Evaluation of Sternal Wound Infection after Median Sternotomy Using 99mTc-Labeled Ubiquicidin 29-41

Previous studies have demonstrated that 99mTc-labeled Ubiquicidin 29-41 (99mTc-UBI) can be used for the detection of bacterial infections as an accurate method.1 This study was conducted to evaluate the clinical use of 99mTc-UBI for the evaluation of sternal wound infection (SWI) after cardiac surgery. Twenty-one patients with suspected SWI after median sternotomy were included. Qualitative and quantitative voxel-based analyses of 99mTc-UBI images were performed by two experienced nuclear physicians and the images were reported as negative, positive for superficial, or positive for deep SWI on the basis of the uptake patterns. SWI was defined according to the Centres for Disease Control and Classifications’ guideline. Among the cases, only one subject with a final diagnosis of non-infectious inflammation was reported as superficial SWI in 99mTc-UBI scintigraphy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for distinguishing SWI from sterile inflammation were equal to 100%, 83.3%, 93.8%, and 100%. After implicating a threshold of 3.08 for the target-to-background ratio, the specificity and PPV reached 100%. The sensitivity, specificity, positive, and negative predictive values for the detection of superficial and deep SWI were 100%, 92.9%, 87.5%, and 100% and 100%, 100%, 100%, and 100%, respectively. There was also a high interobserver agreement with all the kappa values exceeding 0.8. The results of the present study suggest that 99mTc-UBI could be of great use as an accurate method for the evaluation of suspected postoperative SWI and could help in the selection of appropriate treatment strategies for these patients.