METHOD FOR TOTAL IRRADIATION OF THE BODY OF A PATIENT

摘要

FIELD: medicine.;SUBSTANCE: method relates to medicine, namely, to radiation therapy, and can be used for total irradiation of the body of the patient. Rotational irradiation of the patient with a predetermined dose of radiation is executed placing the patient on the treatment table in the rotation plane of a linear electron accelerator rotated around the rotation isocentre with the field and angle of rotation set on the accelerator. Prior to rotational irradiation of the patient, the sector of rotation of the irradiator is therein additionally divided into 11 segments, for each of said segment the correction coefficient k(∝) is calculated by the formula: , wherein is the angle of the irradiator, is the distance from the source to the isocentre of the accelerator, equal to 100 cm, is the distance from the isocentre to a half of the anterior-posterior size of the phantom, is half of the anterior-posterior size of the phantom, is the thickness of the organic glass, is the linear beam attenuation coefficient for the material of the phantom, is the linear beam attenuation coefficient for the material of the screen intended for increasing the dose on the surface of the body of the person. The amount of monitor units is determined, accounting for the set dose and correction factor, by the formula: wherein MU(seg) is the amount of monitor units for a set segment, seg° is the segment value in degrees, MU(full arc) is the experimentally obtained value of monitor units for rotary gantry beam from 305° to 55°, wherein in a plastic phantom installed at a gantry angle of 0° at the centre of the light field, the set dose will be on half of the anterior-posterior size thereof, full arc° is the size of a full arc 110°, k(∝) is the averaged correction coefficient for the set segment. The patient is then placed on the treatment table in the plane of rotation of the accelerator so that at a gantry value of 0° the centre of the light field is located at half the height of the patient. An organic glass screen with a thickness of 1 cm is installed over the patient at a distance of 55 cm from the treatment table and irradiation is executed with a set field of 10.6x40 cm and a rotation angle of 110°.;EFFECT: method ensures creation of uniform distribution of a set absorbed dose in the body for most patients due to the adjustment of the amount of monitor units within individual segments of the rotational irradiation sector.;1 cl, 7 dwg, 10 tbl, 2 ex