Treatment monitoring with (18)F-FDG PET/CT in a patient with peritoneal tuberculosis

The Value of 18F-FDG PET/CT in the Diagnosis of Tuberculous Pleurisy and in the Differential Diagnosis between Tuberculous Pleurisy and Pleural Metastasis from Lung Adenocarcinoma

Objectives

This study aims to investigate the diagnostic value of 18F-FDG PET/CT in tuberculous pleurisy (TBP) and the differential diagnostic value of 18F-FDG PET/CT between TBP and pleural metastasis from lung adenocarcinoma (PMLAC).

Materials and Methods

The features of pleura on PET and hybrid CT were retrospectively studied in 20 patients with TBP and 32 patients with PMLAC. The ROC curve was used to evaluate the diagnostic effectiveness of these indices for TBP and PMLAC, and binary logistic regression analysis was conducted to identify independent predictors of TBP and PMLAC.

Results

There were significant differences in pleural 18F-FDG uptake pattern on PET (P=0.001), pleural morphology pattern on CT (P=0.002), the maximum diameter of the pleural nodule (P=0.001), and interlobular fissure nodule (P=0.001) between TBP and PMLAC groups. The diffused pleural FDG uptake type on PET (odds ratio (OR) = 6.0, 95% CI 2.216–16.248, P=0.001) and the lamellar pleural thickening type on CT (OR = 4.4, 95% CI 2.536–7.635, P=0.001) were independent predictors of TBP, with 60% and 55% sensitivity, 96.6% and 90.6% specificity, and 82.7% and 77.0% accuracy. The combined diagnostic sensitivity, specificity, and accuracy for TBP were 70%, 87.5%, and 80.8%. The mixed pleural FDG uptake type on PET (OR = 5.106, 95% CI 2.024–12.879, P=0.001), the mixed pleural thickening type on CT (OR = 2.289, 95% CI 1.442–3.634, P=0.001), and the maximum diameter of the pleural nodule (OR = 1.027, 95% CI 1.012–1.042, P=0.001) were independent predictors of PMLAC, with 78.1%, 71.9%, and 87.5% sensitivity, 85%, 80%, and 85% specificity, and 80.8%, 75%, and 86.5% accuracy. The combined diagnostic sensitivity, specificity, and accuracy for PMLAC were 96.9%, 85%, and 90.4%.

Conclusions

18F-FDG PET/CT is of great clinical value in the diagnosis of TBP and in the differential diagnosis between TBP and PMLAC.

PET/CT for differentiating between tuberculous peritonitis and peritoneal carcinomatosis: The parietal peritoneum

OBJECTIVES

Tuberculous peritonitis (TBP) mimics peritoneal carcinomatosis (PC). We aimed to investigate the discriminative use of PET/CT findings in the parietal peritoneum.

MATERIALS AND METHODS

Parietal peritoneal PET/CT findings from 76 patients with TBP (n = 25) and PC (n = 51) were retrospectively reviewed. The lesion locations were noted as right subdiaphragmatic, left subdiaphragmatic, right paracolic gutters, left paracolic gutters, and pelvic regions. The distribution characteristic consisted of a dominant distribution in the pelvic and/or right subdiaphragmatic region (susceptible area for peritoneal implantation, SAPI) (SAPI distribution), a dominant distribution in the remaining regions (less-susceptible area for peritoneal implantation, LSAPI) (LSAPI distribution), or a uniform distribution. PET morphological patterns were classified as F18-fluorodeoxyglucose (F-FDG) uptake in a long beaded line (string-of-beads F-FDG uptake) or in a cluster (clustered F-FDG uptake) or focal F-FDG uptake. CT patterns included smooth uniform thickening, irregular thickening, or nodules.

RESULTS

More common findings in the parietal peritoneum corresponding to TBP as opposed to PC were (a) ≥4 involved regions (80.0% vs 19.6%), (b) uniform distribution (72.0% vs 5.9%), (c) string-of-beads F-FDG uptake (76.0% vs 7.8%), and (d) smooth uniform thickening (60.0% vs 7.8%) (all P < 0.001), whereas more frequent findings in PC compared with TBP were (a) SAPI distribution (78.4% vs 28.0%), (b) clustered F-FDG uptake (56.9% vs 20.0%), (c) focal F-FDG uptake (21.6% vs 4.0%), (d) irregular thickening (51.0% vs 12.0%), and (e) nodules (21.6% vs 4.0%) (P < 0.001, P < 0.05, P > 0.05, P < 0.05, P > 0.05, respectively).

CONCLUSION

Our data show that PET/CT findings in the parietal peritoneum are useful for differentiating between TBP and PC.