Incidental Finding of Pulmonary Embolus in CT Studies of Oncological Patients Undergoing Clinical Trials

Eyal Klang 1 Philip Lawson 1 Stephen Raskin 1 Raanan Berger 3 Shelly Soffer 2 Marianne Michal Amitai 1 Tehila Kharizman 1 Eli Konen 1
1Department of Radiology, The Chaim Sheba Medical Center
2Sackler Faculty of Medicine, Tel Aviv University
3Department of Oncology, The Chaim Sheba Medical Center

PURPOSE: The purpose of this study is to determine the frequency of incidental pulmonary embolism (PE) among oncology patients undergoing clinical trials and to determine the association between incidental PE and Response Evaluation Criteria In Solid Tumors (RECIST) categories of response.

MATERIALS AND METHODS: An institutional review board approval was granted for this retrospective study and the requirement for informed consent was waived.

This study was conducted in a large, single-center, tertiary facility. A computerized search was conducted in our oncological clinical trials database for patients who underwent CT studies with intravenous contrast between 1/1/2012 and 21/6/2017. All the patients in the study were oncological patients with metastatic disease who were enrolled in clinical trials and who underwent baseline and follow-ups chest-abdomen-pelvis CT as part of a clinical trial.

RECIST 1.1 categories of response were calculated for each CT study at the time of interpretation. Categories of response include: Baseline, Complete Response (CR), Stable Disease (SD), Partial Response (PR) and Progressive Disease (PD).

The retrieved dataset was scanned to identify CT studies with a diagnosis of incidental PE.

The frequency of incidental PE in oncological clinical trial patients was calculated. The association between incidental PE and the presence of was RECIST PD status evaluated.

RESULTS: During the study period 1070 patients (ages 59.4±13.0, M:F 585:485) underwent 3818 chest-abdomen CT studies. The total number of months that enrolled patients were followed up, from baseline CT to last follow-up CT, was 7292 months, giving an average of 6.8 months of follow-up per patient. During the study period, 18 patients had incidental PE. Thus, the frequency of incidental PE in oncological clinical trial patients was 3% of incidental PE per year of follow-up.

The patients with PE underwent 94 CT studies. Sixteen studies showed PD; of them 8/16 (50%) showed incidental PE, making incidental PE associated with PD category of response (p<0.001, Odds ratio 11.8).

CONCLUSION: Radiologists and clinicians should be aware of the higher incidence of PE in oncological patients undergoing clinical trials who manifest PD status.

Eyal Klang
Eyal Klang