Therapeutic Response Monitoring
In the current climate of cost constraints, the ability to monitor effective response at an early stage is a major advantage. Ozsahin et al. demonstrated that following effective therapy for invasive aspergillosis, 18F-FDG PET findings reverted to normal. Animal experiments have also shown that 18F-FDG PET is accurate for monitoring responses following antibiotic therapy in the setting of soft tissue infection. In a clinical study, 18F-FDG uptake returned to normal levels after successful antifungal therapy for a lung abscess caused by candidal infection and after therapy for Pneumocystis carinii pneumonia.
Few noninvasive biomarkers for pulmonary inflammation are currently available that can assess the lung-specific response to anti-inflammatory treatments. Chen et al. evaluated the ability of 18F-FDG PET to measure the pulmonary anti-inflammatory effects of hydroxymethylglutaryl-co-enzyme A reductase inhibitors (statins) and recombinant human-activated protein C (rhAPC) in a human model of experimentally induced lung inflammation in 18 healthy volunteers. They showed that 18F-FDG PET imaging is a sensitive method for quantifying the lung-specific response to anti-inflammatory therapies and may serve as an attractive platform for assessing the efficacy of novel anti-inflammatory therapies at early phases in the drug development process (Fig. 5).
Therapy response assessment in patient with histology-proven sarcoidosis
Baseline lower panel and follow-up upper panel 18F-FDG PET/CT scans (from left to right: MIP, axial PET, axial CT and axial fused PET/CT) after 6 months of treatment show interval reduction of FDG activity at the mediastinal (orange arrow) and bilateral hilar (yellow arrow) lymphadenopathy indicating good response to therapy. FDG, fluorodeoxyglucose; MIP, maximum intensity projection.
Curr Opin Pulm Med. 2011;17(3):197-205. © 2011 Lippincott Williams & Wilkins
Cite this: Combined PET and X-ray Computed Tomography Imaging in Pulmonary Infections and Inflammation - Medscape - May 01, 2011.