Dual-energy CT in patients with NSCLC, possible benefit in detection of metastatic lymph nodes and monitoring therapy response
Abstract
Aim: Assessment of the possibility of using the two-phase post-contrast dual energy CT (DE-CT) to assess the development of lymph nodes in patients with NSCLC during chemotherapy and staging using PET/CT. Methods: The group of 38 patients with NSCLC with a total of 108 lymph nodes.
In all the FDG-PET/CT was used for staging and during treatment followed by two DE-CT. Lymph nodes were divided according to the SUV (standard uptake value) into two groups ? negative (SUVmax > 2,5) and positive (SUVmax > 2,5).
Te iodine uptake (mg/ml) in the lymph nodes in the arterial and venous phase and the calculated value of the AEF (arterial enhancement fraction). According to the SUV and the size change were lymph nodes divided into four groups: PET positive progressive, PET positive regressive, PET negative progressive and PET negative regressive.
Development of the observed values (AEF, iodine uptake in the arterial and venous phase) was compared in each group. Results: A statistically signifcant diference of the AEF and iodine uptake in the venous phase was observed between a group of proved lymph node metastases, which progressed further and a group of negative lymph nodes, that was infltrated during treatment.
Furthermore the correlation between the AEF and response to treatment was confrmed, in lymph node metastases with a positive treatment response the value AEF decreased and on contrary increased in resistant lymph nodes. Conclusion: Our study confrmed the possibility of using a two-phase DE-CT, such as functional imaging methods for evaluation of the therapy response in lymph node metastases.