(18)F-FDG PET/CT bone/bone marrow findings in Hodgkin's lymphoma may circumvent the use of bone marrow trephine biopsy at diagnosis staging

18F-FDG-PET/CT response after first-line treatment as a prognostic factor for survival in peripheral T-cell lymphoma: a Spanish retrospective study

BACKGROUND

An accurate assessment of tumor viability after first-line treatment is critical for predicting treatment failure in peripheral T-cell lymphomas (PTCLs). 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) has been adopted as the preferred assessment method in clinical trials, but its impact in clinical practice should be examined. This study aims to determine the prognostic significance of18F-FDG-PET/CT for survival following first-line treatment in PTCL patients.

RESEARCH DESIGN AND METHODS

Retrospective observational study including 175 patients diagnosed with PTCL between 2008 and 2013 in 13 Spanish sites.

RESULTS

Fifty patients were evaluated with18F-FDG-PET/CT following first-line therapy: 58% were18F-FDG-PET/CT-negative and 42% were18F-FDG-PET/CT-positive. Disease progression occurred in 37.9% of18F-FDG-PET/CT-negative patients and in 80.9% of18F-FDG-PET/CT-positive patients (p = 0.0037). Median progression-free survival and overall survival were 67 and 74 months for18F-FDG-PET/CT-negative patients, and 5 (p < 0.0001) and 10 months (p < 0.0001), respectively, in18F-FDG-PET/CT-positive patients. After multivariate analysis, only B symptoms emerged as a negative predictive factor of complete response (RR 7.08; 95% CI 1.60-31.31; p = 0.001).

CONCLUSIONS

18F-FDG-PET/CT identifies high-risk PTCL patients who will have poor prognosis and survival following first-line treatment. However, more research is needed to confirm the best treatment options for PTCL patients.

PET/CT in Hodgkin Lymphoma: An Update

¹⁸F-FDG-PET/CT is now an integral part of the workup and management of patients with Hodgkin's lymphoma (HL). PET/CT is currently routinely performed for staging and for response assessment at the end of treatment. Interim PET/CT is typically performed after 1-4 of 6-8 chemo/chemoimmunotherapy cycles ± radiation for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics such as the standardized uptake value (SUV), metabolic tumor volume, total lesion glycolysis, and their changes with treatment are being investigated as more reproducible and, potentially, more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value. This review highlights the most relevant applications of PET/CT in HL, its strengths and limitations, as well as recent efforts to implement PET/CT-based metrics as promising tools for precision medicine. Finally, the value of PET/CT for response assessment to immunotherapy is discussed.

Positron emission tomography/computed tomography in the management of Hodgkin and B-cell non-Hodgkin lymphoma: An update

¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is now an integral part of lymphoma staging and management. Because of its greater accuracy compared with CT alone, PET/CT is currently routinely performed for staging and for response assessment at the end of treatment in the vast majority of FDG-avid lymphomas and is the cornerstone of response classification for these lymphomas according to the Lugano classification. Interim PET/CT, typically performed after 2 to 4 of 6 to 8 chemotherapy/chemoimmunotherapy cycles with or without radiation, is commonly performed for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-adapted or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics, such as the standardized uptake value, changes (Δ) in the standardized uptake value, metabolic tumor volume, and total lesion glycolysis, are being investigated as more reproducible and potentially more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value, emphasizing the need for more specific molecular probes. This review highlights the most relevant applications of PET/CT in Hodgkin and B-cell non-Hodgkin lymphoma, its strengths and limitations, as well as recent efforts at implementing PET/CT-based metrics as promising tools for precision medicine.

Diagnostic performance of F-18 FDG PET/CT in the detection of bone marrow involvement in paediatric hodgkin lymphoma: A meta-analysis

OBJECTIVES

The present study aimed to investigate the diagnostic performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the detection of bone marrow involvement (BMI) in paediatric Hodgkin lymphoma (HL) through a systematic review and meta-analysis.

METHODS

PubMed, Cochrane, and EMBASE databases were searched from the earliest available date of indexing till March 31, 2020 for studies evaluating the diagnostic performance of F-18 FDG PET/CT in the detection of BMI in paediatric HL.

RESULTS

Across seven studies (1265 patients), the pooled sensitivity of F-18 FDG PET or PET/CT was 0.95 (95% confidence interval [CI]: 0.87-0.98) with heterogeneity (I² = 86.2, p < 0.001), and the pooled specificity was 0.97 (95% CI: 0.84-1.00) with heterogeneity (I² = 97.2, p < 0.001). Likelihood ratio syntheses provided an overall positive likelihood ratio of 37.8 (95% CI: 5.2-274.9) and a negative likelihood ratio of 0.05 (95% CI: 0.02-0.14). The pooled diagnostic odds ratio was 732 (95% CI: 55-9806). The area under the summary receiver operating characteristic curve was 0.98 (95% CI: 0.97-0.99).

CONCLUSIONS

The present meta-analysis revealed high sensitivity and specificity of F-18 FDG PET/CT for the detection of BMI in paediatric HL. Currently, the literature regarding the use of F-18 FDG PET/CT for the detection of BMI in paediatric HL is limited. Large multicentre studies are necessary to substantiate the diagnostic accuracy of F-18 FDG PET/CT in the detection of BMI in paediatric HL.

ADVANCES IN KNOWLEDGE

Through a meta-analysis, this study provided a more reliable assessment of the diagnostic utility of F-18 FDG PET/CT, which exhibited good diagnostic accuracy in the detection of BMI in paediatric HL.

Diagnostic performance of 18F-2-fluoro-2-deoxy-D-glucose PET/computerized tomography in identifying bone marrow infiltration in new patients with diffuse large B-cell lymphoma and Hodgkin lymphoma

OBJECTIVE

To compare between F-2-fluoro-2-deoxy-D-glucose PET/computerized tomography (F-FDG PET/CT) and routine iliac bone marrow biopsy (BMB) in assessment of bone marrow infiltration (BMI) in Hodgkin lymphoma and diffuse large B-cell lymphoma (DLBCL) patients at initial presentation.

