Combination checkpoint blockade and laser interstitial thermal therapy in radiographically progressive non-small cell lung cancer brain metastases

Background: Laser interstitial thermal therapy (LITT) is a minimally invasive surgical treatment being employed frequently for radiographically progressive brain metastases. Considerable interest exists in combining LITT-mediated in situ vaccination to license immune checkpoint blockade (ICB). No studies have examined the clinical feasibility of this combination in brain metastases.

Methods: All patients receiving LITT for radiographically progressive non-small cell lung carcinoma (NSCLC) brain metastases at a single center from 2015 to 2023 were retrospectively reviewed. Combination therapy was defined as ICB within 6 weeks of LITT. Clinical data, post-LITT freedom from local progression, and overall survival (OS) were collected. Adverse events (AEs) were evaluated according to Common Terminology Criteria.

Results: Eighteen patients received LITT + ICB for a total of 19 lesions. The median time between therapies was 2.29 weeks (range 0.85-5.98). In comparison to NSCLC patients receiving LITT alone or with targeted therapy (LITT only) (n = 25), there was no decrement in procedural outcomes. Patients receiving LITT + ICB discontinued steroids at a median of 11 (4-147) days post-LITT vs. 24 (3-242) days for patients receiving LITT only (P = .62). At study cutoff, the local control rate was 18/19 (94.7%) lesions in the LITT + ICB group and 22/25 (88.0%) in the LITT only group. There were 3 and 5 AEs ≥Grade 3 in the LITT + ICB and LITT-only groups, respectively.

Conclusions: Combination of LITT and ICB does not compromise procedural outcomes or time to steroid discontinuation in NSCLC. Prospective studies are needed to assess biomarkers of immune response.