This phenomenon also affects the rate of immune escape, since this rate is determined by the balance of CTL killing and the WT fitness advantage. This analysis predicts that the optimal timing for the selection of immune escape variants will be immediately after the peak of viremia and that the development of escape variants at

later times will lead to slower selection. This has important implications Tubastatin A for comparative studies of immune escape and reversion in different infections and for identifying epitopes with high fitness cost for use as vaccine targets.”
“OBJECTIVE: Patients with convexity and parasagittal (CPS) meningiomas treated with stereotactic radiosurgery (SRS) have been shown to be at risk for posttreatment symptomatic peritumoral edema (SPTE). We sought to analyze the pattern of this complication and compare it with the SPTE experienced in our patients treated with fractionated stereotactic radiotherapy.

METHODS: From January 2003 to October 2005, 32 patients with CPS meningiomas were treated. Thirty patients with a total of 38 lesions had sufficient follow-up for analysis. Group A (n = 14) patients were treated with single fraction SRS, and Group B (n 16) patients were treated with fractionated stereotactic radiotherapy. The lesion volume was different between www.selleckchem.com/products/eft-508.html the two groups with the Group B median volume (7.46 cm(3)) being larger than

that for Group A (2.84 cm(3)) (P = 0.0008). Conversely age, follow-up, sex, prior surgical events, number of lesions, tumor location, and atypical histology did not differ between these Poziotinib research buy groups. The median marginal dose for patients in Group A was 14 Gy (range, 12.5-18 Gy). For Group B, six patients received a median marginal dose of 50.4 Gy in 28 fractions, and 10 patients received a marginal dose of 25 Gy in five fractions.

RESULTS: Seven of the 30 patients treated in this

series developed posttreatment SPTE. The incidence of SPTE in Group A (six of 14 patients) was significantly higher than that in Group B (one of 16 patients) (P = 0.031). The median time to onset of SPTE in the six patients in Group A was 4 months. In Group B, one patient had onset of SPTE in 3 months. On univariate analysis, larger tumor volume (P = 0.0014) and tumor margin dose >14 Gy in patients undergoing SRS (P = 0.031) was associated with onset of SPTE. Age, previous surgery, and tumor location were not associated with onset of SPTE.

CONCLUSION: Despite larger lesion volumes, fractionated stereotactic radiotherapy is associated with less risk of posttreatment SPTE than SRS for patients with CPS meningiomas in our series. For patients treated with SRS, smaller volume and dose <1 4 Gy seems to be safe. Longer follow-up will be required to compare late complications and tumor control rates in these patients.