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.
In 2017, the European Medicines Agency approved rituximab biosimilars (R-biosimilars) for treatment of diffuse large B-cell lymphoma (DLBCL). Thereafter, the Netherlands was one of the first countries to implement R-biosimilars, given lower costs compared with rituximab originator (R-originator). This study’s objective was to investigate whether overall survival (OS) of patients with DLBCL receiving R-biosimilars is similar to patients treated with R-originator. DLBCL patients ≥18 years, diagnosed between 2014 and 2018, who received at least 1 cycle of rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) were identified in the Netherlands Cancer Registry. Patients were categorized into R-originator or R-biosimilars groups based on data from a central repository of the Dutch medicinal drug market. The primary end point was 3-year OS, defined as the time between diagnosis and all-cause death. By the end of 2018, 91% of purchased rituximab were biosimilars. In total, 4429 patients were identified with 876 in the R-biosimilars group and 3553 in the R-originator group. Patients in the R-biosimilars group less frequently received >6 cycles of R-CHOP compared with patients treated with R-originator (24% vs 30%, P = .003). The 3-year OS did not differ between patients treated with R-originator or R-biosimilars (73% vs 73%, P = .855). This was confirmed with a multivariable Cox regression analysis accounting for sex, age, International Prognostic Index score, and number of R-CHOP cycles. In conclusion, the 3-year OS is similar for patients treated with CHOP in combination with R-originator or R-biosimilars and, therefore, favors the use of R-biosimilars in DLBCL treatment management.
Semiquantitative
18
F-fluoro-2-deoxy-D-glucose positron emission tomography (
18
F-FDG PET) parameters have been proposed as prognostic markers in classical Hodgkin lymphoma (cHL). In non-Hodgkin lymphoma necrosis as assessed by
18
F-FDG PET or computed tomography (CT) (necrosis
visual
) correlates with an adverse prognosis. We investigated whether semiquantitative
18
F-FDG PET metrics correlate with necrosis
visual
, determined the incidence of necrosis
visual
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
18
F-FDG PET and a contrast enhanced CT scan. Semiquantitative
18
F-FDG PET parameters were determined using Hermes Hybrid 3D software. Necrosis
visual
, defined by photopenic tumor areas on
18
F-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. Necrosis
visual
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 necrosis
visual
. In exploratory univariate survival analysis for PFS the covariates IPS, bulky disease, MTV and TLG were prognostic, while necrosis
visual
was not.
M. (2022). Machine learning in the differentiation of follicular lymphoma from diffuse large B-cell lymphoma with radiomic [F-18]FDG PET/CT features. European Journal of Nuclear Medicine and Molecular Imaging.
ObjectivesMYC gene rearrangements in diffuse large B cell lymphomas (DLBCLs) result in high proliferation rates and are associated with a poor prognosis. Strong proliferation is associated with high metabolic demand and tumour necrosis. The aim of this study was to investigate differences in the presence of necrosis and semiquantitative 18F-FDG PET metrics between DLBCL cases with or without a MYC rearrangement. The prognostic impact of necrosis and semiquantitative 18F-FDG PET parameters was investigated in an explorative survival analysis.MethodsFluorescence in situ hybridisation analysis for MYC rearrangements, visual assesment, semiquantitative analysis of 18F-FDG PET scans and patient survival analysis were performed in 61 DLBCL patients, treated at a single referral hospital between 2008 and 2015.ResultsOf 61 tumours, 21 (34%) had a MYC rearrangement (MYC+). MYC status was neither associated with the presence of necrosis on 18F-FDG PET scans (necrosisPET; p = 1.0) nor associated with the investigated semiquantitative parameters maximum standard uptake value (SUVmax; p = 0.43), single highest SUVmax (p = 0.49), metabolic active tumour volume (MATV; p = 0.68) or total lesion glycolysis (TLG; p = 0.62). A multivariate patient survival analysis of the entire cohort showed necrosisPET as an independent prognostic marker for disease-specific survival (DSS) (HR = 13.9; 95% CI 3.0–65; p = 0.001).ConclusionsMYC rearrangements in DLBCL have no influence on the visual parameter necrosisPET or the semi-quantiative parameters SUVmax, MATV and TLG. Irrespective of MYC rearrangements, necrosisPET is an independent, adverse prognostic factor for DSS.Key Points
• Retrospective analysis indicates that MYC rearrangement is not associated with necrosis on
18
F-FDG PET (necrosis
PET
) scans or semiquantitative
18
F-FDG PET parameters.
• Necrosis
PET
is a potential independent adverse prognostic factor for disease-specific survival in patients with DLBCL and is not influenced by the presence of MYC rearrangements.
Electronic supplementary materialThe online version of this article (10.1007/s00330-019-06178-9) contains supplementary material, which is available to authorized users.
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