Management postoperativer Ergebnisse bei Patienten mit Hirnmetastasen: eine Überarbeitung des ursprünglichen Graded Prognostic Assessment.

Graded Prognostic Assessment (GPA) has been proposed for various brain metastases (BM) tailored to primary histology and molecular profiles. The residual tumor burden (RTB) is a strong predictor of overall survival. We validated the GPA score and introduced "volumetric GPA" in the largest cohort of operated patients and further explored the role of RTB as an additional prognostic factor.

A total of 630 patients with BM between 2007 and 2020 were included. The four GPA components were analyzed. The validity of the original score was assessed using Cox regression and a modified index incorporating RTB was developed by comparing the accuracy, sensitivity, specificity, F1-score, and AUC parameters.

GPA categories showed an association with survival: age (p <0.001, hazard ratio (HR) 2.9, 95% confidence interval (CI) 2.5–3.3), Karnofsky performance status (KPS) (p <0.001, HR 1.3, 95% CI 1.2–1.5), number of BM (p = 0.019, HR 1.4, 95% CI 1.1–1.8), and presence of extracranial manifestation (p <0.001, HR 3, 95% CI 1.6–2.5). The median survival for GPA 0–1 was 4 months, GPA 1.5–2 12 months, GPA 2.5–3 21 months, and GPA 3.5–4 38 months (p <0.001). RTB was identified as an independent prognostic factor. A cut-off of 2 cm3 was used for further analysis, which showed a median survival of 6 months (95% CI 4–8) vs 13 months (95% CI 11–14, p <0.001) for patients with RTB >2 cm3 and <2 cm3 respectively. RTB was added as an additional component for a modified volumetric GPA score. Survival rates of the modified GPA score were: GPA 0–1 4 months, GPA 1.5–2 7 months, GPA 2.5–3 18 months, and GPA 3.5–4 34 months. Both scores showed good stratification, with the new score showed a trend towards better discrimination in patients with more favorable prognoses.

The prognostic value of the original GPA was confirmed in our cohort of patients who underwent surgery for BM. The RTB was identified as a parameter of high prognostic significance and was incorporated into an updated "volumetric GPA".This score provides a novel tool for prognosis and clinical decision-making in patients undergoing surgery. This method may be useful for stratification and patient selection in future clinical trials.