The concept and evolution of involved site radiation therapy for lymphoma

Multicenter phase II study of moderate low-dose radiotherapy in indolent non-Hodgkin lymphoma: CLCG-iNHL-01 protocol

Background: Radiotherapy is an effective treatment for indolent non-Hodgkin lymphoma (iNHL); however, the optimal radiotherapy dose remains to be determined. We hypothesize that a suitable dose may exist between 4 and 24 Gy. Methods: This prospective multicenter phase II trial intends to recruit 73 sites of iNHL patients, who will receive involved-site radiotherapy of 12 Gy in four fractions. The primary objective is the 6-month clinical complete response rate. Tumor tissue, blood and conjunctival specimens will be collected to identify potential predictive biomarkers. Discussion: The CLCG-iNHL-01 trial will evaluate the efficacy and toxicity of 12 Gy in patients with iNHL and provide information on a novel hypofractionation regimen of low-dose radiotherapy. Clinical Trial Registration: NCT05543070 (ClinicalTrials.gov).

Reappraisal of the role of radiation therapy in lymphoma treatment

Radiation therapy (RT) for lymphomas has improved dramatically with modern imaging and treatment techniques, encompassing only the necessary volume with minimal doses to normal structures. Prescribed radiation doses are reduced, and fractionation schedules are under revision. With effective systemic treatment only initial macroscopic disease is irradiated. With no or less effective systemic treatment, possible microscopic disease is also included. Risks of long-term side effects of RT have diminished dramatically and should be weighed against risks from more systemic treatment or increased risk of relapse. Lymphoma patients are often elderly, they tolerate modern limited RT very well. Lymphomas refractory to systemic treatments often remain radioresponsive, and brief, mild RT may offer effective palliation. New roles for RT are emerging with immune therapies. RT for "bridging," keeping the lymphoma under control while waiting for immune therapy, is well established. Enhancement of the immune response to lymphomas, so-called "priming," is being intensively researched.

Excellent response to very-low-dose radiation (4 Gy) for indolent B-cell lymphomas: is 4 Gy suitable for curable patients?

Two doses of VLDRT at 2 Gy are associated with an impressive overall response rate of 90% across diverse indolent B-cell lymphomas.

Patients with early-stage, potentially[AQ4] curable disease had outcomes similar to those treated with 4 Gy as part of a novel RT strategy.

Radiotherapy plays an important role in managing highly radiosensitive, indolent non-Hodgkin lymphomas, such as follicular lymphoma and marginal zone lymphoma. Although the standard of care for localized indolent non-Hodgkin lymphomas remains 24 Gy, de-escalation to very-low-dose radiotherapy (VLDRT) of 4 Gy further reduces toxicities and duration of treatment. Use of VLDRT outside palliative indications remains controversial; however, we hypothesize that it may be sufficient for most lesions. We present the largest single-institution VLDRT experience of adult patients with follicular lymphoma or marginal zone lymphoma treated between 2005 and 2018 (299 lesions; 250 patients) using modern principles including positron emission tomography staging and involved site radiotherapy. Outcomes include best clinical or radiographic response between 1.5 and 6 months after VLDRT and cumulative incidence of local progression (LP) with death as the only competing risk. After VLDRT, the overall response rate was 90% for all treated sites, with 68% achieving complete response (CR). With a median follow-up of 2.4 years, the 2-year cumulative incidence of LP was 25% for the entire cohort and 9% after first-line treatment with VLDRT for potentially curable, localized disease. Lesion size >6 cm was associated with lower odds of attaining a CR and greater risk of LP. There was no suggestion of inferior outcomes for potentially curable lesions. Given the clinical versatility of VLDRT, we propose to implement a novel, incremental, adaptive involved site radiotherapy strategy in which patients will be treated initially with VLDRT, reserving full-dose treatment for those who are unable to attain a CR.

Total tumor burden in lymphoma - an evolving strong prognostic parameter

Total metabolic tumor volume (TMTV), a new parameter extracted from baseline FDG-PET/CT, has been recently proposed by several groups as a prognosticator in lymphomas before first-line treatment. TMTV, the sum of the metabolic volume of each lesion, is an index of the metabolically most active part of the tumor and highly correlates with the total tumor burden. TMTV measurement is obtained from PET images processed with different software and techniques, many being now freely available. In the various lymphoma subtypes where it has been measured, such as diffuse large B-cell lymphoma, Hodgkin lymphoma, Follicular Lymphoma, and Peripheral T-cell lymphoma, TMTV has been reported as a strong predictor of outcome (progression-free survival and overall survival) often outperforming the clinical scores, molecular predictors, and results of interim PET. Combined with these scores, TMTV improves the stratification of the populations into risk groups with different outcomes. TMTV cut-off separating the high-risk from the low-risk population impacts the outcome whatever the technique used for its measurement and an international harmonization is ongoing. TMTV is a unique and easy tool that could replace the surrogate of tumor burden included in the prognostic indexes used in lymphoma and help tailor therapy. Other parameters extracted from the baseline PET may give an information on the dissemination of this total tumor volume such as the maximum distance between the lesions. Trials based on TMTV would probably demonstrate its predictive value.

