Role of prophylactic cranial irradiation in patients with limited disease small cell lung cancer: A Danish single institution cohort.

Background and purpose: Prophylactic cranial irradiation (PCI) is part of standard treatment for patients with limited disease small cell lung cancer (LD-SCLC), treated with curative intent. However, doubt has been raised about the efficacy of PCI in a modern clinical setting. Therefore, we examined factors impacting PCI receival, the cumulative incidence of symptomatic brain metastases, and overall survival (OS) with and without PCI. Patient/material and methods: Records of 190 patients with LD-SCLC consecutively treated between 2012 and 2021 at our institution were reviewed. Patients were grouped based on whether they received PCI (PCI, n = 119) or not (no PCI, n = 71). Baseline characteristics, Kaplan-Meier estimates of OS, and cumulative incidence of symptomatic brain metastases were compared for the two groups.

Results: PCI no patients were older, had a poorer performance status, were more often treated in 2018-2021 and had more frequently a brain magnetic resonance imaging (MRI) at the time of diagnosis. No PCI median OS was 19 months compared to 24 months for PCI, not significantly different (p = 0.40). During follow-up 54 patients (28.4%) developed symptomatic brain metastases, with no statistically significant difference in the numbers of patients with, and cumulative incidence of, symptomatic brain metastases between the two groups (p = 0.35 and p = 0.21, respectively).

Interpretation: Despite patients not receiving PCI being older and in poorer performance status, no statistically significant difference in OS or cumulative incidence of brain metastasis were observed compared to patients who received PCI. This supports uncertainty regarding the role of PCI.