Response rates and recurrence patterns after low-dose radiotherapy with 4 Gy in patients with low-grade lymphomas

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).

Ultra-low dose external beam radiotherapy for presumed choroidal lymphoma: a case report

Primary choroidal lymphoma is a rare, slowly progressive intraocular malignancy. Most are low grade B cell lymphomas, often involving tissues adjacent to the choroid such as the subconjunctival space, lacrimal gland or orbit. Ideally, these lesions are biopsied to establish histopathological diagnosis. The most accessible ocular structure is biopsied. Obtaining tissue by transvitreal choroidal biopsy imparts a small but significant risk of ocular morbidity, including the need for multiple surgeries, retinal detachment and vision loss.

External beam radiotherapy (EBRT) is a common and effective treatment of low-grade lymphomas. EBRT has been found to very successfully treat primary marginal zone lymphomas of the ocular adnexa, which are typically of the same cell type as most primary choroid lymphomas. Ultra-low dose EBRT, most commonly using a total dose of 4 Gy, has been shown to be as effective as higher doses of radiotherapy for follicular or marginal zone lymphomas. The use of this low dose regimen for conjunctival lymphomas has been recently explored. The role of EBRT, and especially ultra-low dose EBRT, for treatment of primary choroidal lymphoma has been confined to case reports.

We describe a case of presumed primary choroidal lymphoma diagnosed on clinical findings alone as the risks of ocular biopsy were deemed too high, and report outcome following treatment with ultra-low dose EBRT.

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.

Increased Risk of Diabetes after Definitive Radiotherapy in Patients with Indolent Gastroduodenal Lymphoma

Purpose

This study aimed to evaluate the effect of radiotherapy (RT) on the risk of diabetes by assessing hemoglobin A1c (HbA1c) levels in patients with gastroduodenal indolent lymphoma.

Materials and Methods

This retrospective study included patients with stage I extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue or follicular lymphoma of the gastroduodenal region who were treated with Helicobacter pylori eradication and/or RT between 2000 and 2019 in our institution. Of total 79 patients with HbA1c test, 17 patients received RT (RT group), while 62 patients did not receive RT (control group). A diabetes-associated event (DAE) was defined as a ≥ 0.5% increase in HbA1c levels from baseline, and diabetes event (DE) were defined as HbA1c level of ≥ 6.5%.

Results

During the median follow-up of 49 months, no local failure occurred after RT and no patients died of lymphoma. The RT group had significantly higher risk for DAEs on univariable analysis (hazard ratio [HR], 4.18; 95% confidence interval [CI], 1.64 to 10.66; p < 0.01) and multivariable analysis (HR, 3.68; 95% CI, 1.42 to 9.56; p=0.01). Further, the DE risk was significantly higher in the RT group than in the control group (HR, 4.32; 95% CI, 1.08 to 17.30; p=0.04) and in patients with increased baseline HbA1c levels (HR, 35.83; 95% CI, 2.80 to 459.19; p=0.01). On multivariable analysis, RT significantly increased the risk of DEs (HR, 4.55; 95% CI, 1.08 to 19.19; p=0.04), even after adjusting baseline HbA1c level (HR, 40.97; 95% CI, 3.06 to 548.01; p=0.01).

Conclusion

Patients who received RT for gastroduodenal indolent lymphoma had an increased risk of diabetes compared to those who did not.

4 Gy versus 24 Gy radiotherapy for follicular and marginal zone lymphoma (FoRT): long-term follow-up of a multicentre, randomised, phase 3, non-inferiority trial

BACKGROUND

The optimal radiotherapy dose for indolent non-Hodgkin lymphoma is uncertain. We aimed to compare 24 Gy in 12 fractions (representing the standard of care) with 4 Gy in two fractions (low-dose radiation).

