title: Estimation of absolute renal uptake with technetium-99m dimercaptosuccinic acid: direct comparison with the radioactivity of nephrectomy specimens.
abstract: OBJECTIVE
  Studies using radionuclides are the most appropriate method for estimating renal function. Dimercaptosuccinic acid chelate labeled with technetium-99m (99mTc-DMSA) is the radiopharmaceutical of choice for high-resolution imaging of the renal cortex and estimation of the functional renal mass. The aim of this study was to evaluate a simplified method for determining the absolute renal uptake (ARU) of 99mTc-DMSA prior to nephrectomy, using the radioactivity counts of nephrectomy specimens as the gold standard.
  
  
  METHODS
  Prospective study at the Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas.
  
  
  METHODS
  Seventeen patients (12 females; range 22-82 years old; mean age 50.8 years old) underwent nephrectomy for various reasons. Renal scintigraphy was performed three to four hours after intravenous administration of a mean dose of 188.7 MBq (5.1 mCi) of 99mTc-DMSA, which was done six to 24 hours before surgery. The in vivo renal uptake of 99mTc-DMSA was determined using the radioactivity of the syringe before the injection (measured using a dose calibrator) and the images of the syringe and kidneys, obtained from a scintillation camera. After surgery, the reference value for renal uptake of 99mTc-DMSA was determined by measuring the radioactivity of the nephrectomy specimen using the same dose calibrator.
  
  
  RESULTS
  The ARU measurements were very similar to those obtained using the reference method, as determined by linear regression (r-squared = 0.96).
  
  
  CONCLUSIONS
  ARU estimation using the proposed method before nephrectomy seems to be accurate and feasible for routine use.
authors: Division of Nuclear Medicine, Department of Radiology, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil. mailto:mar.lima@terra.com.br
authors: Mariana da Cunha
authors: Mda C
authors: Lopes de Lima
authors: Celso Darío
authors: CD
authors: Ramos
authors: Sérgio Quirino
authors: SQ
authors: Brunetto
authors: Marcelo
authors: M
authors: Lopes de Lima
authors: Ubirajara
authors: U
authors: Ferreira
authors: Elba Cristina
authors: EC
authors: Sá Camargo Etchebehere
authors: Allan de Oliveira
authors: Ade O
authors: Santos
authors: Nelson
authors: N
authors: Rodrigues Netto Júnior
authors: Edwaldo Eduardo
authors: EE
authors: Camargo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000502:physiology; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D007677:Kidney Function Tests; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid