Prognostic Value of Bone Marrow FDG Uptake Pattern of PET/CT in Newly Diagnosed Diffuse Large B-cell Lymphoma

The Impact of Bone Marrow Involvement on Prognosis in Diffuse Large B-Cell Lymphoma: An 18F-FDG PET/CT Volumetric Segmentation Study

BACKGROUND

This study assessed the prognostic value of tumor burden in bone marrow (BM) and total disease (TD), as depicted on 18F-FDG PET/CT in 140 DLBCL patients, for complete remission after first-line systemic treatment (iCR) and 3- and 5-year overall survival (OS3 and OS5).

METHODS

Baseline 18F-FDG PET/CT scans of 140 DLBCL patients were segmented to quantify metabolic tumor volume (MTV), total lesion glycolysis (TLG), and SUVmax in BMI, findings elsewhere (XL), and TD.

RESULTS

Bone marrow involvement (BMI) presented in 35 (25%) patients. Median follow-up time was 47 months; 79 patients (56%) achieved iCR. iCR was significantly associated with TD MTV, XL MTV, BM PET positivity, and International Prognostic Index (IPI). OS3 was significantly worse with TD MTV, XL MTV, IPI, and age. OS5 was significantly associated with IPI, but not with MTVs and TLGs. Univariate factors predicting OS3 were XL MTV (hazard ratio [HR] = 1.29), BMI SUVmax (HR = 0.56), and IPI (HR = 1.92). By multivariate analysis, higher IPI (HR = 2.26) and BMI SUVmax (HR = 0.91) were significant independent predictors for OS3. BMI SUVmax resulted in a negative coefficient and hence indicated a protective effect.

CONCLUSIONS

Baseline 18F-FDG PET/CT MTV is significantly associated with survival. BMI identified on 18F-FDG PET/CT allows appropriate treatment that may improve survival.

Diffuse bone marrow uptake on 18F-fluorodeoxyglucose positron emission tomography/computed tomography with copper-deficiency anemia

A 59-year-old man with pancytopenia underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography for suspected carcinomatosis. The scan revealed diffuse bone marrow uptake, prompting further investigation. Bone marrow analysis revealed no malignant cells; however, erythroblasts with cytoplasmic vacuolization were observed. Subsequent testing showed low serum copper and ceruloplasmin levels, indicating copper deficiency. Copper supplementation resulted in significant improvement in cytopenia. Notably, the bone marrow uptake on subsequent scans decreased significantly. This case highlights the importance of considering copper deficiency as a potential cause of diffuse bone marrow uptake of 18F-fluorodeoxyglucose on positron emission tomography/computed tomography.

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.

Glucose uptake and distribution across the human skeleton using state-of-the-art total-body PET/CT

A growing number of studies have demonstrated that the skeleton is an endocrine organ that is involved in glucose metabolism and plays a significant role in human glucose homeostasis. However, there is still a limited understanding of the in vivo glucose uptake and distribution across the human skeleton. To address this issue, we aimed to elucidate the detailed profile of glucose uptake across the skeleton using a total-body positron emission tomography (PET) scanner. A total of 41 healthy participants were recruited. Two of them received a 1-hour dynamic total-body ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET scan, and all of them received a 10-minute static total-body ¹⁸F-FDG PET scan. The net influx rate (K_i) and standardized uptake value normalized by lean body mass (SUL) were calculated as indicators of glucose uptake from the dynamic and static PET data, respectively. The results showed that the vertebrae, hip bone and skull had relatively high K_i and SUL values compared with metabolic organs such as the liver. Both the K_i and SUL were higher in the epiphyseal, metaphyseal and cortical regions of long bones. Moreover, trends associated with age and overweight with glucose uptake (SUL_max and SUL_mean) in bones were uncovered. Overall, these results indicate that the skeleton is a site with significant glucose uptake, and skeletal glucose uptake can be affected by age and dysregulated metabolism.

