[18F-FDG PET/CT Metabolic Parameters and Circulating Tumour DNA Mutation Abundance in Diffuse Large B-Cell Lymphoma: Correlation and Survival Analysis].

OBJECTIVE: To investigate the correlation between 18Fluoro-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) metabolic parameters and peripheral blood circulating tumour DNA (ctDNA) in patients with diffuse large B-cell lymphoma (DLBCL), and the prognostic value of these two types of parameters in predicting progression-free survival (PFS). METHODS: Clinical, PET/CT and ctDNA data of DLBCL patients who underwent peripheral blood ctDNA testing and corresponding PET/CT scans during the same period were retrospectively analyzed. At the time of ctDNA sampling and PET scan, patients were divided into baseline and relapsed/refractory (R/R) groups according to different disease conditions. CtDNA mutation abundance was expressed as variant allele frequency (VAF), including maximum VAF (maxVAF) and mean VAF (meanVAF). Total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG) were obtained by the 41% maximum normalized uptake value method, and the distance between the two farthest lesions (Dmax) was used to assess the correlation between PET parameters and ctDNA mutation abundance using Spearman correlation analysis. The receiver operating characteristic (ROC) curves were used to obtain the optical cut-off values of those parameters in predicting PFS in the baseline and R/R groups, respectively. Survival curves were outlined using the Kaplan-Meier method and log-rank test was performed to compare survival differences. RESULTS: A total of 67 DLBCL patients ï¼»28 males and 39 females, median age 56.0(46.0, 67.0) yearsï¼½ were included and divided into baseline group (29 cases) and R/R group (38 cases). Among these PET parameters, baseline TMTV, TLG, and Dmax were significantly correlated with baseline ctDNA mutation abundance, except for maximum standardized uptake value (SUVmax) (maxVAF vs TMTV: r=0.711; maxVAF vs TLG: r=0.709; maxVAF vs Dmax: r=0.672; meanVAF vs TMTV: r=0.682; meanVAF vs TLG: r=0.677; meanVAF vs Dmax: r=0.646). While in all patients, these correlations became weaker significantly. Among R/R patients, only TMTV had a weak correlation with meanVAF (r=0.376). ROC analysis showed that, the specificity of TMTV, TLG and Dmax in predicting PFS was better than mutation abundance, while the sensitivity of ctDNA mutation abundance was better. Except R/R patients, TMTV, TLG, Dmax, and VAF were significantly different at normal/elevated lactate dehydrogenase in baseline group and all patients (all P<0.05). Survival curves indicated that high TMTV (>109.5 cm3), high TLG (>2 141.3), high Dmax (>33.1 cm) and high VAF (maxVAF>7.74%, meanVAF>4.39%) were risk factors for poor PFS in baseline patients, while only high VAF in R/R patients (both maxVAF and meanVAF >0.61%) was a risk factor for PFS. CONCLUSION: PET-derived parameters correlate well with ctDNA mutation abundance, especially in baseline patients. VAF of ctDNA predicts PFS more sensitively than PET metabolic parameters, while PET metabolic tumour burden with better specificity. TMTV, TLG and VAF all have good prognostic value for PFS. PET/CT combined with ctDNA has potential for further studies in prognostic assessment and personalized treatment.

[Roles of PET/CT in Predicting the Prognosis of Diffuse Large B Cell Lymphoma Patients Treated with Chimeric Antigen Receptor T Cell Therapy].

OBJECTIVE: To investigate the prognosis prediction value of PET/CT in DLBCL patients treated with CAR-T therapy. METHODS: The effects of PET/CT were retrospectively explored on 13 R/R DLBCL patients who were treated with CAR-T therapy. Parameters reflecting tumor metabolic burden, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were measured before and after CAR-T treatment. RESULTS: Patients with larger baseline MTV or longer sum of longest diameters showed shorter overall survival (OS) time than those with low tumor burden. Patients achieved complete remission (CR), partial remission (PR) and minor remission (MR) determined by response evaluation criteria in lymphoma (RECIL) in 12 weeks showed progression-free survival and OS time superior to those of patients with no remission. In addition, it was found that 2 patients with residual masses classified as PR by contrast-enhanced CT of patients were evaluated as complete metabolic response by PET/CT imaging. CONCLUSION: PET/CT shows a great value in the evaluation of prognosis and response in CAR-T-treated R/R DLBCL patients.

