Distribution and predictors of F-18-FDG uptake values of non-malignant cervical lymph nodes in pediatric patients.

BACKGROUND: F-18-flurodeoxyglucose (FDG) PET/CT is routinely used for staging, evaluation of response to treatment and follow-up of most pediatric malignancies. Cervical lymph nodes can be involved in some pediatric malignancies, but increased uptake in non-malignant cervical lymph nodes is not exceptional in this population. The aim of the present study is to identify predictors of the maximum uptake in non-malignant cervical lymph nodes in the pediatric population. METHODS: 191 FDG PET/CT studies of pediatric patients without malignant involvement of cervical lymph nodes were retrospectively reviewed. The maximal Standard Uptake Value in the hottest cervical lymph node (SUVmaxCLN), as well as demographic, technical and imaging variables were recorded. The predictive effect of those variables on SUVmaxCLN was estimated using linear regression models. RESULTS: Increased FDG activity in cervical nodes was observed in 136/191 studies (71%). The mean SUVmaxCLN was 2.2 ± 1.3. Ipsilateral palatine tonsil SUVmax, mean liver uptake, and treatment status were all statistically significant predictors of SUVmaxCLN. However, in multivariate regression analysis, only ipsilateral palatine tonsil SUVmax was found to be significant. In addition, SUVmaxCLN was greater than the mean liver uptake in 50% of all studies. This proportion was higher in younger children, reaching 77% of studies of children younger than six years. CONCLUSION: SUVmax in ipsilateral palatine tonsil is a strong predictor of the maximal uptake value of non-malignant cervical lymph nodes in children. The intensity of uptake in non-malignant cervical lymph nodes is frequently higher than liver uptake in children, and this tendency increases for younger patients. TRIAL WAS REGISTERED: In the internal hospital registry under TRN 0209-22-HMO on date 23.04.2022.

Quarter-Century PET/CT Transformation of Oncology: Lymphoma.

The clinical landscape of lymphomas has changed dramatically over the last 2 decades, including significant progress made in the understanding and utilization of imaging modalities and the available treatment options for both indolent and aggressive lymphomas. Since the introduction of hybrid PET/CT scanners in 2001, the indications of 18F-fluorodeoxyglucose (FDG) PET/CT in the management of lymphomas have grown rapidly. In today's clinical practice, FDG PET/CT is used in successful management of the vast majority patients with lymphomas.

Domain-adapted Large Language Models for Classifying Nuclear Medicine Reports.

Purpose: To evaluate the impact of domain adaptation on the performance of language models in predicting five-point Deauville scores on the basis of clinical fluorine 18 fluorodeoxyglucose PET/CT reports. Materials and Methods: The authors retrospectively retrieved 4542 text reports and images for fluorodeoxyglucose PET/CT lymphoma examinations from 2008 to 2018 in the University of Wisconsin-Madison institutional clinical imaging database. Of these total reports, 1664 had Deauville scores that were extracted from the reports and served as training labels. The bidirectional encoder representations from transformers (BERT) model and initialized BERT models BioClinicalBERT, RadBERT, and RoBERTa were adapted to the nuclear medicine domain by pretraining using masked language modeling. These domain-adapted models were then compared with the non-domain-adapted versions on the task of five-point Deauville score prediction. The language models were compared against vision models, multimodal vision-language models, and a nuclear medicine physician, with sevenfold Monte Carlo cross-validation. Means and SDs for accuracy are reported, with P values from paired t testing. Results: Domain adaptation improved the performance of all language models (P = .01). For example, BERT improved from 61.3% ± 2.9 (SD) five-class accuracy to 65.7% ± 2.2 (P = .01) following domain adaptation. Domain-adapted RoBERTa (named DA RoBERTa) performed best, achieving 77.4% ± 3.4 five-class accuracy; this model performed similarly to its multimodal counterpart (named Multimodal DA RoBERTa) (77.2% ± 3.2) and outperformed the best vision-only model (48.1% ± 3.5, P ≤ .001). A physician given the task on a subset of the data had a five-class accuracy of 66%. Conclusion: Domain adaptation improved the performance of large language models in predicting Deauville scores in PET/CT reports.Keywords Lymphoma, PET, PET/CT, Transfer Learning, Unsupervised Learning, Convolutional Neural Network (CNN), Nuclear Medicine, Deauville, Natural Language Processing, Multimodal Learning, Artificial Intelligence, Machine Learning, Language Modeling Supplemental material is available for this article. © RSNA, 2023See also the commentary by Abajian in this issue.

