SIE, SIES, GITMO revised guidelines for the management of follicular lymphoma

Sulfur Exafluoride Contrast-Enhanced Ultrasound Showing Early Wash-Out of Marked Degree Identifies Lymphoma Invasion of Spleen with Excellent Diagnostic Accuracy: A Monocentric Study of 260 Splenic Nodules

Contrast-enhanced ultrasonography (CEUS) use for detecting lymphoma in the spleen was questioned because of the risk of its inadequate diagnostic accuracy. The aim of the present study was to validate CEUS exam for the identification of spleen involvement by lymphoma in patients at risk. A total of 260 nodules from the spleens of 77 patients with lymph node biopsy-proven non-Hodgkin lymphoma (NHL; n = 44) or Hodgkin lymphoma (HL; n = 33) at staging (n = 56) or follow-up (n = 21) were collected in a hematology Italian center and retrospectively analyzed. Nodules were classified as malignant lymphoma if ≥0.5 cm (long axis) with arterial phase isoen-hancement and early (onset <60 s after contrast agent injection) wash-out of marked (≤120 s after contrast agent injection) degree. Other perfusional combinations at CEUS scans qualified lesions as benign or inconclusive. Diagnostic reference standard was clinical laboratory imaging monitoring for 230 nodules, and/or histology for 30 nodules. The median nodule size was 1.5 cm (range 0.5−7 cm). According to the reference standard, 204 (78%) nodules were lymphomas (aggressive-NHL (a-NHL), 122; classic-HL (c-HL), 65; indolent (i)-NHL, 17) and 56 (22%) were benign (inflammation, infection, and/or mesenchymal) lesions. Sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of CEUS for detecting lymphoma in the spleen were 95%, 100%, 100%, 85%, and 96%, respectively. Marked wash-out range of 55−90 s (median, 74 s), 92−120 s (median, 100 s), and 101−120 s (median, 114.5 s) was 100%, 96.6%, and 77% predictive of a-NHL, c-HL, and i-NHL splenic nodular infiltration, respectively. The CEUS perfusional pattern of arterial phase isoenhancement with early wash-out of marked degree was highly accurate for the detection of lymphomatous invasion of spleen in patients at risk, enabling its use for a confident non-invasive diagnosis.

Baseline [18F]FDG PET/CT may predict the outcome of newly diagnosed follicular lymphoma in patients managed with initial "watch-and-wait" approach

OBJECTIVES

To investigate if baseline [¹⁸F]FDG PET/CT can predict the outcome of follicular lymphoma (FL) in patients managed with an initial "watch-and-wait" approach.

METHODS

Thirty-eight newly diagnosed FL patients who were managed with an initial "watch-and-wait" approach and undergone baseline [¹⁸F]FDG PET/CT were retrospectively enrolled. The standard uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of FL lesions were measured on PET/CT. Patients were followed up for at least 24 months or until initiation of FL therapy. The endpoint was the time to initiation of lymphoma treatment (TLT).

RESULTS

After a median follow-up of 28 months (range 3-94 months), lymphoma treatment was initiated in 21/38 (55.3%) patients (median 15 months, range 3-51 months). Patients with TLT < 24 months showed SUVmax and TLG values significantly higher than those with TLT ≥ 24 months (p < 0.05). Receiver operating characteristic analysis demonstrated cutoff values of SUVmax > 9.5, MTV > 90.62 ml, and TLG > 144.96 SUVbw*ml were optimal for predicting TLT < 24 months. Kaplan-Meier analysis showed SUVmax > 9.5, MTV > 90.62 ml, and TLG > 144.96 SUVbw*ml had statistically significant correlations with shorter TLT (p < 0.01). Lymph node regions ≥ 3 and lymph nodes > 3 cm had almost significance (p < 0.1). In multivariate analysis, SUVmax > 9.5 (HR 3.2 [95% CI 1.1-9.2], p = 0.033) and TLG > 144.96 SUVbw*ml (HR 9.3 [95% CI 1.8-47.7], p = 0.008) were demonstrated to be independent predictive factors for shorter TLT.

