# Guidelines for Diagnosis, Treatment, and Follow-Up of Patients with Follicular Lymphoma-Spanish Lymphoma Group (GELTAMO) 2025

## TL;DR

This paper presents updated guidelines for diagnosing, treating, and monitoring follicular lymphoma, emphasizing personalized approaches and new immunotherapies.

## Contribution

The guidelines integrate emerging immunotherapies like CAR-T and bispecific antibodies into clinical management strategies for follicular lymphoma.

## Key findings

- Excisional biopsy is recommended for histopathological diagnosis of follicular lymphoma.
- PET-CT is advised for staging and evaluating treatment response.
- CAR-T therapy and bispecific antibodies are highlighted as promising treatment options for relapsed disease.

## Abstract

Follicular lymphoma (FL) is an indolent B-cell malignancy that typically responds well to first-line therapy. However, many patients experience multiple relapses, and early disease progression is associated with lower survival. These guidelines, developed by the Spanish GELTAMO group, provide an updated, evidence-based overview of the diagnosis, staging, treatment, and follow-up of FL. They summarize current recommendations for optimal clinical management, including the integration of emerging immunotherapies such as CAR-T cell and bispecific antibody therapies. The aim is to support clinicians in personalizing treatment strategies and improving patient outcomes by incorporating the latest therapeutic advances.

Background: Follicular lymphoma (FL) is the second most common B-cell lymphoma in Western countries, typically presenting as an indolent disease with prolonged overall survival. Despite favorable initial responses to therapy, most patients experience relapse, and early progression is associated with poor outcomes. Methods: This guideline provides evidence-based recommendations from the Spanish GELTAMO group on the diagnosis, staging, treatment, and follow-up of FL. A systematic literature review was conducted, and recommendations were graded according to the GRADE system. Results: Histopathological diagnosis should be based on excisional biopsy. PET-CT is recommended for staging and response evaluation. For localized disease, involved-site radiotherapy (ISRT) remains the treatment of choice. In asymptomatic patients with advanced-stage disease and low tumor burden, a watch-and-wait approach is appropriate, although rituximab monotherapy is also acceptable. For advanced-stage disease with high tumor burden, immunochemotherapy with anti-CD20 antibodies (rituximab or obinutuzumab) combined with CHOP, CVP, or bendamustine is recommended, followed by maintenance therapy. Management of relapsed disease is tailored based on tumor burden, treatment history, and timing of relapse. Although novel immunotherapies (CAR-T therapy and bispecific antibodies) are emerging as promising options, autologous stem cell therapies may still be a valid option in young patients with early relapse who are sensitive to immunochemotherapy. Conclusions: FL is a heterogeneous disease requiring individualized management strategies. Recent advances in immunotherapy and molecular diagnostics are reshaping the therapeutic landscape. These updated GELTAMO recommendations aim to provide practical guidance for optimal FL management in clinical practice.