Room: AAPM ePoster Library
Purpose: To perform comprehensive functional imaging assessments of the lungs, heart, and tumor before and after radiation therapy for non-small cell lung cancer (NSCLC) in 2 patients.
Methods: Two Stage III NSCLC patients were imaged before and 6 weeks after radiotherapy; one with coronary artery stents (patient 1), and one with no previous cardiac history (patient 2). Both patients had primary tumors in the left upper lobe. The imaging protocol on the GE Revolution CT scanner consisted of two dynamic contrast-enhanced (DCE) scans: rest and an adenosine-induced stress scan. 18F-FDG PET images were acquired on a Siemens 3T hybrid PET/MR scanner using a glucose suppression technique. Perfusion analysis of the heart and tumour was completed using CT-Perfusion5 software (GEHC). Myocardial perfusion reserve was calculated as the ratio of blood flow of stress/rest scans. End-inspiration and end-expiration CT images were non-rigidly registered using Elastix, and ventilation was calculated using an established density-based method. Myocardial mean standard uptake volume (meanSUVbw) was compared using the standard six-segment model. Tumor mean SUVbw was computed in MIM software.
Results: A global increase in myocardial uptake and decrease in tumor uptake were observed with FDG-PET after treatment in both patients. Myocardial perfusion reserve measured with DCE-CT increased in some segments but decreased in others for patient 1, but decreased in all segments for patient 2. Tumor blood flow visually increased for both patients. CT specific ventilation in the treated lobe decreased after treatment for both patients.
Conclusion: Here we demonstrated the feasibility of collecting extensive functional imaging data with two imaging sessions before and after radiation therapy for Stage III NSCLC and showed that these methods are sensitive to changes 6 weeks after treatment and may suggest an acute inflammatory response. This protocol may be used to provide important patient-specific information for clinical decision making.