CONCLUSIONS

Metabolic indices (SUVmax and TLG) of baseline [¹⁸F]FDG PET/CT could predict the outcome independently in FL patients under an initial "watch-and-wait" approach.

KEY POINTS

• "Watch-and-wait" approach is part of the overall treatment plan in asymptomatic patients with low tumor burden FL. However, the time to initiation of active treatment varies from months to years. • In our retrospective study of 38 patients with FL managed with an initial "watch-and-wait" approach, the SUVmax and TLG were demonstrated to be independent predictive factors for time to initiation of FL treatment. • Baseline [¹⁸F]FDG PET/CT may help to better select patients with FL who are most likely to benefit from "watch-and-wait" management.

18F-FDG PET/computed tomography may predict the outcome of newly diagnosed indolent non-Hodgkin lymphoma in patients managed with initial 'watch-and-wait' approach

OBJECTIVE

The aim of this study was to investigate the role of F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in the outcome of non-Hodgkin lymphoma (NHL) in patients managed with initial 'watch-and-wait' treatment.

METHODS

Sixteen patients with newly diagnosed NHL treated with initial watchful waiting were retrospectively recruited. They had a baseline F-FDG PET/CT and at least one follow-up PET/CT. The standard uptake values (SUV), metabolic tumor volume (MTV) and total lesions glycolysis (TLG) of lymphoma were measured in PET/CT. They were followed up for at least 2 years or until disease progression. The endpoint was the time to initiation of lymphoma treatment (TLT).

RESULTS

Comparing the baseline and the follow-up PET/CT, four out of 16 patients showed spontaneous regression of lymphoma, three of the 16 patients had stable disease and the remaining nine of the 16 patients had progressive disease in the follow-up PET/CT. After a median follow-up of 32 months (range 14-90 months), 10/16 patients had progressive disease and chemotherapy was initiated. The median TLT was 21.0 months. In univariate analysis, MTV and TLG in baseline PET/CT were significant to predict TLT. Kaplan-Meier curves showed a statistical difference for TLT in the two groups of patients stratified by MTV or TLG at baseline (median TLT, 66.0 months vs. 12.0 months, P = 0.007). However, patients' age, Ann Arbor staging, International Prognostic Index and SUVmax were not significant.

CONCLUSION

A proportion of patients with NHL might experience spontaneous regression of lymphoma. F-FDG PET/CT turned out as a prognostic factor for TLT in patients with NHL under watchful waiting.

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.

Can early switch to rituximab-bendamustine in a patient with follicular non-Hodgkin lymphoma progressing during R-CHOP be considered frontline treatment?: A case report

RATIONALE

Follicular non-Hodgkin lymphoma (fNHL) is a neoplasm characterized by an indolent course and chemosensitivity, but also by disease recurrence. Bendamustine is often used as frontline treatment or second line. HEADING DIAGNOSIS:: fNHL.

PATIENT CONCERNS

A 63-year-old Caucasian male with diagnosis of fNHL lymphoma underwent to cyclophosphamide, doxorubicin, vincristine, and prednisone associated with rituximab chemoimmunotherapy, during which interim reevaluation showed progressive disease and severe toxicity.

INTERVENTIONS

Early switch to rituximab-bendamustine.

OUTCOMES

This regimen was well tolerated, patient compliance was optimal, there were no delays in administration and no infectious episodes. An interim reevaluation after 3 courses revealed that the patient was fit, the blood cell count was normal, and lymphadenopathies and nocturnal sweating had completely regressed. Of note, the PET/CT scan did not show fluorodeoxyglucose pathological uptake, clearly confirming disease regression.

LESSONS

Early switching to a bendamustine-rituximab-based scheme, even during conventional chemotherapy, decreases toxicity and reduces the risk of treatment interruption or delay, with favorable effects on overall response and prognosis.

Chronic Benign CD8+ Proliferation: A Rare Affection that Can Mimic a Lymphoma Relapse

Chronic benign CD8+ proliferation is a rare syndrome that can take the form of a variety of other diseases. Peripheral adenopathy, cytopenia, and infiltration of the liver, kidneys, bowels, or other organs are the most common clinical presentations of the syndrome. CD8+ expansion can be clonal and nonclonal. It generally occurs in patients with innate or acquired immunodeficiency (HIV+) or in patients receiving immunosuppressive therapy. It has been found repeatedly in patients who developed severe hypogammaglobulinemia after treatment with rituximab. Diagnosis of the disease can be difficult because it can mimic relapse of a lymphoma, and a common biopsy examination cannot identify the problem at first. The authors describe a case of a patient pretreated with rituximab who developed agammaglobulinemia and peripheral adenopathy. Biopsy of an enlarged lymph node showed "reactive lymphadenitis." Additionally, a flow-cytometric examination revealed a pathological population of CD8+ lymphocytes. The treatment, which differed from treatments of lymphoma relapse, consisted of corticosteroids and IVIG substitutions and has led to a regression of clinical symptoms. With more frequent usage of rituximab, one can expect increased occurrence of a very rare CD8+ expansion that can reliably emulate the relapse of a lymphoma.

Whole body magnetic resonance in indolent lymphomas under watchful waiting: The time is now

ᅟ: The indolent non-Hodgkin lymphomas (i-NHLs) are characterised by 'indolent' clinical behaviour with slow growth and prolonged natural history. The watchful waiting (WW) strategy is a frequently employed treatment option in these patients. This implies a strict monitoring by imaging examinations, including 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) and CT. A major concern is radiation exposure due to regularly monitoring by conventional imaging procedures. Several studies have demonstrated the reliability of whole-body magnetic resonance imaging (WB-MRI) for lymphoma staging. WB-MRI could be useful for active surveillance in i-NHLs providing the suspect of disease progression that can be then confirmed by additional diagnostic procedures, including 18F-FDG-PET/CT. The directive 2013/59 by the European Union claims that if a radiation-free imaging technique allows obtaining the same diagnostic results, it should be invariably used. In this setting, WB-MRI may be considered a reasonable option in i-NHLs under WW, replacing imaging modalities that cause exposure to ionising radiations. This will help to reduce the cancer risk in i-NHL patients for whom chemo-/radiotherapy remain the usual treatment options following the usually long WW phase. The scientific community should raise the awareness of the risk of ionising radiations in i-NHLs and the emphasise the need for establishing the proper place of WB-MRI in lymphoma imaging.

KEY POINTS

• Watchful waiting is a reasonable option in patients with indolent non-Hodgkin lymphomas. • Imaging is crucial to monitor patients with indolent non-Hodgkin lymphomas. • CT and ¹⁸ F-FDG-PET/CT are commonly used, implying a substantial radiation exposure. • WB-MRI is highly reliable in lymphoma staging. • WB-MRI may be considered to monitor indolent non-Hodgkin lymphomas under watchful waiting.

Radiotherapy plus rituximab as first-line regimen for localized follicular lymphoma

Early-stage follicular lymphoma (FL) can be cured with involved-field radiotherapy (IF-RT); however, many patients relapse in non-irradiated areas. A combined association with chemotherapy could increase treatment efficacy, but toxic effects could be unacceptable. In vitro synergistic effect between rituximab (R) and RT has been observed, but clinical data are limited. We retrospectively analyzed 41 early-stage FL patients receiving R and IF-RT as first-line treatment. We administered R 375mg/m² weekly for four courses, before or after IF-RT (median dose 24 Gy). Primary outcome was PFS, secondary endpoints were CR rate, OS and safety. All patients achieved CR, after a median follow-up of 46 months only three patients relapsed after 18, 26 and 42 months; estimated 5-year PFS was 90%. We suggest R in association with IF-RT could represent a feasible first-line treatment option for early-stage FL and could increase efficacy without additional toxicity compared to available data about RT alone.

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.