The Diagnostic Accuracy of Bone Marrow Biopsy Versus PET/CT Scan in Identifying Bone Marrow Involvement in Diffuse Large B Cell Lymphoma Patients at a Cancer Hospital

Background It is of great importance to assess bone marrow involvement (BMI) in diffuse large B cell lymphoma (DLBCL) for staging, prognostic, and therapeutic purposes. The gold standard method used for the identification of bone marrow involvement is bone marrow biopsy (BMB), but it has certain drawbacks. In recent years, positron emission tomography/computed tomography (PET/CT) has become a highly effective method in the diagnosis and staging of lymphoma. Objective The objective of this study is to estimate the diagnostic accuracy of PET/CT in identifying bone marrow involvement in DLBCL patients in a cancer care hospital in Lahore, using BMB as a reference standard. Methods This descriptive cross-sectional study was conducted at the Department of Pathology of Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC) from January 1, 2013, to December 31, 2018. A retrospective data of 146 patients fulfilling the inclusion and exclusion criteria was retrieved from the hospital information system (HIS). The inclusion criteria include patients aged 18-80 years, of either gender, and with a confirmed diagnosis of DLBCL on tissue biopsy. The exclusion criteria include patients who had started chemotherapy or radiotherapy for DLBCL or were using granulocyte colony-stimulating factor (G-CSF) prior to their PET/CT scan. All patients underwent PET/CT and BMB, and the diagnostic accuracy of PET/CT was calculated, with BMB taken as the reference standard. Results The mean age of cases was 52.73 ± 16.27 years. There were 95 (65.1%) male and 51 (34.9%) female cases, with a high male-to-female ratio. In the present study, 32.19% of cases had bone marrow involvement on BMB, and 34.2% of cases had bone marrow involvement on PET/CT. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy of PET/CT were found to be 93.61%, 93.93%, 88%, 96.88%, and 93.84%, respectively. Conclusion It is concluded that PET/CT scan has good sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy. So, it is suggested to choose this non-invasive technique because the presence of a disease in extra-medullary space can also be detected and the evaluation of bone marrow in the whole body can be performed. PET/CT scan is an effective imaging modality in the detection of bone marrow involvement in DLBCL patients, and its relative advantages over bone marrow biopsy might conclude this to be a preferred technique.

Development and validation of nomograms by radiomic features on ultrasound imaging for predicting overall survival in patients with primary nodal diffuse large B-cell lymphoma

Objectives

To develop and validate a nomogram to predict the overall survival (OS) of patients with primary nodal diffuse large B-cell lymphoma(N-DLBCL) based on radiomic features and clinical features.

Materials and methods

A retrospective analysis was performed on 145 patients confirmed with N-DLBCL and they were randomly assigned to training set(n=78), internal validation set(n=33), external validation set(n=34). First, a clinical model (model 1) was established according to clinical features and ultrasound (US) results. Then, based on the radiomics features extracted from conventional ultrasound images, a radiomic signature was constructed (model 2), and the radiomics score (Rad-Score) was calculated. Finally, a comprehensive model was established (model 3) combined with Rad-score and clinical features. Receiver operating characteristic (ROC) curves were employed to evaluate the performance of model 1, model 2 and model 3. Based on model 3, we plotted a nomogram. Calibration curves were used to test the effectiveness of the nomogram, and decision curve analysis (DCA) was used to asset the nomogram in clinical use.

Results

According to multivariate analysis, 3 clinical features and Rad-score were finally selected to construct the model 3, which showed better predictive value for OS in patients with N-DLBCL than mode 1 and model 2 in training (AUC,0. 891 vs. 0.779 vs.0.756), internal validation (AUC, 0.868 vs. 0.713, vs.0.756) and external validation (AUC, 914 vs. 0.866, vs.0.789) sets. Decision curve analysis demonstrated that the nomogram based on model 3 was more clinically useful than the other two models.

Conclusion

The developed nomogram is a useful tool for precisely analyzing the prognosis of N-DLBCL patients, which could help clinicians in making personalized survival predictions and assessing individualized clinical options.