Impact on survival through consolidation radiotherapy for diffuse large B-cell lymphoma: a comprehensive meta-analysis

Rituximab has improved response rates and overall survival in B-cell lymphoma (DLBCL). Radiotherapy is an effective treatment modality for lymphomas, but there is uncertainty on its use as consolidation after chemo-immunotherapy mainly in advanced stages. We evaluated its efficacy with a comprehensive meta-analysis and a systematic search of Pubmed, Embase, Cochrane, and abstracts from ASCO, ASH, ESMO and ASTRO published from June 1966 and December 2018. We identified 11 trials that evaluated consolidation radiotherapy following chemotherapy in a randomized fashion in 4'584 patients. The primary endpoint of this meta-analysis was PFS. As three of the eleven trials were retracted, this data is based on 2414 patients. For the primary endpoint (PFS), we found a hazard ratio (HR) of 0.77 (0.51 to 1.17, pooled (tau2: 0.25; I2: 85%), and a HR of 0.80 (0.53 to 1.21, pooled (bivariate meta-analysis). For overall survival, the HR is 0.93 (0.61 to 1.40; pooled (tau2: 0.25; I2: 74%) and 0.86 (0.58 to 1.27) in a bivariate meta-analysis. The lack of benefit did not change over time (p-value: 0.95 (tau2: 0.32; I2: 88%), and was also absent for PFS when stratifying for chemotherapy, the use of Rituximab, age, the dose of radiotherapy, application to patients in complete remission and with bulky disease. None of the trials used a PET-guided approach. This meta-analysis revealed no survival benefit when consolidation radiotherapy is given to unselected DLBCL patients following chemotherapy. These results need to be considered in future trials in the PET-CT era.

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.

Brentuximab Vedotin Combined With Chemotherapy in Patients With Newly Diagnosed Early-Stage, Unfavorable-Risk Hodgkin Lymphoma

PURPOSE

To improve curability and limit long-term adverse effects for newly diagnosed early-stage (ES), unfavorable-risk Hodgkin lymphoma.

METHODS

In this multicenter study with four sequential cohorts, patients received four cycles of brentuximab vedotin (BV) and doxorubicin, vinblastine, and dacarbazine (AVD). If positron emission tomography (PET)-4-negative, patients received 30-Gy involved-site radiotherapy in cohort 1, 20-Gy involved-site radiotherapy in cohort 2, 30-Gy consolidation-volume radiotherapy in cohort 3, and no radiotherapy in cohort 4. Eligible patients had ES, unfavorable-risk disease. Bulk disease defined by Memorial Sloan Kettering criteria (> 7 cm in maximal transverse or coronal diameter on computed tomography) was not required for cohorts 1 and 2 but was for cohorts 3 and 4. The primary end point was to evaluate safety for cohort 1 and to evaluate complete response rate by PET for cohorts 2-4.

RESULTS

Of the 117 patients enrolled, 116 completed chemotherapy, with the median age of 32 years: 50% men, 98% stage II, 86% Memorial Sloan Kettering-defined disease bulk, 27% traditional bulk (> 10 cm), 52% elevated erythrocyte sedimentation rate, 21% extranodal involvement, and 56% > 2 involved lymph node sites. The complete response rate in cohorts 1-4 was 93%, 100%, 93%, and 97%, respectively. With median follow-up of 3.8 years (5.9, 4.5, 2.5, and 2.2 years for cohorts 1-4), the overall 2-year progression-free and overall survival were 94% and 99%, respectively. In cohorts 1-4, the 2-year progression-free survival was 93%, 97%, 90%, and 97%, respectively. Adverse events included neutropenia (44%), febrile neutropenia (8%), and peripheral neuropathy (54%), which was largely reversible.

