ABSTRACT
Objective: Stereotactic radiotherapy [SRT] has been increasingly used for treatment of brain metastases in recent years. The goal of this study was to evaluate the clinical outcomes in patients with brain metastases treated with LINAC-based SRT
Methods: Patients who underwent SRT at our institution between 2013 and 2017 were retrospectively analyzed. Treatment plans were generated using either iPlan stereotactic treatment planning system [Brainlab Ag, Feldkirchen, Germany] or Eclipse V11.0.47 [Varian Medical Systems, Palo Alto, CA, USA] and patients were treated on a TrueBeam machine equipped with a robotic couch. The treatment response was assessed using RANOBM criteria. The primary endpoint was local control. Secondary endpoints were distant brain control, overall survival and treatment toxicity
Results: Fifty-six patients [28 males and 28 females] with 100 lesions were identified for this study from July 2013 to November 2017. The median age at the time of SRT was 65 years [range 16-86]. The most common histologies were lung [66percent] and breast [26percent]. Seventeen lesions [17percent] were treated postoperatively. Median GPA score [graded prognostic assessment] was 2.5.Treatment regimens consisted of: 1 fraction [median dose = 20 Gy], 3 fractions [median dose = 27 Gy], 5 fractions [median dose = 30 Gy] and 6 fractions [median dose = 30 Gy] in 27percent, 18percent, 41percent and 14percent of the lesions respectively. The median GTV size was 2.44cc [range 0.1-119.67cc] and the median PTV size was 5.03cc [range 0.32-197.22cc]. At a median follow-up of 9.4 months, 7 patients recurred locally. The 1-year local control rate was 88percent and the mean local control was 33 months. The 1-year and mean distant brain control were 45percent and 16.8 months respectively and the 1-year and mean overall survival were 70percent and 29.5 months respectively. A GPA score > 2 was significantly associated with better overall survival than a GPA score
Conclusion: Our institution experience showed that LINAC-based SRT is an effective local ablative treatment for brain metastases with an excellent toxicity profile
ABSTRACT
Rabies is a severe and lethal disease that produces a slight inflammatory response during the infection process. We analyzed the immunopathological mechanisms that occur in the central nervous system (CNS) using mice genetically selected for maximal or minimal acute inflammatory reaction (AIRmax or AIRmin). As viral samples, we adopted the antigenic variant 3 (AgV3) of rabies virus from hematophagous bats and a fixed virus strain (PV1 43/3). Titration of specific antibodies was performed using enzyme-linked immunosorbent assay (ELISA). We observed a slight increase in IgG and IgG1 isotypes in infected AIRmax mice. Incubation period, determined by intracerebral inoculation with 100 LD50, was 6-7 days for PV1 43/4 strain and 9-10 days for AgV3. No difference in viral replication was noticed between AIRmax and AIRmin mice. Mortality was 100 percent with both viral strains. Histopathological analysis of brains and spinal cords showed inflammatory foci in all regions of the CNS. No differences were noticed in the number of neutrophils. Negri bodies were observed in practically all sites analyzed. Results suggested that inflammatory reaction is not a determining factor in the susceptibility to rabies infection.