FDG PET-CT in Clinical Management of a Rare Case of Primary Hepatic Lymphoma: Role and Challenges.

The common differential diagnoses for multiple space-occupying hepatic lesions (SOL) are metastases, multifocal hepatocellular carcinoma, and abscess. Primary hepatic lymphomas are rare entities that present many challenges with regard to their management. Fluorodeoxyglucose positron emission tomography-computed tomography is extensively used for the staging and response assessment of lymphomas but it can be challenging and difficult to interpret in cases with isolated liver involvement. We hereby present the case of an 82-year-old lady who presented with multiple liver SOL.

Corrigendum: Standardized classification schemes in reporting oncologic PET/CT.

[This corrects the article DOI: 10.3389/fmed.2022.1051309.].

Predicting diffuse large B-cell lymphoma outcomes with lesion-to-liver maximum standardized uptake value for interim-treatment and end-of-treatment positron emission tomography-computed tomography.

Background: 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) has been used in response evaluation systems for malignant lymphomas and is an important tool for determining efficacy and prognosis. The Deauville 5-point scale (D-5PS) is an 18F-FDG PET-CT image-interpretation protocol for patients with lymphoma. Nevertheless, a number of limitations in visual image interpretation, such as interobserver disagreement and the increase of false-positive results, suggests that new parameters are needed. In this study, we aimed to evaluate the prognostic values of interim-treatment (I-) and end-of-treatment (EOT) PET-CT by comparing D-5PS to the semiquantitative lesion-to-liver maximum standardized uptake value ratio (RLL). Methods: A total of 90 patients with diffuse large B-cell lymphoma (DLBCL) (45 I-PET and 45 EOT-PET) were analyzed, and the RLL was calculated. Patients were additionally evaluated using the D-5PS system. We determined the optimal cutoff value of RLL using receiver operating characteristic (ROC) analysis. Kaplan-Meier survival analysis was used to compare the outcome predictions, while multivariate Cox regression analysis was used to identify the predictive factors. Results: Among the patients examined, 41 (20 I-PET and 21 EOT-PET) experienced progression, and 49 (25 I-PET, 24 EOT-PET) did not. The optimal cutoff values of the RLL for predicting disease progression were 1.37 for I-PET (sensitivity 75%, specificity 88%) and 2.03 for EOT-PET (sensitivity 45.5%, specificity 100%), while the cutoffs of the D-5PS were scores 4 for I-PET (sensitivity 80%, specificity 72%) and 5 for EOT-PET (sensitivity 40.9%, specificity 100%). The prognostic efficacy was higher for the RLL at interim than for the D-5PS [area under the curve (AUC) =0.848 vs. 0.741]. The EOT prognostic efficacy of both evaluation methods was essentially equivalent (AUC =0.785 vs. 0.725). Univariate and multivariate analyses showed that RLL and D-5PS were independent factors affecting DLBCL outcomes for both interim and EOT assessment. Conclusions: RLL and D-5PS have independent predictive values for the interim and EOT evaluation of outcomes in patients with DLBCL. The RLL has better interim predictive ability than does D-5PS and can optimize D-5PS interpretation, thus improving interim outcome prediction.

Prognostic Value of FDG PET/CT in Patients with Nodal Peripheral T-Cell Lymphoma.

This study evaluated the prognostic significance of FDG PET/CT in patients with nodal peripheral T-cell lymphoma (PTCL). We retrospectively reviewed patients with histologically confirmed nodal PTCL who underwent FDG PET/CT at baseline, after three cycles of first-line chemotherapy (interim), and at the end of therapy. Response was assessed visually using the Deauville 5-point scale (D5PS); scores of 1, 2, and 3 were considered PET-negative, and scores of 4 and 5 were considered PET-positive. The associations between FDG PET/CT findings and survival were assessed using Cox regression analysis. A total of 79 patients (44 males and 35 females; median age 56 years) were included in this study. In response assessment, 17 (22%) had an interim PET-positive result and 10 (13%) had an end-of-therapy PET-positive result. During a median follow-up of 50 months, 37 patients (47%) presented with disease progression and 30 patients (38%) died. The estimated 5-year progression-free survival (PFS) and overall survival (OS) were 57% and 64%, respectively. An interim PET-positive result was the only significant indicator of PFS. Higher International Prognostic Index and end-of-therapy PET-positive result were significant independent prognostic factors of OS. Interim and end-of-therapy FDG PET/CT responses based on D5PS are meaningful in predicting the outcomes of patients with nodal PTCL.