PATIENTS AND METHODS

A retrospective analysis of 138 patients (50 Hodgkin lymphomas, 88 DLBCLs). The study included 70 males and 68 females with median age of 43 years. All patients underwent F-FDG PET/CT and iliac crest BMB before treatment. Any focal or patchy FDG uptake in the bone marrow, superior-to hepatic uptake was interpreted as abnormal with or without corresponding CT changes. Treatment response was evaluated clinically with each cycle of chemotherapy, radiologically after three cycles and at the end of treatment.

RESULTS

The overall diagnostic performance showed significant higher sensitivity of F-FDG PET/CT than that of BMB (73.9 versus 62.5%, P = 0.046), while the specificity was higher in BMB than in F-FDG PET/CT (100% in BMB versus 93.5% in F-FDG PET/CT). In Hodgkin lymphoma, sensitivity, negative predictive value (NPV) and accuracy were significantly higher in F-FDG PET/CT compared with BMB, being 87.5, 94.4 and 96% versus 50, 81 and 84% (P = 0.02, 0.03, 0.04, respectively). However, for DLBCL patients, almost comparable results were found between both tests in terms of sensitivity, NPV and accuracy (66.7, 83.9 and 81.8% versus 68.8, 84.9 and 88.6%, respectively). After PET/CT scan, 12 patients (8.6%) were upstaged to stage IV, eight of them were negative by BMB.

CONCLUSION

F-FDG PET/CT seemed to be an excellent diagnostic test in assessment of BMI at initial assessment and staging of Hodgkin lymphoma and DLBCL patients.

Direct comparison of diagnostic accuracies of F-18 FDG PET and MRI for detection of bone marrow involvement in lymphoma patients; A meta-analysis

BACKGROUND

The purpose of the current study was to compare the diagnostic accuracies of F-18 FDG PET or PET/CT and MRI for detection of bone marrow involvement (BMI) in lymphoma patients through a systematic review and meta-analysis.

METHODS AND MATERIALS

The PubMed, Cochrane database, and EMBASE database, from the earliest available date of indexing through July 31, 2020, were searched for studies evaluating direct comparison of diagnostic performance of F-18 FDG PET or PET/CT and MRI for BMI in lymphoma patients. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR + and LR-), and constructed summary receiver operating characteristic curves.

RESULTS

Across 5 studies (212 patients), the pooled sensitivity of F-18 FDG PET or PET/CT was 0.65 (95 % CI; 0.42-0.82) a pooled specificity of 0.90 (95 % CI; 0.85-0.94). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 6.4 (95 % CI; 3.3-12.4) and negative likelihood ratio (LR-) of 0.39 (95 % CI; 0.21-0.73). The pooled DOR was 16 (95 % CI; 5-56). The pooled sensitivity of MRI was 0.78 (95 % CI; 0.55-0.91) and a pooled specificity of 0.86 (95 % CI; 0.67-0.95). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 5.6 (95 % CI; 1.8-17.0) and negative likelihood ratio (LR-) of 0.26 (95 % CI; 0.1-0.65). The pooled DOR was 22 (95 % CI; 3-149). In meta-regression analysis, no variable was the source of the study heterogeneity.

CONCLUSION

F-18 FDG PET or PET/CT and MRI showed similar diagnostic performances for the detection of BMI in lymphoma patients. Further large multicenter studies would be necessary to substantiate the diagnostic accuracy of F-18 FDG PET or PET/CT and MRI for the diagnosis of BMI in lymphoma patients.

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.

(2S,4R)-4-[18F]Fluoroglutamine as a PET Indicator for Bone Marrow Metabolism Dysfunctional: from Animal Experiments to Clinical Application

PURPOSE

Previous reports confirmed that (2S,4R)-4-[¹⁸F]Fluoroglutamine ([¹⁸F]GLN) accumulated in bone and bone marrow. This study investigates the potential of using [¹⁸F]GLN positron emission tomography (PET) to monitor changes of bone marrow activity after chemotherapy (myelosuppression).

PROCEDURES

Bone marrow inhibition model in mice was induced by an intravenous injection of chemotherapy drug (doxorubicin or rituximab) and the inhibition was confirmed by routine blood cell counts. Bone uptakes of these four radiotracers (2-deoxy-2-[¹⁸F]fluoro-D-glucose, [¹⁸F]GLN, 3'-dexoy-3'-[¹⁸F]fluorothymidine ([¹⁸F]FLT), and sodium [¹⁸F]fluoride) in the mice were measured after i.v. injection and dissection of femur and tibia, and the uptakes in bone-only (BO) and bone marrow (BM) were obtained after separating bone from bone marrow. Additionally, six volunteers were recruited and evaluated with [¹⁸F]GLN. The PET-/CT-guided volumes of interests (VOI) in cervical, thoracic, lumbar vertebra, and skull cortical bone were defined as bone marrow or bone for evaluation, respectively.

RESULTS

[¹⁸F]GLN showed a relatively high bone marrow uptake in mice (up to 9.5 ± 1.3 % ID/g) at 1 h after injection, which was 2.1 times that of [¹⁸F]FLT. The [¹⁸F]GLN uptakes in the bone marrow were substantially inhibited by chemotherapy drug. The decrease of [¹⁸F]GLN's bone marrow uptake was consistent with the reduction of white blood cells (myelosuppression). For [¹⁸F]GLN/PET imaging in humans, the SUV_mean value of bone marrow (1 h after i.v. injection) was between 3.1 and 3.6 in the healthy volunteers (n = 3), and between 1.8 and 2.2 (n = 3) (P < 0.001) in myelosuppression patients, showing a clear reduction of bone marrow uptake.

CONCLUSIONS

Dissection experiments in mice showed that [¹⁸F]GLN displayed relatively high bone marrow uptake, and the uptake was sensitive to bone marrow inhibition induced by doxorubicin/rituximab. The same conclusion was confirmed [¹⁸F]GLN/PET imaging in humans. Therefore, [¹⁸F]GLN/PET imaging may be a useful tool to assess reduction of bone marrow activity in cancer patients, who may be at risk of myelosuppression after chemotherapy.

