How I Follow Hodgkin Lymphoma in First Complete (Metabolic) Remission?

Hodgkin lymphoma is characterized by a high cure rate in the modern era of medicine regardless of stage, but patients suffer from a high risk of comorbidity associated with the administered therapy. The main aim of this review article is to assess and analyze the various comorbidities associated with Hodgkin lymphoma and address the survivorship of patients, including fertility, secondary cancers due to cardiovascular toxicity, and quality of life. Furthermore, this review explores the optimal strategy for detecting relapse. The treatment paradigm of Hodgkin lymphoma has shifted, with a paradigm shift toward achieving a high cure rate and low toxicity as a standard of care in this patient population. Checkpoint inhibitors, especially nivolumab, in combination with chemotherapy are increasingly being studied in the first line of therapy. However, their long-term toxicity remains to be assessed in longer follow-up. In conclusion, Hodgkin lymphoma survivors, regardless of their treatment, should be followed up individually by a multidisciplinary survivorship team in order to detect and properly treat the long-term side effects of therapy.

Imaging recommendations in pediatric lymphoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are both malignancies originating in the lymphatic system and both affect children, but many features differ considerably, impacting workup and management. This paper provides consensus-based imaging recommendations for evaluation of patients with HL and NHL at diagnosis and response assessment for both interim and end of therapy (follow-up).

Accuracy and prognostic impact of FDG PET / CT and biopsy in bone marrow assessment of follicular lymphoma at diagnosis: A Nation‐Wide cohort study

BACKGOUND

In the workup of follicular lymphoma (FL), bone marrow biopsy (BMB) assessment is a key component of FLIPI and FLIPI2, the most widely used outcome scores. During the previous decade, several studies explored the role of FDG-PET/CT for detecting nodal and extranodal disease, with only one large study comparing both techniques.

METHODS

The aim of our study was to evaluate the diagnostic accuracy and the prognostic impact of both procedures in a retrospective cohort of 299 FL patients with both tests performed at diagnosis. In order to avoid a collinearity bias, FLIPI2 was deconstructed in its founding parameters, and the bone marrow involvement (BMI) parameter separately included as: a positive BMB, a positive PET/CT, the combined "PET/CT and BMB positive" or "PET/CT or BMB positive". These variables were also confronted independently with the POD24 in 233 patients treated with intensive regimens.

RESULTS

In the total cohort, bone marrow was involved in 124 and 60 patients by BMB and PET/CT, respectively. In terms of overall survival, age > 60 y.o. and the combined "PET/CT or BMB positive" achieved statistical independence as a prognostic factor. In patients treated with an intensive regimen, only the combined "PET/CT or BMB positive" added prognostic value for a shorter overall survival, when confronted with the POD24.

CONCLUSION

Our results show that in FL both BMB and PET/CT should be considered at diagnosis, as their combined assessment provides independent prognostic value in the context of the most widely use clinical scores.

Positron Emission Tomography Molecular Imaging for Phenotyping and Management of Lymphoma

Positron emission tomography (PET) represents molecular imaging for non-invasive phenotyping of physiological and biochemical processes in various oncological diseases. PET imaging with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) for glucose metabolism evaluation is the standard imaging modality for the clinical management of lymphoma. One of the ¹⁸F-FDG PET applications is the detection and pre-treatment staging of lymphoma, which is highly sensitive. ¹⁸F-FDG PET is also applied during treatment to evaluate the individual chemo-sensitivity and accordingly guide the response-adapted therapy. At the end of the therapy regiment, a negative PET scan is indicative of a good prognosis in patients with advanced Hodgkin's lymphoma and diffuse large B-cell lymphoma. Thus, adjuvant radiotherapy may be alleviated. Future PET studies using non-¹⁸F-FDG radiotracers, such as ⁶⁸Ga-labeled pentixafor (a cyclic pentapeptide that enables sensitive and high-contrast imaging of C-X-C motif chemokine receptor 4), ⁶⁸Ga-labeled fibroblast activation protein inhibitor (FAPI) that reflects the tumor microenvironment, and ⁸⁹Zr-labeled atezolizumab that targets the programmed cell death-ligand 1 (PD-L1), may complement ¹⁸F-FDG and offer essential tools to decode lymphoma phenotypes further and identify the mechanisms of lymphoma therapy.

FDG-PET/CT in Lymphoma: Where Do We Go Now?

18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is an essential part of the management of patients with lymphoma at staging and response evaluation. Efforts to standardize PET acquisition and reporting, including the 5-point Deauville scale, have enabled PET to become a surrogate for treatment success or failure in common lymphoma subtypes. This review summarizes the key clinical-trial evidence that supports PET-directed personalized approaches in lymphoma but also points out the potential place of innovative PET/CT metrics or new radiopharmaceuticals in the future.