Validation of the ΔSUVmax for Interim PET Interpretation in Diffuse Large B-Cell Lymphoma on the Basis of the GAINED Clinical Trial.

The GAINED phase 3 trial (ClinicalTrials.gov identifier: NCT01659099) evaluated a PET-driven consolidative strategy in patients with diffuse large B-cell lymphoma. In this post hoc analysis, we aimed to compare the prognostic value of the per-protocol PET interpretation criteria (Menton 2011 consensus) with the change in the SUVmax (ΔSUVmax) alone. Methods: Real-time central review of 18F-FDG PET/CT was performed in 581 patients after 2 cycles (PET2) and 4 cycles (PET4) of immunochemotherapy using the Menton 2011 criteria, combining the ΔSUVmax (cutoffs of 66% and 70% at PET2 and PET4, respectively) and the Deauville scale. In "special cases," when the baseline SUVmax was less than 10.0 or the interim residual tumor SUVmax was greater than 5.0, the Menton 2011 experts' consensus agreed that the ΔSUVmax may not be reliable and that the Deauville score is preferable. Prognostic values of Menton 2011 and ΔSUVmax were evaluated by Kaplan-Meier analyses in terms of progression-free survival (PFS). Results: Seventeen percent of patients at PET2 (100/581) and 8% at PET4 (49/581) had PET-negative results by ΔSUVmax but were considered to have PET-positive results according to Menton 2011 with residual SUVmax of greater than 5.0. For the population with PET2-positive results, 2-y PFS was 70% (range, 58%-80%) with ΔSUVmax alone, whereas the outcome tended to be better for those who were considered to have PET-positive results by Menton 2011, 81% (range, 72%-87%). Conversely, all 10 patients with baseline SUVmax of less than 10.0 had PET2-positive results by ΔSUVmax but were considered to have PET2-negative results by Menton 2011. These patients had the same 2-y PFS as patients with PET2-negative/PET4-negative results, indicating that the ΔSUVmax yielded false-positive results in this situation. Conclusion: We recommend the use of the ΔSUVmax alone rather than the Menton 2011 criteria for assessing the interim metabolic response in patients with diffuse large B-cell lymphoma, except when the baseline SUVmax is less than 10.0.

The variation of quantitative parameters and Deauville scores with different reconstruction algorithms in FDG PET/CT imaging of lymphoma patients.

INTRODUCTION AND OBJECTIVES: 18F-FDG PET with the Deauville score (DS) is a unique semiquantitative method for lymphoma. However, type of standard uptake values (max, mean, and peak) reconstruction algorithms could affect DS. We compared the Bayesian Penalized Likelihood reconstruction algorithm (BPL) with Ordered Subsets Expectation Maximization (OSEM) on quantitative parameters and DS in lymphoma. We investigated the effect of the size of the lymph node on quantitative variation. PATIENTS AND METHODS: Raw PET data of 255 lymphoma patients were reconstructed separately with Q.Clear (GE Healthcare), a BPL, and SharpIR (GE Healthcare), an OSEM algorithm. In both images, each patient's liver, mediastinal blood pool, and SUVs (SUVmax, SUVmean, and SUVpeak) of a total of 487 lesions selected from the patients were performed. DSmax, DSmean, and DSpeak were compared. RESULTS: In our study, DS increased significantly with BPL (p < 0.001), and the DS increased to 4-5 in thirty patients evaluated as 1-2-3 with OSEM. It was found that the quantitative values of the lymph nodes increased statistically with BPL (p < 0.001), and the liver from the reference regions were significantly decreased (p < 0.001). In addition, difference in lymph node was independently associated with size of lesion and was significantly more pronounced in small lesions (p < 0.001). The effects of BPL algorithm were more pronounced in SUVmax than in SUVmean and SUVpeak. DS-mean and DS-peak scores were less changed by BPL than DS-max. CONCLUSION: Different reconstruction algorithms in FDG PET/CT affect the quantitative evaluation. That variation may affect the change in DS in lymphoma patients, thus affecting patient management.

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

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.

Validation of Deauville Score for Response Evaluation in Hodgkin's Lymphoma.

Context: Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) for treatment monitoring in patients with lymphoma is one of the most well-developed clinical applications. Deauville five-point score (DS) is recommended for response assessment in international guidelines. DS gives the threshold for adequate or inadequate response to be adapted according to the clinical context or research question. Aims: We aimed to validate DS in Hodgkin's lymphoma (HL) by retrospectively assigning this score to F-18 FDG PET-computed tomography (CT) studies done before 2016 and analyzing its concordance with the line of management. The secondary aim was to assess the reproducibility of DS in the interpretation of PET-CT scans. Subjects and Methods: A total of 100 eligible consecutive patients underwent F-18 FDG PET-CT scans between January 2014 and December 2015. Their interim, end of treatment, and follow-up PET scans were retrospectively visually analyzed and assigned DS by three nuclear medicine physicians. Concordance was defined as agreement between the DS assigned and the line of treatment. Interobserver variability was calculated using weighted Kappa and presented with 95% confidence interval. Results: Among 212 scans assigned DS, 165 scans showed agreement between the DS and line of treatment. Of these, 95.2% of scans scored DS 1-3 were kept on following or the same treatment plan was continued and patients did well. Among the scans that showed discordance, 24 scans scored DS 4/5 were continued on the same treatment regimen and the next assessment showed disease progression. Conclusions: Our study confirmed that DS is a useful tool to aid in reporting F-18 FDG PET-CT in the management of HL with good positive and negative predictive values. This study also demonstrated good interobserver agreement.

Patients and Families' Participation in Multidisciplinary Tumor Conferences Improves Patient and Family-Focused Cancer Care: Lessons Learned From a Debate on the Role of Radiation Therapy in Primary Mediastinal Non-Hodgkin Lymphoma.

Incorporation of patients' preferences often leads to improved outcomes when included in the multidisciplinary tumor conference/board (MTC). However, patients' wishes are not included or considered in the MTC decision-making. We need better strategies and approaches for patient-inclusive, shared decision-making. When finding ourselves at a crossroads regarding the next step in a patient's treatment, we saw a unique opportunity for an MTC with the patient and her husband in attendance. The results of a full literature review regarding the role of consolidative radiation therapy (RT) in a patient with primary (thymic) B-cell lymphoma after completion of chemotherapy and fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT) scan with a Deauville score of 4 were presented in a creative, engaging debate-style forum with visual aids. The patient and her husband were able to follow the discussion and, in the end, a consensus recommendation, heavily focused on the patient's preferences, was offered and adopted, which ultimately resulted in the avoidance of excess treatment and likely improved her long-term quality of life outcome. These collaborative and innovative interactions benefit not only our patients but enrich our lives too as healthcare providers and strengthen us as a cancer care team in terms of understanding diversity in decision-making processes.

Are Semiquantitative Methods Superior to Deauville Scoring in the Monitoring Therapy Response for Pediatric Hodgkin Lymphoma?

Tailoring treatment in patients with Hodgkin lymphoma (HL) is paramount to maximize outcomes while avoiding unnecessary toxicity. We aimed to compare the performance of SUVmax reduction (ΔSUVmax%) and the PET ratio (rPET) versus the Deauville score (DS) for assessing the chemotherapy response in pediatric HL patients undergoing 18F-FDG PET-CT. Fifty-two patients with biopsy-proven HL (aged 8-16 years) were enrolled at baseline, interim (after the second or third chemotherapy round) and post-therapy (on completion of first-line chemotherapy). Interim and post-therapy DS, ΔSUVmax% and rPET were compared as response predictors. Patients were classified as responders or non-responders based on a 24-month clinical follow-up. Interim DS showed a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of 100%, 80.4%, 100%, 40% and 82.7%, respectively, in predicting the therapy response. Post-therapy DS showed a sensitivity, specificity, PPV, NPV and accuracy of 66.7%, 97.8%, 95.7%, 80% and 94.2%, repsectively. Interim ΔSUVmax% showed a sensitivity, specificity, PPV, NPV and accuracy of 83.3%, 82.6%, 97.4%, 38.5% and 82.7%, respectively, with a 56.3% cutoff. Post-therapy ΔSUVmax% showed a sensitivity, specificity, PPV, NPV and accuracy of 83.3%, 84.8%, 97.5%, 41.7% and 84.6%, respectively, with a 76.8% cutoff. Compared to ΔSUVmax%, DS showed a significantly higher sensitivity, specificity (p < 0.05) and NPV (p < 0.01). The sensitivity, specificity, PPV, NPV and accuracy of rPET in predicting the therapy response at 24 months were 76.1%, 100%, 100%, 35.3% and 78.8%, respectively, with a cut-off of 1.31. DS and rPET showed comparable predictive performance (p > 0.58). In conclusion, DS is an easier method with better performance than ΔSUVmax% and rPET in predicting the chemotherapy response in pediatric HL patients.

