A metaanalysis of 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography in the staging and restaging of patients with lymphoma

Evaluating the cost-effectiveness of [18F]FDG-PET/CT for investigation of persistent or recurrent neutropenic fever in high-risk haematology patients

BACKGROUND

A recent randomised trial demonstrated [18F]fluorodeoxyglucose positron-emission tomography in combination with low-dose CT (FDG-PET/CT), compared to standard of care computed tomography (CT) imaging, positively impacted antimicrobial management and outcomes of acute leukaemia and haematopoietic stem cell transplant recipients with persistent and recurrent neutropenic fever. We conducted an economic evaluation from a healthcare perspective alongside the clinical trial.

METHODS

Unit costs in Australian dollars were applied to all resources used (antimicrobials, diagnostic tests, ICU and hospital bed days). Effectiveness was measured as number of patients with antimicrobial rationalisation, 6-month mortality and quality-adjusted life years (QALYs) derived from patient-reported trial-based health-related quality-of-life. Generalised linear models were used to analyse costs and outcomes. Incremental cost-effectiveness ratios (ICERs) for all outcomes and net monetary benefit (NMB) for QALYs were calculated. We performed bootstrapping with 1000 replications using the recycled predictions method.

RESULTS

The adjusted healthcare costs were lower for FDG-PET/CT (mean $49,563; 95%CI 36,867, 65,133) compared to CT (mean $57,574; 95% CI 44,837, 73,347). The difference in QALYs between the two groups was small (0.001; 95% CI -0.001, 0.004). When simulated 1000 times, FDG-PET/CT was the dominant strategy as it was cheaper with better outcomes than the standard CT group in 74% of simulations. The estimated NMBs at willingness-to-pay thresholds of $50,000 and $100,000 per QALY were positive, thus FDG-PET/CT remained cost-effective at these thresholds.

CONCLUSIONS

FDG-PET/CT is cost effective when compared to CT for investigation of persistent/recurrent neutropenic fever in high-risk patients, providing further support for incorporation of FDG-PET/CT into clinical guidelines and funding.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov, NCT03429387.

Fluorodeoxyglucose-Positron Emission Tomography in Relapsed/Refractory Hodgkin Lymphoma: A Practical Approach

BACKGROUND

Positron emission tomography (PET) with the use of 18F-fluorodeoxyglucose (FDG), implemented with low-dosage computer tomography, is to be considered as the most important evolution of imaging in the management and assessment of classical Hodgkin lymphoma patients.

SUMMARY

According to Lugano response criteria, FDG-PET is mandatory to define metabolic response to frontline therapy and moreover it is important in the definition of nonresponders or refractory disease patients. Refractory disease is reported in about 15% of patients, with some variations based on the choice of first-line chemotherapy, and particularly in advanced stages, up to 40% eventually relapse within 3 years.

KEY MESSAGES

The aim of this review was to highlight a practical way to use FDG-PET in the subset of HL, with some notes of its use in first-line patients, and particularly centered on relapsed or refractory setting with a final focus of the evaluation of response by FDG-PET in the new treatment era of immunocheckpoint inhibitors.

European Association of Nuclear Medicine (EANM) Focus 4 consensus recommendations: molecular imaging and therapy in haematological tumours

Given the paucity of high-certainty evidence, and differences in opinion on the use of nuclear medicine for hematological malignancies, we embarked on a consensus process involving key experts in this area. We aimed to assess consensus within a panel of experts on issues related to patient eligibility, imaging techniques, staging and response assessment, follow-up, and treatment decision-making, and to provide interim guidance by our expert consensus. We used a three-stage consensus process. First, we systematically reviewed and appraised the quality of existing evidence. Second, we generated a list of 153 statements based on the literature review to be agreed or disagreed with, with an additional statement added after the first round. Third, the 154 statements were scored by a panel of 26 experts purposively sampled from authors of published research on haematological tumours on a 1 (strongly disagree) to 9 (strongly agree) Likert scale in a two-round electronic Delphi review. The RAND and University of California Los Angeles appropriateness method was used for analysis. Between one and 14 systematic reviews were identified on each topic. All were rated as low to moderate quality. After two rounds of voting, there was consensus on 139 (90%) of 154 of the statements. There was consensus on most statements concerning the use of PET in non-Hodgkin and Hodgkin lymphoma. In multiple myeloma, more studies are required to define the optimal sequence for treatment assessment. Furthermore, nuclear medicine physicians and haematologists are awaiting consistent literature to introduce volumetric parameters, artificial intelligence, machine learning, and radiomics into routine practice.

Role of Artificial Intelligence in PET/CT Imaging for Management of Lymphoma

Our review shows that AI-based analysis of lymphoma whole-body FDG-PET/CT can inform all phases of clinical management including staging, prognostication, treatment planning, and treatment response evaluation. We highlight advancements in the role of neural networks for performing automated image segmentation to calculate PET-based imaging biomarkers such as the total metabolic tumor volume (TMTV). AI-based image segmentation methods are at levels where they can be semi-automatically implemented with minimal human inputs and nearing the level of a second-opinion radiologist. Advances in automated segmentation methods are particularly apparent in the discrimination of lymphomatous vs non-lymphomatous FDG-avid regions, which carries through to automated staging. Automated TMTV calculators, in addition to automated calculation of measures such as Dmax are informing robust models of progression-free survival which can then feed into improved treatment planning.

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.

