Is CT thorax, abdomen and pelvis a useful test in patients with weight loss?

Introduction: Unintentional weight loss is an important clinical problem. The role of CT is not firmly established in the workup of these patients. The aim of this study is to determine the diagnostic yield of CT Thorax, Abdomen and Pelvis (CT TAP) in patients with unexplained weight loss and to determine whether clinical or laboratory variables are associated with positive CT findings.

Methods: A retrospective review was performed of CT TAP examinations over 12 months with weight loss as an indication. Patients' electronic records and radiology reports were reviewed. Clinical and laboratory variables were assessed for correlation with positive findings on CT.

Results: 461 CT TAP studies with weight loss as the primary indication were identified. 124 were excluded; 82 due to a recent history of malignancy, 41 because CT TAP was used for staging of a new malignancy and one study was incomplete. This left 337 eligible examinations. 217 studies had findings of no clinical relevance, 50 studies were normal, 40 studies identified a possible cause of weight loss and 30 studies identified a definite cause. Of the 40 where a possible cause was identified, further work up led to a diagnosis which explained the weight loss in 13 patients. The diagnostic yield of CT TAP was 12.8%. Age, abdominal symptoms, degree of weight loss, anaemia, tumour markers and LDH did not significantly correlate with positive findings on CT.

Conclusion: CT TAP is a helpful investigation in patients with unexplained weight loss with a diagnostic yield of 12.8%.