CT abdomen and pelvis to investigate for occult malignancy in patients with first unprovoked pulmonary embolism, is it justified?

Background: Unprovoked venous thromboembolism can be the first manifestation of undetected malignancy. The national institute of clinical excellence (NICE) recommends to consider a CT abdomen pelvis (CT-AP) in patients with first unprovoked pulmonary embolism (PE) >40 years. This is limited to patients who have no features of cancer based on initial examination and investigation1. A previous retrospective study of patients with unprovoked PE who received CT-AP detected just 3 (4%) patients with unexpected malignancies2. This suggests that the number of new malignancies detected by CT-AP in this group is not significant and does not justify the risk of radiation exposure. Aim: To establish whether CT abdomen and pelvis detects a significant number of occult mailignancies in patients over 40 years with first unprovoked PE. Method: We performed retrospective analysis of all patients diagnosed with an unprovoked PE in a 6 month period at Wirral University Teaching Hospital. The records of 222 patients with confirmed PE were analysed to establish if the PE was unprovoked and of those to ascertain if they had had a CT-AP and if this detected malignancy. Results: 104 (47%) of the 222 patients diagnosed with PE had an unprovoked PE. 53 (51%) patients with unprovoked PE had a CT abdomen pelvis . Of these only 1 patient (1.8%) was detected to have unexpected malignancy. Conclusion: In patients with first unprovoked PE, CT abdomen and pelvis should not be performed routinely as it does not detect a significant number of underlying malignancies.