Technetium-99m-L,L-Ethylenedicysteine Is More Effective Than Technetium-99m Diethylenetriamine Penta-acetic Acid for Excluding Obstruction in Patients With Pyelocalicinal Dilation

Lima, Mariana C.L.; de Lima, Marcelo Lopes; Pepe, Carlos F.V.; Etchebehere, Elba C.S.C.; Santos, Allan O.; Amorim, Bárbara J.; Camargo, Edwaldo E.; Ferreira, Ubirajara; Palma, Paulo C.R.; Ramos, Celso D.

doi:10.1016/j.urology.2009.12.032

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Volume 76, Issue 2 , Pages 283-288, August 2010

Technetium-99m-L,L-Ethylenedicysteine Is More Effective Than Technetium-99m Diethylenetriamine Penta-acetic Acid for Excluding Obstruction in Patients With Pyelocalicinal Dilation

Mariana C.L. Lima
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Reprint requests: Mariana C. L. Lima, M.D., Serviço de Medicina Nuclear Av. Zeferino Vaz, s/n, Caixa Postal 6142, Campinas/SP–Brazil, CEP 13081-970
Marcelo Lopes de Lima
- Division of Urology, Department of Surgery, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Carlos F.V. Pepe
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Elba C.S.C. Etchebehere
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Allan O. Santos
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Bárbara J. Amorim
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Edwaldo E. Camargo
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Ubirajara Ferreira
- Division of Urology, Department of Surgery, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Paulo C.R. Palma
- Division of Urology, Department of Surgery, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Celso D. Ramos
- Division of Nuclear Medicine, Department of Radiology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil

Received 29 November 2009; accepted 20 December 2009. published online 08 March 2010.

Objective

To evaluate the utility of diuretic dynamic renal scintigraphy (DDRS) with technetium-99m-L,L-ethylenedicysteine (^99mTc-EC) in patients with indeterminate or possible false-positive results for urinary obstruction by technetium-99m diethylenetriamine penta-acetic acid (^99mTc-DTPA) DDRS.

Methods

A total of 92 patients (63 male; mean age, 16.6 ± 21.25 years) were studied, with a total of 103 kidneys presenting indeterminate (20/103) or possible false-positive results for obstruction attributable to reduced renal function or severe kidney dilation (83/103) by ^99mTc-DTPA DDRS (<60% of radiopharmaceutical excreted in 20 minutes—half-time clearance [T½] >15 minutes). Patients were reimaged after intravenous injection of ^99mTc-EC, with dynamic images before and after furosemide administration using the same acquisition parameters applied in the previous ^99mTc-DTPA study. Time interval between ^99mTc-DTPA and ^99mTc-EC renograms was 2-64 days. The percentage of excreted material 20 minutes after furosemide was calculated using both radiopharmaceuticals, and were statistically compared using the paired samples t test.

Results

The excretion after furosemide injection was 25.3% ± 18.2% for ^99mTc-DTPA and 41.2% ± 26.1% for ^99mTc-EC, with a statistically significant difference between both radiopharmaceuticals (P <.0001). Using ^99mTc-EC obstruction was excluded in 36 of 103 kidneys, which excreted >60%. A total of 10 of 83 kidneys (12.0%) with an obstructive pattern by ^99mTc-DTPA study turned out to be indeterminate by ^99mTc-EC DDRS. There was an agreement between ^99mTc-EC and ^99mTc-DTPA studies in 54 of 83 kidneys with obstructive (65.1%) and in 3 of 20 (15.0%) with indeterminate patterns.

Conclusions

^99mTc-EC was more effective than ^99mTc-DTPA for excluding obstruction, presenting less false-positive and indeterminate results. ^99mTc-EC can substitute ^99mTc-DTPA to evaluate patients with urinary tract dilation.