JP7498476B2 - Intravaginal insert for high dose rate brachytherapy for cervical cancer - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) February 28, 2020 https://doi.org/10.1016/j.patent-law-2020-01028. org/10.5114/jcb. 2020.92406

The present invention relates to an intravaginal insertion device for high-dose-rate brachytherapy for cervical cancer.

High-dose-rate brachytherapy for cervical cancer is a therapy used for curative gynecological radiation therapy for patients with advanced cervical cancer. This high-dose-rate brachytherapy for cervical cancer is performed by grasping the three-dimensional positional relationship between the brachytherapy source, the lesion, and normal tissue from CT images. More specifically, first, straw-shaped needle applicators that will later be filled with brachytherapy sources are inserted and placed near or inside the cervical lesion while checking with CT or ultrasound images. When inserting and placing multiple needle applicators, the position of the first needle applicator is confirmed with CT or ultrasound images, and then the insertion point and direction of additional needle applicators relative to the target site is determined based on the confirmed position of the first needle applicator while observing the CT or ultrasound images.

The insertion point and direction of the additional needle applicator into the cervical lesion should be determined not only by CT images or ultrasound images, but also by direct visual evaluation, from the viewpoint of accuracy and efficiency. However, even if a vaginal speculum with a spreading function (see, for example, Patent Document 1) is used to insert a sealed radioactive source into the vagina, the outer surface of the conventional vaginal speculum is curved, so that it is virtually impossible to insert and place a linear needle applicator from the outer surface. In addition, most conventional vaginal speculums are made of metal, and have an electron density not close to that of water, so they are not suitable for radiation therapy. Even if a metal vaginal speculum is used to determine the insertion point and direction of the needle applicator into the cervical lesion and insert it, and then replace it with a vaginal indwelling device for radiation therapy made of a material that does not have the above-mentioned inconveniences, there are problems in terms of accuracy and efficiency because it causes deformation of the cervix and utero-vaginal part. Therefore, the reality is that it is necessary to rely only on CT images or ultrasound images.

Patent No. 6617896

The present invention was made in consideration of the above-mentioned conventional problems and actual circumstances, and aims to provide an intravaginal insertion device that can perform high-dose-rate brachytherapy for cervical cancer by inserting and placing a needle applicator while directly visually observing cervical lesions, not just using CT or ultrasound images.

As a result of extensive research into solving the above problems, the inventors discovered that extremely good results could be obtained by forming a linear guide groove on the outer wall of a vaginal insertion device made of a biocompatible synthetic resin into which a brachytherapy needle applicator, which is subsequently filled with a brachytherapy source, can be inserted, and thus completed the present invention.

That is, the present invention solves the above problems by providing an intravaginal insertion device for high-dose-rate brachytherapy for cervical cancer, which is characterized by having a substantially cylindrical vaginal insertion section made of biocompatible synthetic resin, in which an appropriate number of guide grooves for inserting needle applicators for brachytherapy are linearly formed in the longitudinal axis direction of the outer peripheral wall.

According to the present invention, the hollow part of the approximately cylindrical vaginal insertion part made of biocompatible synthetic resin is open, so that the needle applicator for brachytherapy can be inserted and placed while directly viewing the cervical lesion. As a result, the insertion point and direction of the additional brachytherapy needle applicator can be determined by directly viewing it from the hollow part of the vaginal insertion part together with the CT image or ultrasound image, so that high dose rate brachytherapy for cervical cancer can be performed with higher accuracy and in a time-efficient manner. In addition, by utilizing the linear guide groove formed on the outer wall of the vaginal insertion part, the needle applicator for the additional brachytherapy can be inserted and placed in the cervical lesion via the vagina, so that even fairly large cervical cancer lesions can be treated.

FIG. 2 is a front explanatory diagram of the intravaginal insertion device of the present invention. FIG. 2 is an enlarged cross-sectional view of line AA in FIG. 1; FIG. 2 is a perspective view of the intravaginal insertion device of the present invention.

The following describes an embodiment of the present invention with reference to the drawings.

