Outcomes of patients with R/R B-cell NHL and limited (<5 sites) pre-CART disease bridged with or without radiotherapy

ABSTRACT

Unirradiated patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (NHL) who undergo anti-CD19 chimeric antigen receptor T-cell therapy (CART) have a predominant localized pattern of relapse, the significance of which is heightened in individuals with limited/localized disease before CART. This study reports on the outcomes of patients with R/R NHL and limited (<5 involved sites) disease bridged with or without radiotherapy. A multicenter retrospective review of 150 patients with R/R NHL who received CART with <5 disease sites before leukapheresis was performed. Bridging treatment, if any, was administered between leukapheresis and CART infusion. Study end points included relapse-free survival (RFS), event-free survival (EFS), and overall survival. Before CART infusion, 48 patients (32%) received bridging radiotherapy (BRT), and 102 (68%) did not. The median follow-up was 21 months. After CART infusion, BRT patients had higher objective response (92% vs 78%; P = .046) and sustained complete response rates (54% vs 33%; P = .015). Local relapse in sites present before CART was lower in the BRT group (21% vs 46%; P = .003). BRT patients had improved 2-year RFS (53% vs 44%; P = .023) and 2-year EFS (37% vs 34%; P = .039) compared with patients who did not receive BRT. The impact of BRT was most prominent in patients who had ≤2 pre-CART involved disease sites, with 2-year RFS of 62% in patients who received BRT compared with 42% in those who did not (P = .002). BRT before CART for patients with limited (<5 involved disease sites) R/R NHL improves response rate, local control, RFS, and EFS without causing significant toxicities.

Role of radiation in chimeric antigen receptor T-cell therapy for patients with relapsed/refractory non-Hodgkin lymphoma: Current studies and future prospects

Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment approach for patients with relapsed/refractory non-Hodgkin lymphoma (R/R NHL). However, the long-term prognosis has been discouraging. Moreover, the urgent resolution of two critical issues is necessary: minimize tumor burden before CAR-T infusion and control fatal toxicities post CAR-T therapy. By combining radiotherapy (RT), the safety and efficacy of CAR-T can be improved. RT can serve as bridging therapy, reducing the tumor burden before CAR-T infusion, thus enabling safe and successful CAR-T infusion, and as salvage therapy in cases of CAR-T therapy failure. This review aims to discuss the current evidence supporting the use of RT in CAR-T therapy for patients with R/R NHL. Although most studies have shown a positive role of RT in combined modality treatments for patients undergoing CAR-T therapy, the synergy gained from these remains uncertain. Furthermore, the optimal dose/fraction and radiation response require further investigation.

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.

Incidence of second primary malignancies in relapsed/refractory B-cell non-Hodgkin's lymphoma patients in England

BACKGROUND

Treatments for relapsed/refractory (r/r) B-cell non-Hodgkin's lymphoma (NHL) may be associated with an increased risk of second primary malignancies (SPMs). Currently available SPM incidence benchmarks are unreliable due to small sample sizes.

METHODS

The Cancer Analysis System (CAS), a population-level cancer database in England, was used to identify patients with incident B-cell NHL diagnosed during 2013-2018 with evidence of r/r disease. Incidence rates (IRs) of SPMs after r/r disease diagnosis were calculated per 1000 person-years (PYs) and stratified by age, sex, and SPM type.

RESULTS

We identified 9444 patients with r/r B-cell NHL disease. Of those who were eligible for SPM analysis, nearly 6.0% (470/7807) developed at least one SPM after r/r disease diagnosis (IR: 44.7; 95% confidence interval [CI]: 40.9-48.9). Of note, 205 (2.6%) had a non-melanoma skin cancer (NMSC) SPM. IR of SPMs was the highest for patients with r/r chronic lymphocytic leukemia/small lymphocytic leukemia (80.0) and lowest for diffuse large B-cell lymphoma (DLBCL) (30.9). Patients with DLBCL had the shortest overall survival after r/r disease diagnosis.

