trial was performed on 25 consecutive patients with gastric cancer with high risk (T3-4, N1-3, G2-3, R0-1). The dose delivered was 45 Gy (1.80 Gy per fraction) in IMRT technique. Concurrent 5-fluorouracil-based chemotherapy at 225 mg/m(2) was administered as a continuous intravenous infusion. Primary endpoints were acute gastrointestinal toxicity (CTC 4.0) and technical feasibility of IMRT in regard to dose planning and radiation delivery.
  
  
  RESULTS
  Early acute events were defined as clinical and chemical adverse effects of IMRT and concurrent chemotherapy during treatment. By definition, 90 days after the end of IMRT has been evaluated as acute-phase toxicity. No patient had grade 4 or higher acute adverse events. Clinical grade 3 toxicity occurred in two patients (8%) with diarrhea and in one case (4%) with nausea. Hematological changes with grade 3 occurred in three cases (12%) with hemoglobin decrease, in five cases (25%) as leukopenia, and in one case (4%) with thrombocytopenia. The mean dose for liver was 16 Gy and the percentage volume exceeding 30 Gy (V30) was 21%. Mean dose for right and left kidney was 9 and 13 Gy, respectively, and V20 was 9% and 13%, respectively. Heart received a median dose of 15 Gy and V40 was 17%. The mean dose to the bowel was 11 Gy and V40 was 6%. Spinal cord had at maximum 33 Gy in median. Specifics of dose distribution, including the coverage, for the target region were as follows: minimum was 33 Gy, maximum 48.6 Gy, and mean dose 44.6 Gy. The prescribed dose (45 Gy) covered 99% and 95% of planning target volume (OTV) in 66% and 92% of cases, respectively. Median PTV was 15.77 ml (range, 805-3,604 ml).
  
  
  CONCLUSIONS
  The data support the practical feasibility of IMRT in adjuvant treatment in high-risk gastric cancer in the postoperative setting as a proof of principle. Acute toxicity has been tolerable.
authors.affiliation: Department for Radiation Oncology, Charité School of Medicine and University Hospital Berlin, Augustenburger Platz 1, 13353, Berlin, Germany, Harun.Badakhshi@charite.de.
authors.forename: Harun
authors.initials: H
authors.lastname: Badakhshi
authors.forename: Arne
authors.initials: A
authors.lastname: Gruen
authors.forename: Reinhold
authors.initials: R
authors.lastname: Graf
authors.forename: Dirk
authors.initials: D
authors.lastname: Boehmer
authors.forename: Volker
authors.initials: V
authors.lastname: Budach
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000627:therapeutic use*; D059186:Chemoradiotherapy, Adjuvant; D005240:Feasibility Studies; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000627:therapeutic use*; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D007262:Infusions, Intravenous; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011832:Radiation Injuries / Q000453:epidemiology; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012306:Risk; D013274:Stomach Neoplasms / Q000473:pathology / Q000628:therapy*
chemical_list: D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil