A high and sustained response rate in refractory or relapsing low-grade lymphoma masses after low-dose radiation: analysis of predictive parameters of response to treatment

Two-year Outcomes of Ultra-low-dose Radiotherapy in the Treatment of Ocular Adnexal B-cell Lymphomas

BACKGROUND

This study focuses on the efficacy and 2-year outcomes of ultra-low-dose radiotherapy (RT) in treating primary and secondary ocular adnexal lymphoma (OAL).

METHODS

A retrospective analysis was conducted on patients with OAL between 2017 and 2022, treated with 4 Gy of RT. The primary and secondary outcomes assessed were response rate, progression-free survival, and lymphoma-related death.

RESULTS

Twenty-one patients with primary and secondary OAL of diverse, presentations, subtypes, and stages were included. The orbital tumors had an average size of 17 × 16 × 16 mm. Of the 14 primary OAL cases, 3 (14%) had T1N0M0 disease, 8 (38%) T2N0M0, and 3 (14%) T3N0M0 (AJCC 8th edition staging); of the 7 secondary OALs, 4 (19%) were stage IE, 2 (10%) stage IIE, and 1 (5%) stage IIIE (Ann Arbor staging). Ultra-low-dose RT yielded a 95% complete response rate and 100% progression-free survival rates, both locally and systemically at 2 years. Mild dry eyes were reported in 14% of patients as a late treatment toxicity.

CONCLUSIONS

Ultra-low-dose RT emerges as an effective and well-tolerated treatment approach for OAL. Our findings support the use of 4 Gy, showcasing high complete response rates (95%) and durable disease control without significant local relapses over an average follow up of 27 months. Our results align with earlier investigations, validating the curative potential of ultra-low-dose RT and reinforcing the concept of achieving favorable outcomes with minimal intervention. This approach may potentially alleviate the burden of long-term ocular side effects associated with higher radiation doses, enhancing the overall quality of life for OAL patients.

Orbital follicular lymphoma with large cell component treated with low-dose radiotherapy: A case report and review of literature

A 77-year-old woman was referred for a one-eyed palpebral edema associated with diplopia. An orbit magnetic resonance imaging showed an orbital mass in the superior medial portion of the internal right orbit without any intraorbital involvement. Biopsies demonstrated a nodular lymphoma with mixed follicular grade 1-2 (60%) and large cell components. The tumor mass was treated with a low-dose radiation therapy (4Gy in 2 fractions) with a complete disappearance of diplopia within one week. At 2-year follow-up, patient was in complete remission. To the best of our knowledge, this is the first case of mixed component follicular and large components orbital lymphoma managed by first-intent low-dose radiation therapy.

Outcome-based multiobjective optimization of lymphoma radiation therapy plans

At its core, radiation therapy (RT) requires balancing therapeutic effects against risk of adverse events in cancer survivors. The radiation oncologist weighs numerous disease and patient-level factors when considering the expected risk-benefit ratio of combined treatment modalities. As part of this, RT plan optimization software is used to find a clinically acceptable RT plan delivering a prescribed dose to the target volume while respecting pre-defined radiation dose-volume constraints for selected organs at risk. The obvious limitation to the current approach is that it is virtually impossible to ensure the selected treatment plan could not be bettered by an alternative plan providing improved disease control and/or reduced risk of adverse events in this individual. Outcome-based optimization refers to a strategy where all planning objectives are defined by modeled estimates of a specific outcome's probability. Noting that various adverse events and disease control are generally incommensurable, leads to the concept of a Pareto-optimal plan: a plan where no single objective can be improved without degrading one or more of the remaining objectives. Further benefits of outcome-based multiobjective optimization are that quantitative estimates of risks and benefit are obtained as are the effects of choosing a different trade-off between competing objectives. Furthermore, patient-level risk factors and combined treatment modalities may be integrated directly into plan optimization. Here, we present this approach in the clinical setting of multimodality therapy for malignant lymphoma, a malignancy with marked heterogeneity in biology, target localization, and patient characteristics. We discuss future research priorities including the potential of artificial intelligence.