TRIAL REGISTRATION

Approved by Institutional Review Board of Peking University Cancer Hospital (No. 2017KT38). Registered 18 August 2017.

FDG-PET Imaging for Hodgkin and Diffuse Large B-Cell Lymphoma-An Updated Overview

Since the mid-1990s, 18F-fluorodeoxglucose (FDG)-positron emission tomography (PET) in combination with computed tomography has come to play a prominent role in the management of malignant lymphomas. One of the first PET applications in oncology was the detection of lymphoma manifestations at staging, where it has shown high sensitivity. Nowadays, this imaging modality is also used during treatment to evaluate the individual chemosensitivity and adapt further therapy accordingly. If the end-of-treatment PET is negative, irradiation in advanced-stage Hodgkin lymphoma patients can be safely omitted after highly effective chemotherapy. Thus far, lymphoma response assessment has mainly been performed using visual criteria, such as the Deauville five-point scale, which became the international standard in 2014. However, novel measures such as metabolic tumor volume or total lesion glycolysis have recently been recognized by several working groups and may further increase the diagnostic and prognostic value of FDG-PET in the future.

Value of bone marrow biopsy in Hodgkin lymphoma patients staged by FDG PET: results from the German Hodgkin Study Group trials HD16, HD17, and HD18

Background

Bone marrow (BM) involvement defines advanced-stage Hodgkin lymphoma and thus has impact on the assignment to treatment. Our aim was to evaluate whether the established BM biopsy may be omitted in patients if 18F-fluorodeoxyglucose positron emission tomography (PET) scanning is carried out during staging.

Patients and methods

Our analysis set consisted of 832 Hodgkin lymphoma patients from the German Hodgkin Study Group trials HD16, HD17, and HD18 who underwent both PET scanning and BM biopsy before treatment. All PET studies were centrally reviewed and BM was categorized as showing focal involvement or not.

Results

Taking BM biopsy as reference standard, baseline PET showed a negative predictive value of 99.9% [95% confidence interval (CI) 99.2% to 100%] with true-negative results in 702 of 703 cases. The sensitivity of PET for detecting BM involvement was 95.0% (95% CI 75.1% to 99.9%) as it could identify 19 out of 20 patients with positive BM biopsy. Moreover, PET found 110 additional subjects with focal BM lesions who would have been considered negative by biopsy.

Conclusions

When compared with BM biopsy, PET was able to detect focal BM lesions in a large number of additional patients. This indicates that conventional BM biopsy may substantially underestimate the actual incidence of BM involvement. Given the high negative predictive value, baseline PET scanning can safely be used to exclude BM involvement in Hodgkin lymphoma. BM biopsy should be considered only in such patients in whom PET-detected lesions lead to a change of treatment protocol.

Registered trials

The trials included in this analysis were registered at ClinicalTrials.gov: HD16-NCT00736320, HD17-NCT01356680, and HD18-NCT00515554.

A comparison of clinical staging using the Lugano versus Ann Arbor classifications in Japanese patients with Hodgkin lymphoma

AIMS

The Lugano classification is a novel staging system for lymphomas established in 2014. In this staging system, ¹⁸ F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) was formally incorporated into standard staging for FDG-avid lymphomas, including Hodgkin lymphoma (HL). We retrospectively analyzed patients with HL who were newly diagnosed and treated at our institution to evaluate the utility of the Lugano classification compared to the Ann Arbor classification in Japanese patients with this type of lymphoma.

METHODS

Patients newly diagnosed with HL between 2005 and 2011 were identified through our departmental database. Data from neck-chest-abdomen-pelvis CT scans, BM examinations, and FDG-PET/CT that were routinely performed for staging at our clinical practice were retrieved and analyzed.

RESULTS

Fifty-four patients with a median age of 35.5 years (range: 15-78 years) were investigated in this retrospective study. The Lugano stage matched the Ann Arbor stage in 46 patients (85%). Six patients (11%) were upstaged while two (4%) were downstaged per the Lugano classification. Four patients (7%) were converted from early stage to advanced stage, but none was converted in the reverse. Among 11 patients (20%) with PET-positive bone/bone marrow lesions, only one (2%) exhibited biopsy-proven bone marrow involvement of HL cells.

CONCLUSION

Our data revealed a high concordance rate between the Lugano and Ann Arbor staging system in Japanese patients with HL. Because of its low diagnostic value, routine bone marrow examination might be unnecessary for staging when FDG-PET/CT is used as a substitute.

Bone marrow biopsy in the initial staging of Ewing sarcoma: Experience from a single institution

BACKGROUND

Ewing sarcoma (ES) is the second most common bone tumor in adolescents and children. Staging workup for ES includes imaging and bone marrow biopsy (BMB). The effective role of BMB is now under discussion.

PROCEDURE

A monoinstitutional retrospective analysis reviewed clinical charts, imaging, and histology of patients with diagnosis of ES treated at the Rizzoli Institute between 1998 and 2017.

RESULTS

The cohort included 504 cases of ES of bone; 137 (27%) had metastases at diagnosis, while the remaining 367 had localized disease. Twelve patients had a positive BMB (2.4%). Eleven had distant metastases detected at initial workup staging with imaging assessment: six patients presented with bone metastases, five with both bone and lung metastases. Only one patient with ES of the foot (second metatarsus) was found to have bone marrow involvement with negative imaging evaluation (0.3%).

CONCLUSIONS

On the basis of our data, we suggest reconsidering the effective role of BMB in initial staging workup for patients with ES with no signs of metastases by modern imaging techniques. In metastatic disease, the assessment of the bone marrow status may remain useful to identify a group of patients at very high risk who could benefit from different treatment strategies.

Tumor Identification of Less Aggressive or Indolent Lymphoma With Whole-Body 11C-Acetate PET/CT

PURPOSE

The aim of this study was to investigate the diagnostic performance of whole-body [C]acetate PET/CT in less aggressive or indolent lymphomas, wherein [F]FDG PET/CT would exhibit limited sensitivity.

