PET/CT before autologous stem cell transplantation predicts outcome in refractory/relapsed follicular lymphoma

Age and lymphocyte/monocyte ratio as prognostic factors for autologous transplantation in the treatment of patients with follicular lymphoma

OBJECTIVE

Follicular lymphoma (FL) is an indolent, lymphoproliferative disease of B-cell origin that has a heterogeneous disease course with varying outcomes. Certain patients may undergo autologous stem cell transplantation. We investigated the outcome of autologous stem cell transplantation in patients with FL.

METHODS

Patients who received autologous stem cell transplantation at the University of Debrecen's Department of Hematology between 2004 and 2021 were retrospectively analyzed. The overall survival (OS) and progression-free survival (PFS) after transplantation of patients with FL were examined. Prognostic factors that may influence the course of the disease were chosen.

RESULTS

Data were collected from 49 patients. OS was influenced only by age, whereas PFS was affected by age and the lymphocyte/monocyte ratio. The combination of age and lymphocyte/monocyte ratio defined a patient population with a particularly unfavorable prognostic risk profile: patients over 47 years of age with a pre-transplant lymphocyte/monocyte ratio greater than or equal to 2.675.

CONCLUSION

Age and lymphocyte/monocyte ratio were identified as useful prognostic factors for PFS in patients with FL following autologous stem cell transplantation.

Standardized classification schemes in reporting oncologic PET/CT

The imaging report is essential for the communication between physicians in patient care. The information it contains must be clear, concise with evidence-based conclusions and sufficient to support clinical decision-making. In recent years, several classification schemes and/or reporting guidelines for PET have been introduced. In this manuscript, we will review the classifications most frequently used in oncology for interpreting and reporting 18F-FDG PET imaging in lymphoma, multiple myeloma, melanoma and head and neck cancers, PSMA-ligand PET imaging for prostate cancer, and 68Ga-DOTA-peptide PET in neuroendocrine tumors (NET).

Post-transplantation Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography in Patients with Lymphoblastic Lymphoma is an Independent Prognostic Factor with an Impact on Progression-Free Survival but not Overall Survival

Purpose: In the present study, we mainly aimed to evaluate the prognostic value of 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]F-FDG) positron emission tomography (PET)/computed tomography (CT) after allogeneic stem cell transplantation (allo-SCT) in lymphoblastic lymphoma (LBL) patients using Deauville Scores (DS). Materials and Methods: A total of 63 LBL patients who benefited from ¹⁸F-FDG PET-CT after allo-SCT in our institution between April 2010 and August 2020 were enrolled in this retrospective study. These above-mentioned patients were divided into two groups based on the Deauville criteria. Diagnostic efficiency of ¹⁸F-FDG PET/CT and integrated CT in detecting lymphoma were calculated. Consistencies were evaluated by comparing 18F-FDG PET/CT and integrated CT results through kappa coefficient. Kaplan-Meier method was used in survival analysis, and the log-rank method was adopted in comparisons. Prognostic factor analysis was performed by the Cox regression model. Results: The sensitivity, specificity, positive predictive value, negative predictive value, accuracy of post-SCT ¹⁸F-FDG PET-CT were 100%(12/12), 92.2%(47/51), 75.0%(12/16), 100%(47/47) and 93.7%(59/63). The consistency of 18F-FDG PET-CT and integrated CT was moderate(Kappa = .702，P < .001). Positive post-SCT 18F-FDG PET-CT was associated with lower progression-free survival (PFS) but not overall survival (OS) (p = .000 and p = .056, respectively). The 3-year PFS of the PET-positive group and PET-negative group was 18.8% and 70.2%, respectively. Multivariate analysis showed that post-SCT PET-CT findings was an independent prognostic factor for PFS (p = .000; HR, 3.957; 95%CI, 1.839-8.514). Other factors independently affecting PFS were sex (p = .018; HR, 2.588; 95% CI, 1.181 − 5.670) and lactate dehydrogenase (LDH) (p = .005; HR, 3.246; 95% CI, 1.419 − 7.426). However, none of the above-mentioned factors were associated with OS. Conclusions: Collectively, we found that 18F-FDG PET-CT after allo-SCT was a strong indicator for PFS, but not OS, which might provide important evidence for the selection of subsequent treatment regimen for LBL patients. Trial registration number: ChiCTR2100046709.