Interim response in diffuse large B cell lymphoma on CT: what is the optimal size reduction (ΔSPD) for predicting outcome?

OBJECTIVES: To investigate whether there was an optimal interim size reduction (iΔSPD) cutoff value that could discriminate diffuse large B cell lymphoma (DLBCL) patients with poor prognosis. METHODS: This retrospective study enrolled 265 newly diagnosed DLBCL patients with baseline and interim (after 3 cycles) contrast-enhanced computed tomographic scan (CECT) available. Two radiologists evaluated CECT images and selected target lesions according to the Lugano Response Criteria. Lymph nodes greater than 15 mm in longest diameter (LDi) and extra-nodal lesions with LDi greater than 10 mm could be chosen as target lesions and used to calculate iΔSPD. A software tool, X-Tile, was used to calculate the optimal iΔSPD cutoff value to differentiate patients with good vs. poor prognosis. Receiver operating characteristic curve analysis, Cox regression analysis, and Kaplan-Meier analyses were further used to validate the optimal cutoff value. RESULTS: The optimal cutoff value of iΔSPD calculated by X-tile was 80%. Compared with 50% and 100%, 80% cutoff value had the intermediate sensitivity and specificity (57.75% and 86.69% for overall survival (OS), 48.98% and 92.22% for progression-free survival (PFS), respectively), but the maximal Youden index (0.4744 for OS, 0.4120 for PFS, respectively) and areas under the curve (0.737 [0.680, 0.789] for OS). Cox regression analysis also revealed that iΔSPD < 80% could independently predict an inferior OS and PFS (both p < 0.001) while neither iΔSPD < 50% nor iΔSPD = 100% could. CONCLUSIONS: iΔSPD with the cutoff value 80% is an independent predictor of PFS and OS for patients with DLBCL. Results suggest that treatment should be modified for patients with iΔSPD < 80%. KEY POINTS: • The aim of interim response assessment is to identify patients whose disease has not responded to or has progressed on induction therapy. • A cutoff value of 80% in size reduction (ΔSPD) is an independent predictor of PFS and OS for DLBCL patients and is better than 50%. • In DLBCL patients with interim ΔSPD < 80%, a change to a more efficient therapy should be considered.

The prognostic role of 18F-FDG PET/CT baseline quantitative metabolic parameters in peripheral T-cell lymphoma.

Objectives: The aim of this study is to investigate the prognostic significance of baseline maximum standard uptake value (SUVmax), whole body SUVmax (WBSUVmax), whole body metabolic tumor volume (WBMTV) and whole body total lesion glycolysis (WBTLG) in patients with peripheral T-cell lymphoma (PTCL). Methods: Eighty patients with PTCL who underwent pretreatment 18F-PET/CT were enrolled in this study. WBMTV and WBTLG were computed by using the margin threshold of SUV>3.0. WBSUVmax was obtained by summing of SUVmax of the whole-body SUVmax of 11 nodal and 10 extra-nodal lesions. Results: Median SUVmax was 13.8 (range, 4.6-35.5), median WBSUVmax was 24.6 (range, 4.6-153.4), median WBMTV was 149 cm3 (range, 4-4545 cm3) and median WBTLG was 1017 (range, 16.5-23739). Six patients with anaplastic large cell lymphoma, ALK positive were excluded in the following statistical analysis for their unique pathological types and good prognosis. The receiver operating curve (ROC) analysis showed that the optimal cut-off values of WBSUVmax, WBMTV and WBTLG with overall survival (OS) were 22.2, 169.5 cm3 and 746.1, respectively. Patients with high WBSUVmax, WBMTV and WBTLG had a poor prognosis. WBSUVmax, WBMTV and WBTLG were associated with international prognostic index (IPI) and prognostic index for T-cell lymphoma (PIT). In multivariate analysis, WBTLG and PIT were independent prognostic factors of both progression free survival (PFS) and OS. Conclusions: Our study shows that high WBTLG, WBMTV and WBSUVmax could predict a relatively poor prognosis, and has a highly significant association with PIT and IPI.WBTLG could be an independent predictive factor for survival outcomes in patients with PTCL.