The value of FDG PET/CT imaging in outcome prediction and response assessment of lymphoma patients treated with immunotherapy: a meta-analysis and systematic review

PURPOSE

Treatment strategies of lymphoid malignancies have been revolutionized by immunotherapy. Because of the inherent property of Hodgkin lymphoma and some subtypes of non-Hodgkin lymphoma as a highly FDG-avid tumor, functional ¹⁸F-FDG PET/CT imaging is already embedded in their routine care. Nevertheless, the question is whether it is still valuable in the context of these tumors being treated with immunotherapy. Herein, we will review the value of ¹⁸F-FDG PET/CT imaging lymphoid tumors treated with immunotherapy regimens.

METHODS

A comprehensive literature search of the PubMed database was conducted on the value of the ¹⁸F-FDG PET/CT for immunotherapy response monitoring of patients with malignant lymphoma. The articles were considered eligible if they met all of the following inclusion criteria: (a) clinical studies on patients with different types of malignant lymphoma, (b) treatment with anti-CD20 antibodies, immune checkpoint inhibitors or immune cell therapies, (c) and incorporated PET/CT with ¹⁸F-FDG as the PET tracer.

RESULTS

From the initial 1488 papers identified, 91 were ultimately included in our study. In anti-CD20 therapy, the highest pooled hazard ratios (HRs) of baseline, early, and late response monitoring parameters for progression-free survival (PFS) belong to metabolic tumor volume (MTV) (3.19 (95%CI: 2.36-4.30)), maximum standardized uptake value (SUVmax) (3.25 (95%CI: 2.08-5.08)), and Deauville score (DS) (3.73 (95%CI: 2.50-5.56)), respectively. These measurements for overall survival (OS) were MTV (4.39 (95%CI: 2.71-7.08)), DS (3.23 (95%CI: 1.87-5.58)), and DS (3.64 (95%CI: 1.40-9.43)), respectively. Early and late ¹⁸F-FDG PET/CT response assessment in immune checkpoint inhibitors (ICI) and immune cell therapy might be an effective tool for prediction of clinical outcome.

CONCLUSION

For anti-CD20 therapy of lymphoma, the MTV as a baseline ¹⁸F-FDG PET/CT-derived parameter has the highest HRs for PFS and OS. The DS as visual criteria in early and late response assessment has higher HRs for PFS and OS compared to the international harmonization project (IHP) visual criteria in anti-CD20 therapy. Early changes in ¹⁸F-FDG PET parameters may be predictive of response to ICIs and cell therapy in lymphoma patients.

The Diagnostic Value of 18F-FDG PET/CT Bone Marrow Uptake Pattern in Detecting Bone Marrow Involvement in Pediatric Neuroblastoma Patients

Objectives

To explore the diagnostic value of ¹⁸F-FDG PET/CT bone marrow uptake pattern (BMUP) in detecting bone marrow involvement (BMI) in pediatric neuroblastoma (NB) patients.

Methods

Ninety-eight NB patients were enrolled in BMI analysis. Four patterns of bone marrow uptake were categorized based on pretreatment ^cF-FDG PET/CT images. Some crucial inspection indexes and ¹⁸F-FDG PET/CT metabolic parameters were analyzed. The BMUP was divided into BMUP1, BMUP2, BMUP3, and BMUP4. Paired-like homeobox 2b (PHOX2B) of bone marrow and blood, bone marrow biopsy (BMB) result, and ¹⁸F-FDG PET/CT were compared to detect BMI. All patients were followed up for at least six months.