A Comprehensive Biological and Synthetic Perspective on 2-Deoxy-d-Glucose (2-DG), A Sweet Molecule with Therapeutic and Diagnostic Potentials

Glucose, the primary substrate for ATP synthesis, is catabolized during glycolysis to generate ATP and precursors for the synthesis of other vital biomolecules. Opportunistic viruses and cancer cells often hijack this metabolic machinery to obtain energy and components needed for their replication and proliferation. One way to halt such energy-dependent processes is by interfering with the glycolytic pathway. 2-Deoxy-d-glucose (2-DG) is a synthetic glucose analogue that can inhibit key enzymes in the glycolytic pathway. The efficacy of 2-DG has been reported across an array of diseases and disorders, thereby demonstrating its broad therapeutic potential. Recent approval of 2-DG in India as a therapeutic approach for the management of the COVID-19 pandemic has brought renewed attention to this molecule. The purpose of this perspective is to present updated therapeutic avenues as well as a variety of chemical synthetic strategies for this medically useful sugar derivative, 2-DG.

Pineal gland hypermetabolic involvement without central nervous system symptoms in a pediatric patient with primary nodular sclerosis subtype classical Hodgkin Lymphoma

This case report presents the first reported pediatric case of primary classical nodular sclerosing Hodgkin Lymphoma (HL) with pineal gland involvement, presenting without CNS symptoms, which completely resolved after 2 cycles of chemotherapy. The 12 year-old male first presented with a right inguinal mass and external iliac lymphadenopathy accompanied by B symptoms. He was diagnosed with stage IV B classical HL, and as part of the staging work-up, a full-body PET/CT scan was performed. In addition to the right inguinal mass, the PET/CT demonstrated increased FDG uptake at the pineal gland along with level II lymph nodes. The patient was treated with ABVE-PC chemotherapy (Doxorubicin, Bleomycin, Vincristine, Etoposide, Prednisone, and Cyclophosphamide) as per standard arm of AHOD1331 COG protocol for newly diagnosed high-risk HL patients, which resolved the pineal mass after 2 cycles without requiring radiation therapy. Following 5 cycles, a full-body PET/CT showed no brain or neck activity, along with decreased size and activity of the right groin mass. To our knowledge, there are no other documented cases of primary HL with specific pineal involvement, and no cases that lack CNS symptoms altogether like this one did. Additionally, this is the third published pediatric case of primary CNS-HL, both of the previous cases were treated with radiotherapy and presented with CNS symptoms. Thus, this case demonstrates the importance of ordering a full-body PET/CT as part of the initial HL work-up and provides evidence that chemotherapy alone is a treatment option for some patients with primary intracranial HL.

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.

Development and validation of a prediction model for 1-year mortality among older adults with Hodgkin Lymphoma who receive dose-intense chemotherapy

BACKGROUND

Older adults with Hodgkin Lymphoma (HL) have poorer outcomes than younger patients. There are little data about which baseline patient and disease factors inform prognosis among older patients. We sought to create a prediction model for 1-year mortality among older patients with new HL who received dose-intense chemotherapy.

METHODS

We included adults ≥65 years old with a new diagnosis of classical HL between 2000-2013 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare dataset who received full-regimen chemotherapy. Through a non-random 2:1 split, we created development and validation cohorts. Multiple imputation was used for missing data. Using stepwise selection and logistic regression, we identified predictive variables for 1-year mortality. The model was applied to the validation cohort. A final model was then fit in the full cohort.

RESULTS

We included 1315 patients. In the development cohort (n = 813), we identified significant predictors of 1-year mortality including age, Charlson comorbidity index (CCI), B symptoms at diagnosis, and advanced stage at diagnosis. The c-statistic was 0.70. When this model was applied to the validation cohort (n = 502), the c-statistic was 0.65. Predictors of 1-year mortality in the final model were CCI (OR = 1.41), B symptoms (OR = 1.54), advanced stage (OR = 1.44), and older age at diagnosis (OR = 1.33).

CONCLUSION

We present a prediction model for use among older adults with HL who receive intensive chemotherapy. We identify risk factors for death within 1 year of diagnosis. Future work will build upon prognostication and shared decision-making after diagnosis for this population.

Post-Chemotherapy Histiocyte-Rich Pseudotumors: Radiologic and Endoscopic Mimics of Residual Lymphoma

Development of post-chemotherapy histiocyte-rich pseudotumor (PHP) is an underrecognized event following therapy in lymphoma patients and may mimic residual tumor using current therapy monitoring protocols. We report a series of 5 patients with PHP along with a review of the literature. In our series, we describe 3 patients with persistent hypermetabolic masses by positron emission tomography-computed tomography, one with persistent terminal ileal nodules on endoscopy, and one with bone marrow involvement, a site not associated with mass-like disease. Twenty-three patients with long-term follow-up were identified from our series and review of the literature. Forty-four percent of patients received additional therapy, and only 4% of patients died of lymphoma. This study illustrates that PHPs are not identified using current lymphoma therapy monitoring algorithms and may result in overtreatment with risk for additional therapy-related complications. The need for confirmatory tissue biopsy in this setting is recommended.

Outcomes Related to FDG-PET-CT Response in Patients With Hodgkin Lymphoma Treated With Brentuximab-Vedotin at Relapse or Consolidation

BACKGROUND

Brentuximab-vedotin (BV) monotherapy has shown high efficacy in heavily pre-treated patients with relapsed or refractory Hodgkin lymphoma (HL) after high-dose chemotherapy or autologous stem cell transplantation (ASCT). We retrospectively analyzed the outcomes of treatment with BV of HL patients and examined the predictive ability of PET-CT for response in this setting.

PATIENTS AND METHODS

Records of 49 HL patients (median age, 39 years, 55% male) treated with BV for relapse (71.4%) or consolidation (28.6%) post-ASCT were analyzed. Patients who did not reach complete response (CR) on PET/CT after 4 cycles (non-responders) discontinued BV and received the next treatment line. Overall survival (OS) and progression-free survival (PFS) were compared between responders and non-responders.