The Role of Autologous and Allogeneic Stem Cell Transplantation in Follicular Lymphoma in The New Drugs Era

Follicular lymphoma (FL) is the second most common histotype of non-Hodgkin’s lymphoma, and it is generally characterized by a heterogeneous clinical course. Despite recent therapeutic and diagnostic improvements, a significant fraction of FL patients still relapsed. In younger and/or fit FL relapsed patients bone marrow transplant (BMT) has represented the main salvage therapy for many years. Thanks to the ability of high-dose chemotherapy to overcome the lymphoma resistance and refractoriness, autologous stem cell transplantation (ASCT) can achieve a high complete remission rate (CR) and favorable outcome regarding progression-free survival (PFS) and overall survival (OS). Allogeneic stem cell transplantation (alloSCT) combines the high dose chemotherapy effect together with the immune reaction of the donor immune system against lymphoma, the so-called ‘graft versus lymphoma’ (GVL) effect. Considering the generally higher transplant-related mortality (TRM), alloSCT is mostly indicated for FL relapsed after ASCT. During the last years, there have been a great spread of novel effective and feasible drugs Although these and future novel drugs will probably change our current approach to FL, the OS post-BMT (ASCT and alloSCT) has never been reproduced by any novel combination. In this scenario, it is important to correctly evaluate the disease status, the relapse risk and the comorbidity profile of the relapsed FL patients in order to provide the best salvage therapy and eventually transplant consolidation.

Is watch and wait still acceptable for patients with low-grade follicular lymphoma?

Follicular lymphoma (FL) represents more than 20% of all non-Hodgkin lymphomas worldwide and approximately 30% of the non-Hodgkin lymphomas diagnosed in the United States. Although occasionally localized at the time of diagnosis, most patients have disseminated disease. However, patients are frequently asymptomatic, and this, in combination with a long median survival, led to the initial studies of observing asymptomatic patients without initial therapy, ie, "watch and wait." Since the initial report of watch and wait as a treatment strategy for patients with low-grade FL, our understanding of the biology of the disease has advanced; multiple active new agents have been introduced into practice, and the survival of patients with low-grade FL has improved. Given these changes, is watch and wait still an acceptable treatment recommendation for a newly diagnosed patient with low-grade FL?

Diagnosis of follicular lymphoma of the gastrointestinal tract: A better initial diagnostic workup

Due to an increasing incidence and more frequent recognition by endoscopists, gastrointestinal follicular lymphoma has been established as a variant of follicular lymphoma. However, due to its rarity, there are no established guidelines on the optimal diagnostic strategy for patients with primary gastrointestinal follicular lymphoma or secondary gastrointestinal involvement of systemic follicular lymphoma. This review offers an overview and pitfalls to avoid during the initial diagnostic workup of this disease entity. Previously reported case reports, case series, and retrospective studies are reviewed and focus on the disease's endoscopic and histological features, the roles of computed tomography and positron emission tomography scanning, the clinical utility of the soluble interleukin-2 receptor, and the possible pathogenesis.

Addition of Rituximab to Involved-Field Radiation Therapy Prolongs Progression-free Survival in Stage I-II Follicular Lymphoma: Results of a Multicenter Study

PURPOSE

Rituximab (Rit) therapy added to involved-field radiation therapy (RT) has been proposed as an effective treatment for stage I-II follicular lymphoma (FL). The results of an observational multicenter study on the Rit-RT combination in limited-stage FL are here reported.

METHODS AND MATERIALS

Data have been collected from 2 consecutive cohorts of 94 patients with stage I-II FL treated between 1985 and 2011 at 5 Italian institutions. All patients had grade 1-3a FL, a median age of 54 years (range: 25-82). The first 51 patients received RT alone (control group), while the subsequent series of 43 patients received 4 rituximab courses (375 mg/m(2), days 1, 8, 15, 22) before RT (Rit-RT). Molecular disease was evaluated by nested bcl-2/IgH PCR or clonal IgH rearrangement was available in 33 Rit-RT patients.