Follicular lymphoma and macrophages: impact of approved and novel therapies

The survival and proliferation of follicular lymphoma (FL) cells are strongly dependent on macrophages, because their presence is necessary for the propagation of FL cells in vitro. To this regard, as also shown for the majority of solid tumors, a high tissue content of tumor-associated macrophages (TAMs), particularly if showing a protumoral phenotype (also called M2), is strongly associated with a poor outcome among patients with FL treated with chemotherapy. The introduction of rituximab, an anti-CD20 antibody that can be used by TAMs to facilitate antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis, has challenged this paradigm. In the rituximab era, clinical studies have yielded conflicting results in FL, showing variable outcomes based on the type of regimen used. This highlighted, for the first time, that the impact of TAMs on the prognosis of patients with FL may depend on the administered treatment, emphasizing the need to better understand how currently available therapies affect macrophage function in FL. We summarize the impact of approved and novel therapies for FL, including radiation therapy, chemotherapy, anti-CD20 monoclonal antibodies, lenalidomide, and targeted agents, on the biology of TAMs and describe their effects on macrophage phagocytosis, polarization, and function. Although novel agents targeting the CD47/SIRPα axis are being developed and show promising activity in FL, a deeper understanding of macrophage biology and their complex pathways will help to develop novel and safer therapeutic strategies for patients with this type of lymphoma.

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.

Low grade, indolent lymphomas of the head and neck: Comparative toxicity of standard versus very low dose radiation therapy

National Comprehensive Cancer Network guidelines recommend radiation therapy (RT) for localized indolent non-Hodgkin lymphomas (iNHL). Many referring physicians avoid RT to the head and neck (HN) due to fears of toxicity. Very low-dose radiation (4 Gy) for select patients produces sustained local control and recently gained popularity. We compared early and late toxicities of standard 24-30 Gy to 4 Gy in patients with HN iNHL. We retrospectively analyzed 266 consecutive patients with HN iNHL receiving RT from 1994 to 2017. Patient characteristics, outcomes, and toxicities were collected from medical records. Early (≤2 months post-RT) and late (>2 months post-RT) toxicities were graded per Common Terminology Criteria for Adverse Events version 4. Grades 1-2 were defined as "low-grade" and 3-4 "high-grade." Toxicity incidence was compared between 4 and >4 Gy, grouped by treated site (orbit, nonorbital head, neck, skin) and early versus late. Median follow-up was 23 months (2-145) and 68 months (2-256) for 4Gy and >4 Gy cohorts, respectively. Median dose for the >4 Gy cohort was 30 Gy (10.5-54 Gy). Early and late toxicity incidences were lower in the 4 Gy cohort compared to >4 Gy across all RT-sites: early toxicity, orbit, 42% versus 96%; nonorbital head, 24% versus 96%; neck, 22% versus 94%; skin, 31% versus 87%; late toxicity, orbit, 20% versus 71%; nonorbital head, 6% versus 66%; neck, 6% versus 57%; skin, 0% versus 46% (4 Gy vs. >4 Gy, respectively). Toxicities among both cohorts were largely low-grade. High-grade early and late toxicities did not occur in the 4 Gy cohort. There was 1 high-grade early toxicity (Grade 3 dry mouth) and 17 high-grade late toxicities (Grade 3 cataracts) in the >4 Gy cohort. RT to HN for iNHL is associated with minimal short- and long-term toxicity and excellent local control among 4 Gy and >4 Gy treatments. In this setting, "toxicity" concerns should not deter oncologists from potentially curative RT. In select patients where toxicity remains a concern, very low dose 4 Gy could be considered.

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.

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.

Radiotherapy in mantle cell lymphoma: A literature review

Mantle cell lymphoma (MCL) is a B-cell malignancy, comprising between 3% and 10% of all adult-onset non-Hodgkin lymphomas. MCL is considered incurable with current treatment modalities and most patients require multiple lines of treatment during their lifetime. MCL is very sensitive to radiotherapy (RT), even when delivered in low doses. In limited-stage MCL, RT can enable the de-escalation of systemic therapy. RT monotherapy is a valid option for frail patients. In advanced-stage disease, RT is very potent mode of palliation, even in heavily pretreated and chemo-resistant patients. Furthermore, it can provide a respite during which systemic treatment is unnecessary. In general, RT has a favorable toxicity profile and can be repeated as necessary for local relapse or distant disease. This effective, safe, and relatively inexpensive modality of therapy has been underutilized for patients with MCL. In this review, we will outline the use of RT for limited and advanced-stage disease and its potential application in combination with novel drugs.

Hematologic Malignancies

Radiation therapy plays a critical role in the management of a wide range of hematologic malignancies. The optimal radiation dose and target volume, and safe and effective ways of integrating radiation with systemic agents, vary depending on the histologic subtypes, stage at presentation, patient performance status, response to systemic therapy if given, treatment intent, and patient preferences. Limiting doses to surrounding organs without sacrificing disease control is of paramount importance. Reducing radiation doses and treatment volume in selected cases, and the use of advanced radiotherapy technology, can improve the therapeutic ratio of patients receiving radiation therapy for hematologic malignancies.

