Utilidad de la tractografía por DTI para el tratamiento de tumores cerebrales supratentoriales y malformaciones arteriovenosas por radiocirugía

Abstract

Introduction: Radiosurgery of supratentorial lesions carries a risk of neurological deficits secondary to damage of critical white matter tracts. DTI tractography allows identification of these tracts, to limit the radiation dose they receive. The efficacy of this technique has not been well defined in the literature. Methods: A systematic, narrative review of the literature was performed. We studied possible constraints for different tracts (in studies correlating dosimetry within tracts and clinical complications), planning modifications induced by integration of DTI tractography and comparison of clinical results, with and without integration of tractography. Results: 12 studies were identified, mostly retrospective series. Major findings were that different tracts seem to have different constraints: in the pyramidal tract, complications appear over 20 Gy of DMAX (with higher risk in internal capsule). The frontal branch of the arcuate fasciculus (FA) seems to have similar constraints. Temporal branch of FA seems to have a lower threshold (with complications appearing over 8 Gy). The posterior optic pathway seems to have similar constraints values than the optic nerve and chiasma (complications begin to appear over 8Gy). The consensus over several studies is that DTI tractography allows to limit radiation dose over studied tracts without compromising tumor or AVM control. Studies including DTI tractography prospectively show almost no complications, and one comparative study shows fewer complications when DTI tractography is used.