Single centre evaluation of the use of CT scans to exclude malignancy for unprovoked DVTs
Session type: E-poster/poster
As malignancy predisposes people to develop deep vein thromboses (DVT), The National Institute for Health and Care Excellence (NICE) recommends considering an abdomino-pelvic CT scan to rule out malignancy, for patients aged over 40 years with a first unprovoked DVT, or those who do not have clinical features suggestive of cancer based on initial investigations.
A list of 1088 patients, from November 2015 to October 2018, with confirmed DVT on ultrasound scans, was retrospectively reviewed. Patients were included if they were older than 40 years of age presenting with a first unprovoked DVT were included (n=446).
Out of the 446 patients included, 19.95% had a CT scan performed (n=89) with the aim of ruling out malignancy. Only 5.62% of these CT scans were found to be positive for malignancy (N=5).
The low incidence of malignancy in unprovoked DVTs has been used to discourage referrals for screening CT scan. We therefore recommend that CT scans only be requested if high suspicion of malignancy remains after the use of first-line investigations. Moreover, additional studies are needed at different centres to amend the recommendation put forward by NICE.
Considering that over the past 5 years, demand for imaging such as CT scans has increased by 10% per year, this audit aims to review the value of performing CT imaging to exclude cancer in patients with a first unprovoked DVT, in order to reduce the cumulative demand for imaging and examine alternate modalities for early detection and prevention of cancer.