Deuces.

The catch 22 for radiation treatment of plasmacytoma is giving a high enough dose for durability but not so high to affect marrow reserves that could have a negative downstream impact on systemic therapy options. Here is a retrospective look at the success rate of palliation with lower dose and smaller fields among 772 patients and over 1500 sites treated at MDACC over the past two decades. Nearly 40% of all treated sites were in the spine. The most common fractionation was 2 Gy x 10, with only 3% receiving >2.5 Gy per fraction. At a median follow-up of >5 years, most enjoyed long survival times with <3% ever requiring re-irradiation. Among 82 spine lesions with both pre- and post-treatment MRI and/or PET, the only significant predictors of local failure were Bilsky score of 3 (HR 7.1) and paraspinal axial thickness (as a continuous variable, HR 2.0). TBL: 20 Gy given in 2-2.5 Gy daily fractions provides durable pain relief for uncomplicated plasmacytomas (read: without Bilksy 3 cord compression or large paraspinal extent) while minimizing marrow fibrosis and risk of reirradiation toxicity. | Elhammali, Haematologica 2020