Whole-Body Magnetic Resonance Imaging: Current Role in Patients with Lymphoma

Imaging of lymphoma is based on the use of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) and/or contrast-enhanced CT, but concerns have been raised regarding radiation exposure related to imaging scans in patients with cancer, and its association with increased risk of secondary tumors in patients with lymphoma has been established. To date, lymphoproliferative disorders are among the most common indications to perform whole-body magnetic resonance imaging (MRI). Whole-body MRI is superior to contrast-enhanced CT for staging the disease, also being less dependent on histology if compared to ¹⁸F-FDG-PET/CT. As well, it does not require exposure to ionizing radiation and could be used for the surveillance of lymphoma. The current role of whole-body MRI in the diagnostic workup in lymphoma is examined in the present review along with the diagnostic performance in staging, response assessment and surveillance of different lymphoma subtypes.

Different roles of surveillance positron emission tomography according to the histologic subtype of non-Hodgkin's lymphoma

BACKGROUND/AIMS

Although the use of surveillance 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is discouraged in patients with diffuse large B-cell lymphoma, its usefulness in different subtypes has not been thoroughly investigated.

METHODS

We retrospectively evaluated 157 patients who showed positive results on surveillance FDG-PET/CT every 6 months following complete response for up to 5 years. All of the patients also underwent biopsies.

RESULTS

Seventy-eight (49.6%) of 157 patients had true positive results; the remaining 79 (50.3%), including eight (5.1%) with secondary malignancies, were confirmed to yield false positive results. Among the 78 patients with true positive results, the disease in seven (8.9%) had transformed to a different subtype. The positive predictive value (PPV) of FDG-PET/CT for aggressive B-cell non-Hodgkin's lymphoma (NHL) was lower than that for indolent B-cell or aggressive T-cell NHL (p = 0.003 and p = 0.018, respectively), especially in patients with a low/low-intermediate international prognostic index (IPI) upon a positive PET/CT finding. On the other hand, indolent B-cell and aggressive T-cell NHL patients showed PPVs of > 60%, including those with low/low-intermediate secondary IPIs.

CONCLUSION

The role of FDG-PET/CT surveillance is limited, and differs according to the lymphoma subtype. FDG-PET/CT may be useful in detecting early relapse in patients with aggressive T-cell NHL, including those with low/low-intermediate risk secondary IPI; as already known, FDG-PET/CT has no role in aggressive B-cell NHL. Repeat biopsy should be performed to discriminate relapse or transformation from false positive findings in patients with positive surveillance FDG-PET/CT results.

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.

Changes in Frequency of Surveillance Imaging of Survivors of Diffuse Large B-Cell Lymphoma After the American Society of Hematology Choosing Wisely Recommendations

In 2013, the American Society of Hematology (ASH) published recommendations with Choosing Wisely to limit surveillance imaging in aggressive lymphoma. We studied surveillance imaging practice patterns for diffuse large B-cell lymphoma (DLBCL) before and after the ASH Choosing Wisely campaign. We used OptumLabs Data Warehouse, a national insurance claims database, to retrospectively study imaging frequency in survivors of DLBCL from 2008 to 2016. Three time periods were defined: Period 1 (2008 to 2010), Period 2 (2011 to 2013), and Period 3 (2014 to 2016). One thousand four hundred seventy-two patients were included. Median follow up was approximately 2 years. During the first and second years of surveillance, imaging remained stable between Period 1 (years 1 and 2: 199 [91%] and 137 [83%], respectively) and Period 2 (years 1 and 2: 257 [88%] and 172 [77%], respectively; P = .38), but decreased in Period 3 (years 1 and 2: 315 [78%] and 83 [61%], respectively; P < .01). In a multivariable logistic regression, year after 2012 was a significant predictor of decreased overuse (more than two scans per year in the first year of surveillance; [odds ratio, 0.49 for 2013 v 2008; P = .02]). Our study demonstrated the rate of surveillance scans-both computed tomography and positron emission tomography imaging-in DLBCL decreased after the ASH Choosing Wisely campaign. Multiple factors, such as changes in recommendations, reimbursement, and provider knowledge base, may have all contributed and should be studied further.

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.

Surveillance in Patients With Diffuse Large B Cell Lymphoma

With improvement in the cure rates for diffuse large B cell lymphoma, the question of surveillance imaging in patients who achieve complete remission after the initial therapy has become relevant. Some of the clinical practice guidelines recommend surveillance scanning. However, several studies have reported no benefit in overall survival with scans. Moreover, studies have highlighted an increased risk for developing secondary malignancies because of exposure to ionizing radiation from the scans. Different international societies have contrasting guidelines for the role of surveillance computerized tomography scans in patients who achieve complete remission after first-line therapy. Any benefit of surveillance imaging must be balanced by the costs, risk of radiation exposure, and lack of survival benefit. The PubMed platform was searched using relevant keywords for English-language articles with no date restrictions. Search terms were cross-referenced with review articles, and additional articles were identified by manually searching reference lists. Results were reviewed by the authors and selected for inclusion based on relevance. We present a review of this current data available for surveillance imaging in patients with diffuse large B cell lymphoma.

