Low-dose radiation for posttransplant lymphoproliferative disorder

Area of Science:

• Pediatric Oncology
• Hematology
• Radiation Oncology

Background:

• Posttransplant lymphoproliferative disorder (PTLD) is a serious complication following hematopoietic stem cell transplantation.
• Standard PTLD treatment involves immunosuppression reduction, anti-CD20 antibodies, or antivirals, with chemotherapy reserved for refractory cases.
• The role and optimal dosing of radiation therapy for PTLD remain underexplored.

Observation:

• Three pediatric patients with biopsy-proven PTLD post-bone marrow transplant (BMT) received low-dose involved field radiation therapy (450 cGy).
• Patients presented with respiratory distress requiring intubation and had received initial medical management including immunosuppression adjustment and anti-CD20 therapy.
• Radiation therapy was administered in three 150-cGy fractions and was well tolerated with no acute complications.

Findings:

• Two patients were successfully extubated shortly after radiation, indicating rapid symptomatic improvement.
• One patient achieved complete radiographic resolution of PTLD, while another showed significant disease regression in the irradiated field.
• A subsequent biopsy in one patient confirmed the absence of lymphoproliferative disease, demonstrating a durable response.

Implications:

• Low-dose involved field radiation therapy is a safe and effective palliative option for pediatric PTLD.
• This treatment modality can lead to durable responses and symptom improvement, potentially avoiding more toxic therapies.
• Further research into radiation therapy protocols for PTLD is warranted to establish its definitive role in treatment algorithms.