RESULTS

After a median follow-up of 19.1 months, all consolidation patients were alive and none progressed. Median OS in 23 relapsed patients that did not achieve CR after 4 cycles and continued to the next treatment was 55.0 months, while all those in CR (n = 24) were alive (P = .0120). No statistically significant differences in OS were observed between responders and non-responders with relapsed HL (P = .1072). Median PFS evaluated after 4 BV cycles was significantly longer in responders compared to non-responders (47.9 vs. 1.5 months, P < .0001). Neuropathy and neutropenia were the main toxicities observed.

CONCLUSIONS

HL patients treated with BV for relapse or consolidation who achieved CR by PET-CT after 4 cycles showed improved PFS and OS compared to non-responders. Non-responders treated for relapsed HL who proceeded to the next treatment line demonstrated comparable OS to responders.

SEGHI Study: Defining the Best Surveillance Strategy in Hodgkin Lymphoma after First-Line Treatment

The optimal strategy for early surveillance after first complete response is unclear in Hodgkin lymphoma. Thus, we compared the various follow-up strategies in a multicenter study. All the included patients had a negative positron emission tomography/computed tomography at the end of induction therapy. From January 2007 to January 2018, we recruited 640 patients from 15 centers in Spain. Comparing the groups in which serial imaging were performed, the clinical/analytical follow-up group was exposed to significantly fewer imaging tests and less radiation. With a median follow-up of 127 months, progression-free survival at 60 months of the entire series was 88% and the overall survival was 97%. No significant differences in survival or progression-free survival were found among the various surveillance strategies. This study suggests that follow-up approaches with imaging in Hodgkin lymphoma provide no benefits for patient survival, and we believe that clinical/analytical surveillance for this group of patients could be the best course of action.

Lugano classification: response evaluation criteria for positron emission tomography/computed tomography in lymphoma follow-up

Background

The purpose of this study is to assess the role of 18 fluorodeoxyglucose positron emission tomography/computed tomography (18FDG PET-CT) in the follow-up of patients with lymphoma after finishing therapy.

Results

This study included 42 lymphomas (25 non-Hodgkin’s lymphoma and 17 Hodgkin’s lymphoma); patients ranging in age from 18 to 70 years were examined by 18FDG PET-CT after therapy and analyzed retrospectively. Confirmatory biopsy was mandatory in cases of suspected disease recurrence and follow-up in cases of complete metabolic response. Positron emission tomography/computed tomography in assessment of lymphoma treatment response reveals significant statistical significance (P < 0.05). It shows 100% sensitivity, 92.8% specificity, and 95.2% accuracy in the prediction of response.

Conclusion

Positron emission tomography/computed tomography plays an important role in detection of response to treatment of lymphoma after finishing therapy.

Influence of oncogenic mutations and tumor microenvironment alterations on extranodal invasion in diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is an aggressive subtype of lymphoma, and multiple extranodal involvement (ENI) indicates adverse clinical outcomes. The aim of this study was to investigate the influence of oncogenic mutations and tumor microenvironment alterations on ENI in DLBCL.

METHODS

The clinical features of 1960 patients with newly diagnosed DLBCL were analyzed, and DNA and RNA sequencing was performed on 670 and 349 patients, respectively. Oncogenic mutations and tumor microenvironment alterations were compared according to ENI and evaluated in zebrafish patient-derived tumor xenograft models.

RESULTS

Multiple ENI was significantly associated with poor performance status, advanced stage, elevated serum lactate dehydrogenase, low response rate, and inferior prognosis. Lymphoma invasion of the bones, spleen, bone marrow, liver, and central nervous system were independent unfavorable prognostic factors. MYD88 was frequently mutated in patients with multiple ENI, co-occurred with mutations in CD79B, PIM1, TBL1XR1, BTG1, MPEG1, and PRDM1, and correlated with invasion of the bones, kidney/adrenal glands, breasts, testes, skin, and uterus/ovaries. For tumor microenvironment alterations, patients with multiple ENI showed higher regulatory T-cell (Treg)-recruiting activity, but lower extracellular matrix-encoding gene expression, than those without ENI and with single ENI. Elevated Treg-recruiting activity was related to mutations in B2M, SGK1, FOXO1, HIST1H1E, and ARID1A, and correlated with invasion of the bone marrow and thyroid. Additionally, mutations in MYD88, PIM1, TBL1XR1, SGK1, FOXO1, HIST1H1E, and ARID1A were associated with decreased major histocompatibility complex class I expression. Zebrafish models further revealed relationships between MYD88 mutations and invasion of the kidneys and gonads, as well as B2M mutations and invasion of the bone marrow. Increased CXCR4 expression is linked to bone marrow invasion in an organotropic way.

CONCLUSIONS

Our findings thus contribute to an improved understanding of the biological behavior of multiple ENI and provide a clinical rationale for targeting ENI in DLBCL.

Clinical Significance of Increased FDG Uptake in the Waldeyer Ring and the Nasopharynx Region Identified by PET-CT in Postchemotherapy Follow-up in Patients With Lymphoma: When Should We Perform Biopsy?

PURPOSE

To identify whether fluorodeoxyglucose (FDG) uptake in the Waldeyer ring (WR)/nasopharyngeal (NP) region by positron emission tomography-computed tomography (PET-CT) was physiologic or pathologic in the follow-up of lymphoma patients receiving postchemotherapy treatment.

PATIENTS AND METHODS

We retrospectively examined FDG uptake in the WR/NP region in 534 patients with lymphoma as assessed by PET-CT used for both diagnosis and follow-up.

RESULTS

Forty-nine patients had FDG uptake in the WR/NP region by PET-CT performed after completion of a chemotherapy regimen. Biopsy was performed for 11 of these patients in whom the uptake was considered to be pathologic, and results indicated the presence of reactive follicular hyperplasia. It was considered to be physiologic in 38 patients. PET-CT was repeated after 1 year, and no significant difference was identified between the standardized maximum uptake values (SUV_max; P = .107). The initial diagnosis of 20 patients was made via biopsy performed in the WR/NP region. The SUV_max for the FDG uptake in these patients, asymmetry, SUV_max of the coexisting lymphadenopathies in the neck, and FDG uptake with a counterpart finding by CT were significantly higher than other groups (P = .047, .001, and .005).

CONCLUSION

When deciding whether to resample after treatment completion, it should be taken into account that, in addition to the SUV_max of the lesion, asymmetry, and the SUV_max of the coexisting lymphadenopathy in the neck, a crucial criterion is whether the FDG uptake has a counterpart finding by CT.

Liver involvement in pediatric Hodgkin lymphoma: A systematic review by an international collaboration on Staging Evaluation and Response Criteria Harmonization (SEARCH) for Children, Adolescent, and Young Adult Hodgkin Lymphoma (CAYAHL)

Hepatic involvement in Hodgkin lymphoma (HL) is uncommon (∼5% of patients) but always implies stage IV disease. Accurate staging is mandatory for making the appropriate risk assignment and treatment decisions. The Staging Evaluation and Response Criteria Harmonization for Childhood, Adolescent and Young Adult Hodgkin Lymphoma (SEARCH for CAYAHL) international working group conducted a systematic literature review of liver involvement in HL patients with the aim to propose a universally acceptable definition for liver involvement in pediatric HL. Thirty-three articles describing 6985 pediatric and adult HL patients were reviewed, of which 539 (7.7%) mentioned liver involvement. The literature did not provide a uniform definition of hepatic involvement and we propose consensus criteria derived from the EuroNet and Children's Oncology Group protocols, where liver involvement is defined as any hepatic lesion on computed tomography scan that correlates with ¹⁸ F-FDG uptake greater than background liver. A clear definition of liver lesions is necessary to consistently identify liver involvement and compare its impact on outcomes among protocols worldwide.

Preliminary clinical assessment of dynamic 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for evaluating the clinicopathological grade in patients with non-Hodgkin's lymphoma: a prospective study

OBJECTIVE

We prospectively assessed the diagnostic capacity of dynamic and dual-time-point F-fluorodeoxyglucose PET/computed tomography and explored the most appropriate scan timing for clinicopathological discrimination of non-Hodgkin's lymphoma.

METHODS

Thirteen patients underwent dynamic scans dynamic scans (5-15, 15-25, and 25-35 minute postinjection) and consecutive dual-time-point scans (1- and 2-hour postinjection). For five indolent and 16 aggressive lymphomas, we statistically compared the maximum standardized uptake value (SUVmax) and the retention index of the SUVmax (RI-SUVmax) for each scan and explored the diagnostic capacities using receiver operating characteristic (ROC) curve analyses.

RESULTS

SUVmax increased progressively over time in all lymphomas and was significantly higher for aggressive lymphoma than for indolent lymphoma in each timephase. RI-SUVmax of dynamic scans (RI-SUV-dynamic) was significantly higher in aggressive than in indolent lymphoma. The cutoff values obtained a sensitivity of 94%, positive-predictive value of 94%, and accuracy of 91% for SUVmax analyses of the dynamic second and third phases, 1-hour early phase, and 2-hour delayed phase, and a sensitivity of 88%, positive-predictive value of 93%, and accuracy of 86% for RI-SUV-dynamic. In contrast, for the dynamic first phase, the cutoff value of SUVmax yielded moderate sensitivity of 69%, a positive-predictive value of 92%, and an accuracy of 71%. The area under the ROC curve (AUC) of the RI-SUV-dynamic had the highest value (0.938), whereas the AUCs of the other ROC analyses were not significantly different.

CONCLUSION

The dynamic second and third phase could potentially provide good predictors of clinicopathological discrimination, as can the early and delayed phases.

Hodgkin Lymphoma, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology for Hodgkin Lymphoma (HL) provide recommendations for the management of adult patients with HL. The NCCN panel meets at least annually to review comments from reviewers within their institutions, examine relevant data, and reevaluate and update their recommendations. Current management of classic HL involves initial treatment with chemotherapy alone or combined modality therapy followed by restaging with PET/CT to assess treatment response. Overall, the introduction of less toxic and more effective regimens has significantly advanced HL cure rates. This portion of the NCCN Guidelines focuses on the management of classic HL.

Computed tomography patterns of pulmonary and pleural involvement in lymphoma

Background

Pulmonary and pleural involvement is fairly common in patients with lymphoma, especially in the setting of progressive or recurrent disease. Pleuropulmonary involvement in lymphoma may occur as a single pattern or as a combination of multiple patterns which can often mimic unrelated pathologies.

Methods

Review of our institutional database from 01 Jan 2015 to 04 Oct 2017 revealed 90 patients with pulmonary and/or pleural lesions attributable to lymphoma. These lesions were classified into various categories, and the pattern of involvement was evaluated.

Results

Pulmonary involvement was seen in 17.6% of patients with Hodgkin lymphoma (HL) and in 10.5% of patients with non-Hodgkin lymphoma (NHL), whereas pleural involvement was seen in 6.5% of patients with NHL. Almost all the patients in our study had findings belonging to multiple categories. Pulmonary involvement in patients with HL was seen in the form of nodules (51.6%), masses (51.6%), and direct extension from a mediastinal/hilar mass (45.2%). Patients with NHL had pulmonary involvement in the form of nodules (42.4%), direct extension from a mediastinal/hilar mass (25.4%), pulmonary masses (18.6%), and interstitial pattern (2.4%). Pleural thickening (61.5%), masses (30.8%), and effusion (15.4%) were the three patterns of pleural involvement.

Conclusion

Nodules and masses were the two commonest patterns of pulmonary involvement in patients with HL, whereas nodules were the commonest pattern noted in patients with NHL. Pulmonary masses were seen more commonly in patients with HL than in those with NHL. Pleural involvement was seen exclusively in patients with NHL.

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

Purpose

Post-transplant lymphoproliferative disorder (PTLD) is a serious complication after solid organ and hematopoietic stem cell transplantation, requiring a timely and accurate diagnosis. In this study, we evaluated the diagnostic performance of FDG-PET/CT in patients with suspected PTLD and examined if lactate dehydrogenase (LDH) levels, Epstein-Barr virus (EBV) load, or timing of FDG-PET/CT relate to detection performance of FDG-PET/CT.

Methods

This retrospective study included 91 consecutive patients with clinical suspicion of PTLD and a total of 97 FDG-PET/CT scans within an 8-year period. Pathology reports and a 2-year follow-up were used as the reference standard. Diagnostic performance of FDG-PET/CT for detection of PTLD as well as logistic regression analysis for factors expected to affect diagnostic yield were assessed.

Results

The diagnosis of PTLD was established in 34 patients (35%). Fifty-seven FDG-PET/CT scans (59%) were true negative, 29 (30%) were true positive, 6 (6%) false positive, and 5 (5%) false negative. Sensitivity of FDG-PET/CT for the detection of PTLD was 85%, specificity 90%, positive predictive value 83%, and negative predictive value 92%, with good inter-observer variability (k = 0.78). Of the parameters hypothesized to be associated with a true positive FDG-PET/CT result for the diagnosis of PTLD, only LDH was statistically significant (OR 1.03, p = 0.04).

Conclusion

FDG-PET/CT has a good diagnostic performance in patients suspected of PTLD, with a good inter-observer agreement. Only LDH levels seemed to influence the detection performance of FDG-PET/CT. EBV-DNA load and timing of FDG-PET/CT after transplantation did not affect FDG-PET/CT diagnostic yield.

Uptake of [18F]fluorodeoxyglucose in initial positron-emission tomography predicts survival in MALT lymphoma

The role of [¹⁸F]fluorodeoxyglucose (FDG) positron-emission tomography (PET) in mucosa-associated lymphoid tissue (MALT) of marginal zone lymphoma remains poorly defined. We correlated initial PET with pathology, clinical factors, and outcome. From January 2001 to July 2012, 173 MALT lymphoma patients with a biopsied lesion identified on PET within 90 days of tissue biopsy were analyzed. PET positivity and intensity of FDG uptake were correlated with clinical factors and patient outcome. Among 173 accrued cases, biopsied site was PET avid in 123 patients (71%); median standardized uptake value (SUV) was 6.0 (range: 0.7-28.0), and SUV >10.0 in 20 patients (16%). PET avidity varied by organ sites. PET positivity correlated with higher International Prognostic Index, but not with 5-year overall survival (OS; 96% vs 88%, PET negative vs positive, P = .229) or 5-year progression-free survival (67% vs 56%, P = .493). SUV was an independent prognostic factor of OS, and an increased SUV was associated with a decreasing 5-year OS. Patients who presented with SUV ≥10 had a higher rate of subsequent large cell transformation (20% vs 5%, P = .035) and inferior OS (78% vs 92%, P = .008). The exact role of FDG PET in the management of MALT lymphoma, beyond initial staging, remains to be defined.

Extralymphatic Disease Is an Independent Prognostic Factor in Hodgkin Lymphoma

PURPOSE

To identify the characteristics and outcomes of patients with extralymphatic Hodgkin lymphoma.

PATIENTS AND METHODS

We performed a retrospective single-institution study of 341 cases comprising 207 male (61%) and 134 female (39%) subjects with a median follow-up of 44 months.

RESULTS

Fifty-five patients (16%) had extralymphatic disease. The sites were lung in 29 patients (44%), bone in 22 (33%), liver in 12 (18%), and kidney in 3 (5%). In 46 patients (86%) only one organ was involved, while in 7 patients (13%) extralymphatic disease was present in 2 sites and in 2 patients (3%) in 3 sites. The extralymphatic disease group had a poorer prognosis than the lymphatic disease group. Complete remission rates in the extralymphatic and lymphatic patient subsets were 65% and 82% (P = .043), respectively.

CONCLUSION

Extralymphatic disease in patients with Hodgkin lymphoma is a rare occurrence (16%) associated with poor clinical outcome.

Extranodal presentation of Hodgkin's lymphoma of the sternum: A case report and review of the literature

Hodgkin's lymphoma (HL) is typically a systemic disease with involvement of the cervical, supraclavicular and mediastinal lymph nodes. An extra-nodal presentation of HL is unusual and seldom encountered in the clinic. The most common sites of presentation for extra-nodal extension are the spleen, liver, lungs, bones and marrow. The bones that are frequently involved are the vertebrae, pelvis, ribs and femur. Involvement of the sternum has occasionally been reported. The current study presents an unusual case on the extra-nodal presentation of HL of the sternum arising in a 25-year-old woman, and reviews the relevant literature with particular emphasis on treatment. The extra-nodal infiltration of HL, and the clinical stage and prognosis of the case are also discussed.