METHODS

Between September 2016 and May 2018, we prospectively evaluated 17 patients (9 men, 8 women; mean age [range], 71 [45-87] years) with pathologically proven less aggressive or indolent lymphomas according to Non-Hodgkin's Lymphoma Classification Project, using both [F]FDG PET/CT and [C]acetate PET/CT (performed on the same day). Detected nodal lesions were recorded according to the Ann Arbor classification. Extranodal (EN) lesions were also evaluated. We compared whole-body lesion detection between [F] FDG PET/CT and [C]acetate PET/CT using the McNemar test.

RESULTS

In all patients, significantly more nodal and EN lesions were detected using [C]acetate PET/CT than [F]FDG PET/CT (nodal: 84 vs 64 regions; P < 0.001; EN: 26 vs 19 regions, P = 0.039). Bone lesions were detected in 8 and 5 patients using [C]acetate PET/CT and [F]FDG PET/CT, respectively (P = 0.25). Among the 14 patients (82.4%) who underwent bone marrow biopsy, bone marrow involvement was detected with sensitivities of 100% (6/6 patients) and 80% (5/6 patients) using [C]acetate PET/CT and [F]FDG PET/CT, respectively. Multiple areas of focal uptake in the spleen of 1 patient were exhibited on [F]FDG PET/CT but not [C]acetate PET/CT.

CONCLUSIONS

[C]acetate PET/CT exhibited greater sensitivity than [F]FDG PET/CT for lesion detection in patients with less aggressive or indolent lymphomas, thus promising applicability as a physiological tracer in the study of such lesions.

Evolving Role of PET-Based Novel Quantitative Techniques in the Management of Hematological Malignancies

"The role of ¹⁸F-fluorodeoxyglucose PET/computed tomography in hematological malignancies continues to expand in disease diagnosis, staging, and management. A key advantage of PET over other imaging modalities is its ability to quantify tracer uptake, which can be used to determine degree of disease activity. Although tracer uptake with PET is conventionally measured in focal lesions, novel quantitative techniques are being investigated that set objective protocols and produce robust parameters that represent total disease activity portrayed by PET. This article discusses recent advances in PET quantification that can improve reliability and accuracy of characterizing hematological malignancies."

Predictive Value of FDG PET/CT Versus Bone Marrow Biopsy in Pediatric Lymphoma

PURPOSE

The aim of this study was to explore the positive predictive value and negative predictive value of FDG PET/CT. The prognostic impact of tumor burden of bone marrow infiltrates was diagnosed by FDG PET/CT at initial presentation.

METHODS

This retrospective study enrolled 140 pediatric patients with pathologically proven lymphoma (113 Hodgkin disease and 27 Non-Hodgkin lymphoma). All patients had pretherapy FDG PET/CT. Bone marrow biopsy (BMB), clinical, radiological, and follow-up data were also collected. The skeleton was divided into 8 segments, and a 5-point scoring system was used for assessment of BM infiltration burden.

RESULTS

Among the 140 lymphoma patients, FDG PET/CT revealed positive BM involvement in 41 patients; 2 of them were false-positive with negative BMB and regional MRI results. Positive predictive value was 95.1% for PET/CT compared with 100% with BMB. All patients diagnosed with positive BMI by BMB were detected by FDG PET/CT. On the contrary, BMB missed 25 patients (17.9%) with statistically significant difference. Negative predictive value was 100% for PET/CT compared with 80.2% for BMB (P < 0.05). FDG PET/CT upstaged 17.9% of the enrolled patients. Bone marrow involvement based on the 5-point scoring system was assessed. No significant difference was demonstrated in therapy outcome between patient with focal BMI (score 2) and extensive BMI (score 5; P = 0.06).

CONCLUSIONS

FDG PET/CT has optimum negative predictive value compared with BMB in detection of bone marrow infiltrations in pediatric lymphoma with upstaging cases missed with BMB. Prognostic impact of BMI based on the 5-point scoring system reveals that the main influence is presence or absence of BMI rather than its tumor burden.

Role of FDG PET-CT in the treatment management of Hodgkin lymphoma

Fluorodeoxyglucose (FDG) positons emission tomography (PET)-computed tomography (CT) is used in many ways at baseline and during the treatment of patients with Hodgkin lymphoma. Many properties of the technique are used in the different steps of patient's management. Initial staging with PET-CT is more accurate than conventional imaging and PET-CT also became the gold standard imaging at the end of treatment with a negative PET-CT mandatory for reaching a complete remission. Early assessment of response by PET-CT is one of the most powerful prognostic factors for progression-free survival of patients with localized and advanced stages and allows guiding treatment. Conversely, previous studies showed that there is no role of FDG PET-CT for the patient's follow-up.

Bone marrow uptake of 18F-fluorodeoxyglucose in Hodgkin lymphoma without bone involvement: comparison between patients with and without B symptoms

Objective

To compare the degree of benign bone marrow uptake of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) between Hodgkin lymphoma patients with and without B symptoms.

Materials and Methods

We analyzed the medical charts of 74 Hodgkin lymphoma patients who underwent ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) prior to the initiation of therapy between October 2010 and September 2013. In all of the patients, the bone marrow biopsy was negative and the ¹⁸F-FDG PET/CT images did not suggest bone marrow involvement. Of the 74 patients evaluated, 54 presented inflammatory (B) symptoms and 20 did not. Regions of interest (ROIs) were drawn on the sternum, the proximal thirds of the humeri, the proximal thirds of the femora, and both iliac wings (totaling seven ROIs per patient). To compare the patients with and without B symptoms, in terms of standardized uptake values (SUVs) for the seven ROIs, we used the Mann-Whitney U test.

Results

For six of the ROIs, the SUVs were higher in the patients with B symptoms than in those without, and the difference was statistically significant (p < 0.05). There was also a tendency toward a statistically significant difference between the two groups in terms of the SUV for the right iliac wing ROI (p = 0.06).

Conclusion

In our sample, the presence of B symptoms was associated with increased ¹⁸F-FDG uptake in bone marrow.

Bone marrow trephine biopsy in Hodgkin's lymphoma. Comparison with PET-CT scan in 65 patients

BACKGROUND AND OBJECTIVES

To compare bone marrow biopsy (BMB) and PET/CT in detecting bone marrow involvement in Hodgkin's lymphoma MATERIAL AND METHODS: Retrospective analysis of 65 patients with both tests in the initial staging or in relapse with special attention to the PET/CT uptake pattern.

RESULTS

In 3 patients (4.6%), the BMB showed bone marrow involvement with the PET/CT being positive in them all: 2 with diffuse+multifocal pattern and one diffuse only. In 11 additional patients (total 14/65, 21%), bone marrow involvement was diagnosed by PET/CT because bone marrow uptake was above hepatic one. The pattern was focal only in 2 cases, multifocal in 5, diffuse in 3 and diffuse+multifocal in one. In these last 4 cases the BMB showed an unspecific myelopathy.

CONCLUSIONS

PET/CT detects all cases with BMB affected and many that escape to biopsy, however when the uptake pattern is diffuse it could be by involvement or reactive hyperplasia and in those cases the BMB should be done.

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.

Efficacy of 18F-2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computerized Tomography for Bone Marrow Infiltration Assessment in the Initial Staging of Lymphoma

Objective:

Currently ¹⁸F-2-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computerized tomography (PET/CT) is being successfully used for staging and follow-up of Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL). Various studies have demonstrated that PET/CT effectively detects bone marrow involvement (BMI) and is concordant with bone marrow biopsy (BMB) findings, thus it is deemed as a complementary method. This study was aimed to evaluate ¹⁸F-FDG-PET/CT efficiency for detection of BMI in HL and NHL.

Methods:

The study included 172 lymphoma cases who were admitted to Akdeniz University Medical School Department of Nuclear Medicine for initial staging with PET/CT. Visual and semiquantitative assessments were performed for PET/CT scan findings of the cases. The maximum standard uptake (SUV_max) value was the quantitative parameter used for ¹⁸F-FDG-PET scan. In visual assessment, bone marrow metabolic activity that is greater than the liver was considered as pathologic. For semiquantitative assessment, regions of interest were drawn for SUV_max estimation, which included iliac crest in cases with diffusely increased metabolic activity and the highest activity area in cases with focal involvement. BMB was considered as the reference test.

Results:

On visual assessment of all the cases, PET/CT was found to yield 31% sensitivity and 85% specificity rate for detection of BMI. On visual assessment of HL cases, sensitivity rate was determined as 80%, and specificity as 78%, while in NHL cases the corresponding values were 24% and 90%, respectively. On semiquantitative assessment of HL cases, considering SUV_max≥4, sensitivity was found as 80% and specificity as 68%. In NHL patients, considering SUV_max≥3.2, sensitivity rate was detected as 65% and specificity as 58%.

Conclusion:

In this study, a moderately high concordance was observed between PET/CT and BMB findings. PET/CT appears to be a significant method for detecting BMI. Although PET/CT is not a substitute for BMB, we suggest it can be used as a guide to biopsy site and a complementary imaging technique for BMB.

18F-FDG PET/CT in the clinical management of patients with lymphoma

The aim of this work was to review the current recommendations for staging and response assessment of patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) in routine clinical practice after chemotherapy and/or stem cell transplantation. A five-point scale (5-PS) from the First International Workshop on PET in Lymphoma in Deauville, France, in 2009, was recommended as the standard tool to score imaging to assess treatment response in patients with lymphoma using ¹⁸F-Fluorodeoxyglucose (FDG) PET/CT. Following the recommendations of the 11th and 12th International Conferences on Malignant Lymphoma held in Lugano (Switzerland), in 2011 and 2013, respectively, a consensus (the so-called Lugano Classification) was reached regarding the use of PET/CT for staging and response assessment in FDG-avid lymphomas. As a result, ¹⁸F-FDG PET/CT was formally incorporated into standard staging for FDG-avid lymphomas. A bone marrow biopsy is no longer indicated for the routine staging of HL and most diffuse large B-cell lymphomas. PET/CT will be used to assess response in FDG-avid histologies using the 5-point scale. The recent introduction of biological agents with immune mechanisms requires flexibility in interpretations of the Lugano criteria due to tumour flare or a pseudo-progression effect produced by these agents. Provisional criteria have been proposed (Lymphoma Response to Immunomodulatory Therapy Criteria) with the introduction of the term 'Indeterminate Response' in order to identify this phenomenon until confirmed as flare/pseudoprogression or true progression. All these recommendations will improve evaluations of patients with lymphoma, and allow comparison of results from clinical practice and trials.

Role of bone marrow biopsy in staging of patients with classical Hodgkin's lymphoma undergoing positron emission tomography/computed tomography

Several studies suggested that staging bone marrow biopsy (BMB) could be omitted in patients with classical Hodgkin's lymphoma (cHL) when a positron emission tomography/computed tomography (PET/CT) is performed at baseline.To address the concordance between BMB and PET/CT in the detection of bone marrow involvement (BMI) and the BMB role in determining the Ann Arbor stage, we retrospectively collected data on 1244 consecutive patients with cHL diagnosed from January 2007 to December 2013. One thousand eighty-five patients who had undergone both BMB and PET/CT were analyzed, comparing the Ann Arbor stage assessed with PET/CT only to that resulting from PET/CT combined with BMB.One hundred sixty-nine patients (16%) showed at least one focal skeletal lesion (FSL) at PET/CT evaluation. Only 55 patients had a positive BMB (5.1%); 34 of them presented at least one FSL at PET/CT. To the contrary, 895 out of 1030 patients with a negative BMB did not show any FSL (86.9%). Positive and negative predictive values of PET/CT for BMI were 20 and 98%, respectively; sensitivity and specificity were 62 and 87%, respectively. Fifty-four out of 55 patients with a positive BMB could have been evaluated as an advanced stage just after PET/CT; only one patient (0.1%) would have been differently treated without BMB.Our data showed a very high negative predictive value of PET/CT for BMI and a negligible influence of BMB on treatment planning, strengthening the recent indications that BMB could be safely omitted in cHL patients staged with PET/CT.

18F-FDG PET-CT imaging versus bone marrow biopsy in pediatric Hodgkin's lymphoma: a quantitative assessment of marrow uptake and novel insights into clinical implications of marrow involvement

OBJECTIVE

To evaluate whether positron emission tomography/computed tomography using fluorine-18 fluoro-deoxyglucose (¹⁸F-FDG PET-CT) predicts bone marrow involvement (BMI) in pediatric Hodgkin's lymphoma (pHL) with sufficient accuracy to supplant routine staging bone marrow biopsy (BMB), and to assess the clinical importance of marrow disease by comparing the prognosis of stage IV HL with BMI versus that without BMI.

METHODS

Data were retrospectively analyzed for all cases of pHL between July 2010 and June 2015 referred for staging ¹⁸F-FDG PET-CT scan and BMB. The reference standard was BMB. Stage IV patients were divided into three groups to compare their progression-free and overall survival: PET+ BMB-, PET+ BMB+, and PET- BMB-.

RESULTS

Of the 784 patients, 83.3% were male and 16.7% female, with age ranging from 2 to 18 years (mean 10.3 years). Among the total cases, 104 (13.3%) had BMI; of these, 100 were detected by PET imaging and 58 by BMB. BMB and ¹⁸F-FDG PET/CT scans were concordant for BMI detection in 728 patients (93%): positive concordance in 54 and negative in 674. Of the 56 discordant cases, four had a false-negative PET scans and were upstaged by BMB, 46 with focal uptake were PET/CT-positive and BMB-negative (not obtained from active sites), and six with diffuse uptake were false-positive on PET due to paraneoplastic marrow activation. The sensitivity, specificity, PPV, and NPV of PET for identifying BMI was 93.6, 94, 53, and 99.4% respectively. On quantitative assessment, mean iBM-SUV_max of bilateral iliac crests was significantly higher in those with BMI versus those without (p < 0.05).

CONCLUSIONS

¹⁸F-FDG PET-CT imaging is more sensitive than BMB for BMI detection in pHL staging. BMB should be limited to those with normal marrow uptake in the presence of poor risk factors or those with diffusely increased uptake to exclude marrow involvement in the background of reactive marrow.

Utility of 18F sodium fluoride PET/CT imaging in the evaluation of postoperative pain following surgical spine fusion

STUDY DESIGN

A retrospective case review of patients who underwent 18F sodium fluoride PET/CT imaging of the spine with postoperative pain following vertebral fusion.

OBJECTIVE

To determine the benefit of 18F sodium fluoride PET/CT imaging in the diagnosis of persistent pain in the postoperative spine. The diagnosis of pain generators in the postoperative spine has proven to be a diagnostic challenge. The conventional radiologic evaluation of persistent pain after spine surgery with the use of plain radiographs, MRI, and CT can often fall short of diagnosis in the complex patient. 18F sodium fluoride PET/CT imaging is an alternative tool to accurately identify a patient's source of pain in the difficult patient.

METHODS

This retrospective study looked at 25 adult patients who had undergone 18F sodium fluoride PET/CT imaging. All patients had persistent or recurrent back pain over the course of a 15-month period after having undergone spinal fusion surgery. All patients had inconclusive dedicated MRI. The clinical accuracy of PET/CT in identifying the pain generator and contribution to altering the decision making process was compared to the use of CT scan alone.

RESULTS

Of the 25 patients studied, 17 patients had increased uptake on the 18F sodium fluoride PET/CT fusion images. There was a high-level correlation of radiotracer uptake to the patients' pain generator. Overall 88% of the studies were considered beneficial with either PET/CT altering the clinical diagnosis and treatment plan of the patient or confirming unnecessary surgery.

CONCLUSION

18F sodium fluoride PET/CT proves to be a useful tool in the diagnosis of complex spine pathology of the postoperative patients. In varied cases, a high correlation of metabolic activity to the source of the patient's pain was observed.

Can Positron Emission Tomography and Computed Tomography Be a Substitute for Bone Marrow Biopsy in Detection of Bone Marrow Involvement in Patients with Hodgkin's or Non-Hodgkin's Lymphoma?

Objective:

Positron emission tomography and computed tomography (PET/CT) has become an important part of staging and treatment evaluation algorithms of lymphoma. We aimed to compare the results of PET/CT with bone marrow biopsy (BMB) with respect to bone marrow involvement (BMI) in patients with Hodgkin’s lymphoma (HL) and aggressive non-Hodgkin’s lymphoma (aNHL).

Materials and Methods:

The medical files of a total of 297 patients diagnosed with HL or aNHL and followed at the hematology clinics of 3 major hospitals in İstanbul between 2008 and 2012 were screened retrospectively and 161 patients with classical HL and aNHL were included in the study. The patients were referred for PET/CT and BMB at the initial staging. BMB was performed as the reference standard for the evaluation of BMI.

Results:

There were 61 (38%) HL and 100 (62%) aNHL patients. Concordant results were revealed between PET/CT and BMB in 126 patients (78%) (52 HL, 74 aNHL), 20 with positive PET/CT and BMB results and 106 with negative PET/CT and BMB results. There were discordant results in 35 patients (9 HL, 26 aNHL), 16 of them with positive BMB and negative PET/CT results and 19 of them with negative BMB and positive PET/CT results.

Conclusion:

We observed that PET/CT is effective to detect BMI, despite it alone not being sufficient to evaluate BMI in HL and aNHL. Bone marrow trephine biopsy and PET/CT should be considered as mutually complementary methods for detection of BMI in patients with lymphoma. In suspected focal involvement, combining biopsy and PET/CT might improve staging results.