METHODS

FoRT (Follicular Radiotherapy Trial) is a randomised, multicentre, phase 3, non-inferiority trial at 43 study centres in the UK. We enrolled patients (aged >18 years) with indolent non-Hodgkin lymphoma who had histological confirmation of follicular lymphoma or marginal zone lymphoma requiring radical or palliative radiotherapy. No limit on performance status was stipulated, and previous chemotherapy or radiotherapy to another site was permitted. Radiotherapy target sites were randomly allocated (1:1) either 24 Gy in 12 fractions or 4 Gy in two fractions using minimisation and stratified by histology, treatment intent, and study centre. Randomisation was centralised through the Cancer Research UK and University College London Cancer Trials Centre. Patients, treating clinicians, and investigators were not masked to random assignments. The primary endpoint was time to local progression in the irradiated volume based on clinical and radiological evaluation and analysed on an intention-to-treat basis. The non-inferiority threshold aimed to exclude the chance that 4 Gy was more than 10% inferior to 24 Gy in terms of local control at 2 years (HR 1·37). Safety (in terms of adverse events) was analysed in patients who received any radiotherapy and who returned an adverse event form. FoRT is registered with ClinicalTrials.gov, NCT00310167, and the ISRCTN Registry, ISRCTN65687530, and this report represents the long-term follow-up.

FINDINGS

Between April 7, 2006, and June 8, 2011, 614 target sites in 548 patients were randomly assigned either 24 Gy in 12 fractions (n=299) or 4 Gy in two fractions (n=315). At a median follow-up of 73·8 months (IQR 61·9-88·0), 117 local progression events were recorded, 27 in the 24 Gy group and 90 in the 4 Gy group. The 2-year local progression-free rate was 94·1% (95% CI 90·6-96·4) after 24 Gy and 79·8% (74·8-83·9) after 4 Gy; corresponding rates at 5 years were 89·9% (85·5-93·1) after 24 Gy and 70·4% (64·7-75·4) after 4 Gy (hazard ratio 3·46, 95% CI 2·25-5·33; p<0·0001). The difference at 2 years remains outside the non-inferiority margin of 10% at -13·0% (95% CI -21·7 to -6·9). The most common events at week 12 were alopecia (19 [7%] of 287 sites with 24 Gy vs six [2%] of 301 sites with 4 Gy), dry mouth (11 [4%] vs five [2%]), fatigue (seven [2%] vs five [2%]), mucositis (seven [2%] vs three [1%]), and pain (seven [2%] vs two [1%]). No treatment-related deaths were reported.

INTERPRETATION

Our findings at 5 years show that the optimal radiotherapy dose for indolent lymphoma is 24 Gy in 12 fractions when durable local control is the aim of treatment.

FUNDING

Cancer Research UK.

Radiation treatment of hemato-oncological patients in times of the COVID-19 pandemic : Expert recommendations from the radiation oncology panels of the German Hodgkin Study Group and the German Lymphoma Alliance

PURPOSE

The coronavirus pandemic is affecting global health systems, endangering daily patient care. Hemato-oncological patients are particularly vulnerable to infection, requiring decisive recommendations on treatment and triage. The aim of this survey amongst experts on radiation therapy (RT) for lymphoma and leukemia is to delineate typical clinical scenarios and to provide counsel for high-quality care.

METHODS

A multi-item questionnaire containing multiple-choice and free-text questions was developed in a peer-reviewed process and sent to members of the radiation oncology panels of the German Hodgkin Study Group and the German Lymphoma Alliance. Answers were assessed online and analyzed centrally.

RESULTS

Omission of RT was only considered in a minority of cases if alternative treatment options were available. Hypofractionated regimens and reduced dosages may be used for indolent lymphoma and fractures due to multiple myeloma. Overall, there was a tendency to shorten RT rather than to postpone or omit it. Even in case of critical resource shortage, panelists agreed to start emergency RT for typical indications (intracranial pressure, spinal compression, superior vena cava syndrome) within 24 h. Possible criteria to consider for patient triage are the availability of (systemic) options, the underlying disease dynamic, and the treatment rationale (curative/palliative).

CONCLUSION

RT for hemato-oncological patients receives high-priority and should be maintained even in later stages of the pandemic. Hypofractionation and shortened treatment schedules are feasible options for well-defined constellations, but have to be discussed in the clinical context.