CONCLUSIONS

This real-world data study suggests that the IR of SPM among patients with r/r B-cell NHL is 44.7 per 1000 PY and that most SPMs diagnosed after r/r disease diagnosis are NMSCs, establishing a basis for the comparison of safety outcomes for new treatments being developed for r/r B-cell NHL.

Salvage radiotherapy for relapsed/refractory non-Hodgkin lymphoma following CD19 chimeric antigen receptor T-cell (CART) therapy

Background and purpose

CD19-targeting chimeric antigen receptor T-cell (CART) therapy is a promising treatment for relapsed/refractory non-Hodgkin lymphoma, but most patients experience post-CART progression. We describe our institutional experience of salvage radiotherapy (SRT) in this setting.

Materials and methods

Of 94 patients who received CART therapy from 2018 to 2020, 21 received SRT for post-CART progression. Patients were divided into two groups: locoregional disease (n = 9 [43 %], all disease encompassable within an RT field) and advanced disease (n = 12 [57 %]). Patterns of failure, progression-free survival (PFS), overall survival (OS), and toxicity were assessed.

Results

Median time from CART infusion to SRT was 4.0 months (range, 0.6-11.5 months). In the locoregional disease group, 8/9 patients (89 %) were treated with comprehensive SRT to a median dose of 37.5 Gy in a median of 15 fractions. In the advanced disease group, all patients (n = 12) were treated with focal SRT to a median dose of 20.8 Gy in a median of 5 fractions. Median follow-up post-SRT was 15.2 months. In-field response was observed in 8/9 (89 %) in the locoregional disease and 8/9 (89 %) evaluable patients in the advanced disease groups. 17/18 evaluable patients (94 %) patients experienced post-SRT progression, all with a distant component. Median OS was 7.4 months; 21 months for locoregional disease versus 2.4 months for advanced disease (p = 0.0002). Median PFS was 1.1 month, and similarly poor regardless of group. No grade ≥ 3 toxicities occurred.

Conclusions

SRT post-CART therapy appears safe with encouraging in-field response but high rates of out-of-field progression, even for those presenting with locoregional disease, highlighting the need for integration of novel systemic agents.

Don't Put the CART Before the Horse: The Role of Radiation Therapy in Peri-CAR T-cell Therapy for Aggressive B-cell Non-Hodgkin Lymphoma

PURPOSE

The optimal approach to incorporate radiation therapy (RT) in conjunction with chimeric antigen receptor (CAR) T-cell therapy (CART) for relapsed/refractory (r/r) B-cell non-Hodgkin lymphoma (bNHL) remains unclear. This study documented the RT local control rate among patients who received bridging radiation therapy (BRT) before CART and compares it with those who received salvage radiation therapy (SRT) after CART. This article further reports on a promising way to use SRT for post-CART disease and identifies predictors for RT in-field recurrence.

METHODS AND MATERIALS

We retrospectively reviewed 83 patients with r/r bNHL who received CART and RT, either as BRT pre-CART infusion (n = 35) or as SRT post-CART infusion (n = 48), between 2018 and 2021. RT was defined as comprehensive (compRT; ie, treated all sites of active disease) or focal (focRT). Limited disease was defined as disease amenable to compRT, involving <5 active disease sites.

RESULTS

At time of RT, patients who received BRT before CART had bulkier disease sites (median diameter, 8.7 vs 5.5 cm; P = .01) and were treated to significantly lower doses (median equivalent 2-Gy dose, 23.3 vs 34.5 Gy; P = .002), compared with SRT post-CART. Among 124 total irradiated sites identified, 8 of 59 (13%) bridged sites and 21 of 65 (32%) salvaged sites experienced in-field recurrence, translating to 1-year local control rates (LC) of 84% and 62%, respectively (P = .009). Patients with limited post-CART disease (n = 37) who received compSRT (n = 26) had better overall survival (51% vs 12%; P = .028), freedom from subsequent progression (31% vs 0%; P < .001), and freedom from subsequent event (19% vs 0%; P = .011) compared with patients with limited disease who received focSRT (n = 11).

CONCLUSIONS

BRT followed by CART appears to be associated with improved LC compared with SRT in r/r bNHL. Nonetheless, SRT offers a promising salvage intervention for limited (<5 sites) relapsed post-CART disease if given comprehensively.

