[The relation between serum levels of calcium and PTH and the positivity of parathyroid scintigraphy with sestamibi--analysis of 194 patients].
To correlate PTH and calcium serum levels with the percentages of positive results on the parathyroid scintigraphy, we retrospectively analyzed 194 patients who performed parathyroid scintigraphy. The distribution of the parathyroid scintigraphy results was visually analyzed in a scatter plot, being calcium (Y axis) and PTH (X axis) serum levels the axes. Six groups of patients were defined: 1) calcium > or = 12 mg/dL; 2) 11 mg/dL calcium < 12 mg/dL; 3) 9.9 mg/dL < or = calcium < 11 mg/dL with PTH > 120 pg/mL; 4) 9.9 mg/dL < or = calcium < 11 mg/dL with 65 pg/mL < PTH < or = 120 pg/mL; 5) 9.9 mg/dL < or = calcium < 11 mg/dL with PTH < or = 65 pg/mL; and 6) calcium < 9.9 mg/dL. The percentage of positive scintigraphy in these groups were respectively: 10/10 (100%), 18/29 (62%), 7/9 (78%), 18/45 (40%), 2/21 (10%) and 1/80 (1%). We conclude that in patients with suspected primary hyperparathyroidism, parathyroid scintigraphies performed before surgery on those with calcium level above 11 mg/dL are frequently positive. In patients with calcium levels between 9.9 mg/dL and 11 mg/dL the pertinence of performing the scintigraphy will depend on the PTH levels, and it will be high for patients with PTH serum level above 120 pg/mL and very low for patients with PTH level below 65 pg/mL. Patients with calcium level below 9.9 mg/dL rarely present positive results on parathyroid scintigraphies.
Centro de Medicina Diagnóstica, Instituto Fleury, São Paulo, SP. paulo.duarte@fleury.com.br
Paulo Schiavon
PS
Duarte
Helena H
HH
Decker
Flávia C
FC
Aldighieri
Cynthia
C
Brandão
Gilberto
G
Alonso
José Gilberto H
JG
Vieira
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood*; D003404:Creatinine / Q000097:blood; D005260:Female; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi
D015415:Biomarkers; C470125:PTH protein, human; D010281:Parathyroid Hormone; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D003404:Creatinine; D002118:Calcium