Results

BMUP had excellent consistency among different physicians. Kappa coefficients of two residents and two attending physicians and between the resident and attending physician, were 0.857, 0.891, and 0.845, respectively. The optimal cut-off value of SUVmax-Bone/Liver was 2.08 to diagnose BMI for BMUP3 patients, and the area under curve (AUC) was 0.873. AUC of PHOX2B of bone marrow (PHOX2B of BM), PHOX2B of blood, BMB, and ¹⁸F-FDG PET/CT were 0.916, 0.811, 0.806, and 0.904, respectively. There was no significant difference between PHOX2B of BM and PET/CT. Positive predictive value, negative predictive value, sensitivity, and specificity in diagnosis of BMI were 92.9%, 92.9%, 97.0%, and 83.9% for PET/CT and 96.7%, 80.6%, 89.6%, and 93.5% for PHOX2B of BM, respectively.

Conclusions

BMUP of pretreatment ¹⁸F-FDG PET/CT is a simple and practical method, which has a relatively high diagnostic efficiency in detecting BMI and might decrease unnecessary invasive inspections in some pediatric NB patients.

Diagnostic Accuracy and Prognostic Relevance of Immunoglobulin Heavy Chain Rearrangement and 18F-FDG-PET/CT Compared With Unilateral Bone Marrow Trephination for Detecting Bone Marrow Involvement in Patients With Diffuse Large B-Cell Lymphoma

BACKGROUND

In diffuse large B-cell lymphoma (DLBCL), bone marrow involvement (BMI) has an important clinical implication as a component of staging and International Prognostic Index. This study aimed to determine whether molecular analysis of immunoglobulin heavy chain (IgH) genes and positron emission tomography-computed tomography (PET/CT) could overcome the limitation of defining morphologic BMI by trephination biopsy and could increase the diagnostic accuracy or prognostic prediction.

METHODS

A total of 94 de novo patients with DLBCL underwent PET/CT, polymerase chain reaction (PCR) test for detection of IgH gene rearrangement, and unilateral bone marrow (BM) trephination at diagnosis.

RESULTS

A total of 9 patients (9.6%) were confirmed to present morphologic BMI (mBMI) based on trephination biopsy. On the other hand, 21 patients (22.3%) were confirmed to have IgH clonality (IgH BMI), while 16 (17.0%) were classified with BMI based on the assessment of PET/CT (PET BMI). Each IgH rearrangement PCR and PET/CT showed the high negative predictive value of detecting the BMI. However, the combined assessment of IgH rearrangement and PET/CT could increase the diagnostic accuracy and specificity with 87.2% and 97.0%, respectively. The survival outcome of patients with double positive PET BMI and IgH BMI was significantly worse than that with either single positive PET BMI or IgH BMI, and even less than patients with neither PET BMI nor IgH BMI (3-year PFS: 50.0% vs. 75.4% vs. 97.9%, P = 0.007, 3-year OS: 50.0% vs. 75.6% vs. 80.1%, P = 0.035, respectively).

CONCLUSION

This study suggests that the combined evaluation of PET/CT and IgH rearrangement could give additional information for predicting therapeutic outcomes in patients with negative morphologic BMI as an important part of the prognosis.

Baseline 18F-FDG PET textural features as predictors of response to chemotherapy in diffuse large B-cell lymphoma

PURPOSE

We sought to investigate the performance of radiomics analysis on baseline 18F-FDG PET/CT for predicting response to first-line chemotherapy in diffuse large B-cell lymphoma (DLBCL).

MATERIAL AND METHODS

Forty-five patients who received first-line rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) chemotherapy for DLBCL were included in the study. Radiomics features and standard uptake value (SUV)-based measurements were extracted from baseline PET images for a total of 147 lesions. The selection of the most relevant features was made using the recursive feature elimination algorithm. A machine-learning model was trained using the logistic regression classifier with cross-validation to predict treatment response. The independent predictors of incomplete response were evaluated with multivariable regression analysis.

RESULTS

A total of 14 textural features were selected by the recursive elimination algorithm, achieving a feature-to-lesion ratio of 1:10. The accuracy and area under the receiver operating characteristic curve of the model for predicting incomplete response were 0.87 and 0.81, respectively. Multivariable analysis revealed that SUVmax and gray level co-occurrence matrix dissimilarity were independent predictors of lesions with incomplete response to first-line R-CHOP chemotherapy.

