The role of FDG-PET imaging and involved field radiotherapy in relapsed or refractory diffuse large B-cell lymphoma

Radiation Therapy Dose Response in Bulky Relapsed/Refractory Large B-Cell Lymphoma

PURPOSE

To assess whether a radiation therapy (RT) dose affects response in bulky tumors in relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL).

METHODS AND MATERIALS

Data from patients with r/r DLBCL treated with salvage- or palliative-intent RT (2008-2020) at a single institution were examined. Index lesion size ≥7.5 cm was defined as bulky. Equivalent doses in 2-Gy fractions (EQD2) were calculated to compare doses between conventional and hypofractionated (≥2.5 Gy/fraction) schemes. Objective response rates (ORRs) were compared using nonparametric Mann-Whitney U test or Kruskal-Wallis test with Dunn's multiple comparison corrections. Freedom from local progression (FFLP) was assessed using Kaplan-Meier and Cox proportional hazard regression analyses.

RESULTS

One hundred eighty-three courses of 151 unique patients were included (salvage: 37% and palliative: 63%). Nonbulky and bulky tumors were irradiated in 109 (60%) and 74 (40%) courses, respectively. Median EQD2 was 33 Gy (IQR, 23-39 Gy) with hypofractionation in 84 (46%) cases. Of those with post-RT imaging (80%), the ORR was 59%, with a trend toward worsened ORR in bulky tumors (50% vs 65%, P = .077). For bulky tumors, RT regimens with EQD2s >30 Gy were associated with better ORR (≤30 Gy vs >30 Gy: 27% vs 64%, P = .0073), whereas a lower EQD2 cutoff was sufficient for nonbulky tumors (≤20 Gy vs >20 Gy: 38% vs 75%, P = .0011). On multivariable regression analysis, bulky tumor size was associated with worsened FFLP (hazard ratio, 2.07; 95% CI, 1.16-3.68; P = .014), whereas high EQD2s >30 Gy were associated with better FFLP (hazard ratio, 0.48; 95% CI, 0.25-0.93; P = .031). Bulky tumors treated with EQD2s ≤30 Gy had the lowest median FFLP (4.0 months), whereas EQD2s >30 Gy had an unreached median FFLP (P = .0047).

CONCLUSIONS

Bulky r/r DLBCL tumors were associated with less favorable tumor control outcomes in the salvage and palliative settings. RT regimens with higher EQD2s (>30 Gy) should be considered if durable local control of bulky tumors is desired.

Hypofractionated radiotherapy for refractory or relapsed aggressive B-cell lymphoma in the rituximab era

BACKGROUND

Radiotherapy (RT) is an effective and available local treatment for patients with refractory or relapsed (R/R) aggressive B-cell lymphomas. However, the value of hypofractionated RT in this setting has not been confirmed.

METHODS

We retrospectively analyzed patients with R/R aggressive B-cell lymphoma who received hypofractionated RT between January 2020 and August 2022 at a single institution. The objective response rate (ORR), overall survival (OS), progression-free survival (PFS) and acute side effects were analyzed.

RESULTS

A total of 30 patients were included. The median dose for residual disease was 36 Gy, at a dose per fraction of 2.3-5 Gy. After RT, the ORR and complete response (CR) rates were 90% and 80%, respectively. With a median follow-up of 10 months (range, 2-27 months), 10 patients (33.3%) experienced disease progression and three died. The 1-year OS and PFS rates for all patients were 81.8% and 66.3%, respectively. The majority (8/10) of post-RT progressions involved out-of-field relapses. Patients with relapsed diseases, no response to systemic therapy, multiple lesions at the time of RT, and no response to RT were associated with out-of-field relapses. PFS was associated with response to RT (P = 0.001) and numbers of residual sites (P < 0.001). No serious non-hematological adverse effects (≥ grade 3) associated with RT were reported.

CONCLUSION

These data suggest that hypofractionated RT was effective and tolerable for patients with R/R aggressive B-cell lymphoma, especially for those that exhibited localized residual disease.

A paradox of choice: Sequencing therapy in relapsed/refractory diffuse large B-cell lymphoma