Impact of Reduced Image Noise on Deauville Scores in Patients with Lymphoma Scanned on a Long-Axial Field-of-View PET/CT-Scanner.

BACKGROUND: Total body and long-axial field-of-view (LAFOV) PET/CT represent visionary innovations in imaging enabling either improved image quality, reduction in injected activity-dose or decreased acquisition time. An improved image quality may affect visual scoring systems, including the Deauville score (DS), which is used for clinical assessment of patients with lymphoma. The DS compares SUVmax in residual lymphomas with liver parenchyma, and here we investigate the impact of reduced image noise on the DS in patients with lymphomas scanned on a LAFOV PET/CT. METHODS: Sixty-eight patients with lymphoma underwent a whole-body scan on a Biograph Vision Quadra PET/CT-scanner, and images were evaluated visually with regard to DS for three different timeframes of 90, 300, and 600 s. SUVmax and SUVmean were calculated from liver and mediastinal blood pool, in addition to SUVmax from residual lymphomas and measures of noise. RESULTS: SUVmax in liver and in mediastinal blood pool decreased significantly with increasing acquisition time, whereas SUVmean remained stable. In residual tumor, SUVmax was stable during different acquisition times. As a result, the DS was subject to change in three patients. CONCLUSIONS: Attention should be drawn towards the eventual impact of improvements in image quality on visual scoring systems such as the DS.

Predicting the pathological invasiveness of early lung adenocarcinoma prior to surgery using Deauville criteria: reliability and validity.

PURPOSE: This retrospective study aimed to investigate the validity and reliability of FDG-PET/CT visual assessment using Deauville criteria to predict pathological invasiveness of early lung adenocarcinoma prior to surgery. MATERIALS AND METHODS: Between April 2020 and January 2022, 51 patients who underwent surgery for pathological stage 0/I lung adenocarcinoma were enrolled. The pulmonary lesions were divided into two groups according to pathological invasiveness: less invasive (including adenocarcinoma in situ and minimally invasive adenocarcinoma and invasive adenocarcinoma. We compared CT size (total and solid size), SUVmax, and Deauville score between the two groups. Furthermore, we investigated inter-rater and intra-rater agreements regarding the Deauville score. Receiver operating characteristic (ROC) curve analysis was performed to identify the diagnostic performance of each method. RESULTS: Based on pathologic diagnoses, 51 lesions in the 51 patients were divided into 6 less invasive and 45 invasive adenocarcinoma lesions. According to quadratic-weighted Kappa statistics, inter-rater (k = 0.93) and intra-rater (k = 0.97) agreements among all five components of the Deauville score indicated high agreement. There was a statistically significant difference in CT solid size, SUVmax, and Deauville score between the two groups. There were no significant differences between CT solid size and FDG-PET/CT assessments (AUC = 0.93 for Deauville score and SUVmax, AUC = 0.84 for CT solid size). CONCLUSION: FDG-PET/CT visual assessment using the Deauville score could assist in deciding upon minimally invasive surgery for early lung adenocarcinoma.

Is local review of positron emission tomography scans sufficient in diffuse large B-cell lymphoma clinical trials? A CALGB 50303 analysis.