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 .

Successful treatment of refractory chylous ascites due to follicular lymphoma with very low-dose radiotherapy

Chylous ascites is an extremely rare complication of lymphoma. Here, we discuss the case of a patient presenting with refractory chylous ascites due to a massive retroperitoneal follicular lymphoma, staged as IVB. The patient was unresponsive to chemoimmunotherapy, which prompted us to consider alternative treatment strategies. Low-dose radiotherapy was initiated and resulted in a marked decrease of the lymphadenopathy and complete regression of the peritoneal fluid. Low-dose radiotherapy represents a well-tolerated, highly effective treatment and should remain an important modality in cases of follicular lymphoma-associated chylous ascites.

Radiotherapy of relapse-refractory follicular lymphoma

PURPOSE

To assess the efficacy of treatment and outcomes of patients with relapsed or refractory follicular lymphoma treated with external beam irradiation.

PATIENTS AND METHODS

Fifteen patients who received external beam radiotherapy for relapsed or refractory follicular lymphoma were studied. The median age was 68.3 years (range: 37.9-87.08 years) with four men and 11 women. Seven patients had early stage (I or II); eight advanced stage (III or IV). Median FLIPI score was 2. Two patients had high tumour bulk disease. Six patients had extranodal invasion, with five patients having bone marrow invasion.

RESULTS

The median time of follow-up after relapse or first-line treatment in case of refractory disease was 61.9 months (range: 9.1-119.7 months). Complete response after external beam radiotherapy was seen in 11 cases (73%) and partial response in two (13%), with a median dose of 30Gy (range: 2-40Gy) and median number of fractions of 15 (range: 2-20). Eight patients (53%) relapsed after external beam radiation therapy in a median of 20.2 months, mostly out of irradiated volumes. Most patients (66%) had a disease control after one or two courses of external beam radiation therapy. At last follow-up, 86% of patients were in remission including those with salvage chemotherapy. The toxicity profile was favourable with toxicity higher than grade 1. In univariate analysis, a Follicular Lymphoma International Prognostic Index (FLIPI) score above 2 was the only predicting factor for non-control disease.

CONCLUSION

For relapsed and refractory follicular lymphoma, external beam radiotherapy should be considered as an effective modality when integrated in a multimodality approach. Randomised studies are warranted to validate this strategy.

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

PURPOSE

Retrospective study of effectiveness, toxicity, and relapse patterns after low-dose radiotherapy (LDRT) in patients with low-grade lymphomas.

METHODS

47 patients (median age 64 years) with 50 lesions were treated with LDRT (2 × 2 Gy). In 60%, LDRT was the primary and curative treatment, in 40% offered as second-line therapy in recurrent disease. Histology included follicular (57%) and marginal zone lymphomas (43%). Patients were followed-up regularly clinically (skin) and with CT or MRI scans.

RESULTS

Median follow-up was 21 months. 84% of the lesions were extranodal disease (32% orbit, 14% salivary glands, 30% skin, and 8% others). Most lesions were ≤5 cm (90%) with a singular affection (74%). 26% of the patients received rituximab simultaneously. Overall response rate (ORR) was 90% (all lesions), 93.3% (primary treatment), and 85% (recurrence treatment); p = 0.341. 2‑year Local progression-free survival (LPFS) for all, curative, and palliative patients was 91.1%, 96.7%, and 83.8%, respectively; p = 0.522. Five relapses were detected: three infield only, and were therefore treated with LDRT or subsequent local RT of 30 Gy. Two patients showed an in- and outfield progression and were consequently treated with chemotherapy. Predictive factors for higher LPFS were tumor size ≤5 cm (p = 0.003), ≤2 previous treatments (p = 0.027), no skin involvement (p = 0.05), singular affection (p = 0.075), and simultaneous rituximab application (p = 0.148). LDRT was tolerated well, without detectable acute or long-term side effects.

CONCLUSION

Primary LDRT is an effective treatment with high ORR and long-lasting remissions in a subset of patients with low-grade lymphoma, and may therefore be a curative treatment option for patients with low tumor burden. LDRT with the CD20 antibody obinutuzumab will soon be tested in a prospective multicenter trial.

