Katashi Satoh MD, PhD, Presenter: Nothing to Disclose

Yoshihiro Nishiyama MD, Abstract Co-Author: Nothing to Disclose

Yuka Yamamoto MD, PhD, Abstract Co-Author: Nothing to Disclose

Yasumichi Yamamoto MD, PhD, Abstract Co-Author: Nothing to Disclose

Motoomi Ohkawa MD, PhD, Abstract Co-Author: Nothing to Disclose

The increasing incidence of malignant pleural mesothelioma (MPM) often caused by prior asbestos exposure has led to the development of new therapeutic approaches and a need for new diagnostic techniques to identify the extent of the disease at an early stage. Some studies have shown that delayed scanning FDG PET may help to differentiate malignant from benign lesions. The purpose of this study was to compare the sensitivity of early and delayed FDG PET in the detection of MPM.

Thirty patients with CT evidence of pleural thickening, or fluid, entered a study to evaluate the accuracy of FDG PET in diagnosing MPM. FDG PET imaging was performed at 1 hour (early) post FDG injection and repeated 2 hours (delayed) after injection. The semi-quantitative analysis using the standardized uptake value (SUV) was determined for both early and delayed images (SUVearly and SUVdelayed, respectively). PET findings were compared with the final results, which were based on surgical pathology or repeated radiographic examinations. All semi-quantitative data were expressed as mean±SD.

Histology demonstrated the presence of MPM in 18 patients and histology and/or clinical follow-up demonstrated benign processes in the remaining 12. Two patients had MPM in bilateral sides. In diagnosing malignancy in patients with MPM, sensitivity, specificity and accuracy were 95%, 83% and 91% on both early and delayed PET, respectively. The mean SUVdelayed (9.35±7.26) in MPM was significantly higher than the mean SUVearly (7.52±5.55) (pearly (1.41±0.50) and SUVdelayed (1.51±0.60) in benign lesions. The mean value of SUVearly and SUVdelayed in MPM were significantly higher than the corresponding values in benign lesions (p<0.001, respectively).

FDG PET imaging was a sensitive method to identify MPM. Especially, the delayed FDG PET imaging is more useful than the early FDG PET imaging to evaluate malignant lesions owing to increased lesion uptake.

The delayed FDG PET imaging was a sensitive method to identify MPM.

Satoh, K, Nishiyama, Y, Yamamoto, Y, Yamamoto, Y, Ohkawa, M, Comparison of Early and Delayed FDG PET for the Evaluation of Malignant Pleural Mesothelioma.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5015064.html