Incidental pulmonary embolism in CT scans of oncological patients with metastatic disease undergoing clinical trials: Frequency and linkage with onset of disease progression (PE-PD association)

Objectives: We aimed to analyze the association between the onsets of PE and of progressive disease (PD) in CT scans of oncological patients undergoing clinical trials. Methods: We retrospectively searched our oncological clinical trials database (1/2012 - 6/2017). We retrieved patients who underwent protocol baseline and follow-up CT scans. RECIST 1.1 categories of response were calculated for each scan at interpretation. The entire dataset was searched for reports with incidental PE. For patients with incidental PE, we collected all the scans conducted up to and including the scan with PE. For each scan, we retrieved the recorded RECIST 1.1 category. We excluded patients with PE at baseline. The frequency of incidental PE in oncological clinical trial patients was calculated. For patients with incidental PE, we evaluated the association between PE and PD. Results: During the study period, 1,070 patients underwent 3,818 CTs. The total number of follow-up months was 7,292 months. 18 patients developed incidental PE during follow-up. Thus, the frequency of incidental PE in oncological clinical trial patients was 3% per year of follow-up. Patients with incidental PE underwent 60 scans up to development of PE. Of 42 non-baseline scans, 6/6 (100%) PD showed PE, and 5/36 (13.9%) non-PD showed PE, making PE onset associated with PD onset (p < 0.001). Conclusion: In oncological clinical trials, the frequency of incidental PE is 3% per year of follow-up. The onset of incidental PE is linked to the onset of PD.