Diffusion tensor imaging corticospinal tractography in gamma knife radiosurgery for arterio-venous malformations.

Autor: Lupidi, F., Ricciardi, G. K., Foroni, R., Mirtuono, P., Longhi, M., De Simone, A., Gerosa, M., Beltramello, A., Nicolato, A.
Předmět:
Zdroj: Journal of Radiosurgery & SBRT; 2013 Supplement 2.1, Vol. 2, p131-132, 2p
Abstrakt: Purpose: To assess motor pathway radiation exposure by means of integration of tractography into the Gamma Knife (GK) treatment planning and to correlate the dose delivery incorporating the corticospinal tract (CST) with clinical outcome. Methods: A Diffusion Tensor Imaging (DTI) study was performed using a 3 Tesla Magnetic Resonance unit in 28 patients with cerebral arterio-venous malformations (cAVMs) in proximity to the CST before undergoing GK radiosurgery. After three-dimensional tracking of the motor pathway, fiber tracts were matched on T1 volumetric data set, then embedded into DICOM sequences and loaded on the GK treatment planning workstation for co-registration with stereotactic imaging data. In 11 patients the evaluation of CST radiation exposure was retrospectively performed after the radiosurgical procedure (Group A); in 17 patients, the integration of corticospinal tractography was applied during the realization of the treatment planning (Group B). Results: During a median follow-up period of 38 months (range, 12-64 months), four post-radiosurgical complications occurred: three patients experienced a motor deficit still present at last observation (two in the Group A, one in the Group B) and one patient in the Group A had a transient side effect. After univariate logistic regression analysis, motor complications were correlated to the volume of the CST receiving ≥ 20 Gy (P = 0.022). The volume of the CST receiving ≥ 12 Gy was significantly related to the development of overall complications (P = 0.025). In the whole series, the location of the cAVMs in the basal ganglia was correlated with higher volumes of the CST receiving ≥ 12 Gy (P = 0.012). The rate of complications resulted lower when applying integration of tractography during treatment planning (5,9% vs. 27,3%). Considering a follow-up period of at least 36 months for the not yet obliterated cAVMs, the cure rate was similar in the two groups of patients (72,7% Group A vs. 70,0 % Group B). Conclusion. The integration of corticospinal tractography based on 3 Tesla DTI into the GK treatment planning is a reliable technique. Our results show that the volume of the CST receiving ≥ 20 Gy and ≥ 12 Gy are predictors of developing post-radiosurgical complications. Although longer follow-up period and wider series are needed to better define the radiation tolerance of the CST, the visualization of the motor fibers allows to optimize the radiosurgical planning. Disclosure: No significant relationships. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index