Diagnostic performance of FDG-PET/CT of post-transplant lymphoproliferative disorder and factors affecting diagnostic yield.

PURPOSE: Post-transplant lymphoproliferative disorder (PTLD) is a serious complication after solid organ and hematopoietic stem cell transplantation, requiring a timely and accurate diagnosis. In this study, we evaluated the diagnostic performance of FDG-PET/CT in patients with suspected PTLD and examined if lactate dehydrogenase (LDH) levels, Epstein-Barr virus (EBV) load, or timing of FDG-PET/CT relate to detection performance of FDG-PET/CT. METHODS: This retrospective study included 91 consecutive patients with clinical suspicion of PTLD and a total of 97 FDG-PET/CT scans within an 8-year period. Pathology reports and a 2-year follow-up were used as the reference standard. Diagnostic performance of FDG-PET/CT for detection of PTLD as well as logistic regression analysis for factors expected to affect diagnostic yield were assessed. RESULTS: The diagnosis of PTLD was established in 34 patients (35%). Fifty-seven FDG-PET/CT scans (59%) were true negative, 29 (30%) were true positive, 6 (6%) false positive, and 5 (5%) false negative. Sensitivity of FDG-PET/CT for the detection of PTLD was 85%, specificity 90%, positive predictive value 83%, and negative predictive value 92%, with good inter-observer variability (k = 0.78). Of the parameters hypothesized to be associated with a true positive FDG-PET/CT result for the diagnosis of PTLD, only LDH was statistically significant (OR 1.03, p = 0.04). CONCLUSION: FDG-PET/CT has a good diagnostic performance in patients suspected of PTLD, with a good inter-observer agreement. Only LDH levels seemed to influence the detection performance of FDG-PET/CT. EBV-DNA load and timing of FDG-PET/CT after transplantation did not affect FDG-PET/CT diagnostic yield.

Relationship between semiquantitative 18F-fluorodeoxyglucose positron emission tomography metrics and necrosis in classical Hodgkin lymphoma.

Semiquantitative 18F-fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG PET) parameters have been proposed as prognostic markers in classical Hodgkin lymphoma (cHL). In non-Hodgkin lymphoma necrosis as assessed by 18F-FDG PET or computed tomography (CT) (necrosisvisual) correlates with an adverse prognosis. We investigated whether semiquantitative 18F-FDG PET metrics correlate with necrosisvisual, determined the incidence of necrosisvisual and explored the prognostic impact of these factors in cHL. From 87 cHL cases treated with ABVD, (escalated) BEACOPP or CHOP chemotherapy between 2010 and 2017, 71 had both a NEDPAS/EARL accredited 18F-FDG PET and a contrast enhanced CT scan. Semiquantitative 18F-FDG PET parameters were determined using Hermes Hybrid 3D software. Necrosisvisual, defined by photopenic tumor areas on 18F-FDG PET and attenuation values between 10 and 30 Hounsfield units (HUs) on CT, was assessed blinded to outcome. Univariate Cox regression survival analyses of progression free survival (PFS) were performed. Necrosisvisual was observed in 18.3% of cHL patients. Bulky disease (tumor mass >10 cm in any direction) (P = 0.002) and TLG (P = 0.041) but no other semiquantitative parameters were significantly associated with necrosisvisual. In exploratory univariate survival analysis for PFS the covariates IPS, bulky disease, MTV and TLG were prognostic, while necrosisvisual was not.

Performance of advanced imaging modalities at diagnosis and treatment response evaluation of patients with post-transplant lymphoproliferative disorder: A systematic review and meta-analysis.