BACKGROUND: Quantitative methods of Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) interpretation, including the percent change in FDG uptake from baseline (ΔSUV), are under investigation in lymphoma to overcome challenges associated with visual scoring systems (VSS) such as the Deauville 5-point scale (5-PS). METHODS: In CALGB 50303, patients with DLBCL received frontline R-CHOP or DA-EPOCH-R, and although there were no significant associations between interim PET responses assessed centrally after cycle 2 (iPET) using 5-PS with progression-free survival (PFS) or overall survival (OS), there were significant associations between central determinations of iPET ∆SUV with PFS/OS. In this patient cohort, we retrospectively compared local vs central iPET readings and evaluated associations between local imaging data and survival outcomes. RESULTS: Agreement between local and central review was moderate (kappa = 0.53) for VSS and high (kappa = 0.81) for ∆SUV categories (<66% vs. ≥66%). ∆SUV ≥66% at iPET was significantly associated with PFS (p = 0.03) and OS (p = 0.002), but VSS was not. Associations with PFS/OS when applying local review vs central review were comparable. CONCLUSIONS: These data suggest that local PET interpretation for response determination may be acceptable in clinical trials. Our findings also highlight limitations of VSS and call for incorporation of more objective measures of response assessment in clinical trials.

FDG PET/CT Maximum Tumor Dissemination to Predict Recurrence in Patients with Diffuse Large B-Cell Lymphoma.

Purpose: We investigated the prognostic value of maximum tumor dissemination (Dmax), the distance between malignant lesions that were farthest apart, as assessed by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), and other clinical factors in patients with diffuse large B-cell lymphoma (DLBCL).We investigated the prognostic value of maximum tumor dissemination (Dmax), the distance between malignant lesions that were farthest apart, as assessed by fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), and other clinical factors in patients with diffuse large B-cell lymphoma (DLBCL). Methods: Patients who underwent FDG PET/CT for initial staging and treatment response evaluation of DLBCL were reviewed retrospectively. Baseline Dmax, maximum standardized uptake value, total summation of all metabolic tumor volumes (tMTV), and total summation of all total lesion glycolysis (tTLG) were measured. The treatment response was evaluated at the interim and end of first-line treatment (EOT) using the Deauville score (DS). FDG PET/CT parameters and other clinical factors including sex, age, serum lactate dehydrogenase (LDH) level, stage, performance status, and the International Prognostic Index (IPI) were analyzed to identify factors prognostic of the time to progression (TTP) and disease-specific survival (DSS). Results: A total of 63 patients were included. Univariate survival analysis identified Dmax (> 275 mm), tMTV (> 180 mL), tTLG (> 1300), interim DS (≥ 4), and EOT DS (≥ 4) as significant predictors of poor TTP. Serum LDH level (> 640 IU/L), IPI (≥ 4), tMTV (> 180 mL), tTLG (> 1300), interim DS (≥ 4), and EOT DS (≥ 4) were significant predictors of DSS. After multivariate survival analysis, Dmax (P = 0.008) and EOT DS (P = 0.005) were independent predictors of TTP. EOT DS was an independent predictor of DSS (P = 0.029). Conclusions: Dmax at the time of diagnosis and the EOT response assessed by FDG PET/CT provide useful prognostic information additive to the IPI in patients with DLBCL.

Performance of Deauville Criteria in [18F]FDG-PET/CT Diagnostics of Giant Cell Arteritis.

In this retrospective study, PET/CT data from 59 patients with suspected giant cell arteritis (GCA) were reviewed using the Deauville criteria to determine an optimal cut-off between PET positivity and negativity. Seventeen standardised vascular regions were analysed per patient by three investigators blinded to clinical information. Statistical analysis included ROC curves with areas under the curve (AUC), Cohen's and Fleiss' kappa (κ) to calculate sensitivity, specificity, accuracy, and agreement. According to final clinician's diagnosis and the revised 2017 ACR criteria GCA was confirmed in 29 of 59 (49.2 %) patients. With a diagnostic cut-off ≥ 4 (highest tracer uptake of a vessel wall exceeds liver uptake) for PET positivity, all investigators achieved high accuracy (range, 89.8-93.2%) and AUC (range, 0.94-0.97). Sensitivity and specificity ranged from 89.7-96.6% and 83.3-96.7%, respectively. Agreement between the three investigators suggested 'almost perfect agreement' (Fleiss' κ = 0.84) A Deauville score of ≥4 as threshold for PET positivity yielded excellent results with high accuracy and almost perfect inter-rater agreement, suggesting a standardized, reproducible, and reliable score in diagnosing GCA. However, the small sample size and reference standard could lead to biases. Therefore, verification in a multicentre study with a larger patient cohort and prospective setting is needed.

