Primary CNS Lymphoma

Question 1

Is consolidative WBRT superior to chemo alone?

Answer 1

No
Thiel (Lancet 2010), Ph III PRT
HD-MTX vs HD-MTX + WBRT (45Gy/30fx)
No diff in OS or PFS with more neurotoxicity in the WBRT group (50 vs 26%)

Question 2

What if we lower the WBRT dose?

Answer 2

MSKCC Multi-Center Trial (JCO 2013), single arm Ph II
Reduced dose WBRT 23.4Gy/13 fractions to pts with CR after rituximab+MPV chemo. Pts got Ara-C after RT.
Consolidative WBRT (and Ara-C) had good control with minimal neurotoxicity.

Question 3

Does Low dose WBRT improve PFS compared to chemo alone?

Answer 3

Don’t know yet, need results of RTOG 1114.

Patients get chemo and then randomized to 23.4Gy/13fx WBRT or no RT, and then 2 additional cycles of chemo.

Question 4

Role of WBRT for salvage?

Answer 4

Yes, an option for recurrent or refractory disease. Other options: additional chemo or high dose chemo + autoSCT.
Nguyen (JCO 2005), 27 pts
36Gy/24fx; some of which got a boost.
10 had CR & 10 had PR
8 had progression/recurrence at f/u.
Delayed neurotoxicity in 3 pts at 25 months, none resulting in death.