The available treatments for relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) have experienced a dramatic change since 2017. Incremental advances in basic and translational science over several decades have led to innovations in immune-oncology. These innovations have culminated in eight separate approvals by the US Food and Drug Administration for the treatment of patients with R/R DLBCL over the last 10 years. High-dose therapy and autologous stem cell transplant (HDT-ASCT) remains the standard of care for transplant-eligible patients who relapse after an initial remission. For transplant-ineligible patients or for those who relapse following HDT-ASCT, multiple options exist. Monoclonal antibodies targeting CD19, antibody-drug conjugates, bispecific antibodies, immune effector cell products, and other agents with novel mechanisms of action are now available for patients with R/R DLBCL. There is increasing use of chimeric antigen receptor (CAR) T-cells as second-line therapy for patients with early relapse of DLBCL or those who are refractory to initial chemoimmunotherapy. The clinical benefits of these strategies vary and are influenced by patient and disease characteristics, as well as the type of prior therapy administered. Therefore, there are multiple clinical scenarios that clinicians might encounter when treating R/R DLBCL. An optimal sequence of drugs has not been established, and there is no evidence-based consensus on how to best order these agents. This abundance of choices introduces a paradox: proliferating treatment options are initially a boon to patients and providers, but as choices grow further they no longer liberate. Rather, more choices make the management of R/R DLBCL more challenging due to lack of direct comparisons among agents and a desire to maximize patient outcomes. Here, we provide a review of recently-approved second- and subsequent-line agents, summarize real-world data detailing the use of these medicines, and provide a framework for sequencing therapy in R/R DLBCL.

Are dynamic or fixed FDG-PET measures of disease of greater prognostic value in patients with relapsed/refractory diffuse large B-cell lymphoma undergoing autologous haematopoietic stem cell transplantation?

Positron emission tomography (PET) response assessment using the Deauville score has prognostic utility in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem-cell transplantation (ASCT). Improved predictive methods are required to identify patients with poor outcomes who may be better considered for other salvage options. We investigated the prognostic value of mean tumour volume (MTV) and maximum standardised uptake value (SUVmax) at pre-salvage and pre-ASCT time-points, and the quantitative changes between scans (∆MTV and ∆SUVmax). One hundred and twenty-five patients with R/R DLBCL underwent salvage immunochemotherapy and ASCT: 80 patients had pre-salvage PET and 90 had pre-ASCT PET available. With a median follow-up of 5.6 years, 5-year progression-free survival (PFS) and overall survival (OS) were 52% and 65%, respectively. For patients with PET-positive residual disease after salvage therapy, pre-ASCT MTV was a significant negative prognosticator for PFS (HR 1.19 per 100 ml, p < 0.001) and OS (HR 1.78 per 100 ml, p < 0.001). Similarly, pre-ASCT SUVmax was negatively associated with PFS (HR 1.08, p < 0.001) and OS (HR 1.08, p < 0.001). Notably, pre-salvage MTV and SUVmax and ∆MTV and ∆SUVmax were not associated with PFS or OS. In conclusion, pre-ASCT MTV and SUVmax appear to be of greater predictive value than the degree of response. Potential application may exist for PET-directed management of R/R DLBCL patients.

Radiation and Chimeric Antigen Receptor T-cell Therapy in B-cell Non-Hodgkin Lymphomas

OPINION STATEMENT

Chimeric antigen receptor T-cell therapy (CAR-T) is a revolutionary advancement in the management of chemotherapy refractory B-cell non-Hodgkin lymphomas representing a potentially curative therapy in scenarios that were previously only palliative. CAR-T cell therapy is associated with unique toxicities as well as practical challenges. One of those challenges is how to manage active lymphoma during the weeks-long CAR-T manufacturing process. Radiation therapy, steroids, and systemic therapy have all been used for what would be considered "bridging therapy" during this time frame. Radiation therapy is a particularly attractive strategy given its proven efficacy in chemotherapy refractory lymphomas; ability to stabilize patients, debulk disease, and palliate symptoms; as well as its potential to enhance the expansion and activity of CAR-T cells. Optimal dose, timing, and method of delivery are yet to be established though there is consensus that it should occur after apheresis if being used as a pre-treatment bridge. Another practical challenge is the management of patients in whom CAR-T cells fail. There is a potential emerging role for salvage radiation therapy, in select patients, for either palliation or as a means to get patients another potentially curative therapy. Collaborative well-designed prospective clinical trials are needed to definitively establish the role for radiation therapy (before or after CAR-T therapy) as well as define the impact on CAR-T cell activity/persistence and associated toxicity.

Does bridging radiation therapy affect the pattern of failure after CAR T-cell therapy in non-Hodgkin lymphoma?

PURPOSE

Analyze the pattern of disease failure after anti-CD19-directed chimeric antigen receptor T-cell therapy (CART) for non-Hodgkin lymphoma, assess the local control rate of bridging radiotherapy (bRT) and characterize in-field recurrences.

METHODS

We retrospectively reviewed 120 patients with NHL who received CART between 2018 and 2020. Baseline characteristics and treatment outcomes were compared between patients who received bRT and those who did not (noRT).

RESULTS

Of the 118 patients included, 14 (12%) received bRT, while 104 (88%) did not. bRT group had more localized and extranodal disease. bRT was delivered with a median dose of 20 Gy (range: 15-36) in 5 fractions (range: 3-24). Pattern of failure analysis revealed that progression involving pre-existing sites was the predominant pattern of failure in both the bRT and noRT groups (86% and 88%, respectively). Median duration of response was 128 days (range: 25-547) for bRT group and 93 days (range: 22-965) for noRT group (p = 0.78). In the bRT group, only 2/15 sites irradiated had infield recurrence and where characterized by bulky disease, SUV_max >20, elevated LDH at the time of CART infusion, and extranodal involvement. The bRT 1-year LC was 86%. Median duration of local response was 257 days (range: 25-630) for radiation-bridged sites.