RESULTS

At a median follow-up of 10.9 years (range: 1.8-22.9), the 10-year progression-free survival (PFS) and overall survival (OS) projections for the whole cohort were 57% and 87.5%, respectively. The 10-year PFS was significantly longer (P<.05) in the Rit-RT group (64.6%) compared to RT alone (50.7%), whereas the 10-year OS projections were not significantly different. On bivariate analysis controlling for stage, there was only a trend toward improved PFS for Rit-RT (HR, 0.55; P=.081). Follicular lymphoma international prognostic index and age were associated with OS but not with PFS on Cox regression analysis. Bone marrow molecular analysis showing PCR positivity at diagnosis was strongly associated with relapse risk upon univariate and multivariate analysis.

CONCLUSIONS

This multicenter observational study suggests a potential benefit of adding rituximab to radiation therapy for stage I-II FL. The results of the currently ongoing randomized studies are required to confirm these results. The study underlines the importance of molecular disease monitoring also for patient with limited-stage disease.

Impact of rituximab maintenance and maintenance schedule on prognosis in first-line treatment of follicular lymphoma. Retrospective analysis from Czech Lymphoma Study Group (CLSG) database

Rituximab maintenance (RM) improves time to progression (PFS) in advanced follicular lymphoma (FL), but the impact of various RM schedules remains unknown. This study performed a retrospective evaluation of RM given for up to 2 years vs observation in 319 untreated FL patients (stage II-IV; grade 1-3A) responding to RCHOP induction and a comparison of two different RM schedules (RM8=eight doses given every 3 months and RM12=12 doses given every 2 months). A total of 183 patients received RM and 136 patients were observed; 5-year PFS was better in the RM arm, 74.1% vs 52.3% (p<0.001), which was projected in 5-year OS 93.8% vs 87.5% (p=0.005). However, 5-year PFS was similar in both the RM8 (n=54) and RM12 (n=56) arms. In the first line, RM significantly prolongs PFS and OS in FL, but different RM schedules bring a similar benefit.

Rituximab for indolent lymphomas before and after allogeneic hematopoietic stem cell transplantation

PURPOSE OF REVIEW

The most substantial advancement in the treatment of indolent B-cell non-Hodgkin lymphoma (NHL), since the advent of combination chemotherapy, has been the introduction of the monoclonal anti-CD20 antibody rituximab. However, the optimal schedule, timing, and duration of rituximab therapy remain controversial.

RECENT FINDINGS

Since its initially reported single-agent activity in 1997, the role of rituximab has greatly expanded and it is now ubiquitously integrated in all treatment phases of indolent NHL. Yet, several questions remain to be addressed: should asymptomatic patients be treated at diagnosis with single-agent rituximab or still kept in watchful waiting, what are the optimal first-line treatments to combine with rituximab, what is the role of maintenance therapy, and is there a benefit in incorporating rituximab in autologous and allogeneic stem cell transplantation schemes for these diseases? Recent and ongoing clinical trials tackling these relevant issues will be presented and critically discussed in this article.

SUMMARY

Excellent outcomes are reported with rituximab therapy in indolent NHL, both early and late in the disease course. Continued study of this most valuable therapeutic agent is warranted to set the optimal treatment approach leading to cure the majority of patients.

The use of anthracycline at first-line compared to alkylating agents or nucleoside analogs improves the outcome of salvage treatments after relapse in follicular lymphoma The REFOLL study by the Fondazione Italiana Linfomi