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.

Impact of Radiation Therapy After High Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation in Patients With Relapsed/Refractory Lymphomas: A Single Center Experience

INTRODUCTION

After high dose chemotherapy (HDC) and autologous stem cell transplantation (auto-SCT), in patients with relapsed/refractory diffuse large B cell lymphoma (DLBCL) and Hodgkin lymphoma (HL), involved field radiation therapy (RT) for consolidation and residual/progressive disease (PD) eradication is a common practice.

MATERIALS AND METHODS

Retrospective single-institution cohort analysis to evaluate the impact of early RT after HDC auto-SCT.

RESULTS

Between 1996 and October 2019, 153 patients (43 DLBCL, 110 HL) underwent RT after HDC auto-SCT. Males 95 (62%), females 58 (38%), median age 24 years. Indications for RT was consolidation 65%: residual disease eradication 16%: and PD eradication 19%. For DLBCL, the median overall survival (OS) for the above indications was not reached (NR):NR:2 months and the KM 5-year OS was 72.6%:64.3%:12.5% respectively (P ≤ .000). Pair-wise analysis showed that consolidation versus residual disease eradication had no difference (P = .88) but both were superior to PD disease eradication (P ≤ 000 and P = .005 respectively). For HL, indication for RT was, 54%:23%:24% respectively. The median OS was NR:NR:28.8 months and KM 5-year OS was 82.3%:78%:30% respectively (P ≤ .000). Pair-wise analysis showed that consolidation versus residual disease eradication had no difference (P = .98) but both were superior to the PD eradication group (P ≤ 000). RT was well tolerated with no significant long-term toxicity.

CONCLUSION

Post HDC auto-SCT RT was well tolerated. DLBCL and HL patients with residual disease treated with the RT had similar long-term survival as those who received RT for consolidation. RT failed to improve the poor survival in patients with post-HDC auto-SCT PD.

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.

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.

Favorable Outcome After Adjuvant Involved-Field Radiotherapy After Autologous Hematopoietic Stem-Cell Transplantation in Patients With High-Risk Relapsed/Refractory Lymphoma: A Single-Center Experience

BACKGROUND

Patients with refractory or relapsed lymphoma diagnosed with bulky disease at relapse or with residual disease after salvage treatment are considered to have a dismal outcome, even after autologous hematopoietic stem-cell transplantation, as a result of disease recurrence. To minimize the risk of relapse after receipt of a transplant, involved-field radiotherapy (IFRT) to sites of either bulky or localized residual disease has been utilized; however, the ideal timing for irradiation remains controversial. The aim of this study was to assess the safety and efficacy of IFRT in the early period after transplantation.

PATIENTS AND METHODS

We retrospectively evaluated the outcome of 24 autografted patients with relapsed/refractory lymphoma who presented with bulky disease at relapse or who had a persistent localized residual mass after salvage treatment and consolidated with IFRT within 4 months after autografting.

RESULTS

No significant toxicity was noticed during the early postradiotherapy period, while graft function was not impaired. After a median follow-up of 3 years for survivors, 21 patients were alive, 19 of whom were event free, while 2 patients died of disease recurrence and 1 died of treatment-related myelodysplastic syndrome. The 3-year overall, lymphoma relapse-free, and event-free survival rates were 86%, 86%, and 82%, respectively.

CONCLUSION

Taking into consideration the poor-risk features of the study cohort, IFRT provided early after autologous hematopoietic stem-cell transplantation showed a safe and well-tolerated toxicity profile and demonstrated long-term effective tumor control, as reflected in the promising survival rates.

Risk of Pneumonitis and Outcomes After Mediastinal Proton Therapy for Relapsed/Refractory Lymphoma: A PTCOG and PCG Collaboration

PURPOSE

Despite high response rates, there has been reluctance to use radiation therapy for patients with relapsed/refractory (r/r) Hodgkin (HL) or aggressive non-Hodgkin lymphoma (NHL) given concerns for subacute and late toxicities. Symptomatic pneumonitis, a subacute toxicity, has an incidence of 17% to 24% (≥grade 2) even with intensity modulated radiation therapy. Proton therapy (PT), which has no exit radiation dose, is associated with a lower dose to lung compared with other radiation techniques. As risk of radiation pneumonitis is associated with lung dose, we evaluated whether pneumonitis rates are lower with PT.

