The Impact of Involved Field Radiation Therapy for Patients Receiving High-Dose Chemotherapy Followed by Hematopoietic Progenitor Cell Transplant for the Treatment of Relapsed or Refractory Hodgkin Disease

Peritransplant Radiation Therapy in Patients With Refractory or Relapsed Hodgkin Lymphoma Undergoing Autologous Stem Cell Transplant: Long-Term Results of a Retrospective Study of the Fondazione Italiana Linfomi

PURPOSE

In this multicenter collaboration, we report real-world data in the largest published series of long-term outcomes for patients with relapsed/refractory (r/r) Hodgkin lymphoma (HL) treated with peritransplant radiation therapy (pt-RT) and high-dose chemotherapy with autologous stem cell transplant (ASCT).

METHODS AND MATERIALS

We conducted a retrospective analysis including data from 12 institutions. Eligibility required histologic diagnosis of HL, receipt of ASCT plus pt-RT between 2004 and 2014 for r/r HL, and age ≥18 years at the time of ASCT. All patients received salvage chemotherapy for maximum debulking before ASCT. Metabolic responses were scored according to the Lugano Classification. The primary endpoint was overall survival (OS). Univariate and multivariate Cox proportional hazards were calculated to estimate the effect of covariates on patients' outcome.

RESULTS

One hundred thirty-one patients were eligible: 68 were male (52%), and median age at ASCT was 32 years (range, 18-70). At the time of diagnosis with r/r HL, 92 patients (70%) had limited (stage I-II) disease, and 10 patients (8%) had bulky disease. Pt-RT was given pre-ASCT in 32 patients (24%) and post-ASCT in 99 (76%); median prescribed dose was 30.6 Gy (range, 20-44 Gy). With median follow-up of 60 months, 3- and 5-year OS were 84% and 77%, while 3- and 5-year progression-free survival were 75% and 72%, respectively. On univariate and multivariate analysis, advanced stage at relapse (hazard ratio [HR], 2.18; P = .04), irradiation of >3 sites (HR, 3.69; P = .01), and incomplete metabolic response after salvage chemotherapy (HR, 2.24; P = .01) had a negative effect on OS. The sequencing of pt-RT (pre- vs post-ASCT) did not affect outcomes.

CONCLUSIONS

Overall, the addition of pt-RT to ASCT for patients with r/r HL is associated with very good outcomes. Limited relapsed disease with ≤3 sites involved and achievement of complete metabolic response after salvage chemotherapy were predictive of more favorable prognosis.

The Role of Radiation Therapy in Patients With Relapsed or Refractory Hodgkin Lymphoma: Guidelines From the International Lymphoma Radiation Oncology Group

Relapsed and refractory Hodgkin lymphoma (HL) challenges clinicians to devise treatment strategies that are effective and safe. This problem is particularly prominent in an era when de-escalation trials are designed to minimize therapeutic toxicities in both early- and advanced-stage disease. Radiation therapy is the single most effective treatment modality for HL, and its integration into salvage regimens, or its independent use in select patients, must be understood to maximize our success in treating these patients. The complexity of treating relapsed or refractory HL derives from the spectrum of primary treatment approaches currently in use that creates heterogeneity in both treatment exposure and the potential toxicities of salvage therapy. Patients can have relapsed or refractory disease after limited or aggressive primary therapy (with or without radiation therapy), at early or delayed time points, with limited or extensive disease volumes, and with varying degrees of residual morbidity from primary therapy. Their response to salvage systemic therapy can be partial or complete, and the use of consolidative stem cell transplantation is variably applied. New biologics and immunotherapeutic approaches have broadened but also complicated salvage treatment approaches. Through all of this, radiation therapy remains an integral component of treatment for many patients, but it must be used effectively and judiciously. The purpose of this review is to describe the different treatment scenarios and provide guidance for radiation dose, volume, and timing in patients with relapsed or refractory HL.

How to Approach a Patient With Limited Stage Hodgkin Lymphoma Who Remains PET Positive at the End of Chemotherapy: Radiation Therapy?

The use of 18-F fluorodeoxyglucose (FDG) positron emission tomography (PET) with computed tomography has emerged as a crucial tool for response-adapted therapy in Hodgkin lymphoma (HL). Although more studies have focused on the predictive value of an interim or early PET obtained after 2 cycles of chemotherapy, there are indications that the end of therapy PET might even be more predictive of outcome. The optimal treatment of patients with limited stage HL who are PET-positive after chemotherapy is unknown. Here we review the prognostic significance of end of treatment PET in early stage HL, the role of consolidative radiotherapy in patients who have FDG-PET avidity at the end of chemotherapy, and discuss the place of salvage chemotherapy and autologous transplantation in these patients.

