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

Success of Ultra-low Dose Radiation Therapy for Primary Cutaneous B-cell Lymphoma

OBJECTIVES

Primary cutaneous B-cell lymphoma (PCBCL) is a relatively rare disease, associated with 5-year overall survival of nearly 95% when treated with external beam radiation therapy (EBRT) alone. However, standard EBRT doses yield acute skin toxicity in more than 70% of patients and grade 3 to 4 acute skin toxicity in nearly 10% of patients. Consequently, the PCBCL treatment paradigm is shifting towards lower EBRT doses. This study evaluates our early experience with ultra-low dose EBRT (total dose of 4 Gy in 2 fractions) for PCBCL.

METHODS

Four biopsy-confirmed PCBCL lesions (1 anterior thigh and 3 chest) in 2 male patients were treated with 2 Gy×2 fraction EBRT using electrons through a clinical setup. The anterior thigh lesion was treated using a clamshell to protect the scrotum from scatter dose. Treatment was achieved using 9 MeV electrons to the 85% isodose line using no bolus, with follow-up every 4 months and potential retreatment if no visible response at 8 to 9 months.

RESULTS

All lesions demonstrated a response to EBRT by 4 months, visibly manifesting as flattening with changes in pigmentation. At the last follow-up (20, 20, 16.5, and 4 mo, respectively), all lesions had flattened with no evidence of local recurrence and no skin toxicity.

CONCLUSIONS

Treatment of PCBCL with ultra-low dose EBRT to 4 Gy total dose in 2 fractions provides durable local control with zero skin toxicity. These results are encouraging for both the success of treatment and the potential to use similarly low doses for retreatment should patients exhibit local recurrence.

Systemic Abscopal Effect of Low-dose Radiotherapy (2 Gy ×2) against Palatine Tonsil Follicular Lymphoma

A 52-year-old man presented with palatine tonsillar swelling caused by follicular lymphoma. His tumor burden was low, but exacerbation of snoring and dysphagia was observed. Considering the first wave of coronavirus disease 2019 (COVID-19) pandemic, he received palliative 4-Gy irradiation to the tonsils in 2 fractions, which induced partial regression of tonsillar swellings and eradication of the circulating lymphoma cells. We suggest that low-dose radiotherapy triggered an abscopal effect of lymphoma, which allowed the patient time to receive COVID-19 vaccination before starting immunosuppressive chemo-immunotherapy.

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.

Efficacy of low-dose radiotherapy (2 Gy × 2) in the treatment of marginal zone and mucosa-associated lymphoid tissue lymphomas

OBJECTIVES

To investigate the efficacy of a schedule of low-dose radiotherapy (LDRT) with 4 Gy (2 Gy x 2) in a cohort of unselected MALT or MZL patients.

METHODS

We retrospectively collected all patients receiving LDRT, either for cure or palliation, for a stage I-IV histologically proven MALT or MZL between 2016 and 2020. Response to LDRT was evaluated with the Lugano criteria. Local control (LC), distant relapse-free survival (DRFS), progression-free survival (PFS) and overall survival (OS) were stratified for treatment intent (curative vs palliative) and estimated by the Kaplan-Meier product-limit.

RESULTS

Among 45 consecutively enrolled patients with a median age of 68 years (range 22-86), 26 (58%) were female. Thirty-one patients (69%) with a stage I-II disease received LDRT as first line therapy and with a curative intent. Overall response rate was 93%, with no significant difference among curative and palliative intent. With a median follow-up of 18 months, LC, DRFS, PFS and OS at 2 years were 93, 92, 76 and 91%, respectively, in the overall population. Patients receiving curative LDRT had a better PFS at 2 years (85% vs 54%, p < 0.01) compared to patients receiving palliative treatment. LDRT was well tolerated in all patients, without any significant acute or chronic side-effect.

CONCLUSIONS

LDRT is effective and well tolerated in patients affected with MALT or nodal MZL, achieving high response rates and durable remission at 2 years.

ADVANCES IN KNOWLEDGE

This study shows the efficacy of LDRT in the treatment of MALT and MZL.

Ultra-low-dose (boom-boom) radiotherapy for management of recurrent ocular post-transplant lymphoproliferative disorder

Purpose

To report a case of recurrent iris post-transplant lymphoproliferative disorder (PTLD) treated with ultra-low-dose (boom-boom) radiotherapy (RT).

Observations

A 12-year-old Caucasian male with a history of bilateral, recurrent iris PTLD of the extranodal marginal zone lymphoma (MALT) type presented with persistent bilateral anterior chamber cellular infiltration, which was incompletely controlled on topical corticosteroids, and with elevated intraocular pressure (IOP) in the right eye secondary to steroid response. The patient was diagnosed with PTLD recurrence and was successfully treated with ultra-low-dose RT to both eyes in 2 fractions of 2 Gy. At 15 month follow-up the patient maintained complete disease control with normal IOP off all topical ophthalmic medications.

Conclusions and Importance

Ultra-low-dose RT for ocular PTLD of the MALT subtype represents a novel therapeutic approach that may provide a durable treatment response and could be considered as either primary or adjuvant therapy for this rare condition.

How to manage early-stage follicular lymphoma

INTRODUCTION

Early-stage follicular lymphoma (FL) is characterized by good prognosis and can be cured with involved-field radiotherapy (IF-RT) in most cases. PET scan is a milestone of diagnostic work-up, with the aim of identifying a truly localized disease; however, staging in most of the studies was without PET.

AREAS COVERED

We have searched in MEDLINE (inclusive dates 1994-2020) data about localized FL management. While high-quality evidence is lacking, current guidelines recommend IFRT or involved-site RT as first-line treatment in limited stages FL. Since a significant proportion of disease relapse occurred in non-irradiated areas, it has been hypothesized that occult disease could be present at diagnosis and could persist after RT, contributing to relapse. Available treatment options include watch-and-wait, chemotherapy, RT plus chemo- or chemo-immunotherapy, and RT combined with rituximab (R).

EXPERT OPINION

RT combined with chemotherapy could increase PFS, but a clear OS benefit is lacking and toxic effects could be unacceptable. A promising strategy is represented by R combined with IF-RT, with low relapse rate outside the radiation fields and without the toxicity reported with chemotherapy. The study of prognostic factors in PET-staged patients, the reduction of RT fields and doses, and a response-adapted strategy represent new perspectives to investigate.

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.