Prognostic Value of Baseline and Interim Total Metabolic Tumor Volume and Total Lesion Glycolysis Measured on 18F-FDG PET-CT in Patients with Follicular Lymphoma.

PURPOSE: The purpose of this study was to investigate the prognostic significance of total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG) in patients with follicular lymphoma (FL) at baseline and mid-treatment with 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans. METHODS: The study analyzed data from 48 patients with FL who were treated in Jiangsu Province Hospital and reviewed their baseline PET-CT scans. TMTV and TLG were computed by using the absolute value of 2.0, 2.5, and 3.0 thresholding method, respectively. RESULTS: Median age was 53 years, 75.0% of patients had stage III to IV disease, 43.8% had a Follicular Lymphoma International Prognostic Index 1 (FLIPI1) score of 3 to 5 and 20.8% had a FLIPI2 score of 3 to 5. Receiver operating characteristic (ROC) curve analysis showed the optimal cut-off values for TMTV3.0 and TLG3.0 were 476.4 (sensitivity, 85.7%; specificity, 78.0%; area under the curve [AUC], 0.760; p=0.003) and 2,676.9 (sensitivity, 71.4%; specificity, 78.0%; AUC, 0.760; p=0.003). On multivariable analysis, TMTV3.0 and TLG3.0 were independent predictors of both progression-free survival (PFS) (hazard ratio [HR], 5.406; 95% confidence interval [CI], 1.326 to 22.040; p=0.019 and HR, 6.502; 95% CI, 1.079 to 39.182; p=0.042) and overall survival (OS) (HR, 4.111; 95% CI, 1.125 to 15.027; p=0.033 and HR, 5.885; 95% CI, 1.014 to 34.148; p=0.049). ROC curve analysis showed the optimal cut-off values for ΔTMTV3.0 and ΔTLG3.0 were 66.3% (sensitivity, 85.7%; specificity, 63.4%; AUC, 0.774; p < 0.001) and 64.5% (sensitivity, 85.7%; specificity, 65.9%; AUC, 0.777; p < 0.001). CONCLUSION: Baseline TMTV and TLG are strong predictors of PFS and OS in FL. Furthermore, interim TMTV (ΔTMTV > 66.3%) and TLG (ΔTLG > 64.5%) reduction are valuable tools for early treatment response assessment in FL patients.

[18F-FDG PET/CT Manifestation and Clinical Analysis of Primary Hepatic Lymphoma].

OBJECTIVE: To explore the imaging characteristics of 18F-FDG PET-CT and clinical presentation of patients with primary hepatic lymphoma (PHL). METHODS: The 18F-FDG PET-CT image data of 6 patients with pathologically diagnosed PHL, were retrospectively analyzed. RESULTS: The six patients included 4 male cases and 2 female cases, with median age of 65 years old , and all the cases were diagnosed as diffuse large B-cell lymphoma. In regarding of 18F-FDG PET-CT imaging, all the cases showed hypodense masses and high FDG uptake, with homogenous density in 5 cases and necrostic area of low density in 1 case. The SUVmax was 6.3, 9.5, 12.8, 22.1, 28.4, and 33.5, respectively. Three typical PET-CT imaging findings were as follows: 4 cases appeared as multiple nodes, 1 case was the type of solitary mass, and 1 case was the type of diffuse infiltration. 5 cases showed a mild enhancement by CT scanning, and 2 cases displayed "blood vessel floating" in. In 2 cases, MRI scanning demonstrated low signal intensity on T1WI, and homogeneous signal intensity on T2WI with mild enhancement. CONCLUSION: The 18F-FDG PET-CT manifestation of PBL has a certain characteristics that can providt helpful to diagnose primary hepatic lymphoma.

[18F-FDG PET/CT Manifestation and Clinical Analysis of Subcutaneous Panniculitis-Like T-Cell Lymphoma].

