Prognostic factors for survival and radiation necrosis after stereotactic radiosurgery alone or in combination with whole brain radiation therapy for 1-3 cerebral metastases.

Lars Hendrik Schüttrumpf,Nathalie Jansen,Maximilian Niyazi,Silke Birgit Nachbichler,Farkhad Manapov,Axel Siefert,Claus Belka

doi:10.1186/1748-717x-9-105

Abstract

BackgroundIn the present study factors affecting survival and toxicity in cerebral metastasized patients treated with stereotactic radiosurgery (SRS) were analyzed with special focus on radiation necrosis.Patients and methods340 patients with 1–3 cerebral metastases having been treated with SRS were retrospectively analyzed. Radiation necrosis was diagnosed by MRI und PET imaging. Univariate and multivariate analysis using a Cox proportional hazards regression model and log-rank test were performed to determine the prognostic value of treatment-related and individual factors for outcome and SRS-related complications.ResultsMedian overall survival was 282 days and median follow-up 721 days. 44% of patients received WBRT during the course of disease. Concerning univariate analysis a significant difference in overall survival was found for Karnofsky Performance Status (KPS ≤ 70: 122 days; KPS > 70: 342 days), for RPA (recursive partitioning analysis) class (RPA class I: 1800 days; RPA class II: 281 days; RPA class III: 130 days), irradiated volume (≤2.5 ml: 354 days; > 2.5 ml: 234 days), prescribed dose (≤18 Gy: 235 days; > 18 Gy: 351 days), gender (male: 235 days; female: 327 days) and whole brain radiotherapy (+WBRT: 341 days/-WBRT: 231 days). In multivariate analysis significance was confirmed for KPS, RPA class and gender. MRI and clinical symptoms suggested radiation necrosis in 21 patients after SRS +/− whole brain radiotherapy (WBRT). In five patients clinically relevant radiation necrosis was confirmed by PET imaging.ConclusionsSRS alone or in combination with WBRT represents a feasible option as initial treatment for patients with brain metastases; however a significant subset of patients may develop neurological complications. Performance status, RPA class and gender were identified to predict improved survival in cerebral metastasized patients.

Highlights

Cerebral metastases are diagnosed in about 30% of patients with advanced tumors [1,2]
Concerning univariate analysis a significant difference in overall survival was found for Karnofsky Performance Status (KPS ≤ 70: 122 days; Karnofsky performance status (KPS) > 70: 342 days), for recursive partitioning analysis (RPA) class (RPA class I: 1800 days; RPA class II: 281 days; RPA class III: 130 days), irradiated volume (≤2.5 ml: 354 days; > 2.5 ml: days), prescribed dose (≤18 Gy: days; > 18 Gy: 351 days), gender and whole brain radiotherapy (+whole-brain radiotherapy (WBRT): 341 days/-WBRT: 231 days)
In multivariate analysis significance was confirmed for KPS, RPA class and gender

Summary

Introduction

Cerebral metastases are diagnosed in about 30% of patients with advanced tumors [1,2]. Patients having more than three brain metastases are generally treated with whole-brain radiotherapy (WBRT). Beside neurosurgical resection stereotactic radiosurgery (SRS) is an effective treatment option for patients with 1–3 brain metastases [3,4]. For radiation treatment some studies have shown that SRS alone might be superior to WBRT alone for survival advantage of RPA class I patients [5,6]. It cannot be excluded that this effect is partially caused by the available salvage options after radiosurgery. In the present study factors affecting survival and toxicity in cerebral metastasized patients treated with stereotactic radiosurgery (SRS) were analyzed with special focus on radiation necrosis

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Results

Discussion

Conclusion