CONCLUSION

Majority of progressions after CART infusion involve pre-existing sites. Bridging RT prior to CART provides excellent in-field local control and durable response. Patients with bulky disease, SUV_max >20, elevated LDH, and extranodal involvement are likely at higher risk of in-field recurrence after bRT and may benefit from higher curative doses of bRT.

Long-term remissions in patients with early relapse of diffuse large B-cell lymphoma following high-dose chemotherapy, autologous stem cell transplantation, and radiotherapy of residual disease

PURPOSE

The prognosis of an early relapse of diffuse large B-cell lymphoma (DLBCL) appears to be poor following autologous stem cell transplantation (ASCT). The aim of this study is to contribute data to the open question on whether additional radiotherapy can improve the outcome.

PATIENTS AND METHODS

Forty-eight patients with an early relapse (median 4 months after the end of initial immunochemotherapy, range 1-11) of DLBCL have been treated in our institution with high-dose therapy (usually the BEAM protocol) and ASCT since 2008 (median age 61 years, range 28-73). Twenty-three patients received ASCT in a second treatment line, 25 in a third line (19 refractory to second-line salvage therapy, 5 after second relapse). Fifteen of these 48 patients received radiotherapy (36-50 Gy, median 40) of residual masses after ASCT.

RESULTS

Three-year overall survival (OS) and progression-free survival (PFS) after second-line ASCT were 61 and 57%, after third-line ASCT 47 and 44%, respectively, without significant differences. A prognostic factor was the International Prognostic Index (IPI) at the start of salvage therapy. Three-year OS and PFS in low-risk patients were 69 and 69%, in low-intermediate-risk 63 and 53%, and in high-intermediate-risk 23 and 23%, respectively (p = 0.033). Twenty-three patients achieved a sustained complete remission (13-146 months, median 62).

CONCLUSION

Sustained long-term remissions can be achieved in patients with early relapse of DLBCL following ASCT in a second or third treatment line, particularly in patients with low- and low-intermediate-risk IPI, following radiotherapy of residual disease after ASCT. Further investigations are required to clarify which patients need an alternative therapy (potentially CAR T‑cells or allogeneic transplantation).

Salvage radiotherapy for primary refractory and relapsed diffuse large B-Cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma, accounting for 30-40% of all non-Hodgkin lymphoma cases and presenting later in life, most often in the sixth decade. Although DLBCL is curable, long-term remission rates are only 60-80%. The most recent major advance in upfront therapy for DLBCL was the monoclonal anti-CD20 antibody rituximab, which was approved in the late 1990s; now, 25 years later, up to 40% of patients will experience primary refractory or relapsed disease, thereby underscoring the importance of salvage therapy. Radiation therapy can be highly effective in DLBCL, both initially as consolidation therapy and later as salvage therapy and is currently being explored in the context of immune and cellular therapies. The aim of this review is to examine the therapeutic approaches for relapsed or refractory DLBCL, with a focus on whether using radiation therapy as salvage therapy can improve the likelihood of cure.

Palliative Radiotherapy for Diffuse Large B-cell Lymphoma

Recent improvements in chemoimmunotherapies, targeted agents, hematopoietic stem cell transplants, and cellular therapies have revolutionized treatment paradigms for patients with diffuse large B-cell lymphoma (DLBCL). Even in the relapsed or refractory setting, contemporary treatment options are delivered with curative intent and can lead to lasting remissions. Although such therapies have improved overall outcomes, they have increasingly led to a wide variety of presentations of recurrent tumors in need of palliation. Here, we review the use of radiotherapy (RT) in the palliation of DLBCL. We draw particular attention to the evolving role for hypofractionated RT and low-dose RT for DLBCL. We review the available literature on these topics and focus on commonly encountered clinical scenarios.

Radiotherapy for Non-Hodgkin Lymphomas

Radiotherapy (RT) plays a diverse and essential role in the contemporary management of non-Hodgkin lymphoma (NHL) and remains the single most powerful monotherapeutic intervention for both aggressive and indolent subtypes. Over the past decade, there have been significant advancements in radiation oncology practice, which have made modern treatments safer and more conformal. Despite this sophistication and evidence supporting a continued role for RT, numerous data suggest that utilization is on the decline. In this review, we discuss the rationale for RT in 4 commonly encountered scenarios: combined modality therapy for limited-stage aggressive NHL, consolidation therapy for advanced-stage aggressive NHL, and the changing roles of salvage RT for relapsed/refractory NHL in an era of new frontiers such as cellular therapies. We also evaluate current strategies to treat indolent histologies. We conclude with perspectives on how RT for the hematological malignancies may continue to evolve.