Ultra-low-dose radiotherapy for definitive management of ocular adnexal B-cell lymphoma

BACKGROUND

The purpose of this study was to report the response to and toxicity of ultra-low-dose radiotherapy (RT) for B-cell ocular adnexal lymphoma (OAL).

METHODS

We conducted a retrospective review of patients with indolent B-cell and mantle cell OAL treated with 4 Gy to the orbit(s) in two 2-Gy fractions. Disease response was assessed clinically and/or radiographically at 2 to 4-month intervals after RT. Data collected included rates of overall response, complete response (CR), partial response (PR), and treatment-related toxic effects.

RESULTS

Twenty-two patients (median age, 65 years) had the following histologic subtypes: mucosa-associated lymphoid tissue (MALT; 14 patients; 64%); follicular lymphoma (5 patients; 23%); mantle cell lymphoma (MCL; 2 patients; 9%); and unclassifiable (1 patient, 4%). The overall response rate was 100%; 19 patients (86%) had a CR and 3 patients (14%) had a PR. The only acute toxic effect was grade 1 dry eye syndrome in 1 patient.

CONCLUSION

Ultra-low-dose RT in patients with OAL is associated with high response rates and minimal toxic effects, and is much shorter in duration and cost. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1095-1100, 2017.

Limited Stage Follicular Lymphoma: Current Role of Radiation Therapy

Radiation therapy (RT) alone has been considered for a long time as the standard therapeutic option for limited stage FL, due to its high efficacy in terms of local disease control with a quite significant proportion of “cured” patients (without further relapses at 10–15 years). Multiple therapeutic choices are currently accepted for the management of early stage FL at diagnosis, and better staging procedures as well as better systemic therapy partially modified the role of RT in this setting. RT has also changed in terms of prescribed dose as well as treatment volumes. In this review, we present and discuss the current role of RT for limited stage FL in light of the historical data and the modern RT concepts along with the possible combination with systemic therapy.

Low dose palliative radiotherapy for refractory aggressive lymphoma

AIM

To determine the efficacy of low-dose palliative radiotherapy in patients with refractory aggressive lymphoma.

BACKGROUND

There are few reports on the administration of palliative radiotherapy to patients with aggressive lymphoma.

MATERIALS AND METHODS

The present study included 11 patients with 30 sites of aggressive lymphoma (diffuse large cell lymphoma, n = 7; mantle cell lymphoma, n = 2; follicular large cell lymphoma, n = 1; and peripheral T cell lymphoma, n = 1). The patients received local palliative radiotherapy after receiving a median of 4 chemotherapy regimens. The radiotherapy doses administered to the 30 sites were as follows: 8 Gy, single fraction (n = 27); 6 Gy, single fraction (n = 1); 4 Gy, single fraction (n = 1); and 4 Gy, 2 fractions (n = 1).

RESULTS

The complete response rate was 45% (5/11); the partial response rate was 36% (4/11). Toxicity occurred at one irradiated site (the mandibular), which showed temporal acute gingivitis; however, medication was not required. Retreatment was required for 3 sites on the head (parotid, face and mandible) due to persistent discomfort. None of the other sites (27/30) required retreatment. A patient with refractory DLBCL underwent radiotherapy (4 Gy, single fraction) for hepatic hilar lymph node involvement but did not recover from jaundice and died of DLBCL.

CONCLUSIONS

Eight Gray single fraction radiotherapy was one of meaningful options for the treatment of refractory aggressive lymphoma in terms of its efficacy and the incidence of adverse events. The use of 8 Gy single fraction radiotherapy is therefore recommended for achieving local control in patients with refractory aggressive lymphoma.

An uncommon cause of dysuria solved by "boom-boom" radiotherapy

BACKGROUND

Chronic lymphocytic leukaemia is a common disease affecting the hematopoietic organs. The disease remains classically indolent for years preceding a blast crisis. However, the disease can affect all parts of the body. We report here an unusual localization.

CASE PRESENTATION

A 72-year-old man was followed for 2 years for an indolent chronic lymphocytic leukaemia while he presented a rapidly progressive dysuria. Prostate biopsies were performed concluding to a prostate involvement by the chronic lymphocytic leukaemia. In the absence of progression according to RAI staging system and Binet's classification, he was treated with local low-dose radiotherapy, twice 2 Gy, allowing for a rapid resolution of the symptoms. No systemic treatment was introduced, and 1 year after the completion of his treatment, he is still under watchful waiting strategy for his chronic lymphocytic leukaemia.