OBJECTIVE: To explore the clinical presentation, imaging characteristics of 18F-FDG PET/CT and prognosis of patients with subcutaneous panniculitis-like T-cell lymphoma (SPTCL). METHODS: The images and clinical data of 7 patients with pathologically confirmed SPTCL who underwent 18F-FDG PET/CT were retrospectively analyzed. RESULTS: Six patients displayed multiple subcutaneous nodules or deeply seated plaques, most commonly on the extremities and trunk, and one patient showed a single lesion on his face. The ulceration of nodules occurred in 3 cases, and the lesions were painful in 5 cases. Both nodal and extranodal involvements were found in 2 cases, respectively. The SUVmax of cutaneous lesions in extremities and trunk were 3.8(1.1-11.3) and 3.9(1.0-10.1), with out significant difference (Z=-0.248, P>0.05), but significant difference was observed between the SUVmax cutaneous lesions with the CT value>0HU group and that of CT value≤0HU group [7.0(3.0-11.3) vs 1.8(1.0-6.9); Z=-7.523, P<0.01]. The SUVmax of all cutaneous lesions, nodal and extranodal involvement were 3.9(1.0-11.3), 5.2(2.1-13.1) and 6.2(4.0-11.4), respectively, with significant difference(P<0.05). The SUVmax of extranodal involvement was apparently higher than that of cutaneous lesions (P<0.05). However, no significant difference of the SUVmax was observed between nodal and extranodal involvement (P>0.0.5), also between nodal involvement and cutaneous lesions (P>0.05). Among 7 cases, 4 were died of multiple cutaneous lesions, and accompanied by hemophagocytic syndrome (HPS) in 3 cases, with median SUVmax of cutaneous lesions exceeded 3.0 in 3 cases, and nodal and extranodal involvement in 2 cases. CONCLUSION: The clinical manifestation of SPTCL is non-specific. 18F-FDG PET/CT is useful for defining the distribution and extent, finding visceral involvement, judging the malignant degree, predicting the prognosis, and making effective therapeutic plan.

[Value of Pretherapeutic 18F-FDG PET/CT in the Diagnosis, Staging and Prognosis Evaluation of Adult Burkitt's Lymphoma].

OBJECTIVE: To investigate the value of pretherapeutic 18F-FDG PET/CT in the focus detection, staging and prognosis evaluation of adult Burkitt's lymphoma(BL). METHODS: The clinical data and detection results of 18F-FDG PET/CT scan of 18 patients with BL before the treatment from December 2008 to February 2015 were analyzed retrospectively. The lesions distribution were observed, the maximal standard uptake value(SUVmax) of 18F-FDG by lesions and the maximal diameter of lymph nodes were measured. One-way analysis of variance was used to analyze the SUVmax, and the Spearman correlation was used to analyze the relationship between SUVmax and the maximum diameter of lymph nodes. The prognostic factors were analyzed by using Kaplan-Meier survival analysis. RESULTS: 18F-FDG PET/CT showed 100% positive detection rate for 18 adults with BL, lymph nodal lesions were found in all the patients, and the most common area was lymphonodi coeliaci (9/18, 50%), 8 cases showed extranodal soft tissue involvement, 6 cases showed gastrointestinal tract, bone marrow involvement was detected in 7 cases, out of which the mutiple-focal involvement was found in 4 cases. The median SUVmax of lymph nodes, extranodal soft tissue and bone marrow was 11.7 (range of 3.4 to 28.5), 9.85 (range of 6.7 to 21.9) and 11.8(range of 5.6 to 23.8), respectively, there were no significant differences among these 3 types of lesions (F=1.013, P=0.369). And the median SUVmax of all lesions was 16.5 (range of 8.8 to 28.5). The clinical staging of 2 patients (2/8, 11.1%) was changed by 18F-FDG PET/CT imaging. The univariate analysis revealed that only the IPI (international prognostic index) could be the prognostic factor (χ2=6.602, P=0.010), but the prognosis was not different between the patients below and above the median SUVmax of all lesions and lymph node (all P>0.05). CONCLUSION: BL in adult is an intensely 18F-FDG-avid tumor, the 18F-FDG PET/CT is an effective imaging tool for the detection and staging of this disease. In our study, the prognostic value of pretherapeutic 18F-FDG PET/CT still is unclear, that is not recommended for the prognosis of the adult BL patients.

