Clinical and radiological response of aggressive dural arteriovenous fistula after combined glue embolization and hypofractionated helical TomoTherapy

Abstract

Purpose: We reported the clinical and radiological outcome of an aggressive dural arteriovenous fistula (DAVF) after combined glue embolization and hypofractionated helical TomoTherapy (Hypo-HT). Materials and methods: Eleven patients whose radiological examinations are consistent with aggressive DAVF were treated with combined glue embolization and Hypo-HT 30-36 Gy in 5-6 fractions. The dosimetric analysis, clinical response and radiological imaging obliteration rate by magnetic resonance angiography or computed tomography angiography were investigated. Results: There were eight males and three females with a male and female ratio of 2·67. The mean age was 51·2 years old (range 37-69). Anatomical imaging sites of disease included transverse-sigmoid sinuses (n = 7), superior sagittal sinus (n = 3) and tentorium cerebelli (n = 1). The mean pitch and MF of treatment plans were 0·273 ± 0·032 and 1·70 ± 0·31, respectively. The average size of PTV were 15·39 ± 7·74 cc whereas the R eff,PTV was 1·50 ± 0·25 cm. The average Dmax and Dmin were 37·52 ± 3·34 and 31·77 ± 2·64 Gy, respectively. HI, CI and CI50 were 0·16 ± 0·06, 1·80 ± 0·56 and 7·85 ± 4·16, respectively. The R eff,Rx and Reff,50%Rx were 1·80 ± 0·24 and 2·90 ± 0·45 cm, respectively. The Reff between 50%Rx and 100%Rx was 1·10 ± 0·28 cm on average. With a mean follow up of 28·5 months (range 9-48), the complete recovery of symptoms was found in 72·7 % (eight patients) within 2-12 months after completion Hypo-HT. Partial recovery was reported in 18·2% (two patients). No clinical response was found in 9·1% (one patient). The total radiographic obliteration rate was 27·3% (three patients), subtotal obliteration was 27·3% (three patients) and partial obliteration was 45·4% (five patients). Conclusions: Satisfactory clinical response of aggressive DAVF was found in all treated patients by combining glue embolization and Hypo-HT. All dosimetric parameters were acceptable. We still need an extended follow up time to assess further radiographic obliteration rate and late side effects of the treatment.