Rectum eccentric four-cavity applicator

Abstract

The invention discloses a rectum eccentric four-cavity applicator. The outside diameter of the applicator is between 25 and 35mm; four supplying radiator ducts are inserted into a cavity of an outer tube and parallel to the axes of the outer tube; the four supplying radiator ducts are all deviated to the circle center of the outer tube, and distributed and fixed in the cavity of the outer tube at intervals along a segment of circular arc in the cross section of the outer tube; and circular arcs between two circle centers of adjacent two supplying radiator ducts are equal, and center angles corresponding to the circular arcs are between 45 and 75 DEG. By adopting the eccentric four-cavity applicator, applicators with different diameters can be selected according to the range where tumors intrude rectum and physiological characteristics of a patient; three or four supplying radiator ducts can be freely selected according to sizes of the tumors to apply radioactive sources; and the weighting of two side tubes can be regulated according to the elimination of the tumors, so that the radiated area in a high dose area is reduced, radiation to normal mucous membrane tissues and back wall of a bladder near the tumors in the rectum is reduced, the incidence rate of complicating diseases in early and late radiation is reduced, and the effect of radiation therapy is improved.

Description

technical field [0001] The invention relates to a medical device for radiotherapy cancer, in particular to an eccentric four-cavity rectal applicator for treating rectal cancer. Background technique [0002] The traditional γ-ray rectal afterloading therapy applicator is a single-cavity applicator, that is, the applicator has only one applicator tube. For example, the remote-controlled high-dose afterloading machine produced by Buchler Factory has a model LA412 11 applicator with an inner diameter of 6 mm and a model LA412 15 with an inner diameter of 4 mm, both of which are single-cavity applicators. The applicator tube of this applicator is located in the center of the applicator, and several rectal dilators with a diameter of 1.5 cm can be attached to the outside. The Russian Radiation Engineering Research Center once designed the "Applicator for Rectal Neutron Afterloading Therapy", and won the gold medal of the "Brussels Eureka-94" World Invention, Research and Industr...

AI Technical Summary

Problems solved by technology

For example, a symmetrical four-cavity applicator with four source tubes evenly distributed in the cavity cross-section of the outer tube has a diameter of 30 mm. Since the four source tubes are evenly distributed in a 360° circle, two The center angle of the arc between the centers of the source tubes is 90°, which has certain advantages in the treatment of tumors at multiple sites, but when treating tumors at single sites, the two adjacent source tubes The distance between the two source tubes is too large, and the straight-line distance between the centers of the two source tubes reaches about 18.00mm, resulting in uneven dose distribution. A low-volume area is likely to appear between the two source tubes, which is likely to cause tumor recurrence

Another example is an eccentric three-cavity applicator with three applicator tubes arranged asymmetrically in the cross-section of the cavity of the outer tube. Since there are only three source tubes, when the structure of distributing the three source tubes in the arc range > 180° is adopted, The central angle of the arc between the two adjacent source tubes is greater than >90°, because the distance between the two adjacent source tubes is too large, the center of the two source tubes The straight-line distance between them is more than 18.00mm, resulting in uneven dose distribution, and a low-dose area is likely to appear between the two source tubes, which is likely to cause tumor recurrence; There is also a small irradiation range, which is not conducive to the treatment of rectal cancer whose tumor invades ≥ 1 / 2 circle of the rectum

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