A case series and literature review on extramedullary hematopoiesis in patients with thalassemia treated with conformal external beam radiation treatment.

Extramedullary hematopoiesis (EMH) is a compensatory response to chronic anemia, commonly observed in thalassemia. EMH can cause neurological complications such as spinal cord compression and paraparesis, as well as other site-specific compressive symptoms necessitating timely intervention. While medical management and surgery have been explored, radiation therapy (RT) remains a safe and effective alternative. This case series presents five patients with thalassemia who developed symptomatic EMH. All patients exhibited compressive symptoms, including lower limb weakness, sensory deficits, and abdominal pain. They were treated with conformal external beam RT using volumetric modulated arc therapy (VMAT) at doses ranging from 20 to 24 Gy in 10-12 fractions. Symptomatic relief was achieved within days of initiating radiation treatment, with near-complete neurological recovery by treatment completion. MRI follow-ups over 1-2 years demonstrated significant regression of EMH masses, and there was no recurrence of symptoms. Radiation was well tolerated and no treatment-related toxicities were observed. This study highlights the role of radiation treatment as a non-invasive and effective treatment modality for symptomatic EMH. The rapid clinical response and durable control observed in these cases reinforce its potential as a primary intervention, particularly in patients who are not responding and progressing on medical management. A dose range of 20-24 Gy in 10-12 fractions by modern radiation delivery techniques is recommended for the management of extramedullary hematopoietic masses.