CONCLUSION

Increased textural heterogeneity in baseline PET images was found to be associated with incomplete response in DLBCL.

Prognostic significance of bone marrow 2-[18F]-fluoro-2-deoxy-d-glucose uptake in diffuse large B-cell lymphoma: relation to iliac crest biopsy results

AIM

To investigate the prognostic significance of bone marrow (BM) 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) uptake in relation to posterior iliac crest BM biopsy (BMB) results in diffuse large B-cell lymphoma (DLBCL).

MATERIALS AND METHODS

Pretreatment integrated positron-emission tomography(PET)/computed tomography (CT) images of 512 DLBCL patients who underwent BMB and received rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy were analysed retrospectively. BM uptake was assessed visually and by maximum standard uptake value (SUVmax). Associations with lymphoma-specific survival (LSS) were assessed using Kaplan-Meier and Cox regression analyses.

RESULTS

FDG(+) BM was observed in 64 cases (41 focal, 12 heterogeneous, 11 diffuse). This finding distinguished iliac crest involvement (positive in 59 and negative in 453) with 89.6% accuracy (459/512) and 93.6% specificity (424/453). In BMB(+) patients, BM-to-liver SUVmax ratio >1.8 concurred perfectly with FDG(+) BM. During 52 months of follow-up, there were 156 lymphoma-related deaths. In the entire population, multivariate analysis revealed high International Prognostic Index (IPI; p<0.001), old age (p=0.003), bulky disease (p=0.011), BMB(+) (p=0.028), and FDG(+) BM (p=0.019) as independent predictors of worse LSS. In the BMB(+) subgroup, high National Comprehensive Cancer Network-revised IPI (NCCN-IPI; p=0.029) and FDG(+) BM (p=0.008) were significant independent predictors. Among BMB(+) patients with low to low-intermediate NCCN-IPI, FDG(+) BM was associated with significantly worse 2-year LSS (33.3% versus 100%; p=0.017). The same was true among those with high-intermediate NCCN-IPI (34.7% versus 76.9%.; p=0.026).

CONCLUSION

Increased BM FDG in DLBCL is a predictor of worse LSS independent of BMB results and other prognostic variables including IPI/NCCN-IPI.

Correlation of texture feature analysis with bone marrow infiltration in initial staging of patients with lymphoma using 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography

Purpose

To explore whether radiomic features of fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomo-graphy-computed tomography (PET/CT) has association with bone marrow infiltration (BMI) in comparison to other conventional PET metrics.

Material and methods

Forty-four patients (with pathologically proven lymphoma disease) underwent staging ¹⁸F-FDG PET/CT scan. Primary tumour was semi-automatically or manually segmented with a threshold standardised uptake value (SUV) of 3. A total of 73 features were extracted from eight different textures. Spearman correlation was used to test the correlation of features with conventional quantitative metrics such as SUV, metabolic tumour volume, and total lesion glycolysis. Specificity and sensitivity (including 95% confidence intervals [CI]) for each of the studied parameters were derived using receiver operative characteristic (ROC) curves. Univariate and multivariate analyses were used to identify independent predictors associated with BMI.

Results

Correlation between conventional PET metrics and features ranged between 0.50 and 0.97 for positive correlation (33 significant association features) and ranged from -0.52 to -0.97 for inverse correlation (three significant association features) for both strong and moderate correlations. Analysis of ROC curves showed that high-intensity long-run emphasis 4 bin, high-intensity large zone emphasis 64 bin, long-run emphasis (LRE) 64 bin, large-zone emphasis 64 bin, max spectrum 8 bin, busyness 64 bin, and code similarity 32 and 64 bin were significant discriminators of BMI among other features (area under curve > 0.682, p < 0.05). Univariate analyses of texture features showed that code similarity and long-run emphasis (both 64 bin) were significant predictors of bone marrow involvement. Multivariate analyses revealed that LRE (64 bin, p = 0.031) with an odds ratio of 1.022 and 95% CI of (1.002-1.043) were independent variables for bone marrow involvement.

