Diagnosing prosthetic vascular graft infection with the antigranulocyte antibody 99mTc-fanolesomab

Abstract

The objectives of this retrospective investigation were to determine the accuracy of 99mTc-fanolesomab, an antigranulocyte antibody, for diagnosing prosthetic vascular graft infection, ascertain optimum imaging times for this indication, and assess safety of this agent. Eighteen patients with 19 prosthetic vascular grafts were included. Indications for graft placement included peripheral vascular disease (8), haemodialysis (7), and aneurysm (4). Patients were imaged 2-5 h and 18-30 h after injection of 555-740 MBq (75-125 microg) 99mTc-fanolesomab. One experienced nuclear physician reviewed images in three separate sessions, early alone, late alone and early plus late images together. When early and late images were read alone, graft activity more intense than native blood pool activity was classified as positive for infection. When early and late images were interpreted together, graft activity which persisted or which increased in intensity over time was classified as positive for infection. Patient records were reviewed for adverse events up to 30 days after injection. Five (26%) prosthetic grafts were infected. Early, late and early plus late imaging were equally sensitive (1.00). Early images were significantly less specific (0.50), than late and early plus late images (0.93) (P<0.05, analysis of proportions). Accuracy of late imaging and early plus late imaging were the same: 0.93. No patient experienced adverse events following radiopharmaceutical injection. 99mTc-fanolesomab imaging, performed 18-30 h after injection, diagnosed prosthetic vascular graft infection safely and accurately (95%). (Although safety was not an issue in this investigation, following reports of serious, including two fatal, events after administration, 99mTc-fanolesomab was withdrawn from the United States market).