Response-adapted radiation therapy for newly diagnosed primary diffuse large B-cell lymphoma of the CNS treated with methotrexate-based systemic therapy.

Abstract

BACKGROUND:

For patients with primary diffuse large B-cell lymphoma of the central nervous system (PCNSL), whole-brain radiation therapy (WBRT) to doses of ≥45 Gy are often given after a partial response (PR) to methotrexate-based induction chemotherapy. We conducted an exploratory analysis to determine whether lower-dose WBRT, given with a boost to sites of persistent disease, might be a reasonable alternative.

METHODS AND MATERIALS:

We retrospectively reviewed the records of 22 patients with PCNSL who received WBRT, with or without a boost, after methotrexate-based induction chemotherapy. Outcomes were compared among patients according to response to chemotherapy using the Kaplan-Meier method.

RESULTS:

Median follow-up was 52 months. All patients with a complete response (CR) (n = 5) received WBRT to 23.4 Gy. One CR patient died after an in-field relapse. Patients with partial response (PR) (n = 10) received a median whole-brain dose of 23.4 Gy with (n = 8) or without (n = 2) a boost; there were 2 relapses within the central nervous system (CNS). All PR patients were alive at the time of analysis. The overall survival (P = .127) and freedom from relapse within the CNS (P = .967) were not different for patients with CR versus PR. Baseline and follow-up neurocognitive evaluations were available for 4 PR patients, and there were no significant differences between pre- and post-treatment evaluations (P > .05 for language, memory, visual-spatial, attention, or motor functions). All patients who progressed or did not respond to chemotherapy and then received WBRT had died at a median time of 3.4 months. Patients who progressed or did not respond to chemotherapy had worse overall survival (P = .001) and freedom from CNS relapse (P = .005) compared with CR patients.

CONCLUSIONS:

Among patients with a PR to induction chemotherapy, reduced-dose WBRT with a boost to residual PCNSL may be a viable treatment approach that merits further investigation.

• Authors: Tommy Sheu, Sarah A Milgrom, Therese Y Andraos, Jillian R Gunther, Linda Chi, Loretta Nastoupil, Nathan Fowler, Yasuhiro Oki, Michelle A Fanale, Luis E Fayad, Fredrick Hagemeister, Sattva S Neelapu, L Jeffrey Medeiros, Chitra Hosing, Yago Nieto, Sairah Ahmed, Amin M Alousi, Bouthaina Dabaja, Chelsea C Pinnix
• Journal: Advances in radiation oncology (Adv Radiat Oncol) 2018 Oct-Dec Vol. 3 Issue 4 Pg. 639-646 ISSN: 2452-1094 [Print] United States
• PMID: 30370365 (Publication Type: Journal Article)