Conclusions

¹⁸F-FDG PET/CT radiomic features are synergistic to visual assessment of BMI in patients diagnosed with lymphoma using ¹⁸F-FDG PET/CT. Further assessment of long-run emphasis is highly warranted.

The Role of Integrated Positron Emission Tomography/Computed Tomography (PET/CT) and Bone Marrow Examination in Staging Large B-Cell Lymphoma

Introduction:

In the era of routine use of positron emission tomography/computed tomography (PET/CT) for staging, it is not yet clear whether PET/CT can replace bone marrow biopsy for the assessment of bone marrow involvement in large B-cell lymphoma.

Objectives:

To compare the clinical utility of bone marrow biopsy and PET/CT scanning in the staging of large B-cell lymphoma.

Methods:

This was a retrospective analysis of all patients who presented to single center over a 4-year period with large B-cell lymphoma who had concurrent PET/CT and bone marrow biopsy performed in the assessment and staging of the lymphoma.

Results:

Out of 89 patients, 24 had bone marrow involvement either by PET/CT, by bone marrow biopsy, or by both. Bone marrow biopsy identified 12 patients (sensitivity 50%, specificity 100%, negative predictive value 84%), whereas PET/CT identified 23 patients (sensitivity 96%, specificity 100%, negative predictive value 98%). No patients were upstaged by the bone marrow biopsy result, and no patients had their treatment plan changed based on the bone marrow biopsy result.

Conclusion:

The results show that PET-CT is more sensitive and has better negative predictive value than bone marrow biopsy. This suggests that PET-CT could replace bone marrow biopsy in detecting bone marrow involvement for staging of large B-cell lymphoma.

The value of 18F-FDG PET/CT in the prediction of clinical outcomes of patients with acute leukemia treated with allogeneic hematopoietic stem cell transplantation

The present study aimed to determine whether ¹⁸F-FDG PET/CT performed before and/or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) can predict clinical outcomes in acute leukemia (AL). A total of 79 examinations comprising 72 patients with AL who underwent ¹⁸F-FDG PET/CT before and/or after allo-HSCT were retrospectively enrolled between January 2011 and January 2019. Outcomes were assessed using overall survival (OS) and disease-free survival (DFS). A total of 63 examinations were PET-positive, while 16 examinations were PET-negative. Increased BM and splenic ¹⁸F-FDG uptake were observed in 24 (19/79) and 14% (11/79) of examinations, respectively. ¹⁸F-FDG-avid lymph nodes were observed in 38% (30/79) of examinations. E_NE_ME_S involvement was detected in 44% (35/79) of examinations. The presence of E_NE_ME_S involvement [OS hazard ratio (HR), 6.399; 95% confidence interval (CI), 1.843–22.224; P=0.003; post-HSCT OS: HR, 7.203; 95% CI, 1.510–34.369; P=0.013; DFS HR, 3.671; 95% CI, 1.145–11.768; P=0.029], post-transplantation minimal residual disease (DFS HR, 4.381; 95% CI, 1.594–12.040; P=0.004; pre-HSCT OS HR, 11.455; 95% CI, 1.336–98.179; P=0.026) and disease status (OS HR, 0.330; 95% CI, 0.128–0.848; P=0.021; post-HSCT OS HR, 0.195; 95% CI, 0.050–0.762; P=0.019; DFS: HR, 0.278; 95% CI, 0.091–0.851; P=0.025) could serve as an adverse prognostic factor in patients with AL treated with allo-HSCT. ¹⁸F-FDG PET/CT before and/or after allo-HSCT was a predictor for OS and DFS in patients with AL. E_NE_ME_S involvement detected using ¹⁸F-FDG PET/CT may help identify patients with AL who are likely to have unfavorable clinical outcomes.