Analysis of Relapsed/Refractory Hodgkin Lymphoma Treated with Autologous Transplantation: A Single-Center Experience

Introduction: Hodgkin lymphoma (HL) is one of the common lymphomas with high cure rate. Aims: The aim was to study the outcome of relapsed/refractory HL treated with autologous transplantation. Objectives: The objective was to study the overall survival, overall response, and disease-free survival of the relapsed/refractory HL after autologous transplantation. Methods: It was a retrospective study conducted over a period of 8 years in our center using computer-based database and medical records as the data source. Results: A total of 22 patients were diagnosed with relapsed/refractory HL of which majority of cases were male patients (59%) with a mean age of 29 years (range: 15–57 years) and were Stage 4A (40.9%), with nodular sclerosis (54.5%). The overall response rate was 81.8% with 9.1% complete response, 72.7% partial response, and 4.5% stable disease; the overall survival was 77.92 ± 6.65 months, and disease-free survival was 69.66 ± 8.13 months. Conclusion: Autologous stem cell transplant plays an integral role in the treatment of patients with relapsed/refractory Hodgkin lymphoma.

Costs and clinical outcomes of patients with diffuse large B-cell lymphoma in first remission: role of PET/CT surveillance

BACKGROUND/AIMS

The role of [18F]-f luorodeoxyglucose positron emission tomography-computed tomography (PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL) in first remission is unclear.

METHODS

Medical costs within the first 3 years of treatment completion and clinical outcomes of 118 patients with DLBCL in first remission with and without surveillance PET/CT (PET/CT [+] group [n = 76] and PET/CT [-] group [n = 42], respectively) were retrospectively analyzed.

RESULTS

In a propensity matched cohort with adjustment for International Prognostic Index risk and relapse, the PET/CT (+) group was shown to have similar medical costs as the PET/CT (-) group. Relapse-free survival (RFS) and overall survival (OS) were comparable between the two groups (median RFS not reached [NR] for both groups, p = 0.133; median OS NR, p = 0.542). Among 76 patients with surveillance PET/CT, 31 (40.8%) had findings suggestive of recurrence and 16 of these (51.6%) were later confirmed to have recurrent disease. Fifteen patients (48.4%) were confirmed to not have recurrence after follow-up CT or PET/CT evaluation (n = 10) and biopsy (n = 4). None of the patients with negative PET/CT findings had disease recurrence. Sensitivity, specificity, positive predictive value, and negative predictive value of PET/CT for detection of recurrence were 1, 0.75, 0.52, and 1, respectively.

CONCLUSION

Surveillance PET/CT resulted in similar clinical outcomes and medical costs compared to no surveillance PET/CT. Approximately half of patients with PET/CT findings of recurrence had no recurrence after follow-up imaging and biopsy, which would not have been carried out if PET/CT had not been performed in the first place.

FDG-PET/CT in the management of lymphomas: current status and future directions

FDG-PET/CT is the current state-of-the-art imaging in lymphoma and plays a central role in treatment decisions. At diagnosis, accurate staging is crucial for appropriate therapy selection: FDG-PET/CT can identify areas of lymphoma missed by CT alone and avoid under-treatment of patients with advanced disease stage who would have been misclassified as having limited stage disease by CT. Particularly in Hodgkin lymphoma, positive interim FDG-PET/CT scans are adversely prognostic for clinical outcomes and can inform PET-adapted treatment strategies, but such data are less consistent in diffuse large B-cell lymphoma. The use of quantitative FDG-PET/CT metrics using metabolic tumour volume, possibly in combination with other biomarkers, may better define prognostic subgroups and thus facilitate better treatment selection. After chemotherapy, FDG-PET/CT response is predictive of outcome and may identify a subgroup who benefit from consolidative radiotherapy. Novel therapies, in particular immunotherapies, exhibit different response patterns than conventional chemotherapy, which has led to modified response criteria that take into account the risk of transient pseudo-progression. In relapsed lymphoma, FDG-PET/CT after second-line therapy and prior to high-dose therapy is also strongly associated with outcome and may be used to guide intensity of salvage therapy in relapsed Hodgkin lymphoma. Currently, FDG-PET/CT has no role in the routine follow-up after complete metabolic response to therapy, but it remains a powerful tool for excluding relapse if patients develop clinical features suggestive of disease relapse. In conclusion, FDG-PET/CT plays major roles in the various phases of management of lymphoma and constitutes a step towards the pursuit of personalized treatment.