Follicular lymphoma (FL) patients experience multiple remissions and relapses and commonly receive multiple treatment lines. A crucial question is whether anthracyclines should be used at first-line or whether they would be better "reserved" for relapse and whether FL outcome can be optimized by definite sequences of treatments. Randomized trials can be hardly designed to address this question. In this retrospective multi-institutional study, time-to-next-treatment after first relapse was analyzed in 510 patients who had received either alkylating agents- or anthracycline- or nucleoside analogs-based chemotherapy with/without rituximab at first-line and different second-line therapies. After a median of 42 months, median time-to-next-treatment after relapse was 41 months (CI95%:34-47 months). After adjustment for covariates, first-line anthracycline-based chemotherapy with/without rituximab was associated with better time-to-next-treatment after any salvage than alkylating agents-based chemotherapy with/without rituximab or nucleoside analogs-based chemotherapy with/without rituximab (HR:0.74, P = 0.027). The addition of rituximab to first-line chemotherapy had no significant impact (HR:1.22, P = 0.140). Autologs stem cell transplantation performed better than any other salvage treatment (HR:0.53, P < 0.001). First-line anthracycline-based chemotherapy significantly improved time-to-next-treatment even in patients receiving salvage autologs stem cell transplantation (P = 0.041). This study supports the concept that in FL previous treatments significantly impact on the outcome of subsequent therapies. The outcome of second-line treatments, either with salvage chemoimmunotherapy or with autologs stem cell transplantation, was better when an anthracycline-containing regimen was used at first-line.

Rate of primary refractory disease in B and T-cell non-Hodgkin's lymphoma: correlation with long-term survival

Background

Primary refractory disease is a main challenge in the management of non-Hodgkin’s Lymphoma (NHL). This survey was performed to define the rate of refractory disease to first-line therapy in B and T-cell NHL subtypes and the long-term survival of primary refractory compared to primary responsive patients.

Methods

Medical records were reviewed of 3,106 patients who had undergone primary treatment for NHL between 1982 and 2012, at the Hematology Centers of Torino and Bergamo, Italy. Primary treatment included CHOP or CHOP-like regimens (63.2%), intensive therapy with autograft (16.9%), or other therapies (19.9%). Among B-cell NHL, 1,356 (47.8%) received first-line chemotherapy with rituximab. Refractory disease was defined as stable/progressive disease, or transient response with disease progression within six months.

Results

Overall, 690 (22.2%) patients showed primary refractory disease, with a higher incidence amongst T-cell compared to B-cell NHL (41.9% vs. 20.5%, respectively, p<0.001). Several other clinico-pathological factors at presentation were variably associated with refractory disease, including histological aggressive disease, unfavorable clinical presentation, Bone Marrow involvement, low lymphocyte/monocyte ration and male gender. Amongst B-cell NHL, the addition of rituximab was associated with a marked reduction of refractory disease (13.6% vs. 26.7% for non-supplemented chemotherapy, p<0.001). Overall, primary responsive patients had a median survival of 19.8 years, compared to 1.3 yr. for refractory patients. A prolonged survival was consistently observed in all primary responsive patients regardless of the histology. The long life expectancy of primary responsive patients was documented in both series managed before and after 2.000. Response to first line therapy resulted by far the most predictive factor for long-term outcome (HR for primary refractory disease: 16.52, p<0.001).

Conclusion

Chemosensitivity to primary treatment is crucial for the long-term survival in NHL. This supports the necessity of studies aimed to early identify refractory disease and to develop different treatment strategies for responsive and refractory patients.

Radioimmunotherapy combined with maintenance anti-CD20 antibody may trigger long-term protective T cell immunity in follicular lymphoma patients

Growing evidence suggests that the patient's immune response may play a major role in the long-term efficacy of antibody therapies of follicular lymphoma (FL). Particular long-lasting recurrence free survivals have been observed after first line, single agent rituximab or after radioimmunotherapy (RIT). Rituximab maintenance, furthermore, has a major efficacy in prolonging recurrence free survival after chemotherapy. On the other hand, RIT as a single step treatment showed a remarkable capacity to induce complete and partial remissions when applied in recurrence and as initial treatment of FL or given for consolidation. These clinical results strongly suggest that RIT combined with rituximab maintenance could stabilize the high percentages of patients with CR and PR induced by RIT. While the precise mechanisms of the long-term efficacy of these 2 treatments are not elucidated, different observations suggest that the patient's T cell immune response could be decisive. With this review, we discuss the potential role of the patient's immune system under rituximab and RIT and argue that the T cell immunity might be particularly promoted when combining the 2 antibody treatments in the early therapy of FL.