Prognostic Value of 2-Deoxy-2-[18F]fluoro-D-glucose Positron Emission Tomography/Computed Tomography after Autologous Hematopoietic Stem Cell Transplantation in Lymphoma Using Deauville Scores

Purpose

In the present study, we mainly aimed to evaluate the prognostic value of 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]F-FDG) positron emission tomography (PET)/computed tomography (CT) after autologous stem cell transplantation (ASCT) in lymphoma. Procedures. A total of 76 lymphoma patients who benefited from [¹⁸F]F-FDG PET-CT (within 3 months and 3–6 months) after ASCT in our institution between April 2010 and December 2019 were enrolled in this retrospective study. These abovementioned patients were divided into two groups based on the Deauville criteria. The Kaplan–Meier method was used in survival analysis, and the log-rank method was adopted in comparison. Prognostic factor analysis was performed by the Cox regression model.

Results

Positive post-ASCT [¹⁸F]F-FDG PET-CT was associated with lower progression-free survival (PFS) and overall survival (OS) (p = 0.001 and p = 0.022, respectively). Univariate analysis showed the post-ASCT PET-CT result was the only independent factor associated with PFS (p = 0.002). Both the number of previous treatments and post-ASCT PET-CT result had a different impact on OS (p = 0.040 and p = 0.028, respectively). Multivariate analysis showed the post-ASCT PET-CT result was the only independent factor associated with OS (p = 0.028). The results showed no significant change from the abovementioned results when DS < 3 was defined as the negative result. For patients who had a PET-CT scan within 3–6 months after ASCT, the negative PET-CT group had a better prognosis including PFS and OS (p = 0.009 and p = 0.025, respectively). However, among the patients receiving PET-CT within 3 months, the result was not statistically significant (p = 0.064 and p = 0.445, respectively).

Conclusion

Collectively, we found that the post-ASCT [¹⁸F]F-FDG PET-CT was a strong indicator for PFS and OS, and a time window of 3–6 months was appropriate for post-ASCT [¹⁸F]F-FDG PET-CT. Trial registration number: ChiCTR2100042745.

Where does transplant fit in the age of targeted therapies?

The role of hematopoietic cell transplantation (HCT) for indolent lymphoma has evolved over the last 5 years with the availability of novel low-toxicity therapies and a better understanding of the prognosis of these entities. However, despite numerous treatment options for patients with follicular lymphoma, none are thought to be curative, and many require ongoing therapy with chronic toxicity. Historical trials indicate that autologous HCT as initial consolidation leads to improved progression-free survival, but not overall survival (OS) and, thus, is not typically recommended. However, autologous HCT for chemosensitive relapse can be carried out with ∼1% early mortality risk, affording disease control lasting a median of 3 to 5 years and the potential to improve OS. These results may compare favorably in efficacy, toxicity, and cost vs multiple sequential novel therapies with shorter durations of benefit. Recent data indicate that autologous HCT in follicular lymphoma patients with early initial progression will result in more than one third being alive and without relapse at 5 years, leading to improved OS when used within a year of the first recurrence. Unlike other available therapies, allogeneic HCT has the potential to cure up to one half of those transplanted with indolent B-cell non-Hodgkin lymphoma, although the risks need to be recognized and appropriate patient and donor selection is critical to ensure the best outcomes. HCT continues to remain a viable option in the current era of multiple targeted agents.