CONCLUSION

BV + AVD × four cycles is a highly active and well-tolerated treatment program for ES, unfavorable-risk Hodgkin lymphoma, including bulky disease. The efficacy of BV + AVD supports the safe reduction or elimination of consolidative radiation among PET-4-negative patients.

Extensive pelvic and abdominal lymphadenopathy with hepatosplenomegaly treated with radiotherapy-A case report

This is a case report of a 65-year-old female patient diagnosed with Grade II Follicular Lymphoma of the pelvic and abdomen was treated with a combination of R-CHOP chemotherapy and radiotherapy.

Advantage of proton-radiotherapy for pediatric patients and adolescents with Hodgkin's disease

Abstract

Radiotherapy is frequently used in the therapy of lymphoma. Since lymphoma, for example Hodgkin’s disease, frequently affect rather young patients, the induction of secondary cancer or other long-term adverse effects after irradiation are important issues to deal with. Especially for mediastinal manifestations numerous organs and substructures at risk play a role. The heart, its coronary vessels and cardiac valves, the lungs, the thyroid and, for female patients, the breast tissue are only the most important organs at risk. In this study we investigated if proton-radiotherapy might reduce the dose delivered to the organs at risk and thus minimize the therapy-associated toxicity.

Methods

In this work we compared the dose delivered to the heart, its coronary vessels and valves, the lungs, the thyroid gland and the breast tissue by different volumetric photon plans and a proton plan, all calculated for a dose of 28.8 Gy (EURO-NET-PHL-C2). Target Volumes have been defined by F18-FDG PET-positive areas, following a modified involved node approach. Data from ten young female patients with mediastinal lymphoma have been evaluated. Three different modern volumetric IMRT (VMAT) photon plans have been benchmarked against each other and against proton-irradiation concepts. For plan-evaluation conformity- and homogeneity-indices have been calculated as suggested in ICRU 83. The target volume coverage as well as the dose to important organs at risk as the heart with its substructures, the lungs, the breast tissue, the thyroid and the spinal cord were calculated and compared. For statistical evaluation mean doses to organs at risk were evaluated by non- parametric Kruskal-Wallis calculations with pairwise comparisons.

Results

Proton-plans and three different volumetric photon-plans have been calculated. Proton irradiation results in significant lower doses delivered to organ at risk. The median doses and the mean doses could be decreased while PTV coverage is comparable. As well conformity as homogeneity are slightly better for proton plans. For several organs a risk reduction for secondary malignancies has been calculated using literature data as reference.

According to the used data derived from literature especially the secondary breast cancer risk, the secondary lung cancer risk and the risk for ischemic cardiac insults can be reduced significantly by using protons for radiotherapy of mediastinal lymphomas.

Conclusion

Irradiation with protons for mediastinal Hodgkin-lymphoma results in significant lower doses for almost all organs at risk and is suitable to reduce long term side effects for pediatric and adolescent patients.

Electronic supplementary material

The online version of this article (10.1186/s13014-019-1360-7) contains supplementary material, which is available to authorized users.

Radiation Therapy for Treatment of Adolescent and Young Adult Hodgkin Lymphoma and Risk for Cardiovascular Disease and Cancer

PURPOSE

To estimate the risk for hospitalizations among survivors of Hodgkin lymphoma diagnosed in adolescence or young adulthood according to exposure to treatment with radiation therapy.

METHODS

Through the files of the Danish Cancer Registry, we identified 1684 five-year survivors of Hodgkin lymphoma, diagnosed at age 15-39 years during the period 1943-2004, and for whom information on radiation therapy was available in the Cancer Registry. Population-based comparisons were identified through the Danish Civil Registration System and matched to the survivors on year of birth and sex. Survivors of Hodgkin lymphoma and comparisons were linked to the Danish National Patient Register for information on hospitalizations. Standardized hospitalization rate ratios (RR) and absolute excess rates (AERs) were estimated for total number of hospitalizations and for hospitalizations for cardiovascular disease, cancer and several other disease groups.

RESULTS

Overall, survivors of Hodgkin lymphoma who received radiation therapy had higher risk (RR 2.0) and AER (AER 588) of hospitalization than survivors not treated with radiation therapy (RR 1.8; AER 399). Especially, the risk for cardiovascular disease and cancer was high among survivors who received radiation therapy (RR 2.8 and 3.6) compared with survivors who did not receive this type of treatment (RR 2.2 and 2.3).

CONCLUSION

Survivors of adolescent and young adult Hodgkin lymphoma treated with radiation therapy had a higher risk of diseases requiring hospitalization than survivors not treated with radiation therapy. Irrespective of the type of treatment received, initiatives that prevent and minimize hospital-requiring late effects in survivors of Hodgkin lymphoma are needed.

