Nodal follicular lymphoma: the role of radiotherapy for stages I and II.

Purpose: To clarify the role of external-beam radiotherapy (RT) in patients with stage I and II nodal follicular lymphoma (FL).

Methods: The literature was reviewed with respect to different treatment strategies in patients with stage I and II nodal FL by screening the PubMed databank.

Results: In patients with stage I and II nodal FL, RT alone with different irradiation techniques (involved-field [IFI]/extended-field [EFI]/total nodal [TNI]/total lymphoid irradiation [TLI]) produces excellent local disease control (approximately 95%) resulting in disease-free survival and overall survival (OS) rates of 37-94% and 40-93% at 5-15 years, respectively. The main cause of failure is out-of-field recurrence. In nonrandomized trials, IFI led to higher relapse rates, but larger irradiation volumes failed to show an impact on OS and were associated with increased toxicity. Additional chemotherapy mostly failed to improve treatment results achieved with RT alone.

Conclusion: Since there is no evidence so far that the prognosis of stage I and II nodal FL can be improved by the use of EFI/TNI/TLI, IFI is recommended internationally. Adequate irradiation doses range between 25-30 Gy to subclinical disease and 36-40 Gy to involved sites. To further improve the curative potential of RT in early-stage FL, novel combined approaches (e.g., RT + immunotherapy with rituximab) are under investigation.