Post-treatment surveillance imaging in lymphoma

Appropriate post-treatment management of patients with lymphoma has been controversial, with imaging frequently performed as post-treatment surveillance. The goal of post-treatment imaging is to identify relapse prior to clinical symptoms, when the burden of disease is lower and the possibility of effective salvage therapy and cure are greater. However, little data exist to support the performance of surveillance imaging after completion of treatment, with the vast majority of studies suggesting there is no clinical benefit to surveillance imaging in asymptomatic patients. Ongoing efforts seek to identify a subset of patients with a higher risk of relapse that might benefit from surveillance imaging, though financial and other costs associated with imaging are non-negligible and must be considered. Here we summarize the current data regarding post-treatment surveillance imaging in lymphoma.

Utility of Routine Surveillance Imaging for Hodgkin Disease following Autologous Transplant: Experiences from a Single Institution

BACKGROUND

Surveillance scans performed after autologous stem cell transplant (auto-HCT) for patients with Hodgkin disease (HD) have no proven survival benefit.

METHODS

We studied survival differences among patients with HD after auto-HCT whose recurrences were detected on clinical history and exam, versus those detected on routine surveillance scan.

RESULTS

Among the 98 patients with HD that underwent auto-HCT from 2000 to 2014 at our institution, 30 relapsed, of which 21 were detected radiologically and 9 clinically. There were no statistically significant differences in patient characteristics between the 2 groups. The median time to progression was 118 days for the clinical cohort and 284 days for the radiological cohort (p = 0.05). Median overall survival (OS) was 728 days for the clinical cohort, and was not reached for the radiological cohort (p = 0.02).

DISCUSSION

In our review, most patients with HD after auto-HCT were diagnosed radiologically. Patients whose relapse was diagnosed clinically were likely to be detected earlier and have a shorter OS. Patients with aggressive disease may be detected when clinically relevant, regardless of scanning. Routine scanning may not be necessary in the majority of patients with HD following auto-HCT.

Minimal Residual Disease Assessment in Lymphoma: Methods and Applications

Standard methods for disease response assessment in patients with lymphoma, including positron emission tomography and computed tomography scans, are imperfect. In other hematologic malignancies, particularly leukemias, the ability to detect minimal residual disease (MRD) is increasingly influencing treatment paradigms. However, in many subtypes of lymphoma, the application of MRD assessment techniques, like flow cytometry or polymerase chain reaction-based methods, has been challenging because of the absence of readily detected circulating disease or canonic chromosomal translocations. Newer MRD detection methods that use next-generation sequencing have yielded promising results in a number of lymphoma subtypes, fueling the hope that MRD detection may soon be applicable in clinical practice for most patients with lymphoma. MRD assessment can provide real-time information about tumor burden and response to therapy, noninvasive genomic profiling, and monitoring of clonal dynamics, allowing for many possible applications that could significantly affect the care of patients with lymphoma. Further validation of MRD assessment methods, including the incorporation of MRD assessment into clinical trials in patients with lymphoma, will be critical to determine how best to deploy MRD testing in routine practice and whether MRD assessment can ultimately bring us closer to the goal of personalized lymphoma care. In this review article, we describe the methods available for detecting MRD in patients with lymphoma and their relative advantages and disadvantages. We discuss preliminary results supporting the potential applications for MRD testing in the care of patients with lymphoma and strategies for including MRD assessment in lymphoma clinical trials.

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.

Surveillance Scans in Lymphoma: Friend or Foe?

OPINION STATEMENT

Advancements in the treatment of lymphoma over the last few decades have allowed more patients to achieve a remission after the completion of therapy. Due to the improvement in response rates, methods to detect recurrence early and accurately during follow-up, especially in patients with potential curable aggressive lymphomas, are a key. Observation has always involved close clinical follow-up with the use of physical exams and routine labs, but rapid changes in technology have allowed CT scans, PET scans, and MRIs to become an integral part of managing patients with lymphoma. While the utility of scans in initial staging and immediately after completion of therapy is well established, the use of these imaging modalities for monitoring recurrence in lymphoma patients is still controversial. Patient advocacy groups and other regulatory committees have questioned the frequency and in some cases even the need for these tests in patients without evidence of active disease given the concern for radiation-associated health risks. Additionally, the extent to which this form of testing impacts the psyche of our patients is not completely known. Given the numerous questions raised about the benefits, safety, and cost-effectiveness of CT imaging, firm guidelines are needed at this time in standard practice and within our clinical trials to limit the use of surveillance imaging. Such efforts are expected to improve the utility of these scans in asymptomatic patients, reduce healthcare costs, and reduce patient exposure to radiation.

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.

Evaluating surveillance imaging for diffuse large B-cell lymphoma and Hodgkin lymphoma

Up to 50% of patients with Hodgkin lymphoma and diffuse large B-cell lymphoma will relapse, requiring additional therapy. Although surveillance imaging is commonly performed in clinical practice, its ability to identify asymptomatic relapses and improve survival for patients is not well defined. We evaluated the surveillance imaging role in relapse detection and reviewed its impact on survival for relapsed patients, and found that current imaging approaches do not detect most relapses prior to clinical signs and symptoms or improve survival.