[Clinical Value of 18F-FDG PET/CT for Patients with B Cell Lymphoma-Associated Hemophagocytic Syndrome].

OBJECTIVE: To investigate the clinical value of 18F-FDG PET/CT for patients with B cell lymphoma-associated hemophagocytic syndrome. METHODS: The clinical characteristics, laboratory parameters and 18F-FDG PET/CT data of 23 newly diagnosed patients sufferred from B cell lymphoma-associated hemophagocytic syndrome were retrospectively analyzed. The correlation between PET and laboratory parameters were determined using Spearman correlation test. The prognostic factors were analyzed by the Kaplan-Meier method. RESULTS: 23 patients were all examined by 18F-FDG PET/CT before chemotherapy, the 18F-FDG uptake of spleen positively correlated with neutrophil count and hemoglobin content (r=0.588, P=0.035;r=0.699, P=0.008), respectively, and the 18F-FDG uptake of bone marrow positively correlated with neutrophil count only (r=0.691, P=0.009). Among all the clinical or laboratorial parameters and 18F-FDG PET/CT, only PET parameter was poor factor affecting prognosis of patients with B cell lymphoma-associated hemophagocytic syndrome. Out of 6 patients received PET/CT scans after 6 cycles of treatment, the 5 patients with negative PET/CT survived, and one patient with positive result died. CONCLUSION: Baseline 18F-FDG PET/CT may provide prognostic information for the management of patients with B cell lymphoma-associated hemophagocytic syndrome, and the data of 18F-FDG PET/CT before chemotherapy may predict the pregnosis of the patients with negative results, and the negative PET/CT results after chemotherapy betokens a better prognosis of patients.

Prognostic value of whole-body SUVmax of nodal and extra-nodal lesions detected by 18F-FDG PET/CT in extra-nodal NK/T-cell lymphoma.

We analyzed data from 54 newly-diagnosed persons with extra-nodal natural killer/T-cell (NK/T) lymphoma, who had a pretreatment 18F-FDG PET/CT study, to determine whether the sum of SUVmax of all the nodal and extra-nodal lesions predicted progression-free survival (PFS) and/or overall survival (OS). Three models (WB1SUVmax, WB2SUVmax, WB3SUVmax) based on the basis of the sum of SUVmax of the whole-body SUVmax of 11 nodal and 10 extra-nodal lesions were tested. The discrimination value of these models was evaluated using time-dependent receiver-operator characteristic (ROC) curves and corresponding areas under the curve (AUC) in training and validation cohorts. Findings were validated in an independent cohort of 15 subjects. ROC curve analysis showed the optimal cut-off values for WB1SUVmax, WB2SUVmax and WB3SUVmax were 15.8 (sensitivity 92%, specificity 67%, AUC 0.811; P<0.001), 12.7 (sensitivity 96%; specificity 57%; AUC 0.785; P<0.001) and 15.8 (sensitivity 88%; specificity 70%; AUC 0.793; P<0.001). Multivariate analyses indicated WB3SUVmax was independently associated with PFS (hazard ratio [HR]=3.67, 95% confidence interval [95% CI]=1.19, 11.29; P=0.023) and OS (HR= 4.51 [1.02, 19.91]; P=0.047). WB3SUVmax calculated based of the sum of the SUVmax of 3 nodal and 10 extra-nodal lesions was significantly associated with PFS and OS.

[PET-CT Manifestation and Clinical Analysis of Waldenstrom Macroglobulinemia].

OBJECTIVE: To investigate the PET-CT manifestation and clinical features of patients with Waldenstrom macroglobulinemia(WM) . METHODS: The clinical features, laboratorial examination results and PET-CT manifestation of 12 patients with WM were analyzed retrospectively. RESULTS: The average age of 12 patients with WM was 63.5 years old, the most common incipient symptoms were fatigue and hyperviscosity syndrome. The median SUVmax of bone marrow was 4.9 (range of 2.1 to 21.9), with diffusely increased 18F-FDG uptake in all the patients. In 6 patients, the median SUVmax of splenomegaly and lymphadenectasis was 3.2 (range of 2.3 to 5.2) and 5.2 (range of 3.6 to 11.2), respectively. The SUVmax of bone marrow, splenomegaly and lymphadenectasis did not related with white blood cell count, hemoglobin level, blood platelet count, ß2- microglobulin level and serum monoclonal IgM of such patients, respectively (both P>0.5). In univariate analysis, serum monoclonal IgM and the SUVmax of lymphadenectasis were found to be the prognostic factors (both P<0.5). CONCLUSION: The 18F-FDG PET-CT feature of Waldenstrom macroglobulinemia has some characteristics which are helpful for setting up the clinical therapeutic schedule.