The value of complete remission according to positron emission tomography prior to autologous stem cell transplantation in lymphoma: a population-based study showing improved outcome

Background

Chimeric antigen-receptor T-cell and bispecific antibody therapies will likely necessitate a reconsideration of the role of autologous stem-cell transplantation (ASCT) in lymphoma. Patients who are likely to profit from ASCT need to be better identified.

Methods

Here, we investigated the value of positron emission tomography/computerized tomography (PET/CT) before ASCT. All 521 patients transplanted for lymphoma 1994–2019 at Karolinska (497 conditioned with BEAM) were included.

Results

Outcome improved over three calendar periods 1994–2004, 2005–2014, 2015–2019 (2-year overall survival [OS]: 66, 73, 83%; P = 0.018). Non-relapse mortality (NRM) at 100 days over the three periods were 9.8, 3.9, 2.9%, respectively. The OS improvement between 1994 and 2004 and 2005–2014 was due to lower NRM (P = 0.027), but the large OS advance from 2015 was not accompanied by a significant reduction in NRM (P = 0.6). The fraction of PET/CT as pre-ASCT assessment also increased over time: 1994–2004, 2%; 2005–2014, 24%; 2015–2019, 60% (P < 0.00005). Complete responses (PET/CT-CR) were observed in 77% and metabolically active partial responses (PET/CT-PR) in 23%. PET/CT-CR was a predictor for survival in the entire population (P = 0.0003), also in the subpopulations of aggressive B-cell (P = 0.004) and peripheral T-cell (P = 0.024) lymphomas. Two-year OS and progression-free survival (OS/PFS) for patients in PET/CT-CR were in relapsed/refractory aggressive B-cell lymphoma 87%/75% and peripheral T-cell lymphoma 91%/78%. The corresponding figures in PET/CT-PR were 43%/44 and 33%/33%. Patients with solitary PET/CT-positive lesions showed acceptable outcome with ASCT followed by local irradiation (2-year OS/PFS 80%/60%). CT was less discriminative: 2-year OS/PFS: CT-CR, 76%/66%; CT-PR, 62%/51%. Outcome was inferior after BEAC compared with BEAM conditioning.

Conclusions

We conclude that the improved outcome reflects better, PET/CT-informed, identification of patients who should proceed to ASCT. The excellent survival of patients in PET/CT-CR indicates that ASCT should remain part of standard therapy for lymphoma.

Proton Therapy as a Bridging Treatment in CAR T-Cell Therapy for Relapsed and Refractory Large B-Cell Lymphoma: Is There a Role?

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma. Since the relapse rate of DLBCL to frontline chemoimmunotherapy and salvage autologous hematopoietic cell transplant is high, CD19-directed chimeric antigen receptor (CAR) T-cell therapy was adopted. Given the time interval needed for CAR T cells to be manufactured (3-5 weeks) and the aggressiveness of these relapsed/refractory lymphomas, some patients do not make it to the CAR T-cell infusion phase. This calls for a bridging therapy to control, debulk, and sensitize the disease during this period. Radiation therapy can serve this purpose and has shown promising results in some studies. Proton therapy, compared to standard radiation therapy, in some locations, can reduce the radiation dose to the organs at risk, which may lead to fewer side effects for patients with lymphomas. Thus, we hypothesize that proton therapy may serve as a promising bridging strategy to CAR T-cell therapy for some patients.

NCCN Guidelines Insights: B-Cell Lymphomas, Version 3.2019

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin's lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

Early experience using salvage radiotherapy for relapsed/refractory non-Hodgkin lymphomas after CD19 chimeric antigen receptor (CAR) T cell therapy

Radiotherapy is potentially an important salvage strategy post-chimeric antigen receptor T cell therapy (CART), but limited data exist. We reviewed 14 patients treated with salvage radiation post-CART progression (SRT). Most received SRT for first post-CART relapse (71%) to sites previously PET-avid pre-CART (79%). Median overall survival (OS) post-SRT was 10 months. Post-SRT, six localized relapses achieved 100% response (3 = complete, 3 = partial), with improved freedom from subsequent relapse (P = 0·001) and OS (P = 0·004) compared to advanced stage relapses. Three were bridged to allogeneic transplantation; at analysis, all were alive/NED. SRT has diverse utility and can integrate with novel agents or transplantation to attempt durable remissions.

