ORIGINAL ARTICLES  VASCULAR AND ENDOVASCULAR PAPERS 

The Journal of Cardiovascular Surgery 2000 December;41(6):891-5

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Peripheral vascular brachytherapy: an introduction

Van Sambeek M. R. H. M., Hagenaars T. #, Van Tongeren R. B. M., Van Dijk L. C. °, Hendriks J. M., Coen V. L. M. A. *

From the Department of Vascular Surgery, # Experimental Echocardiography, o Radiology and * Radiotherapy Erasmus University Medical Center, Rotterdam and the Leyenburg Hospital, The Hague, The Netherlands

The ­response of ­cells to ion­ising radi­a­tion has ­been exten­sively ­studied for the ­past 30 ­years. ­When radi­a­tion is ­absorbed in bio­log­ical mate­rial, it can ­directly ­ionise a crit­ical ­site (­direct ­effect) or ­interact ­with ­other mole­cules to pro­duce reac­tive ­free rad­i­cals, ­which can sub­se­quently ­damage crit­ical bio­log­ical mole­cules (indi­rect ­effect). DNA is con­sid­ered the crit­ical ­target dam­aged by ion­ising radi­a­tion by ­both ­direct and indi­rect pro­cesses. ­Since radio­therapy had ­proven to be effec­tive in the treat­ment of non-malig­nant pro­life­ra­tive pro­cesses, it was ­assumed ­that ­this adjunc­tive treat­ment ­would ­also ­inhibit vas­cular resten­osis. The ­major dif­fer­ence ­between ­external and intra­vas­cular radi­a­tion is ­dose dis­tri­bu­tion. Intra­vas­cular ­delivery ­results in ­extremely ­high ­doses to the ­lumen ­with a ­fall-off in ­dose as a func­tion of dis­tance ­from the ­source; ­whereas, ­external ­beam ­would ­deliver a uni­form ­dose ­over the ­entire ­volume of ­tissue ­treated. ­Unlike in the cor­o­nary cir­cu­la­tion ­most of the periph­eral ves­sels ­treated are ­greater ­than 3 mm in diam­eter; in ­fact ­many are 7 to 10 mm in diam­eter. ­Since β radi­a­tion is ­related to ­lower pen­e­tra­tion prop­er­ties and ­more het­er­o­ge­neous dis­tri­bu­tion of radi­a­tion in com­par­ison to γ radiation, it is there­fore nec­es­sary to use a γ radiation ­source ­because it ­would be dif­fi­cult to irra­diate the sub-­intimal ­tissue ­with a β source cen­tred in a ­large ­vessel. Radi­a­tion can and ­does ­have the poten­tial to ­destroy ­blood ves­sels. The chal­lenge in vas­cular bra­chy­therapy is to ­treat ­blood ves­sels to a ­point ­where resten­osis is inhib­ited; yet the ­vessel is not irrep­a­rably dam­aged.