Association of progression-free or event-free survival with overall survival in diffuse large B-cell lymphoma after immunochemotherapy: a systematic review

To investigate progression-free survival (PFS) and event-free survival (EFS) as early efficacy endpoints in diffuse large B-cell lymphoma (DLBCL), this systematic review included phase III randomized controlled trials (RCTs), phase II trials, and retrospective studies in newly diagnosed DLBCL receiving rituximab-containing chemotherapy through databases search up to 2019. Quality control was performed, where studies with high risk of bias were excluded. Prediction models were first established using the RCTs, and then externally validated in the phase II and retrospective populations. Trial-level surrogacy analysis was conducted by correlating the logarithmic (log) hazard ratio (HR) for PFS or EFS and log HR for OS. Correlation analysis at treatment arm-level was performed between 1-, 2-, 3-, and 5-year PFS or EFS rates and 5-year OS. The correlation was evaluated using the Pearson correlation coefficient r in weighted linear regression, with weight equal to patient size. Sensitivity analyses were performed to assess the consistency of predictive model by leaving one subgroup of trials out at a time. Twenty-six phase III RCTs, 4 phase II trials and 47 retrospective studies were included. In trial-level surrogacy, PFS (r, 0.772; 95% confidence interval [CI], 0.471-0.913) or EFS (r, 0.838; 95% CI, 0.625-0.938) were associated with OS. For rituximab immunochemotherapy treatment arms in RCTs, there was a linear correlation between 1 and 5-year PFS (r, 0.813-0.873) or EFS (r, 0.853-0.931) and 5-year OS. Sensitivity analysis demonstrated reasonable overall consistency. The correlation between PFS and OS was externally validated using independent phase II, and retrospective data (r, 0.795-0.897). We recommend PFS and EFS as earlier efficacy endpoints in patients with DLBCL primarily treated with rituximab-containing immunochemotherapy.

BISPHOSPHONATES FOR THE TREATMENT OF CALCITRIOL-INDUCED HYPERCALCEMIA

Objective

Calcitriol excess is a less common cause of hypercalcemia than hyperparathyroidism. Hypercalcemia due to calcitriol excess is usually managed acutely with intravenous (IV) fluid administration and dietary calcium restriction. Steroids and ketoconazole are second-line agents. There is evidence supporting the role of bone resorption in the genesis of hypercalcemia in vitamin D intoxication and for a rapid response of hypercalcemia to treatment with bisphosphonates. We seek to demonstrate the utility of bisphosphonates in calcitriol-induced hypercalcemia (CIH).

Methods

We present the case of a patient with recurrent CIH from a follicular lymphoma who achieved normalization and subsequent stabilization of serum calcium levels following bisphosphonate administration.

Results

A 77-year-old woman with a history of non-small cell lung cancer was admitted with dry mouth, polyuria, weight loss, and fatigue. She was found to have a calcium level of 14.7 mg/dL (normal range is 8.5 to 10.2 mg/dL), 25-hydroxyvitamin D of 47 ng/mL (normal range is 30 to 60 ng/mL), 1,25-dihydroxyvitamin D of 89 pg/mL (normal range is 18 to 72 pg/mL), and parathyroid hormone of 19 pg/mL (normal range is 15 to 65 pg/mL), which recurred despite treatment with IV fluids and strict low-calcium diet. She received 5 mg of IV zoledronic acid and normocalcemia was maintained thereafter, without any diagnosis-specific treatment for >3 months. Positron emission tomography with computed tomography eventually showed new innumerable foci of increased uptake in the skeleton and lymph node biopsy revealed grade 3A follicular lymphoma.

Conclusion

The first choice for CIH is treating the underlying cause. Bisphosphonates are, however, useful until a diagnosis is made, as they may be safer than steroids and can provide rapid relief even with a single treatment with minimal side effects.