Response to hyperfractionated accelerated radiotherapy in chemotherapy-refractory non-Hodgkin lymphoma

Patients with chemotherapy-refractory non-Hodgkin lymphoma (NHL) have a poor prognosis with a median overall survival (OS) of only 10 months. To investigate the role of radiotherapy (RT) in such patients, we conducted a retrospective review of 17 patients with biopsy-proven refractory NHL who received hyperfractionated accelerated RT between 2000 and 2017. Forty-seven percent had stages I and II and 53% had stages III and IV disease. Majority (59%) had diffuse large B-cell lymphoma. One-year local control rate was 82%. Fifty-nine percent proceeded to hematopoietic stem cell transplantation (HSCT). At a median follow-up time of 8.8 months (range: 13 days to 17.4 years), 10 were alive with five in remission. Six patients were long-term survivors with a median OS of 8.1 years. Hyperfractionated accelerated RT in chemotherapy-refractory NHL provides durable local disease control in the majority of cases. Combined with HSCT, the RT regimen may also provide long-term disease remission in a subset of patients.

Role of Radiation Therapy in Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma: Guidelines from the International Lymphoma Radiation Oncology Group

Approximately 30% to 40% of patients with diffuse large B-cell lymphoma (DLBCL) will have either primary refractory disease or relapse after chemotherapy. In transplant-eligible patients, those with disease sensitive to salvage chemotherapy will significantly benefit from high-dose therapy with autologous stem cell transplantation. The rationale for considering radiation therapy (RT) for selected patients with relapsed/refractory DLBCL as a part of the salvage program is based on data regarding the patterns of relapse and retrospective series showing improved local control and clinical outcomes for patients who received peritransplant RT. In transplant-ineligible patients, RT can provide effective palliation and, in selected cases, be administered with curative intent if the relapsed/refractory disease is localized. We have reviewed the indications for RT in the setting of relapsed/refractory DLBCL and provided recommendations regarding the optimal timing of RT, dose fractionation scheme, and treatment volume in the context of specific case scenarios.

How I manage patients with relapsed/refractory diffuse large B cell lymphoma

Despite progress in the upfront treatment of diffuse large B cell lymphoma (DLBCL), patients still experience relapses. Salvage chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard second‐line treatment for relapsed and refractory (R/R) DLBCL. However, half of the patients will not be eligible for transplantation due to ineffective salvage treatment, and the other half will relapse after ASCT. In randomized studies, no salvage chemotherapy regimen is superior to another. The outcomes are affected by the secondary International Prognostic Index at relapse and various biological factors. The strategy is less clear in patients who require third‐line treatment. A multicohort retrospective non‐Hodgkin lymphoma research (SCHOLAR‐1) study conducted in 636 patients with refractory DLBCL showed an objective response rate of 26% (complete response 7%) to the next line of therapy with a median overall survival of 6·3 months. In the case of a response followed by transplantation, long‐term survival can be achieved in DLBCL patients. There is clearly a need for new drugs that improve salvage efficacy. Encouraging results have been reported with chimeric antigen receptor ‐T cell engineering, warranting further studies in a well‐defined control group of refractory patients. The Collaborative Trial in Relapsed Aggressive Lymphoma (CORAL) was used as a handy framework to build the discussion.

The role of radiotherapy as salvage and/or consolidation treatment in relapsed/refractory and high-risk diffuse large B-cell lymphoma

OBJECTIVE

Many salvage therapies have been proposed for relapsed/refractory (R/R) diffuse large B-cell lymphomas or for consolidation in the case of suboptimal response. Radiotherapy (RT) is one modality of salvage therapy, but its place is currently not well defined.

METHOD

This study reports a retrospective review of patients receiving unplanned radiotherapy for R/R diffuse large B-cell lymphoma (DLBCL) or primary mediastinal B-cell lymphoma (PMBCL), or as consolidation therapy after second-line chemotherapy, treated in our hospital.

RESULTS

Fifty-one patients with a median age of 53.5 years [19-89] were selected. The histologic type was DLBCL in 35 cases (68%), PMBCL in 8 cases (16%), and secondary transformed NHL in 8 cases (16%). Median aaIPI was 1 [0-4], and 17 patients (33%) had a high tumor burden (bulky disease). Sixteen patients (31%) were irradiated for a response considered to be insufficient, 18 patients (36%) were refractory, and 17 patients (33%) had relapsed. Patients were irradiated with a median dose of 40 Gy [15-44], 29 (57%) by a conformal 3D technique and 22 (43%) by tomotherapy. With a median follow-up of 36 months [1.0-127.8] after irradiation, 5-year progression-free survival (PFS) and overall survival (OS) were 62% and 72%, respectively. In multivariate analysis, adverse factors associated with PFS and OS in our cohort were age >70 years (HR = 5.06, P = .02) and post-RT relapse (HR = 12.24, P = .002), whereas favorable factors were number of lines of chemotherapy <3 (HR = 0.02, P = .03) and bulky disease (HR = 0.02, P = .009).

CONCLUSION

Due to its low toxicity and ease of use, radiotherapy should therefore remain an available option in patients with R/R DLBCL or as consolidation therapy in patients with high-risk disease, mostly in patients with chemo-sensitive disease or bulky disease.

