title: Quantification of CT-assessed radiation-induced lung damage in lung cancer patients treated with or without chemotherapy and cetuximab.
abstract: OBJECTIVE
  Prediction models for radiation-induced lung damage (RILD) are still unsatisfactory, with clinical toxicity endpoints that are difficult to quantify objectively. We therefore evaluated RILD more objectively, quantitatively and on a continuous scale measuring the lung tissue density changes per voxel.
  
  
  METHODS
  Patients treated with radiotherapy (RT) alone, sequential and concurrent chemo-RT with and without the addition of cetuximab were studied. Follow-up computed tomography (CT) scans were co-registered using deformable registration to baseline CT scans. CT density changes were correlated to the RT dose delivered in every part of the lungs.
  
  
  RESULTS
  One hundred and seventeen lung cancer patients were included. Mean dose to tumor was 60 Gy (range 45-79.2 Gy). Dose response curves showed a linear increase in the dose region between 0 and 65 Gy having a slope (based on coefficients of the multilevel model) expressed as a lung density increase per dose of 0.86 (95% CI 0.73-0.99), 1.31 (95% CI 1.19-1.43), 1.39 (95% CI 1.28-1.50) and 2.07 (95% CI 1.93-2.21) for patients treated only with RT (N=19), sequential chemo-RT (N=30), concurrent chemo-RT (N=49), and concurrent chemo-RT with cetuximab (N=19), respectively.
  
  
  CONCLUSIONS
  CT density changes allow quantitative assessment of lung damage after fractionated RT, giving complementary information to standard used clinical endpoints. Patients receiving cetuximab showed a significantly larger dose response compared with other treatments.
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .|e Department of Physics , Oakland University , Rochester , Michigan, MI , USA.
authors.forename: Hoda
authors.initials: H
authors.lastname: Sharifi
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .
authors.forename: Wouter
authors.initials: W
authors.lastname: van Elmpt
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .
authors.forename: Cary
authors.initials: C
authors.lastname: Oberije
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .
authors.forename: Georgi
authors.initials: G
authors.lastname: Nalbantov
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .|b Department of Radiology , Maastricht University Medical Center , Maastricht , The Netherlands .
authors.forename: Marco
authors.initials: M
authors.lastname: Das
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .
authors.forename: Michel
authors.initials: M
authors.lastname: Öllers
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .
authors.forename: Philippe
authors.initials: P
authors.lastname: Lambin
authors.affiliation: d Department of Pulmonology , University Medical Center , Maastricht , The Netherlands , and.
authors.forename: Anne-Marie C
authors.initials: AM
authors.lastname: Dingmans
authors.affiliation: a Department of Radiation Oncology (MAASTRO clinic) GROW , School for Oncology and Developmental Biology, Maastricht University Medical Center , Maastricht , The Netherlands .|c Department of Radiation Oncology , University Hospitals Leuven/KU Leuven , Belgium .
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ruysscher
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D000068818:Cetuximab / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000473:pathology*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects; D055752:Small Cell Lung Carcinoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D014057:Tomography, X-Ray Computed
chemical_list: D000068818:Cetuximab