Whole brain or whole body?
The Study: PRECIS was a randomized, but non-comparative, phase 2 trial of consolidative whole brain radiation (WBRT) or autologous stem-cell transplant (ASCT) in patients <60 years old. All received induction with R-MBVP x 2 followed by R-AraC x 2. Regardless of response (which was only 73%), patients then were randomized to WBRT of 2 Gy x 20 with no boost or a thiotepa-based ASCT regimen. The results, while not strictly comparative, provide an interesting look at the challenges of determining the best consolidation. Numerically, progression-free survival at 2 years appeared much better with ASCT (87%) compared to WBRT (63%). But! There was no difference in overall survival due to a >10% mortality rate with ASCT, which also happened to be used as a salvage option after WBRT. Despite the 1 in 10 chance of dying from ASCT—which, by the way, the protocol specified should be ≤5%—the authors felt the neurocognitive effects of WBRT were simply intolerable.
Bottom Line: Consolidative ASCT for PCNSL appears to result in a lower relapse rate than consolidative WBRT, perhaps cancelled out by a considerable risk of treatment-related mortality. | Houillier, J Clin Oncol 2019