18F FDG PET/CT in the management of patients with post-transplant lymphoproliferative disorder

Objectives Post-transplant lymphoproliferative disorder (PTLD) is a rare but serious complication in transplant patients. While 18F FDG PET/CT has been used for the evaluation of patients with PTLD, its utility has yet to been proven. We were therefore prompted to review our experience with 18F FDG PET/CT in PTLD.

Methods We retrospectively reviewed the records of 28 consecutive patients who had undergone 18F FDG PET/CT imaging for PTLD from 1/2004 to 7/2011 at our isntitution. 18F FDG PET/CT findings were compared to other imaging modalities performed concurrently and a chart review of pertinent information was performed.

Results There were 14 women and 14 men, 2-70 year-old (average: 23.5 years). 23 had biopsy proven PTLD; 2 were treated as having disease due to positive 18F FDG PET/CT findings despite lack of biopsy proof; and 3 had PTLD excluded due to negative 18F FDG PET/CT findings. 84% of the patients with PTLD had extra-nodal involvement. In 70% of the cases, PET/CT detected occult or suggested malignancy in lesions equivocal on other scans. Furthermore, the more aggressive PTLD subtype had significantly higher SUVmax values compared to the less aggressive forms, 11.2 ± 7.8 versus 4.5 ± 3.2 respectively (P: 0.004).

Conclusions Our study suggests that 18F FDG PET/CT is beneficial in the management of patients with PTLD as both nodal and extra-nodal lesions demonstrated intense 18F FDG uptake. A potential benefit of 18F FDG PET/CT is its ability to detect occult lesions not visualized on other imaging modalities, particularly extra-nodal lesions. In addition, 18F FDG PET/CT may identify PTLD subtypes, as the more aggressive subtype cases presented with extra-nodal disease and had higher SUVmax values compared to the less aggressive ones