Advancing CNS Tumor Management: Proton Therapy in Focus

Proton craniospinal irradiation produced a marked survival advantage for patients with leptomeningeal metastasis in a randomized 98‑patient trial: median CNS progression–free survival 8.2 versus 2.3 months and median overall survival 11.3 versus 4.9 months—differences that materially extend CNS control and overall survival.

The randomized study enrolled 98 patients and directly compared craniospinal proton therapy with conventional involved-field radiotherapy. CNS progression–free survival was the primary end point and overall survival a key secondary end point; both favored pCSI with statistical significance. The design and interim findings of the pCSI trial support the robustness of the observed effect within this cohort.

Benefit concentrated in patients who matched the trial eligibility profile—those with the performance status and disease characteristics specified at enrollment. Applying those selection criteria identifies the patients most likely to derive the observed benefit.

Toxicity was manageable and consistent with expected sequelae of craniospinal irradiation; adverse events were treated with standard supportive measures and monitoring. The safety dataset did not reveal unexpected prohibitive toxicities and supports considering pCSI for appropriately selected patients.

Adoption of craniospinal proton techniques requires proton access, dedicated craniospinal planning workflows, and coordinated hematologic and supportive-care monitoring—resources distinct from involved-field radiotherapy. Systems readiness, scheduling capacity, and multidisciplinary coordination will shape the pace of clinical uptake.

The trial’s findings may prompt reassessment of radiotherapy strategy for select patients with leptomeningeal metastasis; broader confirmation and capacity planning will determine how rapidly these results reshape practice.

Key Takeaways:

• Randomized data show a clear efficacy signal—median CNS‑PFS 8.2 vs 2.3 months and median OS 11.3 vs 4.9 months—indicating a substantial numeric benefit in this trial cohort.
• Patients matching the trial eligibility profile (performance status and disease features consistent with enrollment) are most likely to benefit.
• Toxicity appears manageable, but higher operational demands for pCSI mean adoption will depend on access, planning capacity, and multidisciplinary evaluation.