Imaging of primary pediatric lymphoma of bone

BACKGROUND

Primary pediatric bone lymphoma is a rare form of non-Hodgkin lymphoma. Unlike nodal forms of lymphoma, imaging abnormalities in lymphoma of bone do not resolve rapidly in conjunction with treatment and radiologic findings can remain abnormal for years, making it difficult to evaluate treatment response.

OBJECTIVE

To evaluate the utility of imaging in assessment of patients with primary pediatric bone lymphoma.

MATERIALS AND METHODS

At our institution between 2004 and 2013, six cases of pathology-proven primary pediatric bone lymphoma were diagnosed. Retrospective chart review was performed to assess imaging utilization. Our data were qualitatively compared with existing literature to construct an algorithm for imaging patients with primary lymphoma of bone.

RESULTS

Imaging evaluation of patients with primary pediatric bone lymphoma was highly variable at our institution. Conventional imaging was routinely used to evaluate response to treatment, despite lack of appreciable osseous change. Imaging in the absence of symptoms did not alter clinical management. Only positron emission tomography CT (PET/CT) proved capable of demonstrating imaging changes from the pretreatment to the post-treatment scans that were consistent with the clinical response to treatment.

CONCLUSION

Surveillance imaging is likely unnecessary in patients with a known diagnosis of pediatric lymphoma of bone. Pretreatment and post-treatment PET/CT is likely sufficient to assess response. There is little data to support the use of interim and surveillance PET/CT.

Clinical approach to diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common subtype of lymphoma. We now recognize that DLBCL corresponds to a biologically heterogeneous family of diseases. Given the potential for cure for most DLBCL patients, appropriate diagnostic and staging evaluation and therapy are essential. Here we review areas of consensus as well as controversy in the evaluation, treatment and monitoring of patients with DLBCL and its related subtypes.

No survival benefit associated with routine surveillance imaging for Hodgkin lymphoma in first remission: a Danish-Swedish population-based observational study

The use of routine imaging for patients with classical Hodgkin lymphoma (HL) in complete remission (CR) is controversial. In a population-based study, we examined the post-remission survival of Danish and Swedish HL patients for whom follow-up practices were different. Follow-up in Denmark included routine imaging, usually for a minimum of 2 years, whereas clinical follow-up without routine imaging was standard in Sweden. A total of 317 Danish and 454 Swedish comparable HL patients aged 18-65 years, diagnosed in the period 2007-2012 and having achieved CR following ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine)/BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisone) therapy, were included in the study. The cumulative progression rates in the first 2 years were 4% (95% confidence interval [CI] 1-7) for patients with stage I-II disease vs. 12% (95% CI 6-18) for patients with stage III-IV disease. An imaging-based follow-up practice was not associated with a better post-remission survival in general (P = 0·2) or in stage-specific subgroups (P = 0·5 for I-II and P = 0·4 for III-IV). Age ≥45 years was the only independent adverse prognostic factor for survival. In conclusion, relapse of HL patients with CR is infrequent and systematic use of routine imaging in these patients does not improve post-remission survival. The present study supports clinical follow-up without routine imaging, as encouraged by the recent Lugano classification.

Role of Surveillance Imaging in Patients With Peripheral T-Cell Lymphoma

INTRODUCTION

The role of surveillance imaging (SI) in patients with peripheral T-cell lymphoma (PTCL) in first complete remission (CR1) is unclear.

MATERIALS AND METHODS

Patients with PTCL were identified through prospectively maintained T-cell lymphoma databases from the National Cancer Centre Singapore/Singapore General Hospital and Weill-Cornell Medical College after institutional review board approval. Patients with leukemia or indolent, composite, and cutaneous lymphomas were excluded. The patients' medical records were retrospectively reviewed to determine the frequency and type of SI used. Of those with relapse, the method of relapse detection and data on symptoms, signs, and elevated lactate dehydrogenase LDH were extracted.

RESULTS

A total of 338 patients were included in the present study. In the first year after achieving CR1, patients had an average of 1.2 and a median of 1 SI performed (range, 0-4). In the second year after achieving CR1, they had an average of 0.78 and a median of 1 SI performed (range, 0-4). Of the 135 patients who achieved CR1, 61 (45%) developed a relapse. Relapses were detected before SI in 48 (84%), and 9 patients had relapses detected during routine SI. Of the 9 patients whose relapses were detected during planned SI, only 3 did not have any symptoms or signs suggestive of relapsed disease. Of these 3 patients, 2 had angioimmunoblastic T-cell lymphoma and 1 had natural killer/T-cell lymphoma.

CONCLUSION

Most PTCL relapses were detected before planned SI, and most patients had symptoms with relapse. Only 3 patients (5.2%) were completely asymptomatic at relapse, suggesting a limited utility of routine imaging for detecting PTCL relapses.

