ИСТИНА

Cur­rently, the cal­cu­la­tion of the pro­ton range in pa­tients re­ceiv­ing pro­ton ther­apy is based on the con­ver­sion of Hounsfield CT units of the pa­tient’s tis­sues into the rel­a­tive stop­ping power of pro­tons. Pro­ton ra­di­og­ra­phy is able to re­duce these un­cer­tain­ties by di­rectly mea­sur­ing pro­ton stop­ping power. How­ever, pro­ton imag­ing sys­tems can­not han­dle the pro­ton beam in­ten­si­ties used in stan­dard pro­ton ther­apy. This means that for im­ple­men­ta­tion of pro­ton ra­di­og­ra­phy it is nec­es­sary to re­duce the in­ten­sity of the pro­tons sig­nif­i­cantly. This study demon­strates the cur­rent ver­sion of the new beam con­trol sys­tem for low pro­ton in­ten­sity ex­trac­tion. The sys­tem is based on au­to­matic re­mov­able unit with spe­cial lu­mi­nes­cence film and sen­si­tive pho­tore­cep­tor. Using of the re­mov­able mod­ule al­lows us to save ini­tial pa­ra­me­ters of the ther­apy beam. Re­mote au­to­matic con­trol of this unit will pro­vide switch ther­apy and imag­ing modes be­tween syn­chro­tron cy­cles. The work de­scribes al­go­rithms of low flux beam con­trol, cal­i­bra­tion pro­ce­dures and ex­per­i­men­tal mea­sure­ments. Mea­sure­ments and cal­i­bra­tion pro­ce­dures were per­formed with cer­ti­fied Pro­tom Fara­day Cup, PTW Bragg Peak Cham­ber and spe­cially de­signed ex­per­i­men­tal ex­ter­nal de­tec­tor. The de­vel­op­ment can be im­ple­mented in any pro­ton ther­apy com­plexes based on the Pro­tom syn­chro­tron. This allow us to use ini­tial syn­chro­tron beam as a tool for pa­tient ver­i­fi­ca­tion and to elim­i­nate pro­ton range un­cer­tain­ties.