Rationale and design of a prospective study on the first integrated PET/dual-energy CT system for staging and image-based radiation therapy planning of lung cancer

BACKGROUND: The aim of this prospective study is to investigate the diagnostic performance of integrated positron emission tomography (PET) /dual-energy computed tomography (DECT) imaging in determining the thoracic nodal status of patients with small-cell lung cancer (SCLC) or non-small-cell lung cancer (NSCLC) and the resulting impact on target volume delineation for radiation therapy planning. METHODS: This is a single-center prospective study including approximately 50 patients with suspected or confirmed SCLC or NSCLC, referred for a PET study. All patients will be examined on a clinical PET/DECT system, where a dual-energy detector was recently installed. The patient will be placed in the system 70 min after the administration of 5 MBq/kg of (18)F-fluorodeoxyglucose ((18)F-FDG). Then, DECT will be acquired after the injection of 100 mL of iodine contrast medium. A PET scan will be acquired from the top of the skull through the inguinal region. Data analysis will be performed on the PET, CT, and iodine map datasets. Information regarding tumor detection, adenopathies, and radiation therapy planning will be assessed based on all three sets of images by two experienced radiologists. CONCLUSION: The results will add insights into the advantages of using PET/DECT for lung cancer staging and for image-guided radiation therapy. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03146117. Registered on 9 May 2017.