Rethinking clinical response and outcome assessment in a biologic age

Standardized response criteria for lymphoma are critical for the evaluation of new therapies. Widely adopted recommendations, most recently the Lugano classification, have been developed primarily for assessment of conventional chemotherapeutic regimens. More recently, several classes of drugs, including immunomodulatory agents, B cell receptor pathway targeting kinases, and checkpoint (PD-1, PDL-1) inhibitors have demonstrated impressive activity in a broad range of histologies. However, they may be associated with features during treatment suggestive of progressive disease despite clinical benefit. Immune response criteria have been proposed for solid tumors, and a modification is needed to be more applicable to lymphomas. Following treatment, conservative use of imaging is recommended based on clinical indications. As newer targeted agents with unique mechanisms of action are developed, current response and follow-up criteria must be made sufficiently flexible for optimal evaluation.

Routine Imaging for Diffuse Large B-Cell Lymphoma in First Complete Remission Does Not Improve Post-Treatment Survival: A Danish–Swedish Population-Based Study

Purpose

Routine imaging for diffuse large B-cell lymphoma (DLBCL) in first complete remission (CR) is controversial and plays a limited role in detecting relapse. This population-based study compared the survival of Danish and Swedish patients with DLBCL for whom traditions for routine imaging have been different.

Patients and Methods

Patients from the Danish and Swedish lymphoma registries were included according to the following criteria: newly diagnosed DLBCL from 2007 to 2012, age 18 to 65 years, and CR after R-CHOP/CHOEP. Follow-up for Swedish patients included symptom assessment, clinical examinations, and blood tests at 3- to 4-month intervals for 2 years, with longer intervals later in follow-up. Imaging was only recommended when relapse was clinically suspected. Follow-up for Danish patients was similar but included routine imaging (usually computed tomography every 6 months for 2 years).

Results

Danish (n = 525) and Swedish (n = 696) patients with DLBCL had comparable baseline characteristics. Cumulative 2-year progression rate after CR was 6% (95% CI, 4 to 9) for International Prognostic Index (IPI) ≤ 2 versus 21% (95% CI, 13 to 28) for IPI > 2. Age > 60 years (hazard ratio [HR], 2.3; 95% CI, 1.6 to 3.4), elevated lactate dehydrogenase (HR, 2.3; 95% CI, 1.4 to 3.8), B symptoms (HR, 1.7; 95% CI, 1.1 to 2.5), and Eastern Cooperative Oncology Group performance status ≥ 2 (HR, 1.8; 95% CI, 1.0 to 3.0) were associated with worse post-CR survival. Imaging-based follow-up strategy had no impact on survival, neither for all patients nor for IPI-specific subgroups.

Conclusion

DLBCL relapse after first CR is infrequent, and the widespread use of routine imaging in Denmark did not translate into better survival. This favors follow-up without routine imaging and, more generally, a shift of focus from relapse detection to improved survivorship.

FDG PET/CT in cancer: comparison of actual use with literature-based recommendations

Purpose

The Region of Southern Denmark (RSD), covering 1.2 of Denmark’s 5.6 million inhabitants, established a task force to (1) retrieve literature evidence for the clinical use of positron emission tomography (PET)/CT and provide consequent recommendations and further to (2) compare the actual use of PET/CT in the RSD with these recommendations. This article summarizes the results.

Methods

A Work Group appointed a professional Subgroup which made Clinician Groups conduct literature reviews on six selected cancers responsible for 5,768 (62.6 %) of 9,213 PET/CT scans in the RSD in 2012. Rapid Evidence Assessment was applied, using the methodology of systematic reviews with predefined limitations to search PubMed, Embase and the Cochrane Library for articles published in English/Danish/Swedish/Norwegian since 2002. PICO questions were defined, data recorded and quality appraised and rated with regard to strength and evidence level. Consequent recommendations for applications of PET/CT were established. The actual use of PET/CT was compared with these, where grades A and B indicated “established” and “useful” and grades C and D “potentially useful” and “non-recommendable” indications, respectively.

Results

Of 11,729 citations, 1,729 were considered for review, and 204 were included. The evidence suggested usefulness of PET/CT in lung, lymphoma, melanoma, head and neck, and colorectal cancers, whereas evidence was sparse in gynaecological cancers. The agreement between actual use of PET/CT and literature-based recommendations was high in the first five mentioned cancers in that 96.2 % of scans were made for grade A or B indications versus only 22.2 % in gynaecological cancers.

Conclusion

Evidence-based usefulness was reported in five of six selected cancers; evidence was sparse in the sixth, gynaecological cancers. Actual use of PET/CT agreed well with recommendations.

Electronic supplementary material

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Baseline and ongoing PET-derived factors predict detrimental effect or potential utility of 18F-FDG PET/CT (FDG-PET/CT) performed for surveillance in asymptomatic lymphoma patients in first remission

PURPOSE

To identify both clinical and FDG PET/CT-derived factors predicting the occurrence of relapse, or conversely, the likelihood of false positive findings in surveillance FDG-PET/CT studies (PETsv).

