Stereotactic radiosurgery with immunotherapy is associated with improved overall survival in patients with metastatic melanoma or non-small cell lung cancer: a National Cancer Database analysis.

PURPOSE: Immunotherapy is now a first-line treatment for metastatic non-small cell lung cancer (NSCLC) and melanomaQuery. It is important to understand the relationship between immunotherapy and radiation to the brain. The aim of this study was to assess the role of stereotactic radiosurgery (SRS) or WBRT in addition to immunotherapy in patients with melanoma or NSCLC metastatic to the brain. METHODS/PATIENTS: Using the National Cancer Database, 2951 patients with NSCLC and 936 patients with melanoma treated with immunotherapy were identified. Patients were classified as having received immunotherapy alone, immunotherapy with SRS, or immunotherapy with whole-brain radiation therapy (WBRT). Kaplan-Meier, multivariate Cox regression analyses, and propensity matching were performed to evaluate the impact of adding SRS to immunotherapy on overall survival (OS). Immortal survival bias was accounted for by only including patients who received radiation before immunotherapy and time zero was defined as the start of immunotherapy. RESULTS: 205(6.9%) and 75(8.0%) patients received immunotherapy with no radiation, 822(27.9%) and 326(34.8%) received SRS and immunotherapy, and 1924(65.2%) and 535(57.2%) received WBRT and immunotherapy for NSCLC and melanoma, respectively. Adding SRS to immunotherapy was associated with improved OS in multivariate analyses (NSCLC HR = 0.81, 95% CI 0.66-0.99, p = 0.044; melanoma HR = 0.63, 95% CI 0.45-0.90, p = 0.011). The addition of WBRT to immunotherapy did not improve OS in patients with melanoma nor NSCLC. CONCLUSIONS: This analysis suggests that treatment with SRS and immunotherapy is associated with improved OS compared to immunotherapy alone for patients with melanoma or NSCLC metastatic to the brain.

Utility of Prophylactic Cranial Irradiation for Extensive-Stage Small-Cell Lung Cancer in the MRI Screening Era.

BACKGROUND: Conflicting data exists regarding the benefit of prophylactic cranial irradiation (PCI) in patients with extensive-stage small-cell lung cancer (ES-SCLC). We sought to retrospectively review outcomes of patients within our network with ES-SCLC treated with and without PCI between 2009 and 2020. METHODS: Endpoints assessed using the Kaplan-Meier estimator were overall survival (OS), freedom from death with uncontrolled intracranial disease (UI-DFS), brain metastasis-free survival (BMFS), and symptomatic BMFS (SBMFS). Log-rank test was performed for univariate comparison of outcomes, with Cox regression performed for univariate and multivariable analysis of OS and UI-DFS. RESULTS: Some 250 patients were determined to be eligible for PCI based on any response to upfront chemotherapy, with 46 patients excluded owing to lack of negative staging brain magnetic resonance imaging (MRI). Brain MRI was performed both at diagnosis and near completion of chemotherapy in 108 patients, with brain metastases identified near completion of chemotherapy in 17 patients (15.7%), excluding them from further analysis. Median OS in remaining eligible 187 patients was 9.0 months, with 2-year Kaplan-Meier estimate of OS of 21.9%. PCI was associated with improved UI-DFS, BMFS, and SBMFS. However, PCI was not associated with improved OS in the entire cohort or the propensity matched cohort. CONCLUSION: Our study suggests screening with MRI following chemotherapy is important because of the identification of unsuspected brain metastases in nearly 16% of patients with response to chemotherapy. PCI is associated with reduction in brain metastases, without a demonstrable impact on OS in the era of MRI screening.

Radiation injury to the normal brain measured by 3D-echo-planar spectroscopic imaging and diffusion tensor imaging: initial experience.

BACKGROUND AND PURPOSE: Whole brain radiation therapy (WBRT) may cause cognitive and neuropsychological impairment and hence objective assessment of adverse effects of radiation may be valuable to plan therapy. The purpose of our study was to determine the potential of echo planar spectroscopic imaging (EPSI) and diffusion tensor imaging (DTI) in detecting subacute radiation induced injury to the normal brain. MATERIALS AND METHODS: Four patients with brain metastases and three patients with lung cancer underwent cranial irradiation. These patients were subjected to 3D-EPSI and DTI at two time points (pre-radiation, and 1 month post-irradiation). Parametric maps of N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), mean diffusivity (MD), and fractional anisotropy (FA) were generated and co-registered to post-contrast T1-weighted images. Normal appearing gray-matter and white-matter regions were compared between the two time points to assess sub-acute effects of radiation using independent sample t-tests. RESULTS: Significantly increased MD (P = .02), Cho/Cr (P = .02) and a trend towards a decrease in NAA/Cr (P = .06) was observed from the hippocampus. Significant decrease in FA (P = .02) from the centrum-semiovale and a significant increase in MD (P = .04) and Cho/Cr (P = .02) from genu of corpus-callosum was also observed. CONCLUSIONS: Our preliminary findings suggest that 3D-EPSI and DTI may provide quantitative measures of radiation induced injury to the normal brain.