title: Cone-beam CT-guided radiotherapy in the management of lung cancer: Diagnostic and therapeutic value.
abstract: BACKGROUND
  Recent studies have demonstrated an increase in the necessity of adaptive planning over the course of lung cancer radiation therapy (RT) treatment. In this study, we evaluated intrathoracic changes detected by cone-beam CT (CBCT) in lung cancer patients during RT.
  
  
  METHODS
  A total of 71 lung cancer patients treated with fractionated CBCT-guided RT were evaluated. Intrathoracic changes and plan adaptation priority (AP) scores were compared between small cell lung cancer (SCLC, n = 13) and non-small cell lung cancer (NSCLC, n = 58) patients.
  
  
  RESULTS
  The median cumulative radiation dose administered was 54 Gy (range 30-72 Gy) and the median fraction dose was 1.8 Gy (range 1.8-3.0 Gy). All patients were subjected to a CBCT scan at least weekly (range 1-5/week). We observed intrathoracic changes in 83 % of the patients over the course of RT [58 % (41/71) regression, 17 % (12/71) progression, 20 % (14/71) atelectasis, 25 % (18/71) pleural effusion, 13 % (9/71) infiltrative changes, and 10 % (7/71) anatomical shift]. Nearly half, 45 % (32/71), of the patients had one intrathoracic soft tissue change, 22.5 % (16/71) had two, and three or more changes were observed in 15.5 % (11/71) of the patients. Plan modifications were performed in 60 % (43/71) of the patients. Visual volume reduction did correlate with the number of CBCT scans acquired (r = 0.313, p = 0.046) and with the timing of chemotherapy administration (r = 0.385, p = 0.013).
  
  
  CONCLUSIONS
  Weekly CBCT monitoring provides an adaptation advantage in patients with lung cancer. In this study, the monitoring allowed for plan adaptations due to tumor volume changes and to other anatomical changes.
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany.
authors.forename: Khaled
authors.initials: K
authors.lastname: Elsayad
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Kriz
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Reinartz
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany.
authors.forename: Sergiu
authors.initials: S
authors.lastname: Scobioala
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany.
authors.forename: Iris
authors.initials: I
authors.lastname: Ernst
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Haverkamp
authors.affiliation: Department of Radiation Oncology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, Building A1, 48149, Muenster, Germany. Hans.eich@ukmuenster.de.
authors.forename: Hans Theodor
authors.initials: HT
authors.lastname: Eich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D018450:Disease Progression; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008168:Lung / Q000528:radiation effects*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010996:Pleural Effusion / Q000000981:diagnostic imaging; D001261:Pulmonary Atelectasis / Q000000981:diagnostic imaging; D011832:Radiation Injuries / Q000000981:diagnostic imaging*; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D012189:Retrospective Studies
keywords: Chemoradiotherapy; Intensity-modulated radiation therapy; Lung neoplasms; Radiotherapy planning, computer-assisted; Radiotherapy, image-guided