Prognostic Value of 18F-FDG PET/CT in Diffuse Large B-Cell Lymphoma Treated with a Risk-Adapted Immunochemotherapy Regimen.

Early identification of patients with diffuse large B-cell lymphoma (DLBCL) who are likely to experience disease recurrence or refractory disease after rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) would be useful for improving risk-adapted treatment strategies. We aimed to assess the prognostic value of 18F-FDG PET/CT parameters at baseline, interim, and end of treatment (EOT). Methods: We analyzed the prognostic impact of 18F-FDG PET/CT in 166 patients with DLBCL treated with a risk-adapted immunochemotherapy regimen. Scans were obtained at baseline, after 4 cycles of R-CHOP or 3 cycles of RR-CHOP (double dose of R) and 1 cycle of CHOP alone (interim) and 6 wk after completing therapy (EOT). Progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier and the impact of clinical/PET factors assessed with Cox models. We also assessed the predictive ability of the recently proposed International Metabolic Prognostic Index (IMPI). Results: The median follow-up was 7.9 y. International Prognostic Index (IPI), baseline metabolic tumor volume (MTV), and change in maximum SUV (ΔSUVmax) at interim scans were statistically significant predictors for OS. Baseline MTV, interim ΔSUVmax, and EOT Deauville score were statistically significant predictors of PFS. Combining interim PET parameters demonstrated that patients with Deauville 4-5 and positive ΔSUVmax ≤ 70% at restaging (∼10% of the cohort) had extremely poor prognosis. The IMPI had limited discrimination and slightly overestimated the event rate in our cohort. Conclusion: Baseline MTV and interim ΔSUVmax predicted both PFS and OS with this sequential immunochemotherapy program. Combining interim Deauville score with interim ΔSUVmax may identify an extremely high-risk DLBCL population.

Combination of Deauville score and quantitative positron emission tomography parameters as a predictive tool of anti-CD19 chimeric antigen receptor T-cell efficacy.

BACKGROUND: Autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is an effective treatment for approximately 40% of relapsed/refractory large B cell lymphomas (LBCL), and early identification of patients at risk for relapse or progression after CAR T-cell therapy represents a clinical need. METHODS: The authors conducted a single-center prospective study on 47 relapsed/refractory LBCL receiving CAR T-cell therapy to evaluate the prognostic value of baseline and after infusion 18 F-fluorodeoxyglucose positron emission tomography (PET)-computed tomography. Qualitative and quantitative metabolic parameters were evaluated before lymphodepletion, at day 30 and 90 post-infusion. RESULTS: Deep variation of standardized uptake value (SUV)mean between baseline and day 30 correlated with response at day 90 (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.01-2.2); p = .04) and better progression-free survival (PFS) (HR, 0.63; 95% CI, 0.41-0.97); p = .04). In the overall population, 1-year PFS was 63% for Deauville score (DS)1-3 and 39% for DS4-5 patients, respectively (p = .02), however, the prognostic role of DS was lost when survivals are analyzed by considering 38 patients not progressing at 30 days. In these patients, in partial response or stable disease, the combination of DS and variation of SUVmean allowed identification of three groups with different prognosis: patients with DS1-3 and those with DS4-5 and decreased SUVmean had similar 1-year PFS of 62% and 61%, whereas patients with DS4-5 and increased SUVmean had a poorer 1-year PFS of 33% (p = .04). CONCLUSIONS: PET parameters and association of DS and variation of SUVmean at 30 days could help in identify patients at high risk of CAR T-cell failure. LAY SUMMARY: This is a single-center prospective study on 47 lymphoma patients receiving commercial chimeric antigen receptor T-cell therapy aimed to evaluate the prognostic value of baseline and after infusion 18 F-fluorodeoxyglucose positron emission tomography. Among patients in partial remission or stable disease at day 30, the authors observed two subgroups with significantly different prognosis; patients with Deauville score (DS)4-5 and a concomitant reduction of standardized uptake value (SUV)mean had higher probability of long-lasting response than those with DS4-5 and an increase of SUVmean .