Single-fraction low-energy electronic brachytherapy for conjunctival lymphoma

Purpose

Conjunctival lymphoma represents an uncommon tumor, accounting for 5-10% of total extranodal lymphomas. Although radiotherapy is a frequent treatment option, limited capacities and lack of specialized centers are common problems in Peru, forcing radiation oncologists to apply short courses of radiotherapy. Here, we report a case series of patients treated with a novel single-shot scheme. Additionally, we present a literature review of the current short-course irradiation strategies.

Cases presentation

Three cases of conjunctival marginal zone (B-cell) lymphoma (marginal zone lymphoma [MZL]/mucosa-associated lymphoid tissue [MALT]) of the fornix are presented. Following biopsy and sonographic assessment of the lesion thickness, we applied a focused single dose of 14 Gy kilovoltage brachytherapy (prescribed to the maximum thickness of the lesion). Follow-up was scheduled in quarterly intervals. After 28, 31, and 40 months of follow-up, none of the three patients treated exhibited acute or chronic toxicities and remained local or distant disease-free.

Conclusions

Single dose kilovoltage brachytherapy was effective and safe in this small cohort of patients. Based on the literature, there is an evidence that local treatment in short-course radiotherapy is effective and should be considered amongst therapeutic options for these patients; however, this novel approach should be evaluated prospectively in a larger cohort.

Oncological outcome and recurrence pattern analysis after involved-field irradiation in combination with rituximab for early-stage nodal and extranodal follicular lymphoma

Purpose

Combined radioimmunotherapy (RIT) in follicular lymphomas (FL) has shown promising treatment efficacy in the Mabthera® and Involved field Radiation (MIR) study. Aim of this study was to analyze treatment efficacy and recurrence patterns after RIT in early-stage nodal and extranodal FL.

Methods

We reviewed 107 patients who were treated with combined RIT in two centers. Treatment consisted of 4 × rituximab followed by RIT with 4 × rituximab and involved field (IF) radiotherapy with 30/40 Gy. Median follow-up period was 71 months. In contrast to the MIR study, extranodal involvement and grade 3A histology were included in the analysis.

Results

Extranodal involvement and grade 3A histology were present in 21.8% and 13.1%, respectively. Overall response rate (ORR) after 4 × rituximab, after completion of RIT, and after 6 months was 78.1%, 98.8%, and 98.8%, respectively, with increasing rates of complete remissions (CR). Predictive factors associated with superior PFS were tumor size, completely excised lymphomas, and response to first 4 × rituximab. 5‑year PFS rate was 87.3%, with mostly outfield recurrences (94.1%). Second-line treatment was effective, with 53.3% CR and 46.7% partial remissions (PR). 5‑year OS was 98.1%. RIT was tolerated well, with mainly grade 1–2 acute side effects.

Conclusion

The real-world efficacy of RIT is comparable with the results of the MIR study. Additionally, this analysis shows that extranodal involvement and grade 3A histology are not associated with inferior PFS.

Repeated courses of low-dose 2 × 2 Gy radiation therapy in patients with indolent B-cell non-Hodgkin lymphomas

Purpose

In patients with indolent B‐cell non‐Hodgkin's lymphoma (B‐NHL), one course of low‐dose radiotherapy (LD‐RT) 2 × 2 Gy is emerging as new option of therapy in palliative setting. Efficacy of LD‐RT when repeated remains to be determinate. This study aims to assess the efficacy of repeated LD‐RT given in patients with indolent B‐NHL.

Materials and Methods

All consecutive adult patients who received two or more courses of LD‐RT 2 × 2 Gy for indolent B‐NHL at Gustave Roussy institution, during the period 1990‐2015 were retrospectively investigated.

Results

Thirty‐three patients received two or more courses of LD‐RT for indolent B‐NHL during the study period. The median age was 57 (range 37‐80) years, histological types were distributed among follicular lymphoma (n = 24 pts; 73%), marginal‐zone lymphoma (n = 6 pts; 18%), and primary cutaneous follicle center lymphoma (n = 3 pts; 9%). The median number of low‐dose radiation therapy courses given per patients was 2 (range 2‐6). The overall response rates following the first and the second course of LD‐RT were 96% and 88%, respectively (P = .31). The 1‐ and 2‐years local control rates following the first courses of LD‐RT were 94% (CI 95: 86‐100) and 94% (CI 95: 86‐98); and were 91% (CI 95: 82‐100) and 88% (CI 95: 77‐100) following the second course of LD‐RT (P = .39).