Consolidative Radiotherapy After Autologous Stem Cell Transplantation for Relapsed or Refractory Diffuse Large B-cell Lymphoma

INTRODUCTION

We evaluated the role of consolidative radiotherapy (RT) for patients undergoing high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) for relapsed or refractory diffuse large B-cell lymphoma (DLBCL).

MATERIALS AND METHODS

We reviewed the medical records of 72 consecutive patients who had undergone ASCT for relapsed or refractory DLBCL at our institution from 2006 to 2014. Pretransplant conditioning consisted of HDC and total body irradiation. Of the 72 patients, 13 received post-transplant consolidative RT at the discretion of the consulted radiation oncologist.

RESULTS

Consolidative RT was associated with significantly improved 2-year locoregional control (LRC) (92% vs. 68%; P = .04). However, no difference was seen in either the 2-year progression-free survival (PFS) (69% vs. 54%; P = .25) or overall survival (OS) (85% vs. 59%; P = .44). Analysis of the subgroup of 19 patients with persistent residual masses ≥ 2 cm on post-transplant imaging demonstrated a significant improvement in LRC (100% vs. 36%; P < .01), PFS (88% vs. 27%; P = .01), and OS (100% vs. 45%; P = .02) with consolidative RT.

CONCLUSION

The use of consolidative RT after HDC and ASCT for relapsed or refractory DLBCL appears to significantly improve LRC. For patients with masses ≥ 2 cm after ASCT, improved 2-year PFS and OS were seen. Prospective trials are needed to further identify the patients who would derive the most benefit from consolidative RT in the ASCT setting.

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.

Prognostic value of FDG-PET prior to autologous stem cell transplantation for relapsed and refractory diffuse large B-cell lymphoma

High-dose chemotherapy (HDT) plus autologous stem cell transplantation (ASCT) is the standard of care for chemosensitive relapsed and refractory diffuse large B-cell lymphoma (rel/ref DLBCL). Interim restaging with functional imaging by positron emission tomography using (18)F-deoxyglucose (FDG-PET) has not been established after salvage chemotherapy (ST) and before HDT-ASCT by modern criteria. Herein, we evaluated 129 patients with rel/ref DLBCL proceeding to HDT-ASCT, with ST response assessment by FDG-PET according to the contemporary Deauville 5-point scale. At 3 years, patients achieving a Deauville response of 1 to 3 to ST experienced superior progression-free survival (PFS) and overall survival (OS) rates of 77% and 86%, respectively, compared with patients achieving Deauville 4 (49% and 54%, respectively) (P < .001). No other pre-HDT-ASCT risk factors significantly impacted PFS or OS. Despite achieving remission to ST, patients with Deauville 4 should be the focus of risk-adapted investigational therapies.

Upfront autologous stem cell transplantation for untreated high-risk diffuse large B-cell lymphoma in patients up to 60 years of age

BACKGROUND

Although rituximab added to CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) is the standard chemotherapy for untreated DLBCL, its therapeutic effect is limited in younger patients with high-intermediate risk or high-risk disease according to the age-adjusted international prognostic index. In fact, the efficacy and safety of HDT plus rituximab followed by ASCT for such patients remain unclear.

PATIENTS AND METHODS

We retrospectively investigated the safety and effectiveness of HDT/ASCT in patients with untreated DLBCL. Twenty-two patients, aged 60 years and younger, with untreated DLBCL (classified as high-intermediate [n = 14 (64%)] or high [n = 8 (32%)] risk) underwent upfront HDT/ASCT between January 2004 and December 2008, achieving either a complete response (CR; n = 15 (68%)) or a partial response (PR; n = 7 (32%)).

RESULTS

The 5-year overall survival rate was 81.0% and the progression-free survival rate was 73.0%, with no significant difference between risk groups based on the international prognostic index. The most common nonhematologic toxicity was febrile neutropenia [n = 9 (41%)]. The cause of all 3 fatalities was exacerbation of the underlying disease, and no treatment-related mortality was observed. No variables with a significant influence on overall survival were identified, but a correlation of the treatment response before transplanation with progression-free survival was suggested (CR vs. PR: 92% vs. 30%, P = .002).

CONCLUSION

These results suggest that adding rituximab to upfront HDT/ASCT is feasible and can improve the outcome in untreated patients with poor-prognosis DLBCL. In the future, upfront HDT/ASCT should be more extensively evaluated in clinical trials.

