Stereotactic radiosurgery for brain metastases: A retrospective cohort study comparing treatment results between two lung cancer patient age groups, 75 years or older vs 65-74 years

CyberKnife-based stereotactic radiosurgery or fractionated stereotactic radiotherapy in older patients with brain metastases from non-small cell lung cancer

PURPOSE

We analyzed clinical results of CyberKnife (CK)-based stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) in older patients (age ≥65 years) affected by brain metastases (BM) from non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Forty-three older patients with 92 BM were treated with CK-based SRS/FSRT at our institution between 2009 and 2019. The end-point was overall survival (OS). Univariate and multivariate analyses were performed to identify the prognostic factors influencing OS. The in-field local control (IFLC) within the SRS/FSRT field was also assessed.

RESULTS

During a median follow-up period of 18 months, the median OS was 32 months. NSCLC-specific graded prognostic assessment (GPA) (p = 0.027) was an independent significant factor affecting OS in the multivariate analysis. The median IFLC period was 31 months, and the total BM volume (p = 0.025) appeared to be a significant feature of IFLC. No adverse events >grade 2 were reported after SRS/FSRT.

CONCLUSION

CK-based SRS/FSRT is a safe and efficient option for older patients with BM arising from NSCLC, showing good OS without severe side effects. GPA, which was consisted in age, performance status, extra-cerebral metastasis, and number of BM, seemed to be predictive factors for OS.

Prognostic analysis of stereotactic radiosurgery for brain metastases: a single-center retrospective study

OBJECTIVES

Brain metastasis (BM) is a common event during the development of many cancers, and is also one of the main causes of death of patients. Stereotactic radiosurgery (SRS) is an effective treatment for BM. The prognostic effects of various clinical factors on local control (LC) and overall survival (OS) after SRS treatment are still unclear. The purpose of this study is to retrospectively analyze the intracranial progression free survival (iPFS) and OS of patients receiving SRS treatment, and explore the relationship between various clinical characteristics and patient prognosis.

MATERIALS AND METHODS

We collected the clinical information of patients who were diagnosed with BM and received SRS treatment in our center between 2018 and 2021. Univariate and multivariate Cox regression analysis and KM analysis for iPFS and OS were conducted in R software to investigate the prognostic effects of clinical characteristics.

RESULTS

In total, 183 patients that received SRS in our center were enrolled in the cohort. The median iPFS for all patients was 8.87 months (95% CI 6.9-10.6), and the median OS was 16.5 months (95% CI 12.9-20.7). BM number >  = 5 (HR 1.965 [95% CI 1.381-2.796], p < 0.001, FDR-corrected p < 0.001) was found to be strong predictor for shorter iPFS and OS. Subgroup analysis showed that patients with cumulative intracranial tumor volume (CITV) >  = 2.14 cm3 and number >  = 5 had shortest iPFS (P < 0.001) and OS (P = 0.007), compared with other subgroups. For patients with more than 5 BMs, SRS plus whole brain radiotherapy (WBRT) could achieve better local control, compared with SRS alone group (P = 0.0357). Peripheral blood inflammation indicators were associated with the prognosis of BM patients in univariate Cox analysis, but not in multivariate Cox analysis.

CONCLUSIONS

BM number is an independent prognostic factor for BM patients. The prognosis of patients in the subgroup with larger CITV and more BM is the worst. For patients with more than 5 BM, the combination of SRS and WBRT can improve the local control, but cannot prolong the OS.

Selected-Lesion Stereotactic Radiosurgery (SL-SRS) as a Novel Strategy in the Treatment of Patients With Multiple Brain Metastases

INTRODUCTION

With the diminishing use of whole-brain radiotherapy (WBRT), there is increasing debate regarding the maximum number of brain metastases that should be treated with stereotactic radiosurgery (SRS). In patients with >10-15 lesions, some groups are proposing a new approach - selected-lesion SRS (SL-SRS) - where only a subset of intracranial lesions are chosen for irradiation. This study is an initial look into this practice.

METHODS

This is a cross-sectional exploratory survey study. A survey of 19 questions was created by the International Radiosurgery Research Foundation (IRRF) using open-ended and multiple-choice style questions on SL-SRS practices and indications with the goal of qualitatively understanding how SL-SRS is being implemented worldwide. The survey was distributed to physicians in the United States (US) and internationally who are members of the IRRF and who perform SRS frequently. Ten out of 50 IRRF institutions provided responses reflecting the practices of 16 physicians.

RESULTS

SL-SRS is being performed at 8/10 institutions. The most common reasons for using SL-SRS included patients with prior WBRT, patients with progressing systemic disease with central nervous system (CNS)-penetrating or immunotherapies available, specific requests from medical oncology, and cooperative studies using this approach. Lesion size was cited as the most important factor when choosing to irradiate any single lesion. The majority of respondents reported 30 mm and 40 mm as size cutoffs (by largest dimension) for treatment of a lesion in eloquent and non-eloquent locations, respectively. Eloquence of lesion location and attributable symptoms were also considered important. Progression of untreated lesions was the most common reason reported for bringing patients back for additional treatment.

CONCLUSION

The responses to this survey show that SL-SRS is being used, allowing for small/asymptomatic brain metastases to be left safely unirradiated. It is currently used in patients who have >10-15 lesions with prior WBRT, those with progression of extracranial disease but with acceptable systemic treatment options, and those with poor functional status. The incorporation of this new approach into clinical trials should be considered for the safe study of the efficacy of new CNS-penetrating systemic therapies.