Short-term predictors of stereotactic radiosurgery outcome for untreated single non-small cell lung cancer brain metastases: a restrospective cohort study.

Stereotactic radiosurgery (SRS) is an option for brain metastases (BM) not eligible for surgical resection, however, predictors of SRS outcomes are poorly known. The aim of this study is to investigate predictors of SRS outcome in patients with BM secondary to non-small cell lung cancer (NSCLC). The secondary objective is to analyze the value of volumetric criteria in identifying BM progression. This retrospective cohort study included patients >18 years of age with a single untreated BM secondary to NSCLC. Demographic, clinical, and radiological data were assessed. The primary outcome was treatment failure, defined as a BM volumetric increase 12 months after SRS. The unidimensional measurement of the BM at follow-up was also assessed. One hundred thirty-five patients were included, with a median BM volume at baseline of 1.1 cm3 (IQR 0.4-2.3). Fifty-two (38.5%) patients had SRS failure at follow-up. Only right BM laterality was associated with SRS failure (p=0.039). Using the volumetric definition of SRS failure, the unidimensional criteria demonstrated a sensibility of 60.78% (46.11%-74.16%), specificity of 89.02% (80.18%-94.86%), positive LR of 5.54 (2.88-10.66) and negative LR of 0.44 (0.31-0.63). SRS demonstrated a 61.5% local control rate 12 months after treatment. Among the potential predictors of treatment outcome analyzed, only the right BM laterality had a significant association with SRS failure. The volumetric criteria were able to identify more subtle signs of BM increase than the unidimensional criteria, which may allow earlier diagnosis of disease progression and use of appropriate therapies.

Development and adaptations of the Graded Prognostic Assessment (GPA) scale: a systematic review.

The Graded Prognostic Assessment (GPA) score has the best accuracy among prognostic scales for patients with brain metastases (BM). A wide range of GPA-derived scales have been established to different types of primary tumor BM. However, there is a high variability between them, and their characteristics have not been described altogether yet. We aim to summarize the features of the existent GPA-derived scales and to compare their predictor factors and their uses in clinical setting. Medline was searched from inception until January 2023 to identify studies related to the development, update, or validation of GPA. The initial search yielded 1,083 results. 16 original studies and 16 validation studies were included, comprising a total of 33,348 patients. 13 different scales were assessed, including: GPA, Diagnosis-Specific GPA, Extracranial Score, Lung-molGPA, Updated Renal GPA, Updated Gastrointestinal GPA, Modified Breast GPA, Integrated Melanoma GPA, Melanoma Mol GPA, Sarcoma GPA, Hepatocellular Carcinoma GPA, Colorectal Cancer GPA, and Uterine Cancer GPA. The most prevalent prognostic predictors were age, Karnofsky Performance Status, number of BM, and presence or absence of extracranial metastases. Treatment modalities consisted of whole brain radiation therapy, stereotactic radiosurgery, surgery, cranial radiotherapy, gamma knife radiosurgery, and BRAF inhibitor therapy. Median survival rates with no treatment and with a specific treatment ranged from 6.1 weeks to 33 months and from 3.1 to 21 months, respectively. Original GPA and GPA-derived scales are valid prognostic tools, but with heterogeneous survival results when compared to each other. More studies are needed to improve scientific evidence of these scales.