METHODS AND MATERIALS

Within an international, multi-institutional cohort, we retrospectively evaluated the incidence and grade of radiation pneumonitis (National Cancer Institute Common Terminology Criteria for Adverse Events v4) among patients with r/r HL or NHL treated with PT.

RESULTS

A total of 85 patients with r/r lymphoma (66% HL, 34% NHL; 46% primary chemorefractory) received thoracic PT from 2009 to 2017 in the consolidation (45%) or salvage (54%) setting. Median dose was 36 Gy(RBE). Before PT, patients underwent a median of 1 salvage systemic therapy (range, 0-4); 40% received PT within 4 months of transplant. With a median follow-up of 26.3 months among living patients, 11 patients developed symptomatic (grade 2) pneumonitis (12.8%). No grade 3 or higher pneumonitis was observed. Dose to lung, including mean lung dose, lung V5, and V20, significantly predicted risk of symptomatic pneumonitis, but not receipt of brentuximab, history of bleomycin toxicity, sex, or peritransplant radiation.

CONCLUSIONS

PT for relapsed/refractory lymphoma was associated with favorable rates of pneumonitis compared with historical controls. We confirm that among patients treated with PT, pneumonitis risk is associated with mean lung and lung V20 dose. These findings highlight how advancements in radiation delivery may improve the therapeutic ratio for patients with relapsed/refractory lymphoma. PT may be considered as a treatment modality for patients with relapsed/refractory lymphoma in the consolidation or salvage setting.

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.

Radiation Therapy as a Bridging Strategy for CAR T Cell Therapy With Axicabtagene Ciloleucel in Diffuse Large B-Cell Lymphoma

PURPOSE

Axicabtagene ciloleucel (axi-cel) is a CD19-directed chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory diffuse large B-cell lymphoma. Bridging therapy may be required for lymphoma control during the manufacturing interval between collection of autologous T cells and final CAR T product administration. The optimal bridging therapy is not known and patients are often chemorefractory. We present a case series of patients receiving radiation as a bridge to axi-cel.

METHODS AND MATERIALS

Between December 2017 and October 2018, 12 patients were intended to receive bridging radiation before axi-cel. The group was characterized by highly aggressive disease including 6 of 12 with "double hit" lymphoma and 6 of 12 with disease ≥10 cm in diameter. All patients received 2 to 4 Gy/fraction to a median dose of 20 Gy (range, 6-36.5 Gy). Half of patients received either 30 Gy in 10 fractions or 20 Gy in 5 fractions. Seven patients received concurrent chemotherapy. Eleven patients underwent axi-cel infusion and one did not. Median follow-up was 3.3 months (range, 1.1-12.0 months).

RESULTS

No significant toxicities were identified during bridging radiation, and no patient experienced in-field progression of disease before axi-cel infusion. One patient experienced abdominal pain, which resolved after dose reduction. Two patients had out-of-field progression of disease during the bridging period. After axi-cel infusion, 3 of 11 patients (27%) experienced severe cytokine release syndrome or neurotoxicity. At 30 days, the objective response rate was 81.8% (11 of 12 evaluable; 1 stable disease, 1 out-of-field progression), with complete response in 27% (3 of 11). At last follow-up, the best objective response rate was 81.8%, with a complete response attained in 45% (5 of 11). Lymphocyte counts decreased slightly in 10 of 12 patients during radiation (median, 0.25 k/uL).

CONCLUSIONS

Radiation (with or without concurrent chemotherapy) can be safely administered as a bridge to axi-cel in high-risk lymphoma. Caution should be taken if irradiation is started before apheresis, and lymphocyte counts should be monitored closely throughout. Future investigation is warranted to optimize the use of bridging radiation before CAR T therapy.

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.