CONCLUSION

Low-dose radiotherapy is an underused effective strategy in indolent lymphoma. In this case, urinary symptoms from a prostate involvement were relieved non-invasively at low cost.

Allogeneic hematopoietic cell transplantation as curative therapy for non-transformed follicular lymphomas

Allogeneic hematopoietic cell transplantation (HCT) offers the chance of cure for patients with non-transformed follicular lymphoma (FL), but is associated with the risk of non-relapse mortality (NRM). The aim of this study was to identify subgroups of FL patients who benefit from HCT. The European Society for Blood and Marrow Transplantation (EBMT) Minimum-Essential-A Data of 146 consecutive patients who received HCT for FL between 1998 and 2008 were extracted from the database of the German Registry 'DRST'. Diagnosis of FL was verified by contact with the reference pathologists. Estimated 1-, 2- and 5-year overall survivals (OS) were 67%, 60% and 53%, respectively. Day 100 NRM was 15%. Thirteen out of 33 patients (40%) with treatment-refractory disease (RD) at the time of transplantation survived long term. Univariate statistical analysis suggested limited chronic GvHD, donor age ⩽42 years and TBI-based conditioning in treatment refractory patients to correlate with favorable OS. Independent prognostic factors for OS were treatment-sensitive disease and limited chronic GvHD for the whole cohort, and additionally TBI-based conditioning for the treatment refractory subgroup. In contrast, patient age ⩾55 years had no impact on outcome. Thus, HCT for FL is associated with acceptable NRM, and offers a substantial chance of cure for patients with RD or advanced age. Donors ⩽42 years should be preferred if available.

Tumor-Absorbed Dose Predicts Progression-Free Survival Following (131)I-Tositumomab Radioimmunotherapy

The study aimed at identifying patient-specific dosimetric and nondosimetric factors predicting outcome of non-Hodgkin lymphoma patients after (131)I-tositumomab radioimmunotherapy for potential use in treatment planning.

METHODS

Tumor-absorbed dose measures were estimated for 130 tumors in 39 relapsed or refractory non-Hodgkin lymphoma patients by coupling SPECT/CT imaging with the Dose Planning Method (DPM) Monte Carlo code. Equivalent biologic effect was calculated to assess the biologic effects of nonuniform absorbed dose including the effects of the unlabeled antibody. Evaluated nondosimetric covariates included histology, presence of bulky disease, and prior treatment history. Tumor level outcome was based on volume shrinkage assessed on follow-up CT. Patient level outcome measures were overall response (OR), complete response (CR), and progression-free survival (PFS), determined from clinical assessments that included PET/CT.

RESULTS

The estimated mean tumor-absorbed dose had a median value of 275 cGy (range, 94-711 cGy). A high correlation was observed between tracer-predicted and therapy-delivered mean tumor-absorbed doses (P < 0.001; r = 0.85). In univariate tumor-level analysis, tumor shrinkage correlated significantly with almost all of the evaluated dosimetric factors, including equivalent biologic effect. Regression analysis showed that OR, CR, and PFS were associated with the dosimetric factors and equivalent biologic effect. Both mean tumor-absorbed dose (P = 0.025) and equivalent biologic effect (P = 0.035) were significant predictors of PFS whereas none of the nondosimetric covariates were found to be statistically significant factors affecting PFS. The most important finding of the study was that in Kaplan-Meier curves stratified by mean dose, longer PFS was observed in patients receiving mean tumor-absorbed doses greater than 200 cGy than in those receiving 200 cGy or less (median PFS, 13.6 vs. 1.9 mo for the 2 dose groups; log-rank P < 0.0001).

CONCLUSION

A higher mean tumor-absorbed dose was significantly predictive of improved PFS after (131)I-tositumomab radioimmunotherapy. Hence tumor-absorbed dose, which can be estimated before therapy, can potentially be used to design radioimmunotherapy protocols to improve efficacy.

Low-dose radiation treatment in pulmonary mucosa-associated lymphoid tissue lymphoma: a plausible approach? A single-institution experience in 10 patients

PURPOSE

To propose an alternative approach for treatment of pulmonary marginal zone lymphoma, using a very small radiation dose (2 × 2 Gy) delivered exclusively to tumor sites.

METHODS AND MATERIALS

Patients had localized pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma according to the World Health Organization classification. The 6-MV radiation treatments were delivered using tumor-limited fields, except in cases of diffuse bilateral involvement. Two daily fractions of 2 Gy were delivered to tumor-limited fields using a 6-MV linear accelerator.