Hodgkin lymphoma: a negative interim-PET cannot circumvent the need for end-of-treatment-PET evaluation

We examined the outcome of a cohort of patients with Hodgkin lymphoma (HL) in order to assess if fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) at the end of treatment (end-PET) can be omitted when the interim PET (int-PET) is negative. Seventy-six ABVD(adriamycin, bleomycin, vinblastine, dacarbazine)-treated patients were retrospectively included. No change in treatment was made on the basis of int-PET results. Suspicious foci on end-PET received biopsy confirmation whenever possible. Median follow-up was 58·9 months. Uptake on int-PET higher than liver (scores 4-5) was rated positive according to the Lugano classification, while a positive end-PET corresponded to scores 3, 4 and 5. Fifteen patients had treatment failure. Sensitivity, specificity, positive predictive value (PPV), negative predictive value and accuracy of int-PET were 46·7%, 85·2%, 43·8%, 86·7% and 77·6%, respectively. For end-PET the figures were: 80%, 93·4%, 75%, 95% and 90·8%. Eight patients with negative int-PET had treatment failure; six of them were identified as non-responders with end-PET. The 5-year progression-free survival (PFS) was 87% for patients with negative int-PET versus 56% with positive int-PET. The 5-year PFS was 96% with negative end-PET versus 23% with positive end-PET. The prognostic information from int-PET as regards PFS (log-rank test P = 0·0048) was lower than that provided by end-PET (P < 0·0001). Int-PET predicted only half of the failures. When used in clinical routine, a negative int-PET study cannot obviate the need for end-PET examination.

Mechanisms underlying the association between obesity and Hodgkin lymphoma

A solid body of knowledge indicates that overweight and obese subjects are prone to develop cancer, aggressive disease, and death more than their lean counterparts. While obesity has been causally associated with various cancers, only a limited number of studies beheld the link with classical Hodgkin lymphoma (HL). Contemporary meta-analysis and prospective studies confirmed the association of body mass index with HL. Besides epidemiological evidence, excess adiposity is known to influence tumor behavior through adipokines, adipose-derived stem cell migration, and metabolism regulation, and by modulating immunoinflammatory response. Nevertheless, the obesity paradox has been described in few cancers. Considering that adipose tissue is an immunomodulatory organ, and that inflammation is the cornerstone of HL pathophysiology, the rationale for being causally related due to endocrine/paracrine interactions cannot be negligible. In this hypothesis-generating review, we explore the biologically plausible links between excess adiposity and HL in light of recent basic and clinical data, in order to create a basis for understanding the underlying mechanisms and foster applied research. The establishment of an association of excess adiposity with HL will determine public health preventive measures to fight obesity and eventually novel therapeutic approaches in HL patients.

FDG-PET imaging in hematological malignancies

The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques.

The Evolving Role of Medical Imaging in Lymphoma Management: The Clinician's Perspective

Hodgkin and non-Hodgkin lymphomas are a heterogeneous group of hematologic neoplasms which arise from malignant lymphocytes. Imaging plays an important role in management of lymphoma patients during diagnosis, staging, and response assessment. Functional imaging may also provide prognostic information and improve the ability to detect extranodal disease. This article provides an overview of the evolving role of various imaging techniques in lymphoma from the clinician's perspective. It serves as an introduction to the other articles in this issue that focus on specific areas of lymphoma imaging.

(18) F-FDG PET-CT and trephine biopsy assessment of bone marrow involvement in lymphoma

The ability of positron emission tomography-computerized tomography (PET-CT) to accurately detect bone marrow involvement (BMI) has been suggested in Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL), but its abilities in other histologies is less established. The aim of this retrospective study was to confirm the role of PET-CT in detecting BMI in DLBCL and HL, and to explore its usefulness in other subtypes. Of the 149 newly diagnosed patients, common subtypes included DLBCL, follicular lymphoma (FL) and HL. In DLBCL, the sensitivity and specificity of PET-CT at diagnosis were 75% and 92%. In FL, the sensitivity and specificity of PET-CT were 67% and 85% at diagnosis, and 73% and 89% at relapse. In HL, the sensitivity and specificity were 100% and 74%. PET-CT was able to detect BMI in patients with negative biopsies. Most of the patients in which PET-CT failed to identify BMI were already advanced stage by imaging. In this analysis, PET-CT was highly accurate for detecting BMI at diagnosis in DLBCL and HL and highly specific in FL at diagnosis and relapse. Results also suggested the diagnostic advantage of PET-CT over bone marrow biopsy in detecting BMI. Prospective evaluation is necessary and may eliminate biopsies in future patients.

Variability of Hepatic 18F-FDG Uptake at Interim PET in Patients With Hodgkin Lymphoma

INTRODUCTION

When evaluating response of Hodgkin lymphoma (HL) to chemotherapy on interim (18)F-FDG-PET/CT, physiological liver uptake is used as reference. Hodgkin lymphoma sites with uptake greater than liver are interpreted as positive. We aimed at examining factors that might influence liver uptake as reference organ.

METHODS

Fifty patients with HL who received baseline (18)F-FDG-PET/CT (PET1) and interim PET (PET2), usually after 2 cycles of adriamycin bleomycin, vinblastine, and dacarbazine chemotherapy, were included retrospectively. SUVmean normalized for body weight (SUVmean) and for lean body mass (SULmean) were obtained from regions of interest in the right lobe of the liver.

RESULTS

On univariate analysis, liver SUVmean on interim PET increased with increasing body mass index (BMI) (P = 0.0453) and were higher in women (P = 0.0401). These factors remained significant on multivariate analysis (P = 0.009 and P = 0.008, respectively). No significant correlation was found with postinjection delay, blood glucose level, and age. Liver SULmean were not affected by the studied variables. Average liver SUVmean in the 50 patients were similar at baseline and interim PET. In 11 patients (22%), however, there was 30% or greater variation in liver SUVmean between PET1 and PET2. No factors explaining intrapatient variation in hepatic uptake between PET1 and PET2 were found on correlation analysis.

CONCLUSION

At interim PET in patients with HL, liver SUVmean depends on BMI and sex, but not liver SULmean. Furthermore, our study, conducted with standard clinical procedure, also confirmed the high range of liver uptake values from one patient to another. Caution is required when using liver SUV as reference in patients with high BMI. Intrapatient fluctuation in liver SUVmean should also be expected.