INFRADIAPHRAGMAL RADIOTHERAPY IN PATIENTS WITH LYMPHOMA: VOLUME DEFINITION AND SIDE EFFECTS

SUMMARY – Lymphomas are very radiosensitive and radiotherapy (RT) was the first treatment modality that enabled cure. It is the most effective single modality for local control of lymphomas. However, as a local form of treatment, curative intention is only possible if all lymphoma tissue can be incorporated in the volume to be irradiated with the prescribed total irradiation dose. That is why RT is a single modality only in early stage of nodular lymphocyte predominance Hodgkin’s lymphoma and low grade non-Hodgkin’s lymphoma. In most patients, RT can be used as consolidation therapy after chemotherapy or as salvage after failure of chemotherapy. In the past two decades, irradiation techniques have been improved in order to spare critical tissues and reduce toxicity. Although effective, RT is a neglected modality of treatment because of the appearance of new drugs and fear of side effects after irradiation. Radiation has been shown to be effective in the treatment of all stages and forms of lymphoma. Study data are still mostly derived from patients that received supradiaphragmal RT; therefore, there is no agreement about the best management approach in patients with infradiaphragmal lymphoma.

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.

Modern radiation therapy for extranodal lymphomas: field and dose guidelines from the International Lymphoma Radiation Oncology Group

Extranodal lymphomas (ENLs) comprise about a third of all non-Hodgkin lymphomas (NHL). Radiation therapy (RT) is frequently used as either primary therapy (particularly for indolent ENL), consolidation after systemic therapy, salvage treatment, or palliation. The wide range of presentations of ENL, involving any organ in the body and the spectrum of histological sub-types, poses a challenge both for routine clinical care and for the conduct of prospective and retrospective studies. This has led to uncertainty and lack of consistency in RT approaches between centers and clinicians. Thus far there is a lack of guidelines for the use of RT in the management of ENL. This report presents an effort by the International Lymphoma Radiation Oncology Group (ILROG) to harmonize and standardize the principles of treatment of ENL, and to address the technical challenges of simulation, volume definition and treatment planning for the most frequently involved organs. Specifically, detailed recommendations for RT volumes are provided. We have applied the same modern principles of involved site radiation therapy as previously developed and published as guidelines for Hodgkin lymphoma and nodal NHL. We have adopted RT volume definitions based on the International Commission on Radiation Units and Measurements (ICRU), as has been widely adopted by the field of radiation oncology for solid tumors. Organ-specific recommendations take into account histological subtype, anatomy, the treatment intent, and other treatment modalities that may be have been used before RT.

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.

Favorable outcomes in elderly patients undergoing high-dose therapy and autologous stem cell transplantation for non-Hodgkin lymphoma

High-dose therapy and autologous stem cell transplantation (HDT-ASCT) can offer potential long-term remission or cure in patients with non-Hodgkin lymphoma (NHL). Limited experience is available on the safety and efficacy of HDT-ASCT in elderly patients. This is a single-center, retrospective study examining outcomes of HDT-ASCT for 202 NHL patients, ages 60 years and older, between January 2001 and December 2012. Overall survival (OS) and progression-free survival (PFS) were analyzed according to age at HDT-ASCT, hematopoietic cell transplantation comorbidity index (HCT-CI), NHL histology, and remission status at the time of HDT-ASCT. The median age was 65 years (range, 60 to 74) and the majority had either diffuse large B cell lymphoma (n = 73, 37%) or mantle cell lymphoma (n = 69, 34%). One hundred and fifteen patients (57%) had high HCT-CI scores at the time of HDT-ASCT. With a median follow-up of 3.6 years (range, 4 to 11.9 years) for survivors, PFS and OS at 3 years were 60% (95% confidence interval [CI], 53% to 68%) and 73% (95% CI, 67% to 80%), respectively. Transplantation-related mortality (TRM) was 4% both at 100 days and at 1 year after HDT-ASCT. Age and HCT-CI score were not associated with OS or PFS, and high HCT-CI did not correlate with TRM. Seven patients (4%) developed secondary myelodysplastic syndrome or acute myeloid leukemia at a median of 35 months (range, 6 to 48) after HDT-ASCT. In this single-center cohort of elderly patients with NHL undergoing HDT-ASCT, this intervention was proven tolerable and effective, with results similar to those of historic controls in younger patients. Our data suggest that age alone should not preclude HDT-ASCT in elderly patients.

