Background and Aims: We evaluated the usefulness of Positon Emission Tomography (PET) with two tracers, 11C-Acetate and 18FFluorodeoxyglucose (FDG), for differentiating focal nodular hyperplasia (FNH), that is managed conservatively, from hepatic adenoma (HA) that needs to be resected. Methods: We prospectively enrolled 30 patients with known or suspected FNH or HA. The diagnostic work-up included Doppler ultrasonography (US), contrast enhanced computed tomography (CT) and/or magnetic resonance imaging (MRI). Fine needle biopsy (FNB) was performed if imaging study was inconclusive. All patients underwent double tracer PET with a single day protocol. The images were acquired with a PET-CT tomograph to obtain image fusion. The tracer uptake was evaluated using the maximum standardized uptake value (SUVmax). The target to background (T/B) ratio was also calculated. Lesions <1 cm were excluded from the analysis owing to the low accuracy of imaging techniques for such small lesions. This selection limited the analysis to 35 FNH and 4 HA. Results: Twenty-five patients had a definitive diagnosis by mean of unequivocal imaging features at conventional techniques. In 5 patients diagnosis was established by mean of histological data. Final diagnosis was FNH in 24 patients (35 lesions), HA in 4 patients (4 lesions); one patient had hepatocellular carcinoma (HCC) and one had metastasis of unknown origin. 31/35 FNH (88.6%) showed intense 11C-Acetate uptake and physiological 18F-FDG liver uptake. Of the remaining 4 FNH, 1 was missed by both tracers, and 3 lesions trapped both tracers. 3/4 HA showed pathological uptake of both tracers; one HA was negative at both tracers. The 2 missed lesions (1 FNH and 1 HA) occurred in severely steatotic livers. Double tracer PET succeeded in distinguishing between FNH and HA in 34/39 lesions (87.2%) and in 25/28 patients (89.3%). HCC showed a complementary uptake of both tracers. Metastasis trapped only 18F-FDG. Conclusions Intense uptake of 11C-Acetate and normal uptake of 18FFDG seems to be the typical uptake pattern of FNH while HA shows pathological uptake of both tracers. Our preliminary results suggest that double tracer PET can be included among the imaging techniques able to differentiate FNH from HA
Magini G, F.M. (2008). Differential diagnosis between focal nodular hyperplasia and hepatocellular adenoma: Potential role of double tracer PET with 11C-Acetate and 18F-FDG. JOURNAL OF HEPATOLOGY, 48(2), 153-153.
Differential diagnosis between focal nodular hyperplasia and hepatocellular adenoma: Potential role of double tracer PET with 11C-Acetate and 18F-FDG
Magini G
;Frigerio M;Farsad M;Serra C;Jovine E;Vivarelli M;Feletti V;Golfieri R;Fanti S;Bernardi M;Trevisani F
2008
Abstract
Background and Aims: We evaluated the usefulness of Positon Emission Tomography (PET) with two tracers, 11C-Acetate and 18FFluorodeoxyglucose (FDG), for differentiating focal nodular hyperplasia (FNH), that is managed conservatively, from hepatic adenoma (HA) that needs to be resected. Methods: We prospectively enrolled 30 patients with known or suspected FNH or HA. The diagnostic work-up included Doppler ultrasonography (US), contrast enhanced computed tomography (CT) and/or magnetic resonance imaging (MRI). Fine needle biopsy (FNB) was performed if imaging study was inconclusive. All patients underwent double tracer PET with a single day protocol. The images were acquired with a PET-CT tomograph to obtain image fusion. The tracer uptake was evaluated using the maximum standardized uptake value (SUVmax). The target to background (T/B) ratio was also calculated. Lesions <1 cm were excluded from the analysis owing to the low accuracy of imaging techniques for such small lesions. This selection limited the analysis to 35 FNH and 4 HA. Results: Twenty-five patients had a definitive diagnosis by mean of unequivocal imaging features at conventional techniques. In 5 patients diagnosis was established by mean of histological data. Final diagnosis was FNH in 24 patients (35 lesions), HA in 4 patients (4 lesions); one patient had hepatocellular carcinoma (HCC) and one had metastasis of unknown origin. 31/35 FNH (88.6%) showed intense 11C-Acetate uptake and physiological 18F-FDG liver uptake. Of the remaining 4 FNH, 1 was missed by both tracers, and 3 lesions trapped both tracers. 3/4 HA showed pathological uptake of both tracers; one HA was negative at both tracers. The 2 missed lesions (1 FNH and 1 HA) occurred in severely steatotic livers. Double tracer PET succeeded in distinguishing between FNH and HA in 34/39 lesions (87.2%) and in 25/28 patients (89.3%). HCC showed a complementary uptake of both tracers. Metastasis trapped only 18F-FDG. Conclusions Intense uptake of 11C-Acetate and normal uptake of 18FFDG seems to be the typical uptake pattern of FNH while HA shows pathological uptake of both tracers. Our preliminary results suggest that double tracer PET can be included among the imaging techniques able to differentiate FNH from HAI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
