CLINICAL CASES   

Gazzetta Medica Italiana Archivio per le Scienze Mediche 2004 December;163(6):285-90

Copyright © 2004 EDIZIONI MINERVA MEDICA

language: English

Treatment evaluation of brain tumors using non-linear analysis of magnetoencephalographic data. A novel technique

Antoniou P. ¹, Anninos P. A. ¹, Piperidou H. ², Adamopoulos A. ¹, Kotini A. ¹, Koukourakis M. I. ³, Sivridis E. ⁴

¹ Laboratory of Medical Physics, Medical School, Democritus University of Thrace, Alexandroupolis, Greece; ² Department of Neurology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece; ³ Department of Radiotherapy, Medical School, Democritus University of Thrace, Alexandroupolis, Greece; ⁴ Department of Pathological Anatomy, Medical School, Democritus University of Thrace, Alexandroupolis, Greece

We ­present the re­sults ­that show­case a nov­el tech­nique ­that can be ­used to in­crease the spec­i­fic­ity of treat­ment eval­u­a­tion pro­ce­dures by ­means of dif­fer­en­tiat­ing the Magnetoencephalo-graphic (MEG) sig­nals re­ceived ­from pa­tients ­with ma­lig­nant cen­tral ner­vous ­system (CNS) le­sions, dur­ing treat­ment us­ing non-lin­e­ar anal­y­sis. We ­present re­cord­ings ­from 2 pa­tients di­ag­nosed ­with ma­lig­nant CNS le­sions. A 122-chan­nel ­SQUID bi­o­mag­ne­tom­e­ter in an ap­pro­pri­ate shield­ed ­room was ­used to ­record the MEG sig­nals and the Grassberger-Procaccia meth­od of ­phase ­space re­con­struc­tion was ap­plied to the re­cord­ed sig­nal ­from ­each pa­tient. By ap­ply­ing the Grassberger-Procaccia meth­od of ­phase ­space re­con­struc­tion to the MEG of pa­tients ­with ma­lig­nant CNS le­sions we ­found ­clear ev­i­dence link­ing the em­bed­ding di­men­sion m in ­which we ­have the on­set of sat­u­ra­tion ­with the ­progress of the treat­ment. These 2 ­case re­ports pro­vide a ­clear in­di­ca­tion ­that the pre­treat­ment MEG sig­nals of CNS ma­lig­nant le­sions ­present ­strong qual­ita­tive and quan­ti­ta­tive dif­fer­enc­es ­from the af­ter-treat­ment MEG sig­nals of the ­same le­sions and ­that non-lin­e­ar anal­y­sis of MEG sig­nals can be ­used for the pur­pose of treat­ment mon­i­tor­ing dur­ing ra­dio­ther­a­py. Further re­search is be­ing con­duct­ed in or­der to as­cer­tain pos­sible quan­ti­ta­tive thresh­olds in the val­ue of the em­bed­ding di­men­sion m ­above ­which sat­u­ra­tion oc­curs and to con­firm the phys­io­log­i­cal mech­a­nism ­which ­would ex­plain our find­ings.