Thymic hyperplasia after chemotherapy in adults with mature B cell lymphoma and its influence on thymic output and CD4(+) T cells repopulation.

To investigate the thymic regenerative potential in adults accepting chemotherapy for lymphoma. The dynamics of thymic activity in 54 adults from baseline to 12 mo post-chemotherapy was analyzed by assessing thymic structural changes with serial computed tomography (CT) scans, and correlating these with measurements of thymic output by concurrent analysis of single-joint (sj) T-cell receptor excision circles (sjTREC) and CD31(+) recent thymic emigrants (RTE) in peripheral blood. Furthermore, the consequence of thymic renewal on peripheral CD4(+) T cell recovery after chemotherapy was evaluated. Time-dependent changes of thymic size and thymic output assessed by both sjTREC levels and CD31(+) RTE counts in peripheral blood were observed during and after chemotherapy. Enlargement of thymus over baseline following chemotherapy regarded as rebound thymic hyperplasia (TH) was identified in 20 patients aged 18-53 y (median 33 y). By general linear models repeated measure analysis, it was found that, patients with TH (n = 20) had a faster recovery of sjTREC levels and CD31(+) RTE counts after chemotherapy than patients with comparable age, gender, diagnosis, disease stage, thymic volume and output function at baseline but without TH (n = 18) (p = 0.035, 0.047); besides, patients with TH had a faster repopulation of both naïve CD4(+) T cell and natural regulatory CD4(+) T cell subsets than those without TH (p = 0.042, 0.038). These data suggested that adult thymus retains the capacity of regeneration after chemotherapy, especially in young adults. The presence of TH could contribute to the renewal of thymopoiesis and the replenishment of peripheral CD4(+) T cell pool following chemotherapy in adults.

Investigating Factors Associated with Thymic Regeneration after Chemotherapy in Patients with Lymphoma.

The factors involved in thymus regeneration after chemotherapy has not been sufficiently explored. This study was aimed to identify the clinical characteristics and single-nucleotide polymorphisms in the gene (IL7R) encoding IL-7Rα associated with thymus renewal after chemotherapy in Chinese Han individuals with lymphoma. The dynamics of thymic activity in 134 adults with Hodgkin lymphoma (HL) and B cell lymphoma from baseline to 12 months post-chemotherapy were analyzed by assessing thymic structural changes using serial computed tomography scans and correlating these with measurements of thymic output by concurrent analysis of single-joint T-cell receptor excision circles (sjTREC) and CD31+ recent thymic emigrants (RTE) in peripheral blood. The association of clinical variables and IL7R polymorphisms with the occurrence of rebound thymic hyperplasia (TH) and the recovery of thymic output following chemotherapy were evaluated. Thymic regeneration was observed, with the evidence that TH occurred in 38/134 (28.4%) cases, and thymic output, assessed by CD31+ RTE numbers and sjTREC content, recovered to baseline levels within 1 year after the end of therapy. The frequencies of the T allele and TT + GT genotype of rs7718919 located in the promoter of IL7R were significantly higher in patients with TH compared with those without TH (P = 0.031 and 0.027, respectively). In contrast, no significant difference was found between two groups with respect to the distribution of allele and genotype frequencies of rs6897932. By general linear models repeated-measure analysis, rs7718919 and rs6897932 were determined to exert no significant effects on the recovery of thymic output after therapy. Univariate analysis revealed host age under 30, the diagnosis of HL, baseline thymic index and CD31+ RTE counts, and rs7718919 genotype as potential predictors for TH after chemotherapy (P < 0.05); after multivariate adjustment, only host age was independently associated with the occurrence of TH (odds ratios = 4.710, 95% confidence intervals: 1.727-12.845, P = 0.002). These findings indicate that patient age is an independent predictor for thymic regrowth after chemotherapy, which should promote awareness among physicians to make a timely diagnosis of TH in young adults and help physicians to prioritize intervention strategies for thymus rejuvenation in this population.