Systematic review of therapy used in relapsed or refractory diffuse large B-cell lymphoma and follicular lymphoma

To identify real-world evidence on outcomes from therapies for relapsed/refractory diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), we systematically reviewed literature in Medline/Embase for DLBCL/FL-related articles on real-world results published during January 2012–May 2016. Among 33 included articles, therapies included stem cell transplant (SCT) and chemotherapy, including experimental regimens. The highest overall survival rates were observed for SCT, long considered an optimal strategy following initial relapse. Prognoses were inferior among DLBCL patients receiving rituximab-based regimens rather than SCT, particularly among studies that exclusively focused on those ineligible for SCT due to age or co-morbidity. A lack of viable treatment options for DLBCL/FL patients ineligible for SCT after relapse remains a significant gap in care.

Non-Hodgkin lymphoma is the most prevalent blood cancer. Diffuse large B-cell lymphoma and follicular lymphoma account for nearly two-thirds of all non-Hodgkin lymphomas. One-third of patients with diffuse large B-cell lymphoma continue on to relapsed or refractory disease. While follicular lymphoma tends to be less aggressive, relapses do occur. Stem cell transplant and chemotherapy/immunotherapy are the current treatment options for relapsed or refractory patients. However, many patients are ineligible for stem cell transplant, due to age or preexisting medical conditions, so safe and effective treatment choices for these patients are a must. The lack of viable treatment options highlights this unmet need.

Current prognostic and predictive factors in follicular lymphoma

Follicular lymphoma (FL) is generally considered an indolent disorder. With modern day treatments, long remissions are often achieved both in the front-line and relapsed setting. However, a subset of patients has a more aggressive course and a worse outcome. Their identification is the main purpose of modern day prognostic tools. In this review, we attempt to summarize the evidence concerning prognostic and predictive factors in FL, including (1) pre-treatment factors, from baseline clinical characteristics and imaging tests to histological grade, the microenvironment and genomic abnormalities; (2) post-treatment factors, i.e., depth of response, measured both by imaging tests and minimal residual disease; (3) factors at relapse and duration of response; and (4) prognostic factors in histological transformation. We conclude that, despite the existence of numerous tools, the availability of some of them is still limited; they generally suffer from notable downsides, and most have unproven predictive value, thus having scarce bearing on the choice of regimen at present. However, with the technological and scientific developments of the last few years, the potential for these prognostic factors is promising, particularly in combination, which will probably, in time, help guide therapeutic decisions.

FDG PET for therapy monitoring in Hodgkin and non-Hodgkin lymphomas

PET using 18F-FDG for treatment monitoring in patients with lymphoma is one of the most well-developed clinical applications. PET/CT is nowadays used during treatment to assess chemosensitivity, with response-adapted therapy given according to 'interim' PET in clinical practice to adults and children with Hodgkin lymphoma. PET is also used to assess remission from disease and to predict prognosis in the pretransplant setting. Mature data have been reported for the common subtypes of aggressive B-cell lymphomas, with more recent data also supporting the use of PET for response assessment in T-cell lymphomas. The Deauville five-point scale incorporating the Deauville criteria (DC) is recommended for response assessment in international guidelines. FDG uptake is graded in relation to the reference regions of normal mediastinum and liver. The DC have been validated in most lymphoma subtypes. The DC permit the threshold for adequate or inadequate response to be adapted according to the clinical context or research question. It is important for PET readers to understand how the DC have been applied in response-adapted trials for correct interpretation and discussion with the multidisciplinary team. Quantitative methods to perform PET in standardized ways have also been developed which may further improve response assessment including a quantitative extension to the DC (qPET). This may have advantages in providing a continuous scale to refine the threshold for adequate/inadequate response in specific clinical situations or treatment optimization in trials. qPET is also less observer-dependent and limits the problem of optical misinterpretation due to the influence of background activity.

