In this post I link to and excerpt from Diagnostic utility of whole body CT scanning in patients with unexplained weight loss [PubMed Abstract] [Full Text HTML] [Full Text PDF]. PLoS One. 2018 Jul 27;13(7):e0200686. doi: 10.1371/journal.pone.0200686. eCollection 2018.
Unexplained weight loss is a non-specific complaint with myriad potential etiologies.
Increasingly, whole body CT studies are being performed in patients with unexplained
weight loss to exclude organic etiologies such as malignancy. Our study aims to assess the
diagnostic accuracy and yield of whole body CT in these patients.
Methods and materials
Patients who had a whole body CT scan* for investigation of unexplained weight loss as their
primary complaint from 2009–2012 were retrospectively reviewed. CT scans were classified
into 4 categories: (1) Definite/highly suspicious for underlying organic cause (2) Indeterminate for underlying organic cause (3) No findings accounting for weight loss and only incidental findings and (4) Normal study. Scan findings were correlated with the final diagnosis after all investigations. Univariate logistic regression was performed to determine associations between patient’s baseline variables and positive CT scan findings.
*All patients more than 18 years of age referred to our university hospital’s radiology department for a whole body CT scan (defined as a contrast enhanced CT of the thorax, abdomen and pelvis) from 1st January 2009 to 31st December 2012 for unexplained weight loss were included. Patients with (i) unenhanced or technically inadequate scans (ii) history of previous/known malignancy and (iii) less than 6 months of follow-up after negative investigations were excluded.
Of 301 eligible patients during the study period, 101 patients were excluded due to known history of malignancy, inadequate follow-up or inadequate scan technique. 200 patients were
included in the final analyses. The sensitivity, specificity, positive predictive value, negative
predictive value and accuracy of CT for organic pathology were 72.0%, 90.7%, 87.0%, 78.9%
and 82.0% respectively. Additional symptoms, abnormal physical examinations, anemia, and
raised tumor markers were significantly correlated with positive CT findings. Overall, the diagnostic yield of whole body CT scan for patients with unexplained weight loss was 33.5%.
Whole body CT imaging may be a useful investigation for the noninvasive workup of patients
with unexplained weight loss, with diagnostic yield of 33.5% and good sensitivity, specificity,
positive and negative predictive values for organic etiologies.