PURPOSE/ OBJECTIVE: Linear accelerator (LINAC) based stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) is delivered with cone or multileaf collimators (MLCs), and favorable dosimetry is associated with reduced radionecrosis in normal brain tissue. This study aims to determine whether cones or MLCs has better dosimetric characteristics, to predict differences in toxicity. METHODS: All patients treated for AVMs using LINAC SRS from 2003-2017 were examined retrospectively. Demographic data, volumes of normal tissue exposed to 12Gy (V12Gy[cc]) and 4Gy (V4Gy[cc]), maximal dose, and dose gradient were analyzed. Univariate and multivariate analyses were used to evaluate relationships between collimator type, dosimetric parameters, and toxicity. Propensity score matching was used to adjust for AVM size. RESULTS: Compared to MLC, cones were independently associated with reduced V12Gy[cc] after propensity score matching (p=0.008) and reduced neurotoxicity (p=0.016). Higher V12Gy[cc] (p=0.0008) and V4Gy[cc] (p=0.002) were associated with increased neurotoxicity. CONCLUSIONS: Treating AVMs with cone-based SRS over MLC-based SRS may improve dosimetry and reduce toxicities.
PURPOSE/ OBJECTIVE: Linear accelerator (LINAC) based stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) is delivered with cone or multileaf collimators (MLCs), and favorable dosimetry is associated with reduced radionecrosis in normal brain tissue. This study aims to determine whether cones or MLCs has better dosimetric characteristics, to predict differences in toxicity. METHODS: All patients treated for AVMs using LINAC SRS from 2003-2017 were examined retrospectively. Demographic data, volumes of normal tissue exposed to 12Gy (V12Gy[cc]) and 4Gy (V4Gy[cc]), maximal dose, and dose gradient were analyzed. Univariate and multivariate analyses were used to evaluate relationships between collimator type, dosimetric parameters, and toxicity. Propensity score matching was used to adjust for AVM size. RESULTS: Compared to MLC, cones were independently associated with reduced V12Gy[cc] after propensity score matching (p=0.008) and reduced neurotoxicity (p=0.016). Higher V12Gy[cc] (p=0.0008) and V4Gy[cc] (p=0.002) were associated with increased neurotoxicity. CONCLUSIONS: Treating AVMs with cone-based SRS over MLC-based SRS may improve dosimetry and reduce toxicities.
Authors: S Yahya; G Heyes; P Nightingale; S Lamin; S Chavda; I Geh; D Spooner; G Cruickshank; P Sanghera Journal: J Clin Neurosci Date: 2017-01-21 Impact factor: 1.961
Authors: A S Shiu; H M Kooy; J R Ewton; S S Tung; J Wong; K Antes; M H Maor Journal: Int J Radiat Oncol Biol Phys Date: 1997-02-01 Impact factor: 7.038
Authors: Mohammad Ali Bitaraf; Ramon Katoozpour; Mazyar Azar; Mohsen Nouri; Seyed Abolghasem Mortazavi; Abbas Amirjamshidi Journal: Asian J Neurosurg Date: 2017 Apr-Jun