Prediction of Overall Survival and Progression-Free Survival by the 18F-FDG PET/CT Radiomic Features in Patients with Primary Gastric Diffuse Large B-Cell Lymphoma

Purpose. To determine whether the radiomic features of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) contribute to prognosis prediction in primary gastric diffuse large B-cell lymphoma (PG-DLBCL) patients. Methods. This retrospective study included 35 PG-DLBCL patients who underwent PET/CT scans at West China Hospital before curative treatment. The volume of interest (VOI) was drawn around the tumor, and radiomic analysis of the PET and CT images, within the same VOI, was conducted. The metabolic and textural features of PET and CT images were evaluated. Correlations of the extracted features with the overall survival (OS) and progression-free survival (PFS) were evaluated. Univariate and multivariate analyses were conducted to assess the prognostic value of the radiomic parameters. Results. In the univariate model, many of the textural features, including kurtosis and volume, extracted from the PET and CT datasets were significantly associated with survival (5 for OS and 7 for PFS (PET); 7 for OS and 14 for PFS (CT)). Multivariate analysis identified kurtosis (hazard ratio (HR): 28.685, 95% confidence interval (CI): 2.067–398.152, p=0.012), metabolic tumor volume (MTV) (HR: 26.152, 95% CI: 2.089–327.392, p=0.011), and gray-level nonuniformity (GLNU) (HR: 14.642, 95% CI: 2.661–80.549, p=0.002) in PET and sphericity (HR: 11.390, 95% CI: 1.360–95.371, p=0.025) and kurtosis (HR: 11.791, 95% CI: 1.583–87.808, p=0.016), gray-level nonuniformity (GLNU) (HR: 6.934, 95% CI: 1.069–44.981, p=0.042), and high gray-level zone emphasis (HGZE) (HR: 9.805, 95% CI: 1.359–70.747, p=0.024) in CT as independent prognostic factors. Conclusion. ¹⁸F-FDG PET/CT radiomic features are potentially useful for survival prediction in PG-DLBCL patients. However, studies with larger cohorts are needed to confirm the clinical prognostication of these parameters.

18F-FDG PET-CT versus MRI for detection of skeletal metastasis in Ewing sarcoma

OBJECTIVE

To determine the level of discrepancy between magnetic resonance imaging (MRI) and ¹⁸F-FDG PET-CT in detecting osseous metastases in patients with Ewing sarcoma.

METHODS

Twenty patients with histopathologically confirmed Ewing sarcoma between 2000 and 2017 who underwent ¹⁸F-FDG PET-CT and MRI within a 4-week range were included. Each imaging modality was evaluated by a separate observer. Reference diagnosis of each lesion was based on histopathology or consensus of an expert panel using all available data, including at least 6 months' follow-up. Sensitivity, specificity, and predictive values were determined. Osseous lesions were analyzed on a patient and a lesion basis. Factors possibly related to false-negative findings were evaluated using Pearson's Chi-squared or Fisher's exact test.

RESULTS

A total of 112 osseous lesions were diagnosed in 13 patients, 107 malignant and 5 benign. Seven patients showed no metastases on either ¹⁸F-FDG PET-CT or MRI. Forty-one skeletal metastases (39%) detected with MRI did not show increased ¹⁸F-FDG uptake on ¹⁸F-FDG PET-CT (false-negative). Lesion-based sensitivities and specificities were 62% (95%CI 52-71%) and 100% (48-100%) for ¹⁸F-FDG PET-CT; and 99% (97-100%) and 100% (48-100%) for MRI respectively. Bone lesions were more likely to be false-negative on ¹⁸F-FDG PET-CT if hematopoietic bone marrow extension was widespread and active (p = 0.001), during or after (neo)-adjuvant treatment (p = 0.001) or when the lesion was smaller than 10 mm (p < 0.001).

CONCLUSION

Although no definite conclusions can be drawn from this small retrospective study, it shows that caution is needed when using ¹⁸F-FDG PET-CT for diagnosing skeletal metastases in Ewing sarcoma. Poor contrast between metastases and active hematopoietic bone marrow, chemotherapeutic treatment, and/or small size significantly decrease the diagnostic yield of ¹⁸F-FDG PET-CT, but not of MRI.