INTRODUCTION AND AIM: Post-transplant lymphoproliferative disorder (PTLD) is a serious complication after solid organ and hematopoietic stem cell transplantation, associated with significant morbidity and mortality. In this systematic review we evaluated the clinical performance of advanced imaging modalities at diagnosis and treatment response evaluation of PTLD patients after solid organ and hematopoietic stem cell transplantation. METHODS: We have carried out a literature search until December 15, 2017 using PubMed/Medline, Embase, "Web of Science" and Cochrane Library databases concerning the performance of computed tomography (CT), magnetic resonance imaging (MRI) and 18F-flurodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) at diagnosis or treatment response evaluation of PTLD patients. RESULTS: A total of 11 studies were included comprising 368 patients, from which FDG-PET(/CT) was the primary imaging modality investigated. The methodological quality according to QUADAS-2 of the reviewed studies was moderate-poor. Subgroup analysis of imaging results for detection and staging in patients with PTLD indicated that FDG-PET/(CT) identified additional lesions not detected by CT and/or MRI in 27.8%, (95% confidence interval [95%CI]) 17.0%-42.0% (I2 = 51.1%), from which extra-nodal sites in 23.6% (95%CI: 7.9%-52.4%) (I2 = 76.6%). False negative results occurred in 11.5% (95%CI: 4.9%-24.5%) (I2 = 73.4%), predominantly in physiological high background activity regions and in early PTLD lesions. False positive results occurred in 4.8% (95%CI: 2.6%-8.6%) (I2 = 0%) predominantly due to inflammatory conditions. Subgroup analysis of imaging results at treatment response evaluation indicated that FDG-PET(/CT) findings altered or guided treatment in 29.0% (95%CI: 14.0%-50.5%) (I2 = 40.1%). False positive results during treatment response evaluation were reported in 20.0% (95%CI: 10.7%-34.2%) (I2 = 0%), predominantly due to inflammatory conditions. CONCLUSION: FDG-PET(/CT) is currently the most frequently investigated imaging modality in PTLD patients. Available studies report promising results in detection, staging and therapy evaluation but suffer from methodological shortcomings. Concerns remain with regard to occurrence of false negatives due to physiological high background activity and early PTLD lesions as well as false positives due to inflammatory conditions.

Randomized, double-blind, placebo-controlled, dose- ranging study of granulocyte-macrophage colony stimulating factor in patients with chronic venous leg ulcers.

Chronic venous leg ulcers are a common ailment with no ideal treatment. Recent reports have shown granulocyte- macrophage colony stimulating factor to be of use in the healing of these chronic wounds. Therefore, we conducted a double-blind, randomized, placebo-controlled study which enrolled 60 patients with chronic venous leg ulcers, whom we treated with placebo or with 200 or 400 microg of granulocyte-macrophage colony stimulating factor by perilesional injections of the drug in four weekly treatment episodes. Observations were conducted at each treatment visit, at weeks 5, 9, 13, and six months after the inclusion in the protocol. The number of healed wounds in the placebo and the treated arms were significantly different (p = 0.05), with 4 of 21 (19%) in the first group having healed at week 13, as compared to 12 of 21 (57%) and 11 of 18 (61%), in the 200 microg and the 400 microg groups, respectively. There were only minor side-effects attributable to the treatment, and the reobservation at 6 months showed that none of the treated ulcers recurred during that period. We conclude that granulocyte-macrophage colony stimulating factor injected perilesionally may be a useful drug for the treatment of chronic venous leg ulcers.

Double-blind randomized placebo-controlled trial of the use of granulocyte-macrophage colony-stimulating factor in chronic leg ulcers.

BACKGROUND: Following encouraging reports on the use of granulocyte-macrophage colony-stimulating factor (GM-CSF) to treat wounds in animals and in man, we conducted a study to test the usefulness of this drug in patients with chronic leg ulcers. METHODS: Patients received a single perilesional injection of GM-CSF, the effect of which was observed weekly and compared with that of a placebo injection in a control group. RESULTS: Treated patients fared much better than controls, prompting an early termination of the study: of 16 GM-CSF treated patients, 3 (19%) had their ulcers healed by week 1; 8 (50%) were healed by week 8; only 1 of 9 controls had the ulcer healed by week 1 (11%), and that was the only ulcer of the group that healed at all. We observed no significant side effects or changes in the hematological and biochemical parameters studied. CONCLUSION: GM-CSF seems a very useful drug for the healing of leg ulcers.