Aim: To evaluate the diagnostic value of PET-CT for predicting peritoneal metastasis of abdominal malignancies.
Methods: One hundred fifty four (154) cases of malignant tumor, including 141 cases of gastric cancer, 9 cases of colon cancer, 2 cases of ovary cancer, and 2 cases of pseudomyxoma, had accepted PET CT from Nov. 2002 to Jan. 2006. One hundred twenty three (123) had also accepted high speed spiral CT (HSSCT) as control. The results were compared with peritoneal lavage, pathological examination and clinical manifestation.
Results: The accuracy of PET-CT for peritoneal metastasis was 87.7%, with sensitivity 72.7%, specificity 93.6%, PPV 82.1% and NPV 89.6%. HSSCT showed an accuracy of 79.7%, sensitivity 47.4%, specificity 94.1%, PPV 78.3%, and NPV 80.0%. PET-CT had significantly better sensitivity than HSSCT (p < 0.05). For gastric cancer patients alone, PET CT had an accuracy of 87.9%, sensitivity 74.4%, specificity 93.1%, PPV 80.6% and NPV 90.5%, significantly better than HSSCT's 78.1, 39.4, 93.8, 72.2, and 79.2% (p < 0.01), respectively. In case of Cy1P0, PET-CT showed a seemingly better sensitivity of 53.3% vs. 13.3% of HSSCT, although not statistically significant because of the number of observations (p = 0.053). And in P1 cases, PET-CT and HSSCT manifested sensitivity of 84.2% vs 63.2%, respectively, without significance (p = 0.141).
Conclusion: PET-CT is useful in predicting peritoneal metastasis of malignancies.