Stereotaktik Radyoterapi Uygulanmış Beyin Metastazlı Hastaların Tedavi Sonuçlarının Değerlendirilmesi

Abstract

Eyüb Yaşar Akdemir, Assesment of Results of Patients with Brain Metastases that Recieved Stereotactic Radiotherapy, Hacettepe University Faculty of Medicine, Thesis in Radiation Oncology, Ankara, 2017

Purpose: In this study we aimed to assess the treatment results and prognostic factors in the patients that recieved stereotactic radiosurgery for their brain metastases.

Patients and Methods: Patients that recieved primary, salvage or combine with whole brain radiotherapy and stereotactic radiosurgery (SRS) between years 2007-2016 in your clinic were assessed retrospectively. All of our patients were treated with Cyberknife. Stereotactic frame hasn't been used on any of our patients. Of the patients that recieved stereotactic radiosurgery (n=457), 754 lesions were treated with median 1 fraction (1-5), median 20 Gy(8-36) radiotherapy.Distribution of primary tumoral lesions in the patients is as follows: Lung (55.4%), breast (23.4%), GIS (4.9%), melanoma (4.1%), kidney (3.7%) and other (8.5%). Median age of our patients is 57 (25-86). While median number of tumors that were treated in the first SRS in the patients is 1(1-15), 83.2% of the patients have 1-3, 16.8% of them have 4 or more metastases.Of the patients that were analysed, 28% recieved combined WBRT + SRS, 26.1% only SRS, 37.8% recieved salvage SRS after WBRT and 8% recieved an unknown combination. Patients were assessed for overall survival, distant brain failure free survival; and the lesions were assessed for factors affecting local control.

Findings: Median overall survival of our sample patients was found to be 9.6 months. No significant difference for the survival was found between patients that recieved salvage SRS, combined WBRT + SRS or only SRS (p= 0.345). In single variant analysis, Karnofsky performance score (KPS), age, time passed between diagnosis of malignity and brain metastasis, time between WBRT and SRS, number of brain metastases, cumulative intracranial tumor volume (CITV), neutrophile lymphocyte ratio (NLR), platelet lymphocyte ration (PLR), hemogloubin (hb) were found to be significant variables for the survival and were included in multi-variant analysis. In multi-variant analysis, KPS score 70 and higher (HR =4,64; 95 % CI 1,48-14,6; p=0,009), time passed between diagnosis of malignity and brain metastasis 12 months or more (HR =2,25; 95 % CI 1,06-4,8; p=0,035), time between WBRT and SRS 10 months or more (HR =6,06; 95 % CI 2,18-16,8; p=0,001) and CITV 3cm3 or less (HR =2,42; 95 % CI 1,01-5,78; p=0,046) were found to be statistically associated with survival. Combined treatment (WBRT+SRS) was found to be stastictically significant in multi-variant analysis for distant brain failure free survival (HR =3,946; 95% CI 1,632-9,541; p=0,002). For local control, there was a significant negative correlation between melanoma histopathology (HR = 4,482; 95% CI 2,211-9,087; p <0,001), cumulative BED10 <10 (HR =1,949; 95% CI 1,285-2,956; p=0,002), lesion volume more than 3cm3 (HR =2,601; 95% CI 1,708-3,960; p<0,001), and local control.

Conclusion: SRS is the primary treatment approach for patients with brain metastases. When choosing patients, on top of performance rating of patients and other prognostic factors, CITV should take precedence over number of lesions in the brain. To increase to local control success, primary histopathology, lesion volume and cumulative BED10 should be taken into consideration.