New Perspectives Offered by Nuclear Medicine for the Imaging and Therapy of Multiple Myeloma

The management of multiple myeloma has fundamentally changed over the years and imaging techniques able to match the therapeutic advances are now much needed. Although many patients now achieve complete response after first-line treatment, relapse is common. Therefore, it would be important to improve the initial prognostic stratification and to detect minimal residual disease after treatment. (18)F-FDG-PET/CT is a useful imaging tool which has a high prognostic value at baseline evaluation and can effectively differentiate active from inactive lesions during induction treatment or after autologous stem-cell transplantation. In combination with biological data, it improves the prediction of relapse. Other PET tracers may soon enter clinical practice and overcome some of the limitations of (18)F-FDG, such as the low sensitivity in detecting early bone marrow infiltration. Excellent results with (11)C-Methionine are reported by Lapa and colleagues in this issue of the Journal. (11)C-Methionine uptake reflects the increased protein synthesis of malignant plasmocytes and correlates well with bone marrow infiltration. Other promising PET ligands include lipid tracers, such as (11)C-Choline or (11)C-acetate, and some peptide tracers, such as (68)Ga-Pentixafor, that targets CXCR4 (chemokine receptor-4), which is often expressed with high density by myeloma cells. Malignant plasma cells are radiosensitive and thus potentially amenable to systemic radionuclide therapy. Indeed, excellent preclinical results were obtained with radioimmunotherapy targeting CD38. Also, preliminary clinical results with peptides targeting CXCR4 (e.g. (177)Lu- or (90)Y-Pentixather) are encouraging. Multiple myeloma may represent a renewal of the already strong partnership between hematologists and nuclear medicine physicians.

Opportunities and limitations of bone marrow biopsy and bone marrow FDG-PET in lymphoma

Bone marrow involvement in lymphoma may have prognostic and therapeutic consequences. Bone marrow biopsy (BMB) is the established method for the evaluation of the bone marrow. (18)F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) plays an important role in lymphoma staging, but its value in the assessment of the bone marrow and whether it can replace BMB is still a topic of debate and investigation. The purpose of this scientific communication is to provide an evidence-based overview about the opportunities and limitations of BMB and FDG-PET in the evaluation of the bone marrow in patients with lymphoma. This article first reviews the basic properties, opportunities and limitations of BMB and bone marrow FDG-PET, and then focuses on the clinical utility of BMB and bone marrow FDG-PET in three major lymphoma subtypes including Hodgkin lymphoma, diffuse large B-cell lymphoma, and follicular lymphoma.

Dealing with bone marrow biopsies in the staging of classical Hodgkin lymphoma: an old issue revisited in the (18)F-fluorodeoxyglucose-positron emission tomography era

Bone marrow biopsy is recommended for staging of classical Hodgkin lymphoma. The aim of this study was to compare bone marrow evaluation by histology with that obtained by (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET). One hundred and three cases of Classical Hodgkin Lymphoma were reviewed. All patients were submitted to FDG-PET evaluation. Bone marrow biopsy results were compared with clinical data and FDG-PET results. Ninety-one cases had available bone marrow biopsies. Overall, there were 16 positive and one suspect case. In five cases, the FDG-PET scan was positive and biopsy was negative: 1/5 was found to correspond to a bone fracture, 3/5 showed marked reactive bone marrow changes and in 1/5 no explanation for the discrepancy was found. FDG-PET showed high sensitivity, supporting the idea that when it is negative, biopsy could be avoided. Care should be taken in patients with a positive FDG-PET, where confirmation by bone marrow biopsy should be recommended.

How I treat advanced classical Hodgkin lymphoma

The development of curative systemic treatment of Hodgkin lymphoma was recently voted one of the top 5 achievements of oncology in the last 50 years (http://cancerprogress.net/top-5-advances-modern-oncology). The high expectation of cure (above 80%) with initial therapy, even for advanced disease, is tempered by the recognition of some important limitations: not all patients are cured, especially those in older age groups, and patients have suffered debilitating or, in some cases, fatal long-term side effects. The challenge for modern treatment approaches is to improve the cure rate and, at the same time, minimize the long-term damage resulting from treatment. After several decades during which we have tested a variety of different ways to combine conventional cytotoxic treatments with or without radiotherapy but have identified no effective new approaches, the field is once again moving forward. The developments that hold the greatest promise in this respect are the application of functional imaging with 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to make an early judgment of the success of treatment and the introduction of some highly active new agents such as antibody-drug conjugates.

Role of imaging in the staging and response assessment of lymphoma: consensus of the International Conference on Malignant Lymphomas Imaging Working Group

PURPOSE

Recent advances in imaging, use of prognostic indices, and molecular profiling techniques have the potential to improve disease characterization and outcomes in lymphoma. International trials are under way to test image-based response–adapted treatment guided by early interim positron emission tomography (PET)–computed tomography (CT). Progress in imaging is influencing trial design and affecting clinical practice. In particular, a five-point scale to grade response using PET-CT, which can be adapted to suit requirements for early- and late-response assessment with good interobserver agreement, is becoming widely used both in practice- and response-adapted trials. A workshop held at the 11th International Conference on Malignant Lymphomas (ICML) in 2011 concluded that revision to current staging and response criteria was timely.

METHODS

An imaging working group composed of representatives from major international cooperative groups was asked to review the literature, share knowledge about research in progress, and identify key areas for research pertaining to imaging and lymphoma.

RESULTS

A working paper was circulated for comment and presented at the Fourth International Workshop on PET in Lymphoma in Menton, France, and the 12th ICML in Lugano, Switzerland, to update the International Harmonisation Project guidance regarding PET. Recommendations were made to optimize the use of PET-CT in staging and response assessment of lymphoma, including qualitative and quantitative methods.

CONCLUSION

This article comprises the consensus reached to update guidance on the use of PET-CT for staging and response assessment for [18F]fluorodeoxyglucose-avid lymphomas in clinical practice and late-phase trials.