Exploring the role of bone marrow increased FDG uptake on PET/CT in patients with lymphoma-associated hemophagocytic lymphohistiocytosis: a reflection of bone marrow involvement or cytokine storm?

The role of 18F-2-fluoro-2-deoxy-D-glucose (FDG) uptake of bone marrow (BM) on positron emission tomography/computed tomography (PET/CT) in patients with lymphoma-associated hemophagocytic lymphohistiocytosis (LA-HLH) remains uncertain. This retrospective study included 34 LA-HLH patients who underwent both PET/CT and comprehensive BM examinations prior to treatment. Comparison between PET/CT and BM examinations for the assessment of bone marrow involvement (BMI) indicated statistical difference (p = 0.039). The specificity of PET/CT in detecting BMI was 11.1% compared to BM examinations. However, a significant correlation was found between PET parameters of BM and laboratory parameters associated with HLH, such as C-reactive protein, ferritin, fibrinogen and soluble CD25. By multivariate analysis, PET parameters of marrow were significantly associated with overall survival. The findings suggest that FDG uptake of marrow might fail to detect lymphomatous BMI, but reflected the level of cytokine storm to a certain extent and might be a prognostic factor in patients with LA-HLH.

[Prognostic Value of Maximum Standard Uptake on Pretreatment ¹8F-FDG PET/CT Scan in Newly Diagnosed Follicular Lymphoma].

OBJECTIVE: To determine the prognostic value of maximum standard uptake (SUV(max)) of pretreatment ¹8F-FDG PET/CT scan in newly diagnosed follicular lymphoma (FL). METHODS: The clinical data and detection results of ¹8F-FDG PET/CT scan of 30 patients with FL before treatment from November 2005 to October 2013 were analyzed retrospectively. The relation of SUV(max) with prognostic factors, therapeutic efficacy and survival time was evaluated in term of pathologic grade, FLIPI2 absence and presence of bulky disease and bone marrow involvement, clinical indicators and outcome of treatment. RESULTS: There was significant differences of SUV(max) among pathological grade 1, grade 2 and grade 3 (P = 0.040), but no significant difference was found among FLIPI 2 low risk group, intermediate risk group and high risk groups (P = 0.431). No difference of SUV(max) was observed in patients with and without bulky disease, or with and without bone marrow involvement (both P > 0.05). SUV(max) was not related with such patient characteristics as stage, ß2-microglobulin level, hemoglobin content, lactate dehydrogenase and Ki-67 (both P > 0.05). And the difference of SUV(max) was no significant for patients with complete remission (CR) and non-CR, or with efficacy and no efficacy (both P > 0.05). With the cutoff values of 10 and 15, the CR rate, overall response rate, 3-year progression-free survival (PFS) rate and 2-year overall survival (OS) rate were not different between the patients with SUV(max) below and above cut-off value (both P > 0.05). CONCLUSION: In our study the prognostic value of SUV(max) on PET/CT is indeterminate, and it can not be used to predict the FL patients prognosis.

[Value of PET/CT after Chemotherapy for Evaluating Therapentic Efficacy of Patients with Diffuse Large B-cell Lymphoma].

OBJECTIVE: To investigate the value of PET/CT after chemotherapy for evaluating therapeutic efficacy of patients with diffuse large B-cell lymphoma (DLBCL). METHODS: (18)F-FDG PET/CT was performed before and after 6-8 cycles of chemotherapy in 73 newly diagnosed patients with DLBCL from September 2005 to January 2012. The results of pre-treatment PET/CT was compared with results of post-treatment PET/CT. These patients were divided into 3 groups: complete response group, partial response group and no response group. The post-treatment PET/CT results was used to assess its ability to predict progression-free survival (PFS) and overall survival (OS). RESULTS: The comparison of PET/CT results before and after chemotherapy showed that 2-year PFS rates of complete response group, partial response group and no response group were 82% (41/50), 45.5% (5/11) and 8.3% (1/12), respectively; and the 3-year OS rates of 3 groups were 88% (44/50), 54.5% (6/11) and 8.3% (1/12) respectively (both P < 0.01). The 2-year PFS rate and the 3-year OS rate of the complete response group and partial response group were significantly higher than those of no response group (both P < 0.05), and there was also significant statistical difference between partial response group and complete response group in 2-year PFS rate and 3-year OS rate (both P < 0.05). CONCLUSION: The post-treatment PET/CT can be accurately used to evaluate the curative efficacy of chemotherapy and prognosis of patients with DLBCL.