Treatment of classical Hodgkin lymphoma in the era of brentuximab vedotin and immune checkpoint inhibitors

The majority of Hodgkin lymphoma patients are now cured with conventional first-line therapy; however, 10-15% of early-stage disease and less than 30% of advanced-stage patients are refractory(rare) or relapsed. Salvage second-line therapy combined with high-dose therapy and autologous stem-cell transplantation can cure 40-50% of patients. Recently novel agents (Brentuximab Vedotin and Immune Checkpoint inhibitors) have demonstrated evidence of therapeutic activity and are potential bridge to an allogeneic stem-cell transplantation. The review is aimed to present not only salvage strategies; indeed, the paper contains paragraphs about therapy and new treatment options at diagnosis.

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.

Diffuse large B-cell lymphoma in very elderly patients over 80 years old: Incorporating consolidative radiation therapy into management decisions

Purpose

The population of patients aged 80 years or older who are diagnosed with diffuse large B-cell lymphoma (DLBCL) continues to increase, but an optimal treatment strategy has not been established. We sought to examine the influence of consolidative radiation therapy (RT) on outcome and toxicity among the very elderly diagnosed with stage I-IV DLBCL.

Methods and materials

We evaluated 131 patients treated at a single institution between 2002 and 2014 who were eligible for RT after successful treatment with chemotherapy.

Results

The median age was 83 years (range, 80-96). Advanced-stage disease was present in 61.8% of patients. Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone was administered to 80% of patients (n = 108), and 23.7% of patients received consolidative RT. Among early-stage (ES) patients treated with 3 to 4 cycles of chemotherapy and RT (n = 12) versus 6 to 8 cycles of chemotherapy alone (n = 17), there were no statistically significant differences in 3-year disease-free, progression-free, or overall survival rates. The 3 year disease-free survival was 91.7% versus 88.2% among patients treated with combined modality therapy versus chemotherapy alone (P = .78). The 3-year overall survival was 82.5% versus 87.5% among patients treated with combined modality therapy compared with chemotherapy alone (P = .852). Anemia and neuropathy occurred more frequently among ES patients who received 6 to 8 cycles of chemotherapy alone. Among advanced-stage patients with bulky disease (n = 35), consolidative RT to sites of bulky disease may have improved local control (3-year local control, 100% vs 60.3%, P = .160).

Conclusions

Among patients aged 80 years or older who have with ES DLBCL, 3 to 4 cycles of chemotherapy followed by RT is at least equivalent in efficacy to chemotherapy alone and is associated with lower levels of toxicity, which suggests that it may be a better choice for therapy when trying to balance treatment efficacy and tolerability.

Brentuximab vedotin and AVD followed by involved-site radiotherapy in early stage, unfavorable risk Hodgkin lymphoma

This multicenter pilot study assessed the safety and efficacy of brentuximab vedotin (BV) and AVD (adriamycin, vinblastine, and dacarbazine) followed by 30 Gy involved site radiation therapy (ISRT). Patients with newly diagnosed, early stage classical Hodgkin lymphoma (HL) with unfavorable-risk features were treated with 4 cycles of BV and AVD. Patients who achieved a negative positron emission tomography (PET) scan (Deauville score of 1-3) received 30 Gy ISRT. Thirty patients received treatment and were assessable for toxicity. Twenty-nine patients completed 4 cycles of BV + AVD, and 25 patients BV + AVD + 30 Gy ISRT. No clinically significant noninfectious pneumonitis was observed. Serious adverse events (≥grade 3) were reported in 4 patients, including febrile neutropenia, peripheral neuropathy, and hypertension. After 2 and 4 cycles of BV + AVD, 90% (26 of 29) and 93% (27 or 29) of patients achieved a negative PET scan, respectively. Two patients with biopsy-proven primary refractory HL were treated off-study. All 25 patients who completed BV + AVD + ISRT achieved a complete response. With a median follow-up of 18.8 months, by intent to treat, the 1-year progression-free survival is 93.3% (95% confidence interval, 84-102). Overall, the treatment was well-tolerated with no evidence of significant pulmonary toxicity. The majority of patients (≥90%) achieved negative interim PET scans after 2 and 4 cycles of BV + AVD. Excluding the 2 primary refractory patients, all patients are disease free, suggesting that this is a highly active treatment program even in patients with substantial disease bulk. This trial was registered at www.clinicaltrials.gov as #NCT01868451.