METHODS

The study included 149 asymptomatic patients with Hodgkin's lymphoma (HL) (n = 55) or diffuse large B cell lymphoma (DLBCL) (n = 94) in first remission. PETSv studies were performed 12, 18, 24 and 36 months thereafter. Logistic regression analysis was performed to identify clinical and imaging-derived predictors of either PET-detected relapse or false-positive (FP) results. Tested clinical variables were: 1) age, 2) HL vs. DLBCL, 3) stage of disease, 4) bulky disease, 5) previous radiotherapy. PET/CT-derived variables were: 1) maximum standardized uptake value at baseline, 2) size-incorporated maximum standardized uptake value (SIMaxSUV) at baseline, 3) positive interim PET(PET-2), 4) presence of hot spots likely to be unrelated to the disease in final PET, 5) residual non-FDG avid mass.

RESULTS

Accuracy was 88 % for PETsv1, 95 % for PETsv2, 95 % for PETsv3 and 91 % for PETsv4. However, PPV was relatively low in all PETsv. Best predictors of relapse were result of interim PET, HL versus NHL type, SIMaxSUV, age ≥ 60. Best predictors of FP were previous radiotherapy and hot spots unrelated to the disease in final PET.

CONCLUSIONS

The present study confirms the need of restricting the use of surveillance PET/CT to patients at high risk of relapse. Information derived from PET/CT performed at baseline (metabolic disease burden), in the course (PET2) and at the end of therapy (unrelated hot spots) can help to select high-risk patients and also to identify patients more likely to present equivocal findings at PETsv.

Value of surveillance studies for patients with stage I to II diffuse large B-cell lymphoma in the rituximab era

BACKGROUND

The role of surveillance studies in limited-stage diffuse large B-cell lymphoma (DLBCL) in the rituximab era has not been well defined. We sought to evaluate the use of imaging (computed tomography [CT] and positron emission tomography [PET]-CT) scans and lactate dehydrogenase (LDH) in surveillance of patients with stage I to II DLBCL.

METHODS

A retrospective analysis was performed of patients who received definitive treatment between 2000 and 2013.

RESULTS

One hundred sixty-two consecutive patients with stage I to II DLBCL were treated with chemotherapy +/- rituximab, radiation, or combined modality therapy. The 5-year rates of overall survival (OS) and freedom from progression (FFP) were 81.2% and 80.8%, respectively. Of the 162 patients, 124 (77%) were followed up with at least 1 surveillance PET scan beyond end-of-treatment scans; of those, 94 of 124 (76%) achieved a complete metabolic response on PET scan after completion of chemotherapy, and this was associated with superior FFP (P=.01, HR=0.3) and OS (P=.01, HR 0.3). Eighteen patients experienced relapse after initial response to therapy. Nine relapses were initially suspected by surveillance imaging studies (8 PET, 1 CT), and 9 were suspected clinically (5 by patient-reported symptoms and 4 by symptoms and physical examination). No relapses were detected by surveillance LDH. The median duration from initiation of treatment to relapse was 14.3 months among patients with relapses suspected by imaging, and 59.8 months among patients with relapses suspected clinically (P=.077). There was no significant difference in OS from date of first therapy or OS after relapse between patients whose relapse was suspected by imaging versus clinically. Thirteen of 18 patients underwent successful salvage therapy after relapse.

CONCLUSIONS

A complete response on PET scan immediately after initial chemotherapy is associated with superior FFP and OS in stage I to II DLBCL. The use of PET scans as posttreatment surveillance is not associated with a survival advantage. LDH is not a sensitive marker for relapse. Our results argue for limiting the use of posttreatment surveillance in patients with limited-stage DLBCL.

Imaging of non-Hodgkin lymphomas: diagnosis and response-adapted strategies

Optimal lymphoma management requires accurate pretreatment staging and reliable assessment of response, both during and after therapy. Positron emission tomography with computerized tomography (PET/CT) combines functional and anatomical imaging and provides the most sensitive and accurate methods for lymphoma imaging. New guidelines for lymphoma imaging and recently revised criteria for lymphoma staging and response assessment recommend PET/CT staging, treatment monitoring, and response evaluation in all FDG-avid lymphomas, while CT remains the method of choice for non-FDG-avid histologies. Since interim PET imaging has high prognostic value in lymphoma, a number of trials investigate PET-based, response-adapted therapy for non-Hodgkin lymphomas (NHL). PET response is the main determinant of response according to the new response criteria, but PET/CT has little or no role in routine surveillance imaging, the value which is itself questionable. This review presents from a clinical point of view the evidence for the use of imaging and primarily PET/CT in NHL before, during, and after therapy. The reader is given an overview of the current PET-based interventional NHL trials and an insight into possible future developments in the field, including new PET tracers.