Conclusion

The repeated courses of LD‐RT offered similar efficacy compare with the first course in patients with indolent B‐NHL. LD‐RT repeated is a simple, easy to give, and non‐toxic asset that could be investigated as treatment option in patients with indolent B‐NHL.

De-escalated radiotherapy for indolent primary cutaneous B-cell lymphoma

OBJECTIVE

Radiotherapy (RT) has an established role in the curative treatment of indolent primary cutaneous B‑cell lymphoma (PCBCL). With the role of low-dose regimens such as 2 × 2 Gy being uncertain, we compared conventional-dose RT to a low-dose approach and investigated outcome and toxicities.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 26 patients with 44 cutaneous lesions treated at our institution between 2007 and 2017, comprising 22 marginal zone lymphoma (PCMZL) lesions and 22 follicle center lymphoma (PCFCL) lesions. Seven lesions (16%) were treated with low-dose RT (LDRT) (4 Gy) and 37 (84%) with conventional-dose RT (≥24 Gy, median 40 Gy). Median follow-up duration was 76 months.

RESULTS

The overall response rate (ORR) was 91% (complete response rate [CRR]: 75%). The 5‑year local control rate (LCR) was 88% and the 10-year LCR was 84%. The response rates were significantly higher following conventional-dose RT (ORR: 92% vs. 86%; CRR: 84% vs. 29%; P = 0.007). In terms of radiation dose, the rate of infield relapses (14% vs. 11%, P = 0.4) and the 5‑year LCR (86% vs. 90%, P = 0.4) were comparable in the LDRT and conventional-dose RT groups. During RT courses, about two-thirds of patients experienced mild toxicities, with grade I and II acute toxicity rates of 61% and 9%, respectively, with lower incidences of grade I (14% vs. 70%) and grade II (0% vs. 8%, P = 0.004) toxicities following LDRT.

CONCLUSION

This long-term analysis confirms the excellent outcome of RT in the management of PCBCL. The LDRT concept with 4 Gy was associated with a comparable LCR and reduced rates of acute toxicity. However, the response rates were significantly lower for this group and LDRT may therefore not be recommended as standard treatment.

Radiotherapy of extranodal low-grade follicular and marginal zone lymphomas: long-term follow-up of 159 patients

OBJECTIVE

To evaluate clinical, histopathologic, and radiation (RT) dose parameters in patients with extranodal low-grade (ENLG) non-Hodgkin lymphoma (NHL) and their possible impact on local control (LC) and survival.

MATERIALS AND METHODS

The medical records of 159 patients with 181 histologically confirmed ENLG-NHL lesions treated at our institution were reviewed retrospectively.

RESULTS

The predominant histological subtype (73%) was marginal zone lymphoma (MZL). Common lesion sites were the gastrointestinal tract (GIT; 33%), skin (26%), and orbit (21%). The majority of patients (88%) presented with stage I/II disease. Thirty-three (20%) lesions were treated with reduced-dose RT (≤30.6 Gy) and 148 lesions (80%) with conventional-dose RT (>30.6 Gy), with an overall median dose of 39.6 Gy (range 4-63). The median follow-up period was 72 months. The 10-year local control (LC), Progression-free survival (PFS), and overall survival (OS) rates were 96, 65, and 82%, respectively. Higher overall response rate (ORR; 98% vs. 94%, p = 0.001) and complete response rate (CRR; 95% vs. 73%, p = 0.001) were observed in patients treated with conventional-dose regimens than in those treated with reduced-dose regimens. Ten-year PFS (p = 0.90) and OS (p = 0.40) was similar between the two dose groups. RT was well tolerated in both dose groups, with no grade 4/5 toxicities. In the multivariate analysis, RT dose and timing (upfront or salvage) were related to LC, whereas age, histology, and complete response (CR) to RT were associated with PFS. Patient age and radiation field size impacted OS.

CONCLUSION

RT is an effective and curative local treatment for early-stage FL and MZL at conventional and reduced radiation doses. Conventional-doses seems to be associated with local response improvement, without significant differences in PFS rates. Age, histology, and response to RT may influence the PFS.

