Therapy monitoring using dynamic MRI: analysis of lung motion and intrathoracic tumor mobility before and after radiotherapy.
A frequent side effect after radiotherapy of lung tumors is a decrease of pulmonary function accompanied by dyspnea due to developing lung fibrosis. The aim of this study was to monitor lung motion as a correlate of pulmonary function and intrathoracic tumor mobility before and after radiotherapy (RT) using dynamic MRI (dMRI). Thirty-five patients with stage I non-small-cell lung carcinoma were examined using dMRI (trueFISP; three images/s). Tumors were divided into T1 and T2 tumors of the upper, middle and lower lung region (LR). Maximum craniocaudal (CC) lung dimensions and tumor mobility in three dimensions were monitored. Vital capacity (VC) was measured and correlated using spirometry. Before RT, the maximum CC motion of the tumor-bearing hemithorax was 5.2 +/- 0.9 cm if the tumor was located in the lower LR (middle LR: 5.5 +/- 0.8 cm; upper LR: 6.0 +/- 0.6 cm). After RT, lung motion was significantly reduced in the lower LR (P < 0.05). Before RT, the maximum CC tumor mobility was significantly higher in tumors of the lower LR 2.5 +/- 0.6 vs. 2.0 +/- 0.3 cm (middle LR; P < 0.05) vs. 0.7 +/- 0.2 cm (upper LR; P < 0.01). After RT, tumor mobility was significantly reduced in the lower LR (P < 0.01) and in T2 tumor patients (P < 0.05). VC showed no significant changes. dMRI is capable of monitoring changes in lung motion that were not suspected from spirometry. This might make the treatment of side effects possible at a very early stage. Changes of lung motion and tumor mobility are highly dependent on the tumor localization and tumor diameter.
Plathow
Christian
C
Department of Diagnostic Radiology, Eberhard-Karls University Tuebingen, Hoppe-Seyler 3, 72060, Tuebingen, Germany. christian.planthow@med.uni-tuebingen.de
Hof
Holger
H
Kuhn
Sabine
S
Puderbach
Michael
M
Ley
Sebastian
S
Biederer
Juergen
J
Claussen
Claus D
CD
Huber
Peter E
PE
Schaefer
Juergen
J
Tuengerthal
Siegfried
S
Kauczor
Hans-Ulrich
HU
D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000532:radiotherapy; D005260:Female; D006801:Humans; D008168:Lung / Q000002:abnormalities / Q000473:pathology*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009068:Movement; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D013147:Spirometry; D035423:Thoracic Cavity / Q000473:pathology; D016896:Treatment Outcome; D014797:Vital Capacity