Cost-effectiveness analysis of routine surveillance imaging of patients with diffuse large B-cell lymphoma in first remission

PURPOSE

Surveillance imaging of asymptomatic patients with diffuse large B-cell lymphoma (DLBCL) in first remission remains controversial. A decision-analytic Markov model was developed to evaluate the cost-effectiveness of follow-up strategies following first-line immunochemotherapy.

PATIENTS AND METHODS

Three strategies were compared in 55-year-old patient cohorts: routine clinical follow-up without serial imaging, routine follow-up with biannual computed tomography (CT) scans for 2 years, or routine follow-up with biannual [(18)F]-fluorodeoxyglucose positron emission tomography-computed tomography (PET/CT) for 2 years. The baseline model favored imaging-based strategies by associating asymptomatic imaging-detected relapses with improved clinical outcomes. Lifetime costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated for each surveillance strategy.

RESULTS

Surveillance strategies utilizing 2 years of routine CT or PET/CT scans were associated with minimal survival benefit when compared with clinical follow-up without routine imaging (life-years gained: CT, 0.03 years; PET/CT, 0.04 years). The benefit of imaging-based follow-up remained small after quality-of-life adjustments (CT, 0.020 QALYs; PET/CT, 0.025 QALYs). Costs associated with imaging-based surveillance strategies are considerable; ICERs for imaging strategies compared with clinical follow-up were $164,960/QALY (95% CI, $116,510 to $766,930/QALY) and $168,750/QALY (95% CI, $117,440 to 853,550/QALY) for CT and PET/CT, respectively. Model conclusions were robust and remained stable on one-way and probabilistic sensitivity analyses.

CONCLUSION

Our cost-effectiveness analysis suggests surveillance imaging of asymptomatic DLBCL patients in remission offers little clinical benefit at substantial economic costs.

Very low utility of surveillance imaging in early-stage classic Hodgkin lymphoma treated with a combination of doxorubicin, bleomycin, vinblastine, and dacarbazine and radiation therapy

BACKGROUND

This study evaluated the need for surveillance imaging in early-stage classic Hodgkin lymphoma (cHL) after planned combined-modality therapy (CMT).

METHODS

Primary early-stage cHL patients who underwent CMT were included. Positron emission tomography (PET)/computed tomography (CT), CT, or both were performed at the initial staging, during or after chemotherapy, and for at least 2 years during follow-up. Imaging studies and medical records were reviewed to determine if and when relapse had occurred. Radiation doses and costs were also calculated from follow-up imaging.

RESULTS

The study included 78 patients with a median follow-up of 46 months; 85% of the patients had stage II disease (32% with bulky disease). Four of 77 interim PET scans were positive; none of these patients relapsed during follow-up, which ranged from 24 to 80 months. After a total of 466 follow-up imaging studies (91% with CT and 9% with PET/CT), no cHL relapse was detected. Eleven abnormal findings were noted on surveillance imaging: 9 were false-positives, and 2 were second primary malignancies. The average cumulative dose per patient from follow-up imaging was 107 mSv, which translated into an estimated lifetime excess cancer risk of 0.5%; the estimated total costs were $296,817 according to Medicare reimbursements.

CONCLUSIONS

Surveillance imaging with either CT or PET/CT can be omitted safely for early-stage cHL treated with a combination of doxorubicin, bleomycin, vinblastine, and dacarbazine and radiation therapy because the risk of relapse is extremely low. This observation also applies to patients with bulky disease. The elimination of surveillance imaging will also reduce healthcare expenses and cumulative radiation doses in these predominantly young patients.

Role of 2-Deoxy-2-[18F]-fluoro-d-glucose-PET/Computed Tomography in Lymphoma

The role of PET and PET/computed tomography (CT) has evolved significantly in the last few decades. 2-Deoxy-2-[18F]-fluoro-d-glucose (FDG)-PET/CT is now an integral part of the management of patients with lymphoma. FDG-PET/CT at the time of initial staging can help in appropriate staging of the patients. Both interim and end-of-therapy PETs have significant prognostic value in patients with Hodgkin lymphoma and aggressive non-Hodgkin lymphoma and more accurately assess for the presence of residual malignancy than anatomic imaging. The impact of interim FDG-PET/CT on risk-adapted strategies is an area of active investigation and the results of ongoing clinical trials will be informative.

Next-generation surveillance strategies for patients with lymphoma

While remission and cure rates for Hodgkin and non-Hodgkin lymphoma continue to improve, surveillance approaches remain controversial, especially in light of recent reports suggesting limited benefit for routine radiologic assessment. Routine cross-sectional imaging results in considerable patient expense and anxiety, and this approach does not clearly improve patient outcomes. Next-generation approaches including minimal residual disease detection may provide an opportunity to identify relapse early and intervene prior to progression of clinical disease. This review discusses the role of surveillance imaging in Hodgkin and non-Hodgkin lymphoma and provides an introduction to serologic assessment of minimal residual disease. Future studies will need to focus on the clinical application of minimal residual disease surveillance and its ability to predict relapse, treatment response and survival.