Role of Consolidative Radiation Therapy After Autologous Hematopoietic Cell Transplantation for the Treatment of Relapsed or Refractory Hodgkin Lymphoma

Purpose

To evaluate the role of the addition of consolidative radiation therapy after high-dose chemotherapy and autologous hematopoietic cell transplantation (AHCT) for relapsed or refractory Hodgkin lymphoma (HL).

Methods and Materials

Medical records were reviewed from a total of 80 consecutive patients who underwent high-dose chemotherapy with AHCT treated under a single protocol at University of Minnesota between November 2005 and January 2014. Of these, 32 patients received radiation therapy after AHCT as planned consolidation.

Results

At a median follow-up of 25 months, the 2-year overall survival (OS) and progression-free survival (PFS) for the entire cohort was 96% and 52%, respectively. Consolidative radiation therapy was found to significantly improve the 2-year PFS (67% vs 42%, P<.01) without a significant change in OS (100% vs 93%, P=.15). On subgroup analysis, consolidative radiation therapy was shown to improve PFS in patients with bulky disease (62% vs 39%, P=.02), B-symptoms (48% vs 28%, P=.05), primary refractory disease (47% vs 32%, P=.02), and those with a partial response on pretransplant imaging (47% vs 32%, P=.02). The improvement seen on 2-year PFS with consolidative radiation therapy remained significant on multivariate analysis (hazard ratio 4.64, 95% confidence interval 1.98–10.88). Minimal toxicity was observed among the patients receiving radiation therapy.

Conclusions

The addition of consolidative radiation therapy after high-dose chemo-therapy and AHCT demonstrated a significant improvement in 2-year PFS and no impact on OS. Radiation therapy was well tolerated, with minimal toxicity. Our study supports a role of consolidative radiation therapy in patients with HL treated with AHCT.

Optimal Therapy for Early-Stage Hodgkin's Lymphoma: Risk Adapting, Response Adapting, and Role of Radiotherapy

PURPOSE OF REVIEW

The aim of this article is to discuss the current role of radiotherapy (RT) for early-stage Hodgkin's lymphoma (HL) in the context of risk-adapted and response-adapted treatment strategy, and describe changes in RT technical approach.

RECENT FINDINGS

In low-risk patients, RT could be omitted but, at the price of a lower progression-free survival, and its role is still debated. Ongoing trials are combining new agents with chemotherapy alone or response-adapted combined modality therapy, and results are awaited. Modern RT incorporates lower doses and smaller fields, together with the implementation of sophisticated delivery techniques aimed to reducing the dose to critical structures such as the heart. The role of RT for early-stage HL is still under debate, and new combinations are emerging; an individualized approach should be recommended, considering all RT technical opportunities to minimize toxicity while maintaining efficacy.

A multi-institutional analysis of peritransplantation radiotherapy in patients with relapsed/refractory Hodgkin lymphoma undergoing autologous stem cell transplantation

BACKGROUND

No consensus exists regarding the use of radiotherapy (RT) in conjunction with high-dose chemotherapy and autologous stem cell transplantation (HDC/ASCT) for patients with relapsed/refractory classical Hodgkin lymphoma (HL). The objectives of the current study were to characterize practice patterns and assess the efficacy and toxicity of RT at 2 major transplantation centers.

METHODS

Eligible patients underwent HDC/ASCT from 2006 through 2015 using the combination of either carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) or cyclophosphamide, BCNU, and etoposide (CBV).

RESULTS

For the cohort of 189 patients, the 4-year overall survival rate was 80%, the progression-free survival rate was 67%, and the local control (LC) rate was 68%. RT was used within 4 months of ASCT for 22 patients (12%) and was given more often for disease that was early stage, primary refractory, or [¹⁸ F]fluorodeoxyglucose (FDG)-avid at the time of HDC/ASCT. Disease recurrence occurring after HDC/ASCT was associated with primary refractory disease and FDG-avidity at the time of HDC/ASCT. RT was not found to be associated with LC, progression-free survival, or overall survival on univariate analysis. In a model incorporating primary refractory HL and FDG-avid disease at the time of HDC/ASCT, RT was found to be associated with a decreased risk of local disease recurrence (hazard ratio, 0.3; P = .02). In patients with primary refractory HL and/or FDG-avid disease at the time of HDC/ASCT, the 4-year LC rate was 81% with RT versus 49% without RT (P = .03). There was one case of Common Terminology Criteria for Adverse Events grade ≥ 3 RT-related toxicity (acute grade 3 pancytopenia).