PET-CT in Staging, Response Evaluation, and Surveillance of Lymphoma

OPINION STATEMENT

Lymphoma represents a broad spectrum of diseases with diverse biology, clinical behavior, and imaging features. Functional imaging with 18-F-fluorodeoxyglucose (FDG)-positron emission tomography combined with computed tomography (PET-CT) is widely recognized as the most sensitive and specific imaging modality for patients with lymphoma and is used as part of staging, response evaluation, and surveillance in patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). Recent efforts at standardizing the conduct and consensus interpretation of PET-CT have facilitated its use in patients on clinical studies and beyond. The role of PET-CT has been affirmed in some clinical situations, such as staging and end-of-treatment evaluation in Hodgkin lymphoma and diffuse large B cell lymphoma (DLBCL), and in the evaluation of aggressive transformation of an indolent lymphoma. However, the role of functional imaging in other histologies and clinical settings is not as clear given the higher rate of false positive results and the costs inherent to PET-CT. There is little evidence to suggest its utility or impact on outcome in most indolent lymphomas, or in the setting of post-treatment surveillance. In addition, there remains controversy about the value of PET-CT in early response assessment during active therapy, particularly in DLBCL. This review will evaluate the evidence surrounding the role of PET-CT in staging, response evaluation and surveillance of Hodgkin and non-Hodgkin lymphoma.

The role of FDG-PET in Hodgkin lymphoma

18-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) is currently the most valuable imaging technique in Hodgkin lymphoma. Since its first use in lymphomas in the 1990s, it has become the gold standard in the staging and end-of-treatment remission assessment in patients with Hodgkin lymphoma. The possibility of using early (interim) PET during first-line therapy to evaluate chemosensitivity and thus personalize treatment at this stage holds great promise, and much attention is now being directed toward this goal. With high probability, it is believed that in the near future, the result of interim PET-CT would serve as a compass to optimize treatment. Also the role of PET in pre-transplant assessment is currently evolving. Much controversy surrounds the possibility of detecting relapse after completed treatment with the use of PET in surveillance in the absence of symptoms suggestive of recurrence and the results of published studies are rather discouraging because of low positive predictive value. This review presents current knowledge about the role of 18-FDG-PET/CT imaging at each point of management of patients with Hodgkin lymphoma.

Low-Dose PET/CT and Full-Dose Contrast-Enhanced CT at the Initial Staging of Localized Diffuse Large B-Cell Lymphomas

Computed tomography (CT) has been used as the reference imaging technique for the initial staging of diffuse large B-cell lymphoma until recent days, when the introduction of positron emission tomography (PET)/CT imaging as a hybrid technique has become of routine use. However, the performance of both examinations is still common. The aim of this work was to compare the findings between low-dose 2-deoxy-2-(¹⁸F)fluoro-d-glucose (¹⁸F-FDG) PET/CT and full-dose contrast-enhanced CT (ceCT) in 28 patients with localized diffuse large B-cell lymphoma according to PET/CT findings, in order to avoid the performance of ceCT. For each technique, a comparison in the number of nodal and extranodal involved regions was performed. PET/CT showed more lesions than ceCT in both nodal (41 vs. 36) and extranodal localizations (16 vs. 15). Disease staging according to both techniques was concordant in 22 patients (79%) and discordant in 6 patients (21%), changing treatment management in 3 patients (11%). PET/CT determined a better staging and therapeutic approach, making the performance of an additional ceCT unnecessary.

The usefulness of (18)F-FDG PET/CT for assessing methotrexate-associated lymphoproliferative disorder (MTX-LPD)

Background

Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a benign lymphoid proliferation or malignant lymphoma in patients who have been treated with MTX. MTX withdrawal and observation for a short period should be considered in the initial management of patients who develop LPD while on MTX therapy. Here we evaluated the diagnostic accuracy and predictive value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for MTX-LPD.

Methods

We retrospectively investigated the cases of 15 patients clinically suspected of having MTX-LPD. A total of 324 anatomic regions (207 nodal and 117 extranodal regions) were assessed by ¹⁸F-FDG PET/CT and by multi-detector row CT (MDCT). Each anatomic region was classified as either malignant or benign. The uptake of ¹⁸F-FDG was assessed semi-quantitatively with the standardized uptake value maximum (SUVmax), the whole-body metabolic tumor volume (WBMTV), and the whole-body total lesion glycolysis (WBTLG) in order to investigate predictive factors of spontaneous regression after the withdrawal of MTX.

Results

MTX-LPD lesions were observed in 92/324 (28.4 %) regions. ¹⁸F-FDG PET/CT showed 90.2 % sensitivity, 97.4 % specificity, and 95.4 % accuracy, values which were significantly higher than those of MDCT (59.8, 94.8, and 84.9 %, respectively. p < 0.002). After the withdrawal of MTX, 9/15 patients (60.0 %) achieved complete response (CR). The SUVmax, WBMTV and WBTLG values of the CR patients were 9.2 (range 2.8–47.1), 44.3 (range 0–362.6) ml, 181.8 (range 0–2180.9) ml, respectively, which were not significantly different from those of the non-CR patients: 10.6 (range 0–24.9), 15.7 (range 0–250.1) ml, and 97.4 (range 0–1052.1) ml.

Conclusions

Although ¹⁸F-FDG PET/CT was a useful tool to detect MTX-LPD lesions, none of the ¹⁸F-FDG PET parameters before the withdrawal of MTX could be used to predict CR after the withdrawal of MTX.

FDG-PET/CT for Detection of Extramedullary Disease in 2 Pediatric Patients With AML

Positron emission tomography combined with computed tomography (PET/CT) is a promising diagnostic procedure for the detection of extramedullary disease (EMD) in acute myeloid leukemia. We studied 2 children with acute myeloid leukemia who underwent PET to assess for EMD at diagnosis as well as in remission. We detected 5 EMD lesions in 2 cases with PET, only 2 of which were detectable on clinical examination. Our cases show PET's increased sensitivity over physical examination alone in assessing and monitoring the extent of this disease.