RESULTS

Ten patients with pulmonary MALT lymphoma entered the study. All but 1 had localized tumor masses. The median follow-up was 56 months (range, 2-103 months). Complete remission or an unconfirmed complete remission was obtained in 60% of patients within the first 2 months, and two additional partial responses were converted into a long-term unconfirmed complete remission. All patients are well and alive, no local progression was observed, and the 5-year progression-free survival rate was 87.5% (95% confidence interval 49%-97%).

CONCLUSIONS

Our results suggest that extremely low radiation doses delivered exclusively to tumor sites might be a treatment option in pulmonary MALT lymphoma.

Postconditioning hormesis put in perspective: an overview of experimental and clinical studies

A beneficial effect of applying mild stress to cells or organisms, that were initially exposed to a high dose of stress, has been referred to as 'postconditioning hormesis'. The initial high dose of stress activates intrinsic self-recovery mechanisms. Modulation of these endogenous adaptation strategies by administration of a subsequent low dose of stress can confer effects that are beneficial to the biological system. Owing to its potentially therapeutic applications, postconditioning hormesis is subject to research in various scientific disciplines. This paper presents an overview of the dynamics of postconditioning hormesis and illustrates this phenomenon with a number of examples in experimental and clinical research.

Low-dose palliative radiotherapy for cutaneous B- and T-cell lymphomas

PURPOSE

To determine the efficacy of low-dose palliative radiotherapy for both low-grade malignant cutaneous B-cell lymphomas (CBCLs) and cutaneous T-cell lymphomas (mycosis fungoides).

METHODS AND MATERIALS

A total of 18 patients with low-grade CBCL (10 primary cutaneous marginal zone B-cell and 8 primary cutaneous follicle center lymphomas) with 44 symptomatic plaques and tumors underwent low-dose (4 Gy in two fractions) local radiotherapy. A total of 31 patients with mycosis fungoides were treated at 82 symptomatic sites, initially with 4 Gy and later with 8 Gy in two fractions.

RESULTS

The complete response rate for CBCL lesions was 72%. Of the 44 B-cell lymphoma lesions, 13 were re-treated to the same site after a median of 6.3 months because of persistent (n = 8) or recurrent (n = 5) symptomatic disease. Of the mycosis fungoides patients treated with 4 Gy in two fractions (17 lesions), 70% failed to respond. Increasing the dose to 8 Gy in two fractions yielded a complete response rate of 92% (60 of 65 lesions). The patients in whom low-dose radiotherapy failed were retreated with 20 Gy in eight fractions.

CONCLUSION

Our results have demonstrated that low-dose involved-field radiotherapy induces a high response rate in both CBCL and cutaneous T-cell lymphoma lesions without any toxicity. Therefore, this treatment is now our standard palliative treatment. At progression, it is safe and feasible to apply greater radiation doses.

Low-dose radiation and its clinical implications: diabetes

Induction of hormesis and adaptive response by low-dose radiation (LDR) has been extensively indicated. Adaptive response induced by LDR was not only resistant to damage caused by a subsequently high-dose radiation, but also cross-resistant to other non-radiation challenges, such as chemicals. Mechanisms by which LDR induces the preventive effect on radiation- or chemical-induced tissue damage include induced or up-regulated expression of protective proteins, such as heat shock proteins and antioxidants. Since oxidative damage to tissues is a major pathogenesis of many human diseases including diabetes, this review will summarize the available data with an emphasis of the preventive effect of LDR on the development of diabetes and the therapeutic effect of LDR on diabetic cardiovascular complications. The available data indicated that pre-exposure of mice to LDR reduced the incidence of alloxan-induced diabetes, and also delayed the onset of hyperglycaemia in diabetes-prone non-obese diabetic mice. Experiments with animals indicated the effectively therapeutic effect of low-intensity or power laser (LIL or LPL) radiation on skin wound healing, which has stimulated clinical use of LIL to cure skin ulcer in diabetic patients. Mechanisms by which LDR prevents diabetes, though are unclear now, may include the induction of pancreatic antioxidants to prevent beta cell from oxidative damage and immunomodulation to preserve pancreatic function. For LIL therapeutic effect on diabetic wound healing, mechanisms may include its antioxidant action, immunomodulation, cell proliferation stimulation as well as improvement of systemic and wound-regional microcirculation. Therefore, although only a few studies indicating LDR prevention of the development of diabetes, many studies have demonstrated LDR, specifically LIL, therapeutic effectiveness of diabetic wound healing. These preliminary results are really encouraging for us to further pursue the clinical implication of LDT to diabetes-related areas.