CONCLUSIONS

In patients undergoing ASCT for relapsed/refractory HL, peritransplantation RT was used more often for disease that was early stage, primary refractory, or FDG-avid after salvage conventional-dose chemotherapy. RT was associated with improved LC of high-risk localized disease and was well tolerated with modern techniques. Cancer 2017;123:1363-1371. © 2016 American Cancer Society.

Potential Benefit of Involved-Field Radiotherapy for Patients With Relapsed-Refractory Hodgkin's Lymphoma With Incomplete Response Before Autologous Stem Cell Transplantation

INTRODUCTION

We investigated for a possible role for peritransplantation involved-field radiotherapy (IFRT) by comparing patients who received IFRT before after autologous stem cell transplantation (ASCT) and patients who received salvage chemotherapy (CT) alone.

PATIENTS AND METHODS

We retrospectively evaluated 73 consecutive patients with Hodgkin lymphoma treated with ASCT between 2003 and 2014. Twenty-one patients (28.8%) received peritransplantation radiotherapy. A Cox regression analysis (multivariate analysis; MVA) was performed to evaluate the prognostic role of any risk factor. Overall survival (OS) and progression-free survival (PFS) were calculated from the date of ASCT. Response to CT and ASCT were evaluated with positron emission tomography (PET) scan.

RESULTS

Median follow-up was 41 months (range, 1-136 months). Overall, no significant difference appeared between patients who received IFRT and patients treated with CT alone; however, patients who were treated with IFRT had worse prognostic factors. In the MVA, advanced stage at relapse and persistent disease before ASCT (evident on PET scan [PET+]) were related to worse PFS and OS. In patients with limited stage disease at relapse and PET+, peritransplantation radiotherapy showed higher 3-year OS rates (91.7% vs. 62.3%) and PFS rates (67.5% vs. 50%) compared with patients treated with CT alone, although this difference was not significant (P = .14 and P = .22, respectively).

CONCLUSION

IFRT used before or after ASCT might partially compensate for worse prognostic factors among the overall population; subgroup analysis showed a trend for survival benefit at 3 years in patients with limited stage disease at relapse and PET+ before ASCT.

Role of cytotoxic therapy with hematopoietic cell transplantation in the treatment of Hodgkin lymphoma: guidelines from the American Society for Blood and Marrow Transplantation

The role of hematopoietic cell transplantation (HCT) in the therapy of Hodgkin lymphoma (HL) in pediatric and adult patients is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are included and were reached unanimously by a panel of HL experts. Both autologous and allogeneic HCT offer a survival benefit in selected patients with advanced or relapsed HL and are currently part of standard clinical care. Relapse remains a significant cause of failure after both transplant approaches, and strategies to decrease the risk of relapse remain an important area of investigation.

Contribution of involved-field radiotherapy to survival in patients with relapsed or refractory Hodgkin lymphoma undergoing autologous stem cell transplantation

OBJECTIVES

To assess the outcomes of overall survival and posttransplantation survival in patients with Hodgkin lymphoma (HL) undergoing autologous stem cell transplantation (ASCT) because of the development of relapse or resistance after chemotherapy (CT) or CT plus radiotherapy (combined modality treatment, CMT).

METHODS

Forty-five patients undergoing ASCT because of the development of relapse or resistance after CT or CMT for HL were enrolled in the study. Radiotherapy was given as involved-field radiotherapy. Patients were treated with CT alone (n=25) or CMT (n=20). These 2 groups were further divided into 2 subgroups: the patients with early-stage (I to II) and advanced-stage (III to IV) HL.

RESULTS

Median patients age was 29 years (range, 16 to 60 y) and the median follow-up was 60 months (range, 12 to 172 mo). In the patients with advanced-stage HL, there was no statistically significant difference in overall survival between irradiated and nonirradiated patients (n=18, irradiated n=4 and nonirradiated n=14). However, in the patients with early-stage disease, there was a significant difference in 5- and 10-year overall survival between the irradiated and nonirradiated groups (81% vs. 48% and 66% vs. 24%, respectively, P=0.045; n=26, irradiated n=16 and nonirradiated n=10). In the univariate analysis, irradiated group and involvement of 1 to 2 nodal regions were found to be significant for overall survival, whereas irradiated group, early stage, and involvement of 1 to 2 nodal regions were found to be significant for posttransplantation survival. However, only irradiated group was found to be significant for posttransplantation survival in multivariate analysis (P<0.05).

CONCLUSIONS

Addition of involved-field radiotherapy to CT in patients undergoing ASCT after relapse or recurrence failed to provide survival benefit in patients with advanced HL, while a survival benefit was observed in patients with early-stage HL. Radiotherapy should be considered as part of CMT in the patients with early-stage HL, which should not be neglected.

High-dose therapy followed by stem cell transplantation in Hodgkin's lymphoma: past and future

Hodgkin's lymphoma (HL) has been a fascinating challenge for physicians and investigators since its recognition during the 19th century. However, many questions still remain unanswered. One issue regards high-dose therapy followed by autologous stem cell transplantation (ASCT), which has yet to find its place among several guidelines. Other topics are still controversial with respect to transplantation for HL, including its role for newly diagnosed patients with advanced stage disease, the optimal timing of transplantation, the best conditioning regimen and the role of allogeneic/haploidentical SCT. Moreover, the potential use of localized radiotherapy or immunologic methods to decrease post-transplant recurrence, the role of novel agents such as brentuximab vedotin and their positioning in the treatment algorithm of resistant/relapsed HL patients, either before transplant to boost salvage therapy or after transplant as consolidation/maintenance, are burning questions without an answer. In this review, the authors try to give an answer to some of these dilemmas.

Involved field radiation therapy following high dose chemotherapy and autologous stem cell transplant benefits local control and survival in refractory or recurrent Hodgkin lymphoma

BACKGROUND AND PURPOSE

Patients with recurrent or primary refractory Hodgkin lymphoma (HL) treated with high dose chemotherapy (HDT) and autologous stem cell transplant (ASCT) commonly relapse post-ASCT in previous disease sites. We sought to evaluate involved field radiation therapy (IFRT) following ASCT and patterns of recurrence, overall survival (OS), and disease specific survival (DSS).

METHODS AND MATERIALS

Between May 1993 and October 2003, 62 (n=66) evaluable patients with refractory/relapsed HL underwent HDT followed by ASCT. Thirty-two (52%) patients received IFRT following transplant. Survival was calculated from the day of hematopoietic stem cell infusion.

RESULTS

Median follow-up was 2.3 years (range 0.03-11.56). Estimated 3-year OS (p=0.05) and DSS (p=0.08) were 69.6% and 82.1% with IFRT and 40% and 57.6% without IFRT on univariate analysis. B-symptoms were adverse on univariate (p=0.007) and multivariate (p=0.01) analysis. HL patients who received IFRT following ASCT had improved local control in areas of previously recurrent disease (p=0.03).

CONCLUSION

OS and DSS showed marginal benefit at 3 years. Given the retrospective nature of our study and attendant selection bias that can be both positive and negative, a future prospective study is warranted to better understand the value of IFRT in the transplant setting.

Refining the role of radiation therapy in pediatric hodgkin lymphoma

The role of radiation therapy in the treatment of pediatric Hodgkin lymphoma has continued to be refined, motivated by the desire to avoid disruption to normal tissue development and function and secondary carcinogenesis. Such progress has occurred in tandem with modifications of the multiagent chemotherapy regimens that have been used in place of or in combination with low-dose involved-field radiation that are also associated with dose-related risks of cardiopulmonary and gonadal dysfunction and leukemogenesis. Consequently, treatment strategies for young patients, who have an excellent prognosis of long-term survival, utilizes a risk-adapted approach that provides optimal efficacy for disease control whereas limiting toxicity associated with both radiation and chemotherapy. Because of the differences in age-related developmental status and gender-related sensitivity to chemotherapy and radiation toxicity, no single treatment approach is ideal for all pediatric patients. This manuscript summarizes results from published clinical trials with the goal of defining optimal treatment strategies for children and adolescents with Hodgkin lymphoma in regards to the use of radiation therapy.

Current status of autologous stem cell transplantation in relapsed and refractory Hodgkin's lymphoma

Despite the relatively high long-term disease-free survival (DFS) rate for patients with Hodgkin lymphoma (HL) with modern combination chemotherapy or combined modality regimens, ∼20% of patients die from progressive or relapsed disease. The standard treatment for relapsed and primary refractory HL is salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT), which has shown a 5-year progression-free survival rate of ∼50%-60%. Recent developments in a number of diagnostic and therapeutic modalities have begun to improve these results. Functional imaging, refinement of clinical prognostic factors, and development of novel biomarkers have improved the predictive algorithms, allowing better patient selection and timing for ASCT. In addition, these algorithms have begun to identify a group of patients who are candidates for more aggressive treatment beyond standard ASCT. Novel salvage regimens may potentially improve the rate of complete remission prior to ASCT, and the use of maintenance therapy after ASCT has become a subject of current investigation. We present a summary of developments in each of these areas.