Therapy of nodal Follicular Lymphoma (WHO grade 1/2) in clinical stage I/II using response adapted Involved Site Radiotherapy in combination with Obinutuzumab (Gazyvaro) - GAZAI Trial (GAZyvaro and response adapted Involved-site Radiotherapy): a study protocol for a single-arm, non-randomized, open, national, multi-center phase II trial

BACKGROUND

Large field irradiation had been standard for early-stage follicular lymphoma (FL) for a long time. Although involved field radiotherapy (IF-RT) was recently favored because of the toxicity of large field irradiation, smaller irradiation fields have been accompanied with an increased risk of out-of-field recurrence. The MIR (MabThera® and Involved field Radiation) trial has shown that the combination of IF-RT at a dose of 30-40 Gy with the anti-CD20 antibody rituximab has led to similar efficacy compared with large field irradiation but with markedly reduced side effects. Immune modulating radiation therapy alone using low-dose radiotherapy (LDRT) of 2 × 2 Gy has been shown to be effective in FL. The GAZAI (GAZyvaro and response Adapted Involved-site Radiotherapy) trial aims to prove the efficacy of LDRT in combination with a novel anti-CD20 therapy.

METHODS/DESIGN

The GAZAI trial is a non-randomized, open, non-controlled, German, multi-center phase II trial that includes patients with early-stage (I and II) nodular FL (grades 1 and 2) confirmed by central histological review. A maximum of 93 patients will be included in the trial. Patients will receive a combined approach of immunotherapy with the fully humanized anti-CD20 antibody obinutuzumab (Gazyvaro®) and involved site radiotherapy (IS-RT) with 2 × 2 Gy. The primary endpoint of the trial is the rate of metabolic complete response (CR), based on fludeoxyglucose positron emission tomography/computed tomography, after obinutuzumab and 2 × 2 Gy IS-RT in week 18. Secondary endpoints are morphologic CR rate in weeks 7 and 18 and month 6, progression-free survival, toxicity, recurrence patterns, overall survival, and quality of life. Additionally, minimal residual disease response is assessed. The risk for a potentially higher recurrence rate after LDRT will be minimized by additional salvage radiation up to the "full dose" of 40 Gy for patients who have less than a metabolic CR and morphologic partial response/CR, which will be evaluated in week 18, offering a response-adapted approach.

DISCUSSION

The goal of this trial is a further reduction of the radiation dose in patients with nodal early-stage FL showing a good response to a combination of LDRT and anti-CD20 immunotherapy and a comparison with the currently published MIR trial.

TRIAL REGISTRATION

EudraCT number: 2016-002059-89. ClinicalTrials.gov identifier: NCT03341520 .

Emerging Treatment Strategies for Primary Breast Extranodal Marginal Zone Lymphoma of Mucosa-associated Lymphoid Tissue

INTRODUCTION

We report our experience in treating patients with primary breast extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) to better elucidate the natural history and optimal treatment approach for these patients.

PATIENTS AND METHODS

Patients with localized primary breast MALT lymphoma treated between 1995 and 2016 were included. Disease-related endpoints including progression-free survival (PFS) were analyzed.

RESULTS

Eleven patients met inclusion criteria; all patients were women with a median age of 62 years (range, 42-75 years). Most (73%) patients presented with stage I disease, and most (73%) patients were treated initially treated with radiation therapy (RT). Local control following RT was 100%; all patients with progression following RT experienced distant relapse. Additionally, none of the 3 patients treated with ultra-low-dose RT (4 Gy) experienced subsequent progression (local or distant). Six (55%) patients progressed after initial therapy, of whom 5 received initial RT; the 5-year PFS after initial therapy was 60%. Salvage systemic therapy was utilized in all patients with progression, with 5 of 6 patients receiving single-agent rituximab. Of the patients treated with salvage therapy, only 1 experienced second relapse, with a 5-year PFS of 100% after salvage systemic therapy. With a median follow-up of 8 years, there were no deaths in the cohort.

CONCLUSIONS

Patients with primary breast MALT lymphoma achieve excellent outcomes. Initial RT affords local control, and although subsequent distant progression is common, salvage rituximab yields high rates of PFS.