The Role of Autologous and Allogeneic Stem Cell Transplantation in Follicular Lymphoma in The New Drugs Era

Follicular lymphoma (FL) is the second most common histotype of non-Hodgkin’s lymphoma, and it is generally characterized by a heterogeneous clinical course. Despite recent therapeutic and diagnostic improvements, a significant fraction of FL patients still relapsed. In younger and/or fit FL relapsed patients bone marrow transplant (BMT) has represented the main salvage therapy for many years. Thanks to the ability of high-dose chemotherapy to overcome the lymphoma resistance and refractoriness, autologous stem cell transplantation (ASCT) can achieve a high complete remission rate (CR) and favorable outcome regarding progression-free survival (PFS) and overall survival (OS). Allogeneic stem cell transplantation (alloSCT) combines the high dose chemotherapy effect together with the immune reaction of the donor immune system against lymphoma, the so-called ‘graft versus lymphoma’ (GVL) effect. Considering the generally higher transplant-related mortality (TRM), alloSCT is mostly indicated for FL relapsed after ASCT. During the last years, there have been a great spread of novel effective and feasible drugs Although these and future novel drugs will probably change our current approach to FL, the OS post-BMT (ASCT and alloSCT) has never been reproduced by any novel combination. In this scenario, it is important to correctly evaluate the disease status, the relapse risk and the comorbidity profile of the relapsed FL patients in order to provide the best salvage therapy and eventually transplant consolidation.

Reappraising the timing of transplant for indolent non-Hodgkin lymphomas

INTRODUCTION

Indolent non-Hodgkin lymphomas (iNHL) remain incurable with standard approaches. The timing of autologous stem cell transplant (ASCT) is changing following the introduction of new drugs that can potentially defer the transplant, improved reduced intensity conditioning (RIC) and haploidentical allogeneic SCT (allo-SCT).

AREAS COVERED

The most relevant aspects concerning the role of hematopoietic stem cell transplantation in the management of iNHL are discussed. Literature search methodology included examination of PubMed index and meeting presentations. Expert commentary: ASCT is not currently employed as consolidation in first-line, being reserved to patients with refractory/relapsed disease. The curative potential of graft-versus-lymphoma (GVL) after RIC allo-SCT could be particularly beneficial in patients with iNHL relapsing after ASCT. This scenario could be modified in the near future by better definition of high-risk patients at diagnosis, by the improvement of minimal residual disease (MRD) evaluation and by the introduction of new drugs in the therapeutic algorithm.

PET Scans for Staging and Restaging in Diffuse Large B-Cell and Follicular Lymphomas

Positron emission tomography (PET)-CT was recommended in updated international guidelines for staging/restaging of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). In FL, PET was previously regarded as a research application only. This review concentrates on new publications related to PET in these diseases. In DLBCL, PET appears appropriate for staging using prognostic indices established with CT and baseline PET parameters, e.g. metabolic tumour volume, are prognostic of outcome. Early complete metabolic response (CMR) predicts end-of-treatment CMR with excellent prognosis. Patients without CMR at interim should not have treatment altered, but have a worse prognosis, and patients with other high risk features may need closer monitoring. The end-of-treatment scan is confirmed as the standard for remission assessment using Deauville criteria, which are also predictive for patients undergoing ASCT. In FL, PET is more sensitive for staging than CT but misses bone marrow involvement. PET-CT identifies patients at risk of progression after induction chemotherapy better than CT.

The role of autologous and allogeneic stem cell transplantation in the management of indolent B-cell lymphoma

Despite improvements over the past decade in the overall survival of patients with indolent non-Hodgkin lymphomas, these lymphomas remain largely incurable with standard therapies. Immunochemotherapy with rituximab-based regimens has become a well-established standard of care in the primary and relapsed disease settings. The role of hematopoietic stem cell transplantation in indolent lymphoma has been defined by the adoption of this therapy largely in the relapse setting because randomized trials in the first-line setting have not shown survival advantages. Allogeneic stem cell transplantation has the possibility for cure because of the potential for immunologic graft-versus-lymphoma effect, but there are significant concerns regarding nonrelapse mortality. Autologous stem cell transplantation offers a safe treatment platform, but relapse remains a significant issue. The role of transplantation in the current treatment landscape of immunochemotherapy has not been conclusively proven, and randomized trials are lacking. This review summarizes the current relevant data regarding transplantation in indolent non-Hodgkin lymphoma and highlights the issues relevant to clinicians in the field.