Response to low-dose involved-field radiotherapy in patients with non-Hodgkin's lymphoma

BACKGROUND

The purpose of this study was to analyze response to palliative low-dose involved-field radiotherapy (LD-IF-RT) (two 2-Gy fractions), explore factors predicting for response, and determine the time course to subsequent treatment.

PATIENTS AND METHODS

Thirty-three patients with advanced or recurrent indolent non-Hodgkin's lymphoma (NHL) received LD-IF-RT to 43 sites. Response was assessed by physical examination and radiographic studies. Median follow-up for individual sites was 14 months. Fisher's exact test was used to evaluate prognostic factors for response and in-field progression.

RESULTS

Overall response was 95%. Thirty-six sites (84%) had a complete response (CR), five sites (12%) had a partial response, and two sites (5%) had progressive disease. The CR rate of head and neck sites was significantly higher than that of pelvic and/or inguinofemoral sites (95% versus 64%, P = 0.04). The CR rate was significantly higher for sites < or =40 mm than for sites >40 mm (90% versus 56%, P = 0.04). Ten sites (23%) had in-field progression diagnosed at a median of 9 months. Sixteen patients (48%) received systemic treatment at a median of 8 months. Fourteen patients (42%) did not require additional treatment.

CONCLUSIONS

LD-IF-RT for selected NHL subtypes has excellent local CR and in-field control rates and may postpone the need for systemic therapy.

Nodular lymphocyte-predominant hodgkin lymphoma

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), a distinct subtype of Hodgkin lymphoma, is a rare disease with a generally favorable prognosis. The hallmark of NLPHL is the presence of the lymphocytic and histiocytic cell, which, in contrast to the classic Reed-Sternberg cell, is CD20+, CD15-, and CD30-. NLPHL tends to have an indolent natural history, a long time to disease progression, a delayed time to relapse, and a high likelihood of presenting as early-stage disease. The evidence to guide the management of patients with NLPHL is limited by the rarity of this disease, but the available data support the use of involved-field radiation therapy alone for localized disease. Treatment-related late effects contribute significantly to the causes of death in patients treated for NLPHL.

In vivo p53 response and immune reaction underlie highly effective low-dose radiotherapy in follicular lymphoma

Very low-dose irradiation (2 x 2 Gy) is a new, effective, and safe local treatment for follicular lymphoma. To understand the biologic mechanisms of this extremely effective response, we compared by microarray the gene-expression profile of patients' biopsies taken before and after radiation. In all patients, a major and consistent induction of p53 target genes was seen. p53 targets involved in cell-cycle arrest and apoptosis showed the same mode of regulation, indicating that, in vivo, both are activated simultaneously. p53 up-regulation and p53-mediated proliferation arrest and apoptosis were substantiated using immunohistochemistry, with activation of both the intrinsic and the extrinsic apoptotic pathways. The other induced genes revealed a whole set of biologically meaningful genes related to macrophage activation and TH1 immune response. Immunohistochemical analysis suggested a specific activation or differentiation of resident macrophages by apoptotic cells. These biologic insights are important arguments to advocate the use of low-dose radiotherapy as an effective palliative treatment for follicular lymphoma. Moreover, this study is the first in vivo report of the radiation-induced p53 apoptotic response in patients and suggests that this apoptotic response is not immunologically silent.

Value of low-dose 2 x 2 Gy palliative radiotherapy in advanced low-grade non-Hodgkin's lymphoma

Low-dose radiotherapy over the last decade has been reported to provide effective palliation for patients with low-grade non-Hodgkin's lymphoma. In this retrospective case series of 10 patients, we report our early experience using low-dose radiotherapy (usually 2 x 2 Gy) for patients with advanced-stage follicular, mucosal associated lymphoid tissue, mantle cell and small lymphocytic lymphomas. Median follow up was 27 weeks. Response rates were high (complete response, 70%; partial response, 20%), the response durable and the toxicity was minimal (no toxicity greater than grade 1). Low-dose irradiation is an effective treatment option for patients with low-grade lymphomas with local symptoms.

Les traitements par les radiations ionisantes dans les lymphomes. Indications actuelles et futures

Presently, radiotherapy is rarely an upfront treatment in patients with lymphomas. The modern evolution of radiation treatment calls for the development of therapeutic niches in which radiotherapy remains absolutely necessary. The development of new imaging techniques and their use in radiation planning systems along with new sophisticated radiation delivery techniques such as IMRT and respiratory gating should permit an increased accuracy an increased accuracy in the treatment of tumor masses and a decrease in late normal tissue complications.

