title: The Clinical Usefulness of (99m)Tc HMPAO Leukocyte/(99m)Tc Phytate Bone Marrow Scintigraphy for Diagnosis of Prosthetic Knee Infection: A Preliminary Study.
abstract: OBJECTIVE
  The preferred radionuclide imaging procedure for diagnosing prosthetic joint infection is combined radiolabeled leukocyte/(99m)Tc sulfur colloid bone marrow scintigraphy, which has an accuracy of over 90 %. Unfortunately, sulfur colloid is no longer available in South Korea. In this study, we evaluated the usefulness of (99m)Tc phytate, a substitute for (99m)Tc sulfur colloid, when combined with radiolabeled leukocyte scintigraphy in suspected prosthetic knee infections.
  
  
  METHODS
  Eleven patients (nine women, two men; mean age 72 ± 6 years) with painful knee prostheses and a suspicion of infection underwent both (99m)Tc HMPAO leukocyte scintigraphy (LS) and (99m)Tc phytate bone marrow scintigraphy (BMS). The combined images were interpreted as positive for infection when radioactivity in the LS at the site of clinical interest clearly exceeded that of the BMS (discordant); they were interpreted as negative when the increased activity in the LS was consistent with an increased activity in the BMS (concordant). The final diagnosis was made with microbiological or intraoperative findings and a clinical follow-up of at least 12 months.
  
  
  RESULTS
  Five of eleven patients were diagnosed as having an infected prosthesis. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the combined LS/BMS were 100 %, 83 %, 83 %, 100 % and 91 %, respectively.
  
  
  CONCLUSIONS
  We find that combined (99m)Tc HMPAO LS/(99m)Tc phytate BMS shows comparable diagnostic performance to other studies utilizing sulfur colloid. Combined (99m)Tc HMPAO LS/(99m)Tc phytate BMS is therefore expected to be an acceptable alternative to combined radiolabeled LS/(99m)Tc sulfur colloid BMS for diagnosing prosthetic knee infections.
authors.affiliation: Department of Nuclear Medicine, Inje University, Pusan Paik Hospital, 633-165 Gaegum-Dong, Pusan jin-Gu, Pusan South Korea.
authors.forename: Kyung Pyo
authors.initials: KP
authors.lastname: Jung
authors.affiliation: Department of Nuclear Medicine, Inje University, Pusan Paik Hospital, 633-165 Gaegum-Dong, Pusan jin-Gu, Pusan South Korea.
authors.forename: Ji Sun
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Nuclear Medicine, Inje University, Pusan Paik Hospital, 633-165 Gaegum-Dong, Pusan jin-Gu, Pusan South Korea.
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Inje University, Pusan Paik Hospital, 633-165 Gaegum-Dong, Pusan jin-Gu, Pusan South Korea.
authors.forename: Su Jung
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Nuclear Medicine, Inje University, Pusan Paik Hospital, 633-165 Gaegum-Dong, Pusan jin-Gu, Pusan South Korea.
authors.forename: Seok Mo
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Inje University, Pusan Paik Hospital, 633-165 Gaegum-Dong, Pusan jin-Gu, Pusan South Korea.
authors.forename: Sang Kyun
authors.initials: SK
authors.lastname: Bae
keywords: 99mTc HMPAO leukocyte scintigraphy; 99mTc phytate; Bone marrow scintigraphy; Prosthetic knee infection