In Figures 1 to 3, 10 is a substantially cylindrical vaginal insertion part, which is composed of a pair of substantially semi-cylindrical bodies 10a, 10b arranged opposite each other. The bases of the pair of substantially semi-cylindrical bodies 10a, 10b are connected by hinges (not shown) in the same way as a vaginal speculum, so that the distance between them can be freely opened and closed. The degree of the distance between them is preferably about 35 mm at maximum. In addition, it is preferable that the tips of the pair of substantially semi-cylindrical bodies 10a, 10b are curved slightly inward in terms of ease of insertion into the vagina.
A pair of grips 20a, 20b for adjusting the distance between the two are provided on the outer sides of the semi-cylindrical bodies 10a, 10b below the hinge connection, and are provided with appropriate locking and fixing means for the open state. As shown in Figures 1 and 3, the grips 20a, 20b protrude less than the handles of conventional vaginal specula, so as not to interfere with the lateral opening (opening in the direction of the arrow Y, which will be described later) during the open operation.
The semi-cylindrical bodies 10a, 10b and the gripping parts 20a, 20b are required to be made of a biocompatible synthetic resin with an electron density close to that of water for radiation therapy. In addition, using a synthetic resin as the material is advantageous in terms of integral molding by a 3D printer. A hard synthetic resin is used. As the synthetic resin, a photocurable resin is preferable, and an ultraviolet-curable resin is more preferable. Examples of ultraviolet-curable resins include acrylate-based resins such as urethane acrylate, acrylic resin acrylate, and epoxy acrylate. Specifically, there is the resin (Formlabs, Inc.) used in Form2 and Form3.
The size of the vaginal insertion part 10 is appropriately selected according to the vaginal size of the patient.

Reference numeral 30 denotes an insertion guide groove for a needle applicator for brachytherapy, which is filled with a brachytherapy source later, and is formed linearly in the longitudinal direction of the outer peripheral wall of the vaginal insertion part 10. The guide groove 30 is preferably formed to have a cross-sectional shape of approximately 3 mm in a substantially semicircular shape in order to smoothly insert a needle applicator for brachytherapy with a diameter of approximately 0.9 mm. In this connection, a high-dose-rate brachytherapy source is generally constructed by welding a capsule (diameter 0.9 mm, length 4.5 mm) containing a radiation source (iridium 192 or cobalt 60) to the tip of a driving wire cable (diameter 0.7 mm).
The number of guide grooves 30 formed is not particularly limited, but in this embodiment, as shown in Figure 2, a total of 10 guide grooves are formed in each of a pair of approximately semi-cylinders 10a, 10b, with five grooves spaced approximately 5 mm apart, making it possible to insert up to 10 sealed brachytherapy sources, and creating a typical pear-shaped radiation distribution produced in conventional high-dose-rate sealed brachytherapy for cervical cancer.

Next, we will explain an example of how to use the intravaginal insertion device of the present invention in this embodiment.

First, the gap between the pair of approximately semi-cylindrical bodies 10a, 10b is closed, and the pair is inserted into the vagina with the gap facing up, while the gripping parts 20a, 20b for manipulating the gap at the base are exposed to the outside of the vagina. Next, the exposed gripping parts 20a, 20b for manipulating the gap are clamped in the direction of the arrow X in the figure, and the gap between the pair of approximately semi-cylindrical bodies 10a, 10b in the vagina is expanded in the direction of the arrow Y in the figure by an arc-shaped rotation via a hinge, and this state is held and fixed by an appropriate means. Then, the cervical lesion is directly visually observed through the expanded part with a larger field of view, and the insertion point and direction of the appropriate brachytherapy source are determined while observing the CT image or ultrasound image, and then inserted and placed. In addition, the needle applicator for brachytherapy is inserted and placed in the lesion in sequence using the linear guide groove 30, and radiation therapy is performed.

10: vaginal insertion portion 10a: approximately semi-cylindrical body 10b: approximately semi-cylindrical body 20a: gripping portion 20b: gripping portion 30: guide groove

Claims (1)

An intravaginal insertion device for high-dose rate brachytherapy for cervical cancer , characterized in that the device is constructed by connecting the bases of a pair of opposing roughly semi-cylinders with hinges so that the distance between them can be expanded and closed, and is provided with a roughly cylindrical vaginal insertion portion made of biocompatible synthetic resin and an appropriate number of needle applicator insertion guide grooves for brachytherapy formed linearly in the longitudinal axis direction of the outer peripheral wall.

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