Hepatobiliary scintigraphy and gamma-GT levels in the differential diagnosis of extrahepatic biliary atresia.

AIM: The aim of this paper is to identify extrahepatic biliary atresia (EHBA) as the cause of cholestasis in neonates with prolonged jaundice and thus accelerate the decision for surgical intervention, which is critical for prognosis. METHODS: We retrospectively studied 21 infants (13 girls, 8 boys) aged 2-16 weeks who have undergone( 99m)Tc-mebrofenin iminodiacetate ((99m)Tc-BrIDA) scintigraphy. They were referred because of direct hyperbilirubinemia and jaundice persisting beyond the 2nd postnatal week. They had received phenobarbitone premedication prior to scintigraphy. Dynamic images for 30 min and then static images (if required) at 1, 2 and 24 h postinjection were acquired. Images were evaluated visually and semiquantitatively, by calculating the liver-to-heart (L/H) ratio. Age, L/H ratios, and serum gamma glutamyl transpeptidase (gamma-GT) levels were compared (Mann-Whitney U test) between infants with EHBA (Group A) and infants without (Group B). The L/H ratios were correlated with age in each group and with gamma-GT in the entire population. RESULTS: A total of 7/21 infants were classified in Group A and 14/21 in Group B. The L/H ratios were significantly lower in Group A. The correlation between L/H ratio and age was negative in EHBA and positive in non-atretic infants. The gamma-GT levels were inversely correlated with the L/H ratios in the entire population, being significantly higher in Group A. CONCLUSION: In long-standing neonatal direct hyperbilirubinemia, (99m)Tc-BrIDA scintigraphy and the L/H ratio index seem to give useful information in the differential diagnosis of EHBA, especially when associated with markedly elevated serum gamma-GT levels.

Value of thyroglobulin to 131I uptake ratio in selection of initial therapy dose of 131I in patients with differentiated thyroid carcinoma.

AIM: To test the hypothesis that the ratio of thyroglobulin (Tg) to 131I uptake in the thyroid bed during the immediate post-thyroidectomy work-up could be used before first 131I treatment to detect patients with residual or metastatic thyroid cancer and justify the administration of a higher ablation dose in selected cases and a possibly better therapeutic effect. METHODS: We retrospectively studied 293 patients with differentiated thyroid carcinoma that received their first 131I treatment in our department. Patients with Tg >100 ng/mL, 131I uptake >10% and measurable Tg-specific autoantibodies, were excluded. According to the post-therapy total body scan (TBS), we divided them in 2 groups: group I, without metastases (negative TBS), and group II, with metastases (positive TBS). The ratio of Tg to 131I uptake measured before the first 131I treatment was calculated in both groups. RESULTS: A total of 248 patients were included in the study; 225 in group I and 23 in group II. Tg to 131I uptake ratio was significantly lower in group I (mean 2.17 ng/mL/%, range 0-36), than in group II (mean 32.7 ng/mL/%, range 2.14-220), (P<0.01). The sensitivity, specificity and accuracy (using a threshold ratio 7 ng/mL/% as normal) were all 95.6% for predicting a positive post-therapy TBS. CONCLUSIONS: The use of a threshold ratio 7 ng/mL/% as the upper limit of normal provides useful information with higher sensitivity and specificity in identifying patients with metastatic disease creating the possibility for the selective use of higher initial iodine therapy doses.