[Application of 18F-FDG PET/CT images in the newly diagnosed extranodal NK/T cell lymphoma].

OBJECTIVE: This study was to explore the use value of (18)F-FDG PET/CT in patients with extranodal NK/T cell lymphoma (ENKTL). METHODS: Both PET/CT and CT images were retrospectively analyzed in 43 newly diagnosed patients with ENKTL, and the anatomical position, extent of foci, subtypes, staging and therapeutic regimen determined by both these 2 imaging methods were compared, and relationship between the maximum standard uptake value (SUV(max)) and subtypes, different staging and constitutional symptoms were evaluated. RESULTS: The top four anatomical positions involved were nose (76.74%), pharynx nasalis (41.86%), Waldeyer's ring (30.23%) and paranasal sinus (27.91%), respectively according to the results of the PET/CT examination, and (18)F-FDG uptake was not found in four patients in the region of upper aerodigestive tract. The PET/CT staging was significantly correlated with constitutional symptoms (P < 0.01). The mean SUV(max) of 43 patients was 13.65 ± 6.35, and the SUV(max) of advanced stages (III/IV) was higher than that of early stage (I/II). Different staging results were found in 21 patients between PET/CT and CT images, 14 patients out of them had direct influence on the treatment plan. Staging of 8 cases was changed from early stage judged by CT image into advaneed stage judged by PET/CT, and radiotherapy regimen of 6 cases at early stage were altered because of the application of PET/CT. CONCLUSION: The location and scope of foci in ENKTL patients can be displayed more accurately by PET/CT, the PET/CT is more accurate and reliable than traditional CT image, and has considerable value in determining the treatment plan, and it should be applied in clinical practice widely.

Thymic hyperplasia following chemotherapy in adults with lymphoma: (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings and correlation with T cell repopulation.

Thymic hyperplasia (TH) after chemotherapy is an infrequent phenomenon in adults. This study analyzed the incidence and metabolic activity of TH on 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in this population. By reviewing 471 PET/CT recordings of 211 adults with lymphoma, increased FDG uptake within an enlarged thymus regarded as TH was observed in 27 patients aged 18-53 years. FDG uptake in hyperplastic thymus was mild and diffuse, with a maximum standard uptake value (SUVmax) of 2.6±0.9. Its intensity varied with different occurrence times following chemotherapy. In addition, by comparing the recovery of T cell subsets in patients with TH (n=20) and without TH (n=28), no impact of the presence of TH was found on the repopulation of total CD4+and CD8+T cells within the first year after treatment. These data may be helpful to avoid misinterpretation of increased thymic uptake in adults.

The significance of 18F-FDG PET/CT in secondary hemophagocytic lymphohistiocytosis.

This study was aimed to investigate the significance of 18F-FDG PET/CT in secondary hemophagocytic lymphohistiocytosis (sHLH) patients. A total of 18 patients received 18F-FDG PET/CT scan at initial diagnosis. All patients (18/18) had at least 3 organs involved, with increased FDG metabolism in different degrees. Fifteen cases (15/18) had definite underlying diseases, including infections (IAHLH), rheumatosis (RAHLH), or malignancy (MAHLH). The SUVmax of patients in MAHLH group was significantly higher than patients in IAHLH group or RAHLH group (P = 0.015, P = 0.045). Furthermore, the SUVmax of patients in IAHLH group was significantly higher than patients of RAHLH group (P = 0.043). Therefore, we concluded that 18F-FDG PET/CT may especially play important role in differential diagnosis of sHLH.