The Value of PET/CT in Detecting Bone Marrow Involvement in Patients With Follicular Lymphoma

Follicular lymphoma (FL) is the 2nd most common type of lymphoma diagnosed in the Western World. Bone marrow (BM) involvement is an adverse prognostic factor in FL, routinely assessed by an arbitrary biopsy of the iliac crest. This study was aimed to investigate the role of positron emission tomography/computed tomography (PET/CT) in identifying BM involvement by FL. In this retrospective, single-center study we reviewed the records of consecutive patients with FL at diagnosis or relapse who underwent staging/restaging workup visual assessment of BM uptake was categorized as either normal, diffusely increased, or focally increased. Quantitative BM fluorine-18-fluro-deoxyglucose (FDG) uptake was measured using mean standardized uptake value (BM-SUVmean). The diagnosis of BM involvement was based on either BM histological findings or disappearance of increased uptake at end-treatment PET/CT in patients who responded to treatment. Sixty eight cases with FL were included. Sixteen (23.5%) had BM involvement, 13 (19.1%) had a biopsy proven involvement, and 3 (4.4%) had a negative BM biopsy, but increased medullary uptake that normalized post-treatment. BM FDG uptake in these patients was diffuse in 8 (50%) and focal in 8 (50%). Focal increased uptake was indicative of BM involvement; however, diffuse uptake was associated with 17 false positive cases (32.7%). Overall, visual assessment of BM involvement had a negative predictive value (NPV) of 100% and a positive predictive value (PPV) of 48.5%. On a quantitative assessment, BM-SUVmean was significantly higher in patients with BM involvement (SUVmean of 3.7 [1.7-6] vs 1.4 [0.4-2.65], P < 0.001). On receiver operator curve (ROC) analysis, BM-SUVmean > 2.7 had a PPV of 100% for BM involvement (sensitivity of 68%), while BM-SUVmean < 1.7 had an NPV of 100% (specificity of 73%). Visual assessment of PET/CT is appropriate for ruling out BM involvement by FL. Although focal increased uptake indicates marrow involvement, diffuse uptake is nonspecific. SUV measurement improves PET/CT diagnostic accuracy, identifying additional 19% of patients with BM involvement that would have been otherwise missed.

Prognostic relevance of pretransplant Deauville score on PET-CT and presence of EBV DNA in patients who underwent autologous stem cell transplantation for ENKTL

High-dose chemotherapy and autologous stem cell transplantation (ASCT) for extranodal natural killer/T-cell lymphoma (ENKTL) is a reasonable option for a subset of patients. The impact of response status, according to positron emission tomography/computed tomography (PET/CT) results and/or presence of circulating EBV DNA prior to ASCT, has not yet been established. We analyzed 27 ENKTL patients with pre-ASCT circulating EBV DNA who had undergone pre-ASCT PET/CT between 2009 and 2014. We classified patients into two groups based on the result of pretransplantation assessment: a favorable risk group (pretransplant five-point Deauville score (DS) of 1-2 based on PET/CT and no detectable EBV DNA) and an unfavorable risk group (DS 1-2 with detectable EBV DNA, DS 3-5 with or without detectable EBV DNA). After a median follow-up of 37 months, overall survival and PFS were significantly different between the two groups (median OS: not reached for favorable risk group vs 7.0 months for unfavorable risk group, P=0.017; median PFS: 16.0 vs 5.0 months, P=0.019). Multivariate analysis revealed that pre-ASCT DS and EBV DNA was the only independent prognostic factor considering stage, IPI and NKPI. Precise assessment of the status of disease before transplantation may provide more benefit from ASCT to ENKTL patients.

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

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