Analysis of Positive Results of 18F-FDG PET/CT Imaging after Hematopoietic Stem Cell Transplantation in Lymphoma

• Published in: Diagnostics (Basel) Vol. 13; no. 12; p. 2027
• Main Authors: Dai, Na, Cai, Rongcui, Deng, Shengming, Sang, Shibiao
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 11.06.2023; MDPI
• Subjects: Deauville score; false-positive FDG uptake; Glucose; Lymphoma; Medical imaging; Medical prognosis; Patients; post-transplantation 18F-FDG PET/CT; Regression analysis; SCT; Stem cell transplantation; Tomography
• ISSN: 2075-4418; 2075-4418
• DOI: 10.3390/diagnostics13122027

Purpose: The purpose of this study was to differentiate between false-positive and true-positive positron emission tomography (PET) results after hematopoietic stem cell transplantation (SCT) for lymphoma involvement by analyzing several clinical variables and specific imaging features. Patients and Methods: Patients with lymphoma who received SCT and underwent post-transplantation 18F-FDG PET/CT scans between January 2013 and April 2021 at our institution were included. Associations between PET positivity and related clinical information were assessed using t-tests and χ2 tests. The significance of variables differentiating benign lesions from malignant FDG-avid lesions was evaluated by logistic regression analysis. Survival probabilities were derived from Kaplan-Meier curves and compared using the log-rank test. Results: A total of 185 patients (235 post-transplantation PET/CT scans) were enrolled in our present study. Compared with those with true-positive PET results, patients with false-positive PET results exhibited a better prognosis. For the autologous SCT group, false-positive cases were more commonly seen when FDG-avid foci appeared outside the sites of the original disease (p = 0.004), and the integrated CT imaging showed negative results (p = 0.000). In multivariate logistic regression analysis, integrated CT results were the only significant factor. For the allogeneic SCT group, false-positive cases were significantly more commonly seen when DS = 4 (p = 0.046), FDG-avid foci appeared outside the sites of the original disease (p = 0.022), and the integrated CT imaging showed negative results (p = 0.001). In a multivariate logistic regression analysis, whether FDG-avid foci were in the sites of the original disease and integrated CT results were both significant factors. Conclusion: False-positive FDG uptake in post-transplantation PET was not uncommon. Several variables could provide an important reference to differentiate false-positive from true-positive post-SCT PET results for lymphoma involvement. Trial registration number: ChiCTR2300067355.