Germinal center B-cell-like versus non-germinal center B-cell-like as important prognostic factor for localized nodal DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin's lymphoma. Although many investigations have been performed on the prognostic factors of DLBCL, no reports have focused on localized nodal DLBCL. We examined the prognostic significance of 39 Japanese patients with localized nodal DLBCL with special reference to the germinal center B-cell-like (GCB) versus non-germinal center B-cell-like (NGCB) types. The median age was 65 years with 23 males and 16 females. Using Hans algorithm of immunohistochemistry, 18 patients (46%) exhibited GCB type and 21 (54%) exhibited NGCB type. Twenty-nine patients (74%) presented with disease in the neck (neck group) and 10 (26%) had disease in non-neck regions (non-neck group). Comparing Hans, Choi, and Muris algorithms, patients with GCB type showed statistically significant progression-free survival (PFS) only with Hans algorithm (P = 0.022, P = 0.100, and P = 0.130, respectively). Patient survival analyses revealed that GCB-type patients by Hans algorithm had a better PFS (P = 0.012), and neck-group patients had better PFS and overall survival (OS) (P = 0.018 and P = 0.012, respectively). Univariate analysis revealed that only neck vs. non-neck exhibited a significant difference in terms of OS (P = 0.026). Multivariate analysis revealed that GCB type by Hans algorithm and neck vs. non-neck were significantly different in terms of PFS (P = 0.025 and P = 0.033, respectively). Therefore, the subclassifications of GCB type vs. NGCB type and neck vs. non-neck are important predictive prognostic factors in localized nodal DLBCL.

Bortezomib in combination with rituximab, dexamethasone, ifosfamide, cisplatin and etoposide chemoimmunotherapy in patients with relapsed and primary refractory diffuse large B-cell lymphoma

Patients with relapsed or refractory diffuse large B-cell lymphoma may experience extended survival with second-line chemotherapy and autologous stem cell transplant (ASCT). Since a major determinant of outcome after ASCT is responsiveness to second-line therapy, the development of more effective second-line treatments is desirable. We investigated the addition of bortezomib to rituximab, dexamethasone, ifosfamide, cisplatin and etoposide (VIPER). Fifteen patients were enrolled, of whom seven were refractory to first-line chemotherapy and only three had maintained first response for 1 year. Nine (60%) patients achieved objective responses, of which three (20%) were IWC-PET (International Workshop Criteria positron emission tomography) complete responses. Median progression-free survival was 3 months, and median overall survival was 10 months. At a median follow-up of 26 months, five patients (33%) remained alive. Treatment was well tolerated with no unexpected toxicity. Although response rates did not meet predefined criteria, activity was at least comparable to other second-line approaches despite a poor-prognosis patient population.

Diffuse large B cell lymphoma: how can we cure more patients in 2012?

Clinically this chapter will focus on 3 important issues critical in the management of diffuse large B cell lymphoma (DLBCL) in 2012: risk stratification, interim PET-CT scanning and the role of high dose therapy and ASCT in the rituximab era for patients with relapsed and primary refractory disease.

Role of Positron Emission Tomography with Fludeoxyglucose F 18 in Personalization of Therapy in Patients with Lymphoma

The widespread availability of functional imaging in clinical practice has revolutionized the care (staging, response assessment, surveillance) of patients with lymphoma. Using positron emission tomography/computed tomography (PET/CT) with fludeoxyglucose F 18 (FDG), the potential exists for prognostic risk stratification and therapeutic adjustment. This review focuses on personalization of therapy using these 2 modalities in 2 lymphoma subtypes: diffuse large B-cell lymphoma and Hodgkin lymphoma.

[¹⁸F]FDG-positron emission tomography coregistration with computed tomography scans for radiation treatment planning of lymphoma and hematologic malignancies

PURPOSE

Positron emission-tomography (PET) using 2-[(18)F]fluoro-2-deoxyglucose (FDG-PET) increases sensitivity and specificity of disease detection in lymphoma and thus is standard in lymphoma management. This study examines the effects of coregistering FDG-PET and computed tomography (CT) (PET/CT) scans on treatment planning for lymphoma patients.

METHODS AND MATERIALS

Twenty-nine patients (30 positive PET scans) underwent PET/CT treatment planning from July 2004 to February 2007 and were retrospectively studied. For each patient, gross tumor volume was blindly contoured on the CT-only and PET/CT studies by a radiation oncologist. Treatment plans were generated for both the CT-only and PET/CT planning target volumes (PTVs) for all patients. Normal tissue doses and PTV coverage were evaluated using dose--volume histograms for all sites.

RESULTS

Thirty-two treatment sites were evaluated. Twenty-one patients had non-Hodgkin lymphoma, 5 patients had Hodgkin lymphoma, and 3 patients had plasma cell neoplasms. Previously undetected FDG-avid sites were identified in 3 patients during PET/CT simulation, resulting in one additional treatment field. Due to unexpected PET/CT simulation findings, 2 patients did not proceed with radiation treatment. The addition of PET changed the volume of 23 sites (72%). The PTV was increased in 15 sites (47%) by a median of 11% (range, 6-40%) and reduced in 8 sites (25%) by a median of 20% (range, 6%-75%). In six (19%) replanned sites, the CT-based treatment plan would not have adequately covered the PTV defined by PET/CT.

CONCLUSIONS

Incorporation of FDG-PET into CT-based treatment planning for lymphoma patients resulted in considerable changes in management, volume definition, and normal tissue dosimetry for a significant number of patients.

