Evaluation of 18-FDG PET diagnostic capabilities for cancer screening in heart transplant patients, a retrospective study

Abstract

Evaluate 18-FDG positron emission tomography (PET) diagnostic capabilities for cancer screening in heart transplant patients. We conducted an anonymized retrospective observational study of heart transplant patients followed in the University Hospital of Montpellier, France. We analyzed 303 18-FDG PET from 158 patients. We compared demographic and clinical characteristics through uni- and multivariate analysis: in the cancer-free group, comparisons were made between the PET false positive (FP) group versus true negative (TN), and in the cancer group, comparisons were made between the PET false negative (FN) group versus true positive (TP). Out of the 303 exams, we found 245 TN, 26 TP, 26 FP and 6 FN. The sensitivity rate was calculated at 81%, the specificity rate at 90%, the positive predictive value at 50%, and the negative predictive value at 97%. The multivariate analysis showed an association between FP diagnosis and graft-PET delay (P value = .046, OR = 5.14, 95% CI [1.18–32.4]) and creatine reactive protein (CRP) ≥ 10 mg/L (P value = .042, OR = 4.21, 95% CI [1.02–17.2]). The estimated probability of FP by logit regression was 0.48 with 95% CI [0.21–0.77] when graft-PET delay ≥ 6 years and CRP ≥ 10 mg/L. No significative statistical link was found for the demographic or clinical characteristics in the FN group of patients with cancer, except for sex (all FN were men). 18-FDG PET performed very well in the follow-up of heart transplant patients for neoplasia screening, with better specificity than sensitivity. However, the study showed that almost 50% of FP can be predicted by considering only the graft-PET delay and CRP.