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.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of adult acute lymphoblastic leukemia: update of the 2006 evidence-based review

Clinical research published since the first evidence-based review on the role of hematopoietic stem cell transplantation (SCT) in the treatment of acute lymphoblastic leukemia (ALL) in adults is presented and critically evaluated in this update. Treatment recommendations changed or modified based on new evidence include: (1) myeloablative allogeneic SCT is an appropriate treatment for adult (<35 years) ALL in first complete remission for all disease risk groups; and (2) reduced-intensity conditioning may produce similar outcomes to myeloablative regimens. Treatment recommendations unchanged or strengthened by new evidence include: (1) allogeneic SCT is recommended over chemotherapy for ALL in second complete remission or greater; (2) allogeneic is superior to autologous SCT; and (3) there are similar survival outcomes after related and unrelated allogeneic SCT. New treatment recommendations based on new evidence include: (1) in the absence of a suitable allogeneic donor, autologous SCT may be an appropriate therapy, but results in a high relapse rate; (2) it is appropriate to consider cord blood transplantation for patients with no HLA well-matched donor; and (3) imatinib therapy before and/or after SCT (for Ph+ ALL) yields significantly superior survival outcomes. Areas of needed research in the treatment of adult ALL with SCT were identified and presented in the review.

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.

Pertussis immunity and response to tetanus-reduced diphtheria-reduced pertussis vaccine (Tdap) after autologous peripheral blood stem cell transplantation

Pertussis is a highly contagious respiratory infection characterized by prolonged cough and inspiratory whoop. Despite widespread vaccination of children aged<7 years, its incidence is steadily increasing in adolescents and adults, because of the known decrease in immunity following childhood immunization. In an effort to reduce pertussis in adolescents and adults, 2 vaccines containing tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) (BOOSTRIX and Adacel) were licensed in 2005 for use in adolescents, 1 of which (Adacel) contains less pertussis toxoid (PT) for use in adults. This study assessed pertussis titers in 57 adult survivors of an autologous peripheral blood stem cell transplantation (PBSCT; median age, 37.5 years), 28 of whom were subsequently vaccinated with Tdap containing 2.5microg of PT (Adacel). The median time to Tdap administration was 3 years posttransplantation. Before vaccination, 87% of the patients lacked pertussis immunity. Only 2 of the 28 patients developed a >2-fold response to PT following vaccination with Tdap. These data suggest that autologous transplantation recipients are highly susceptible to pertussis and that immunization with 2.5microg of PT induces an inadequate response. Prospective trials evaluating BOOSTRIX, containing 8microg/dose of PT (approved for adults in December 2008) are warranted in this vulnerable population undergoing transplantation.

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

We examined the role of fluorodeoxyglucose-positron emission tomography (FDG-PET) and the addition of involved field radiotherapy (IFRT) as potential modifiers of salvage therapy. From January 2000 to June 2007, 83 patients with chemosensitive relapsed or primary refractory diffuse large B-cell lymphoma (DLBCL) underwent FDG-PET scans following second-line chemotherapy before high-dose therapy with autologous stem cell rescue (HDT/ASCR). We evaluated the prognostic value of having a negative FDG-PET scan before HDT/ASCR and whether IFRT improved the outcomes. Median follow-up was 45 months, and the 3-year PFS, disease-specific survival (DSS) and OS were 72, 80 and 78%, respectively. Multivariate analysis revealed that a positive FDG-PET scan had worse PFS (hazard ratio=(HR) 3.4; P=0.014), DSS (HR=7.7; P=0.001) and OS (HR=5.4; P=0.001), and that patients not receiving IFRT had worse PFS (HR=2.7; P=0.03) and DSS (HR=2.8, P=0.059). Patients who received IFRT had better local control with fewer relapses within prior involved sites compared with those that did not receive IFRT (P=0.006). These outcomes confirm the important prognostic value of FDG-PET scans before undergoing HDT/ASCR. It also suggests that the role of IFRT should be evaluated further.