PET-Based Percutaneous Needle Biopsy

PET can be used to guide percutaneous needle biopsy to the most metabolic lesion, improving diagnostic yield. PET biopsy guidance can be performed using visual or software coregistration, electromagnetic needle tracking, cone-beam computed tomography (CT), and intraprocedural PET/CT guidance. PET/CT-guided biopsies allow the sampling of lesions that may not be clearly visible on anatomic imaging, or of lesions that are morphologically normal. PET can identify suspicious locations within complex tumors that are most likely to contain important diagnostic and prognostic information.

The evolving role of response-adapted PET imaging in Hodgkin lymphoma

(18)F-fluorodeoxyglucose positron emission tomography with (FDG-PET) has a well-established role in the pre- and post-treatment staging of Hodgkin lymphoma (HL), however its use as a predictive therapeutic tool via responded-adapted therapy continues to evolve. There have been a multitude of retrospective and noncontrolled clinical studies showing that early (or interim) FDG-PET is highly prognostic in HL, particularly in the advanced-stage setting. Response-adapted treatment approaches in HL are attempting to diminish toxicity for low-risk patients by minimizing therapy, and conversely, intensify treatment for high-risk patients. Results from phase III noninferiority studies in early-stage HL with negative interim FDG-PET that randomized patients to chemotherapy alone versus combined modality therapy showed a continued small improvement in progression-free survival for patients who did not receive radiation. Preliminary reports of data escalating therapy for positive interim FDG-PET in early-stage HL and for de-escalation of therapy [i.e. bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine and prednisone (BEACOPP)] for negative interim FDG-PET in advanced stage HL (i.e. deletion of bleomycin) have demonstrated improved outcomes. Maturation of these studies and continued follow up of all response-adapted studies are needed. Altogether, the treatment of HL remains an individualized clinical management choice for physicians and patients. Continued refinement and optimization of FDG-PET is needed, including within the context of targeted therapeutic agents. In addition, a number of new and novel techniques of functional imaging, including metabolic tumor volume and tumor proliferation, are being explored in order to enhance staging, characterization, prognostication and ultimately patient outcome.

The role of fluorine-18 fluorodeoxyglucose PET in prognosis evaluation for stem cell transplantation of lymphoma: a systematic review and meta-analysis

The role of fluorine-18 fluorodeoxyglucose PET (F-FDG PET) in prognostic evaluation of pre-stem cell transplantation (SCT) and post-SCT is still uncertain. A systematic review and meta-analysis were carried out to detect the prognostic power of F-FDG PET. 'PubMed', EMBASE, and Springer were searched for relevant articles. Subgroup analysis was carried out to evaluate the F-FDG PET in predicting the prognosis between Hodgkin lymphoma (HL) and non-Hodgkin lymphoma. Finally, 17 studies that included 1192 patients were eligible, 16 studies for progression-free survival (PFS) and 12 studies for overall survival (OS). For the pre-SCT PET or PET/computed tomography scan, the combined hazard ratios (HRs) of PET for PFS and OS were 2.32 and 2.64, respectively. Subgroup analysis showed that the HRs of PFS for HL and non-Hodgkin lymphoma were 3.28 and 2.00, respectively. For the post-SCT PET scan, the combined HR for PFS was 4.61. The sensitivity analysis showed that exlcusion of any single study had no significant effect on HR. We found that F-FDG PET was especially effective in predicting pre-STC and post-STC prognosis. The patients with a negative PET scan had a better prognosis compared with those with a positive scan in PFS and OS. In the subgroup analysis, F-FDG PET had a higher value in predicting prognosis before SCT for HL patients.

PET-directed therapy in Hodgkin lymphoma: Ready for prime time?

Advances in chemotherapy and radiation therapy have allowed the vast majority of patients with Hodgkin lymphoma to be cured, but some of these patients develop treatment-related complications, including second malignancies, cardiovascular disease, and thyroid disease. Efforts to decrease exposure of patients to more chemotherapy or radiation therapy than is necessary to cure their disease have led to a trend toward shortened treatment regimens in patients with low-risk disease. Predicting which patients will relapse, and therefore might benefit from a more intense treatment regimen, has been a clinical challenge. PET has emerged as a useful modality in the diagnosis and management of Hodgkin lymphoma, and has been studied as a potential tool to help the oncologist to utilize the optimal chemotherapy and radiation therapy regimen for each patient.

Use of 18F-FDG PET/CT imaging for evaluation of patients with primary splenic lymphoma

Primary splenic lymphoma (PSL) is a rare disease, and its management differs from other splenic malignancies. The purpose of the present study was to evaluate the role of 18F-FDG PET/CT in patients with PSL.

METHODS

We retrospectively evaluated the data of 17 patients with PSL (median age, 46 years; range, 3-64) who had undergone 50 18F-FDG PET/CT studies. Of the 50 PET/CTs, 15 were done for primary diagnosis/staging and 35 were done for restaging. PET/CT images were evaluated both qualitatively and quantitatively [maximum standardized uptake value (SUVmax)]. Combination of clinical/imaging follow-up and/or histopathologic diagnosis was taken as reference standard.