Effective palliation by low dose local radiotherapy for recurrent and/or chemotherapy refractory non-follicular lymphoma patients

In this work, we have studied the response rates and duration of response after low-dose (4 Gy) involved field radiotherapy (LD-IF-RT) in relapsed or chemotherapy refractory indolent and aggressive lymphoma patients. 71 patients (177 symptomatic sites) received LD-IF-RT consisting of 39 males and 32 females with a median age of 69 years (range 43-93). Patients included were those with small lymphocytic lymphoma/chronic lymphocytic leukaemia (n=23), marginal zone lymphoma, nodal type (n=18), mantle cell lymphoma (n=17), and diffuse large B-cell lymphoma (n=13). Bulky disease (5 cm) was present in 73% of all patients. A median of two prior chemotherapy regimens (range 0-10) preceded LD-IF-RT. Median time since diagnosis was 31 months (range 1-216 months). Time to (local) progression was calculated according to the Kaplan-Meier method. Differences in response rates were compared using the chi2-test. The results showed that overall response rate was 87%; complete remission (CR) was reached in 34 patients (48%) and a partial remission (PR) in 28 patients (39%). Stable disease (SD) was maintained in nine patients (13%). The median time to progression (TP) was 12 months and the median time to local progression (TLP) was 22 months. The 34 CR patients showed a median TP of 16 months and a median TLP of 23 months. None of the factors studied (age, sex, lymphoma subtype, radiotherapy regimen, number of prior regimens or time since diagnosis, number of positive sites or largest lymphoma diameter) were found to relate to response. At time of death 70% of patients were without in-field progression after LD-IF-RT. It appears that LD-IF-RT is a valuable asset in the management of relapsed disease in both indolent and aggressive lymphoma and should be considered to palliate symptoms in patients with recurrent and/or chemotherapy refractory disease.

Efficacy and safety of tositumomab and iodine-131 tositumomab (Bexxar) in B-cell lymphoma, progressive after rituximab

PURPOSE

To determine overall response (OR) and complete response (CR) rates, response duration, progression-free (PFS) and overall survival and safety with the tositumomab and iodine-131 tositumomab ((131)I tositumomab) therapeutic regimen in patients with indolent, follicular large-cell, or transformed B-cell lymphoma, progressive after rituximab.

PATIENTS AND METHODS

From July 1998 to November 1999, 40 patients (24 rituximab nonresponders: 11 with response < 6 months, and five with response > or = 6 months) received a therapeutic dose (0.65 to 0.75 Gy per platelet count) of (131)I tositumomab based on total-body dosimetry in this prospective phase II study. The median number of prior treatments was four; 59% of patients were chemotherapy-resistant.

RESULTS

Confirmed OR (65%) and CR (38%) rates were not significantly associated with prior rituximab response. With a median follow-up of 3.3 years, the median PFS was 10.4 months, 24.5 months for responders, and not reached for CR patients. Among follicular grade 1 or 2 patients with tumors < or = 7 cm (n = 21), the OR and CR rates were 86% and 57%. Estimated 3-year PFS in this subgroup was 48%, compared with 11% for all others (P = .002). Transient grade 3 to 4 marrow toxicity was seen in 50% of patients. Two patients, one of whom received two subsequent chemotherapy regimens, developed secondary myelodysplasia.

CONCLUSION

(131)I tositumomab is effective in CD20-positive lymphoma progressive after rituximab, with a 65% OR rate and median PFS of 24.5 months for responders. Patients with follicular grade 1 or 2 histology and tumors < or = 7 cm achieved very high OR and CR rates, with 48% PFS at 3 years.

Radiobiology of radioimmunotherapy: targeting CD20 B-cell antigen in non-Hodgkin's lymphoma

The radiobiology of radioimmunotherapy is an important determinant of both the toxicity and the efficacy associated with the treatment of B-cell non-Hodgkin's lymphoma with radiolabeled anti-CD20 monoclonal antibodies. The properties of the target, CD20, and the mechanisms of action of both the monoclonal antibodies and the associated exponentially decreasing low-dose-rate radiotherapy are described. The radiation dose and dose-rate effects are discussed and related to both the tumor responses and normal organ toxicity. Finally, the use of either unlabeled or radiolabeled anti-CD20 monoclonal antibodies as a component of combined modality therapy (including the sequential or concurrent use of sensitizers) and future directions of the field are discussed.