Using hyperpolarised helium-3 MRI to detect changes in ventilation after lung radiotherapy
Year: 2008
Session type: Poster / e-Poster / Silent Theatre session
Weston Park Hospital, Sheffield, UK
Abstract
Background
Hyperpolarized helium-3 MRI (3He MRI) may be a useful supplementary tool for the evaluation of lung cancer radiotherapy (RT) and its side effects. The aim of this study was to test the feasibility of using 3He MRI to evaluate radiation induced lung changes.
Method
5 NSCLC patients who received lung radiotherapy were assessed. 3He gas was polarized on site and ventilation images were acquired during a breath-hold of a 1L 3He/N2 mixture. Images were acquired before radiotherapy and at 3 months. MRIs were registered to each other and to the treatment planning and post treatment CTs.
Results
In 4 patients, a reduction in ventilation was seen in the high dose volume. In 3, this reduction correlated well with radiation induced damage apparent on CT. Ventilation improved as a result of tumour response in one case. This patient had a left upper lobe adenocarcinoma with associated collapse. Pre RT images showed a large ventilation defect at this site. Post RT, a response in the primary was shown by resolution of the lobar collapse on CT. This is matched by an improvement in the 3He ventilation in the left upper lobe. CT showed evidence of pneumonitis in the left lower lobe. The 3He images showed a decrease in the functional area of ventilation in this region. Correspondingly, DLCO reduced by 16%.
Conclusion
3He MRI ventilation provides a novel and safe method of assessment of functional lung pathophysiology. Changes can correlate well with both tumour response and radiation induced lung injury.
Background
Hyperpolarized helium-3 MRI (3He MRI) may be a useful supplementary tool for the evaluation of lung cancer radiotherapy (RT) and its side effects. The aim of this study was to test the feasibility of using 3He MRI to evaluate radiation induced lung changes.
Method
5 NSCLC patients who received lung radiotherapy were assessed. 3He gas was polarized on site and ventilation images were acquired during a breath-hold of a 1L 3He/N2 mixture. Images were acquired before radiotherapy and at 3 months. MRIs were registered to each other and to the treatment planning and post treatment CTs.
Results
In 4 patients, a reduction in ventilation was seen in the high dose volume. In 3, this reduction correlated well with radiation induced damage apparent on CT. Ventilation improved as a result of tumour response in one case. This patient had a left upper lobe adenocarcinoma with associated collapse. Pre RT images showed a large ventilation defect at this site. Post RT, a response in the primary was shown by resolution of the lobar collapse on CT. This is matched by an improvement in the 3He ventilation in the left upper lobe. CT showed evidence of pneumonitis in the left lower lobe. The 3He images showed a decrease in the functional area of ventilation in this region. Correspondingly, DLCO reduced by 16%.
Conclusion
3He MRI ventilation provides a novel and safe method of assessment of functional lung pathophysiology. Changes can correlate well with both tumour response and radiation induced lung injury.