Early post transplant (F-18) 2-fluoro-2-deoxyglucose positron emission tomography does not predict outcome for patients undergoing auto-SCT in non-Hodgkin and Hodgkin lymphoma

Positron emission tomography (PET) in conjunction with computed tomography is a frequently used modality for staging patients with lymphoma. Utility of PET-computed tomography before or early following auto-SCT has not been as rigorously evaluated. We retrospectively analyzed patients who received auto-SCT for treatment of relapsed or refractory non-Hodgkins lymphoma or Hodgkins disease between the years of 1996 and 2007. Patients who had either a PET scan following salvage chemotherapy within 14 weeks of transplantation (pre-PET), and/or a PET scan 6-14 weeks following transplantation (post-PET) were included. A total of 90 patients were identified for analysis. The median follow-up time is 3.3 years, with a range of 0.13-12.0 years. The median PFS was 4.6 years, and median OS was 5.1 years. At the time of this analysis, 34 patients (37%) experienced disease relapse, and 25 (27%) of the patients died from disease progression. In multivariate Cox proportional hazards analysis, post-PET did not predict for outcome, pre-PET positivity predicted for decrease in PFS. In conclusion, post-PET scan did not predict for PFS or OS in multivariate analysis. Positive pre-PET scan did predict for PFS as seen in previous studies, and may help identify patients who would benefit from innovative post transplant therapies.

Fluorine-18-fluorodeoxyglucose positron emission tomography in response assessment before high-dose chemotherapy for lymphoma: a systematic review and meta-analysis

BACKGROUND

We conducted a systematic review and meta-analysis to better define the prognostic ability of fluorine-18-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) following salvage chemotherapy for relapsed or refractory Hodgkin's lymphoma (HL) and aggressive non-Hodgkin's lymphoma.

METHODS

We searched PubMed (from inception to January 31, 2010), bibliographies, and review articles without language restriction. Two assessors independently assessed study characteristics, quality, and results. We performed a meta-analysis to determine prognostic accuracy.

RESULTS

Twelve studies including 630 patients were eligible. The most commonly evaluated histologies were diffuse large B-cell lymphoma (n = 313) and HL (n = 187), which were typically treated with various salvage and high-dose chemotherapy regimens. Studies typically employed nonstandardized protocols and diagnostic criteria. The prognostic accuracy was heterogeneous across the included studies. (18)F-FDG PET had a summary sensitivity of 0.69 (95% confidence interval [CI], 0.56-0.81) and specificity of 0.81 (95% CI, 0.73-0.87). The summary estimates were stable in sensitivity analyses. In four studies that performed direct comparisons between PET and conventional restaging modalities, PET had a superior accuracy for predicting treatment outcomes. Subgroup and metaregression analyses did not identify any particular factor to explain the observed heterogeneity.

CONCLUSION

(18)F-FDG PET performed after salvage therapy appears to be an appropriate test to predict treatment failure in patients with refractory or relapsed lymphoma who receive high-dose chemotherapy. Some evidence suggests PET is superior to conventional restaging for this purpose. Given the methodological limitations in the primary studies, prospective studies with standardized methodologies are needed to confirm and refine these promising results.

Feasibility of helical tomotherapy for debulking irradiation before stem cell transplantation in malignant lymphoma

PURPOSE

Preliminary clinical experience has suggested that radiation therapy (RT) may be effectively incorporated into conditioning therapy before transplant for patients with refractory/relapsed malignant lymphoma. We investigated the feasibility of debulking selective lymph node irradiation before autologous and/or allogeneic stem cell transplantation (SCT) using helical tomotherapy (HT).

METHODS AND MATERIALS

Six consecutive patients with refractory malignant lymphoma were referred to our institution for salvage HT before SCT. All patients had been previously heavily treated but had bulky residual tumor despite chemotherapy (CT) intensification. Two patients had received previous radiation therapy. HT delivered 30-40 Gy in the involved fields (IF), using 6 MV photons, 2 Gy per daily fraction. Total duration of treatment was 28 to 35 days.

RESULTS

Using HT, doses to critical organs (heart, lungs, esophagus, and parotids) were significantly decreased and highly conformational irradiation could be delivered to all clinical target volumes. HT delivery was technically possible, even in patients with lesions extremely difficult to irradiate in other conditions or in patients with previous radiation therapy. No Grade 2 or higher toxicity occurred. Four months after the end of HT, 5 patients experienced complete clinical, radiologic, and metabolic response and were subsequently referred for SCT.

CONCLUSIONS

By more effectively sparing critical organs, HT may contribute to improving the tolerance of debulking irradiation before allograft. Quality of life may be preserved, and doses to the heart may be decreased. This is particularly relevant in heavily treated patients who are at risk for subsequent heart disease. These preliminary results require further prospective assessment.