Initial response to salvage therapy determines prognosis in relapsed pediatric Hodgkin lymphoma patients

BACKGROUND

Pediatric Hodgkin lymphoma (HL) is a highly curable disease; however, prognostic factors for the survival of patients who develop recurrent disease have not been clearly defined.

METHODS

This was a retrospective analysis of 50 pediatric patients with HL who relapsed or progressed between 1990 and 2006 and who were retrieved with intense cytoreductive treatment regimens followed by autologous stem cell transplantation and radiation therapy. A Cox proportional hazards model was used to determine risk factors for second treatment failure and death.

RESULTS

The median patient age was 16.1 years (range, 4.9-22.1 years) at the time of HL diagnosis. Fifteen patients developed progressive disease during therapy, 14 patients relapsed early, and 21 patients relapsed late. Patients who remained alive at the time of this study had been followed for a median of 4.4 years (range, 1.2-16.6 years). The 5-year overall survival rate for patients who had an inadequate response (n = 14) to initial salvage therapy was only 17.9% (95% confidence interval [CI], 3.1%-42.5%) compared with 97.2% (95% CI, 81.9%-99.6%) for patients who responded (n = 36; P < .0001). In a multivariate Cox regression analysis of overall survival, an inadequate response to initial salvage therapy was the only significant variable (hazard ratio, 43.6; 95% CI, 5.4-354; P = .0004).

CONCLUSIONS

The current results indicated that pediatric patients with relapsed HL who have an inadequate response after initial primary salvage chemotherapy have a very poor prognosis and should be considered for novel therapies directed at biologic or immunologic targets.

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.

Involved-Field Radiotherapy Before High-Dose Therapy and Autologous Stem-Cell Rescue in Diffuse Large-Cell Lymphoma: Long-Term Disease Control and Toxicity

Purpose

To analyze outcome, prognostic factors, and toxicities in patients with diffuse large-cell lymphoma (DLCL) who received involved-field radiotherapy (IFRT) before high-dose chemotherapy with autologous stem-cell rescue (ASCR).

Patients and Methods

Between January 1990 and August 2006, 164 patients with relapsed or refractory DLCL received IFRT at Memorial Sloan-Kettering Cancer Center (New York, NY) before high-dose chemotherapy and ASCR. IFRT was delivered to involved sites measuring more than 5 cm or to sites with residual disease more than 2 cm. Radiotherapy was administered in 1.5-Gy fractions twice daily to a total dose of 30 Gy. Progression-free survival and overall survival were calculated, and short- and long-term toxicity was assessed according to National Cancer Institute Common Toxicity Criteria (version 2.0). Median follow-up was 60 months (range, 2 to 187 months).

Results

Two- and 5-year progression-free survival was 62% and 53%; 2- and 5-year overall survival was 67% and 58%, respectively. Sixty-seven patients relapsed; only 10 patients relapsed completely within the radiotherapy field. There were seven early treatment-related mortalities and 11 secondary cancers (including four myelodysplastic syndromes), one of which occurred within the IFRT site and five after total-body irradiation.

Conclusion

Minimal treatment-related mortality and morbidity resulted from short, intensive, involved-field radiotherapy before high-dose chemotherapy and ASCR, which was incorporated into a salvage regimen for patients with relapsed/refractory DLCL. This chemoradiotherapy salvage regimen resulted in a low local relapse rate that could potentially translate into an improved total outcome.

Relapsed and Refractory Hodgkin's Lymphoma: New Avenues?

Relapse or progression following therapy for Hodgkin's lymphoma occurs in 10% to 60% of patients depending on initial clinical stage. Patterns of failure in advanced disease determine prognosis of salvage therapy. Progression or early relapse after less than 12 months requires intensive salvage therapy. Only late, isolated, asymptomatic relapse, which occurs in less than 25% of those relapsing from systemic therapy, can be treated with conventional-dose chemotherapy with or without radiation. Overall about 40% to 50% of relapses from advanced disease can be salvaged with higher percentages for patients relapsing from early stage disease.

Stem cell transplantation in Hodgkin lymphoma

Hematopoietic stem cell transplantation is an effective treatment for patients with relapsed or refractory Hodgkin lymphoma. Treatment outcome is better among patients who demonstrate sensitivity to salvage chemotherapy. Approximately half of the patients undergoing autologous stem cell transplantation will be cured and sequential high-dose therapy has been proposed as a means of improving these results further. Lifelong medical surveillance is required following transplantation to monitor for late toxicity, including second malignancy. For young patients who relapse following transplantation, reduced-intensity allogeneic transplantation has shown encouraging response rates, while second autologous stem cell transplantation, radiotherapy and palliative single-agent chemotherapy are other options. For patients with multiple relapses and chemotherapy refractory disease, novel approaches are necessary.