title: Measurement of tumor diameter-dependent mobility of lung tumors by dynamic MRI.
abstract: OBJECTIVE
  To assess the influence of tumor diameter on tumor mobility and motion of the tumor bearing hemithorax during the whole breathing cycle in patients with stage I non-small-cell lung cancer (NSCLC) using dynamic MRI.
  
  
  METHODS
  Breathing cycles of thirty-nine patients with solitary NSCLCs were examined using a trueFISP sequence (three images per second). Patients were divided into three groups according to the maximal tumor diameter in the transverse plane (<3, 3-5 and >5 cm). Continuous time-distance curves and deep inspiratory and expiratory positions of the chest wall, the diaphragm and the tumor were measured in three planes. Motion of tumor-bearing and corresponding contralateral non-tumor bearing regions was compared.
  
  
  RESULTS
  Patients with a tumor >3 cm showed a significantly lower diaphragmatic motion of the tumor bearing compared with the non-tumor bearing hemithorax in the craniocaudal (CC) directions (tumors 3-5 cm: 23.4+/-1.2 vs 21.1+/-1.5 cm (P<0.05); tumors >5 cm: 23.4+/-1.2 vs 20.1+/-1.6 cm (P<0.01). Tumors >5 cm in the lower lung region showed a significantly lower mobility compared with tumors <3 cm (1.8+/-1.0 vs 3.8+/-0.7 cm, P<0.01) in the CC directions.
  
  
  CONCLUSIONS
  Dynamic MRI is a simple non-invasive method to differentiate mobility of tumors with different diameters and its influence on the surrounding tissue. Tumor diameter has a significant influence on tumor mobility and this might be taken into account in future radiotherapy planning.
authors.affiliation: Department of Radiology, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Plathow
authors.forename: Christian
authors.initials: C
authors.lastname: Fink
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ley
authors.forename: Michael
authors.initials: M
authors.lastname: Puderbach
authors.forename: Monika
authors.initials: M
authors.lastname: Eichinger
authors.forename: Ivan
authors.initials: I
authors.lastname: Zuna
authors.forename: Astrid
authors.initials: A
authors.lastname: Schmähl
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
mesh_terms: D000328:Adult; D000368:Aged; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009068:Movement; D011878:Radiotherapy / Q000379:methods; D015203:Reproducibility of Results; D012119:Respiration