title: Utility of ⁹⁹mTc-human serum albumin diethylenetriamine pentaacetic acid SPECT for evaluating endoleak after endovascular abdominal aortic aneurysm repair.
abstract: OBJECTIVE
  The purpose of this study was to assess the utility of (99m)Tc-human serum albumin diethylenetriamine pentaacetic acid ((99m)Tc-HSAD) SPECT in the detection of endoleaks after endovascular abdominal aortic aneurysm repair.
  
  
  METHODS
  Fifteen patients (11 men, four women) with aneurysm sac expansion of 5 mm or greater after endovascular abdominal aortic aneurysm repair underwent three-phase CT, (99m)Tc-HSAD SPECT, and CT during aortography. Sensitivity calculations for three-phase CT and (99m)Tc-HSAD SPECT were performed with CT during aortography as the reference standard. The volume of each endoleak was measured with CT during aortography. Seven subjects underwent embolization with N-butyl cyanoacrylate (NBCA)-Lipiodol (ethiodized oil, Guerbet and metallic coils. Three-phase CT and (99m)Tc-HSAD SPECT were repeated after embolization to assess their efficacy.
  
  
  RESULTS
  Endoleaks were interpreted as perigraft radioisotope accumulation in 12 patients (80.0%) on (99m)Tc-HSAD SPECT images, in 13 patients (86.7%) on three-phase CT images, and in 15 patients (100%) on CT during aortography. The mean endoleak volume visualized with (99m)Tc-HSAD SPECT was 8.37 cm(3) (range, 5.2-15.1 cm(3)), and the volume not visualized was 3.47 cm(3) (2.5-4.6 cm(3)), a statistically significant difference (p = 0.019). In two patients, (99m)Tc-HSAD SPECT depicted endoleaks evident at delayed phase CT during aortography but not at three-phase CT, suggesting they were slow-filling endoleaks. Accumulation of (99m)Tc-HSAD corresponding to endoleaks disappeared after embolization, but CT evaluation of embolization was impeded by artifacts of NBCA-Lipiodol and metallic coils.
  
  
  CONCLUSIONS
  Technetium-99m-labeled HSAD SPECT proved less sensitive than three-phase CT but depicted endoleaks with volumes 5.2 cm(3) or greater as perigraft radioisotope accumulation. Slow-filling endoleaks can be visualized with (99m)Tc-HSAD SPECT, which can be used to evaluate the efficacy of embolization.
authors.affiliation: 1 Department of Radiology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-shi, Wakayama 641-8510, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Nakai
authors.forename: Hirotatsu
authors.initials: H
authors.lastname: Sato
authors.forename: Morio
authors.initials: M
authors.lastname: Sato
authors.forename: Akira
authors.initials: A
authors.lastname: Ikoma
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Sonomura
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Okamura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D057867:Endoleak / Q000000981:diagnostic imaging* / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents / Q000009:adverse effects*; D013668:Technetium Tc 99m Aggregated Albumin; D016284:Technetium Tc 99m Pentetate; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; C057162:technetium Tc 99m DTPA HSA; D016284:Technetium Tc 99m Pentetate
keywords: 99mTc-HSAD; abdominal aortic aneurysm; embolization; endoleak; endovascular abdominal aortic aneurysm repair