RESULTS

Of the total 50 F-FDG PET/CT studies, 27 studies (54%) were positive and 23 (46%) were negative for disease. PET/CT was true positive in 25 studies, true negative in 22 studies, false positive in 2 studies, and false negative in 1 study. Overall, per study-based sensitivity was 96.2%, specificity was 91.7%, and accuracy was 94%. In those studies performed for diagnosis/staging (15/50), PET/CT was true positive in all 15, with an accuracy of 100%. In those studies performed for restaging (35/50), sensitivity was 90.9%, specificity was 91.7%, and accuracy was 91.4%. No significant difference was seen in the accuracy of PET/CT between staging and restaging groups (P=0.601). On 18F-FDG PET/CT, splenic involvement was seen in 24 studies, lymph nodal involvement in 5 studies, liver involvement in 3 studies, and bone marrow involvement in 1 study. More than one site of disease was seen in 9 PET/CT studies. On semiquantitative analysis, the overall mean splenic lesion SUVmax was 6.9±7.9 (median, 4.6; range, 1.3-29). The mean value of ratio of SUVmax of splenic lesions and SUVliver was 4.4±5.5 (median, 2.4; range, 0.9-24.2). On comparison of areas under the curve, the mean value of ratio of SUVmax of splenic lesions and SUVliver was found to be superior to SUVmax alone for this differentiation of involvement from normal spleen (P=0.018).

CONCLUSION

18F-FDG PET/CT seems useful in patients with primary splenic lymphoma and shows high diagnostic accuracy.

The role of FDG-PET in defining prognosis of Hodgkin lymphoma for early-stage disease

Given the excellent survival rates for early-stage Hodgkin lymphoma (HL), the young age of many patients, and concerns regarding acute and late treatment-related toxicities, there is a desire to have a predictive tool that enables therapy to be tailored toward the individual patient. Early (or interim) 18F-fluorodeoxyglucose positron emission tomography with computerized tomography (FDG-PET/CT), as a test of tumor sensitivity to ongoing/planned therapy, has been shown to be prognostic for survival in HL. Based on results of interim FDG-PET/CT, therapy may be subsequently modified through minimization or via intensification for low- and high-risk patient populations, respectively (ie, response-adapted therapy). Important data have been generated to standardize the interpretability and reproducibility of interim FDG-PET/CT (eg, the Deauville 5-point system), and observational and noncontrolled prospective studies have produced evidence supporting the hypothesis that response-adapted therapy may potentially serve as a predictive tool. Furthermore, results from noninferiority phase 3 clinical trials randomizing early-stage HL patients with negative interim FDG-PET/CT to combined modality therapy versus chemotherapy alone have been reported. The current collective findings from these randomized early-stage HL studies have shown that acute relapse rates are lower with combined modality therapy, even in patients with negative interim FDG-PET/CT. Additional randomized response-adapted studies are ongoing and novel FDG-PET/CT applications involving quantitative techniques and innovative imaging modalities are being investigated to identify more robust imaging biomarkers. Treatment of early-stage HL remains a clinical management choice for physicians and patients to make with consideration of acute and long-term outcomes.

The role of FDG-PET in defining prognosis of Hodgkin lymphoma for early-stage disease

Given the excellent survival rates for early-stage Hodgkin lymphoma (HL), the young age of many patients, and concerns regarding acute and late treatment-related toxicities, there is a desire to have a predictive tool that enables therapy to be tailored toward the individual patient. Early (or interim) (18)F-fluorodeoxyglucose positron emission tomography with computerized tomography (FDG-PET/CT), as a test of tumor sensitivity to ongoing/planned therapy, has been shown to be prognostic for survival in HL. Based on results of interim FDG-PET/CT, therapy may be subsequently modified through minimization or via intensification for low- and high-risk patient populations, respectively (ie, response-adapted therapy). Important data have been generated to standardize the interpretability and reproducibility of interim FDG-PET/CT (eg, the Deauville 5-point system), and observational and noncontrolled prospective studies have produced evidence supporting the hypothesis that response-adapted therapy may potentially serve as a predictive tool. Furthermore, results from noninferiority phase 3 clinical trials randomizing early-stage HL patients with negative interim FDG-PET/CT to combined modality therapy versus chemotherapy alone have been reported. The current collective findings from these randomized early-stage HL studies have shown that acute relapse rates are lower with combined modality therapy, even in patients with negative interim FDG-PET/CT. Additional randomized response-adapted studies are ongoing and novel FDG-PET/CT applications involving quantitative techniques and innovative imaging modalities are being investigated to identify more robust imaging biomarkers. Treatment of early-stage HL remains a clinical management choice for physicians and patients to make with consideration of acute and long-term outcomes.

Testicular fluorine-18 fludeoxyglucose uptake on positron emission tomography CT in patients with lymphoma: clinical significance and management impact

OBJECTIVE

This is the first case series examining the role of fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography-CT (PET-CT) in the diagnosis of lymphoma, and its impact on the clinical management of patients with secondary testicular involvement. This study explores the clinical significance of abnormal testicular uptake, maximum standardized uptake values and the diagnostic value of the CT component in PET-CT scans of these patients.

METHODS

The case notes and PET scans of 12 patients with diagnosis of lymphoma that were reported to have abnormal (18)F-FDG uptake in the testes were examined. Case notes were reviewed for the underlying diagnosis, indication for the scan and its effect on the management decision.

RESULTS

12 patients demonstrated abnormal (18)F-FDG uptake on the PET-CT scans (mean age, 63 years; range, 37-82 years). Seven patients were diagnosed with testicular lymphoma. Six out of the seven (86%) patients received additional intrathecal chemotherapy in addition to their systemic chemotherapy, and one patient had testicular radiotherapy.

CONCLUSION

This study establishes the importance of identifying and reporting abnormal (18)F-FDG uptake in the testes on PET-CT in patients with lymphoma. (18)F-FDG PET-CT is superior to conventional imaging in identifying testicular lymphoma and has significant management impact. It also emphasizes the importance of incorporating the testes as part of the scan coverage.

ADVANCES IN KNOWLEDGE

The appearances of testicular lymphoma on (18)F-FDG PET-CT can be variable and abnormal testicular uptake warrants further investigations and confirmation. FDG PET-CT is an important tool and can be used in addition to conventional imaging in the identification of testicular lymphoma.