title: CT scan prior to radiotherapy in unresectable, locally advanced, non-small cell carcinoma of the lung: is it always necessary?
abstract: OBJECTIVE
  There is broad consensus regarding evaluating response to chemotherapy (CHT) by means of computerized tomography (CT) in patients with localized or locally advanced non-small cell lung carcinoma (NSCLC). We present a study comparing the usefulness of CT versus chest X-ray (XR) and clinical findings when indicating radiotherapy (RT) following CHT.
  
  
  METHODS
  Ninety-eight of 150 subjects with unresectable locally advanced NSCLC were blindly and independently evaluated by XR and CT, with pairs of chest XR and CT (before and after CHT). A null hypothesis (H0) was established of the conditioned probability of detecting progression by CT and not by XR of 10 % or more, with a statistical power of 80 %.
  
  
  RESULTS
  Sensitivity, specificity, positive and negative predictive value of XR versus CT were 98, 89, 99, and 80 % respectively. A 4 % (p = 0.0451) probability of improvement of CT versus XR was calculated, enabling the H0 to be ruled out.
  
  
  CONCLUSIONS
  The CT failed to prove to be significantly superior to the chest XR + clinical picture in indicating a change in treatment approach in patients with unresectable locally advanced NSCLC after CHT.
authors.affiliation: Radiology Service, Hospital Universitario Central de Asturias, Avenida de Roma, s/n, ES-33011, Oviedo, Asturias, Spain. dhousev@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Calvo Temprano
authors.affiliation: Medical Oncology Service, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Esteban
authors.affiliation: Medical Oncology Service, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Jiménez Fonseca
authors.affiliation: Radiology Service, Hospital Universitario Central de Asturias, Avenida de Roma, s/n, ES-33011, Oviedo, Asturias, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Fernández-Mariño
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D018287:Carcinoma, Large Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D005500:Follow-Up Studies; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D009367:Neoplasm Staging; D011379:Prognosis; D013902:Radiography, Thoracic / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Chest X-ray; Computerized tomography; Lung cancer; Lung cancer staging; Non-small cell carcinoma of the lung; RECIST