What is the recommended approach to radiotherapy for patients with localized lymphoma and Sjogren's syndrome?

Radiotherapy for Localized Lymphoma in Sjögren's Syndrome

For patients with localized lymphoma in Sjögren's syndrome, locoregional radiation therapy (24-30 Gy) is the recommended first-line treatment for symptomatic disease. 1

Treatment Approach Based on Lymphoma Type

Small Lymphocytic Lymphoma (SLL)

• Localized SLL (Lugano Stage I) should be treated with locoregional radiation therapy at doses of 24-30 Gy 1
• Radiation therapy is particularly effective for controlling local symptoms and may be curative in early localized disease 1
• Patients with localized SLL that progresses after initial radiation therapy should be treated as described for patients with more advanced SLL (Lugano stage II-IV) 1

Marginal Zone Lymphoma (MZL)

• For patients with marginal zone lymphomas in early disease stages (stage I or non-bulky stage II), treatment should include radiotherapy (with or without chemotherapy) 1
• MALT lymphoma, the most common lymphoma subtype in Sjögren's syndrome, often responds well to localized radiation therapy 2, 3
• In patients with only localized disease and low Sjögren's disease activity, a conservative approach or "watchful waiting" strategy may be justified 3

Radiation Dosing and Technique

• For localized lymphoma in Sjögren's syndrome, recommended radiation doses are typically 24-30 Gy 1
• For peripheral T-cell lymphomas, which are less common in Sjögren's syndrome but may occur, doses of 30-40 Gy are recommended, with preference for 40 Gy if residual lymphoma is present after chemotherapy 1
• The treated volume should include only the initially involved volume with appropriate margins for uncertainty, according to the principles of involved site radiotherapy (ISRT) 1
• Modern advanced radiation treatment techniques should be used to minimize long-term toxicity 1

Risk Stratification and Monitoring

• Patients with high Sjögren's disease activity (defined by M-protein, cryoglobulins, IgM rheumatoid factor >100 KIU/l, severe extraglandular manifestations) have higher risk of lymphoma progression and may require more aggressive treatment 3, 4
• Close monitoring is essential for patients with risk factors for lymphoma progression, including palpable purpura, low C4 levels, and mixed monoclonal cryoglobulinemia 5
• CT scans may be useful for evaluation of symptoms or bulky disease, but serial CT scans are not recommended for asymptomatic patients 1

Special Considerations

• In rare patients, radiation therapy may be contraindicated or suboptimal due to comorbidities or potential for long-term toxicity 1
• For patients with disseminated MALT lymphoma or with concomitant high Sjögren's disease activity, systemic therapy (chemotherapy or rituximab) may be considered instead of or in addition to radiotherapy 1
• Rituximab may be considered in patients with severe, refractory systemic disease, particularly for symptoms linked to cryoglobulinemic-associated MALT lymphoma 1
• Patients with high-grade lymphomas (such as diffuse large B-cell lymphoma) should receive standard rituximab-based chemotherapy regimens, potentially combined with radiotherapy 1, 6

Prognosis and Follow-up

• Low-grade lymphomas in Sjögren's syndrome (particularly MALT lymphomas) tend to evolve slowly and may occasionally regress spontaneously 2
• Cutaneous relapses do not necessarily indicate worse prognosis, but systemic progression requires more aggressive treatment 6
• Regular follow-up with assessment of known risk factors, including cryoglobulin-related markers, is mandatory for high-risk patients 4