In modern medical procedures that require both imaging and treatment by x-rays, it is desirable to have a patient table top (also referred to as a couch top) that is transparent to x-radiation. The advent of Cone Beam CT has made it increasingly important that performance of the table top during x-ray imaging be properly taken in to account. Any metal in the CT slice can cause artifacting which reduces image quality and can interfere with calculations that are used to determine the optimum patient radiation dosage. Examples of equipment capable of X-ray and Cone Beam CT application on radiation therapy equipment include Varian Medical System's On Board Imager (OBI) and Elekta's XVI system.
Traditionally, radiation therapy table tops have been made from metal. Up until now, incorporating metal was necessary in order to carry the weight of the patient. Newer radiation therapy treatment table tops generally have metal free imaging and treatment sections, but contain an integral metal tip extension base for attaching extensions and accessories. This “universal tip” is used for certain procedures, but is not required for others. Since it is a permanent part of the table top, it interferes with imaging and treatment at the tip of the table top. It would thus be preferable for this tip to be removable so that it is only attached to the table top when needed. One manufacturer includes a removable tip extension, however, the attachment method of this tip extension (the Medical Intelligence I-beam™ table top) base requires that metal be permanently built in to the tip of the table top. This embedded metal interferes with both imaging and treatment radiation.
Brachytherapy and urological procedures often require attaching accessories to the tip of the patient table top. These include items such a stirrups to hold the patients legs and the stepper devices that are used to aim and insert the catheters through which the radioactive seeds are delivered. Traditionally, only static x-rays were taken during these procedures. However, once again, the advent of modem 3D imaging techniques such as Cone Beam CT has made it possible to acquire a three dimensional understanding of the position of the organ of interest and the device or devices that are being used to treat the patient. Through DICOM, the data from these images can be input into treatment planning software so that improved treatment delivery can be achieved. All of this makes it desirable to be able to take metal free images through the entire table top.
The present invention addresses the above limitations in the prior art and provides a removable tip extension base that can be accurately and repeatably mounted at the end of a table top that is completely metal free in the area of interest for imaging and treatment. The table top is composed primarily of polymer composites reinforced with carbon fibers or other non-metallic fibers such as Kevlar®. The table top allows for accurately and repeatably mounting of removable tip extension members, radiographic phantoms, immobilization devices, brachytherapy steppers, and other devices to the end and sides of the patient table top. However, when the accessories are removed, the result is a completely metal free table top. This improves imaging performance and in particular it improves performance with the new Cone Beam CT technologies that are becoming more prevalent on c-arms and high-energy radiation treatment (Radiation Therapy) machines. In addition, tip extensions of specific function can also be produced this way.
Specifically, the present invention provides a radiolucent patient table top system comprising a patient table with a front, an underside, at least one side and a mounting support structure and further comprising;
The present invention further provides a radiolucent patient table with at least one support beam and comprising a removable tip extension base that has a back face and is attached to the patient table and wherein the tip extension base provides a universal attachment mechanism for attaching one or more accessories to the table.
The present invention also provides a removable modular clamp comprising an upper body, a lower body and a modular center section.
In another embodiment, the present invention provides a method of performing brachytherapy treatment procedures using a table top of the present invention comprising;
In yet another embodiment, the present invention provides a method of treating a patient's head, neck or abdomen with external beam radiation therapy using a table top of the present invention comprising;
The present invention is based on clamping the tip extension to the sides of the table top. This clamping method is unique because it allows extremely high tip loads to be absorbed by the table top. Since the clamps attach to a section of the side of the table top, a large moment load can be reacted. In order to accurately and repeatably mount to the table top, the present invention provides a male and female mating feature along the front edge of the table top. This locates the Tip Extension Base from side to side and can also be used to locate the Tip Extension Base front to back and up and down (X, Y and Z coordinates). Alternatively, the surfaces (top, bottom, front and sides) of the table top can be used to locate the Tip Extension Base.
In a preferred embodiment, a groove or bump runs down the length of either side of the table top to allow the clamps a feature to lock on to, making it harder to dislodge that clamp once it is tightened. By placing indexing features down the length of either side of the couch top, the clamps can be located at a specific longitudinal coordinate. Clamps can be designed so that they can be placed at these discreet locations, located continuously along the length. In order to locate the clamp at the indexing features, the clamp can contain the mating feature, spring loaded pins or other methods of ensuring that the clamp is accurately located. In addition, clamps can be designed so that one clamp can be used in either manner. By producing a modular clamp, a variety of additional accessories can be developed, in addition to the available specific devices and the tip extension base. This clamp is produced in sections so that common parts become the building blocks for other accessories.
It is desirable that table tops designed for medical applications to be free of features on their top surface that could collect fluids. In a preferred embodiment, a clamp groove is placed longitudinally down either side of the bottom of the table top. This provides a feature that can be grabbed by a clamp but does not present a fluid gathering site.
Although we have shown a flat upper surface in most of the accompanying figures, this means that the top of the clamp rises above the top plane of the table top. This can become an obstruction in cases where additional devices may need to be placed on the top surface of the table top. In a preferred embodiment, the edges of the table top can be recessed either locally or completely along each edge so that the top of the clamp is flush or slightly below the top surface of the table top.
A table top of the instant invention provides a particularly good platform for modern brachytherapy that is coupled with C-arm or Cone Beam CT technology. A new methodology for imaging and treating the patient in which minimal movement of the patient is required is possible with the present invention. This is particularly important in brachytherapy because imaging of the patient commonly occurs after the delivery needles have been inserted into sensitive areas such as the perineum. Moving the patient at this time can be quite risky. An example of the methodology applied to gynecological or prostrate procedures that can now be followed is to:
1) Attach a drop leaf tip extension (leg support board) to the tip of the table top which allows the patient's legs to be rotated to horizontal. The leaf is initially placed in the down or vertical position so that the patient can easily sit at the tip of the table top.
2) The patient then lies back on the table top and the drop leaf extension is rotated to horizontal. Thereby, placing the patient in the horizontal position.
3) Stirrups may then be attached and the patient's legs are then placed up in the stirrups. The drop leaf tip extension can now be removed, leaving the lower abdomen area free for imaging studies. By using radiolucent composite stirrups we are able to image through them, including when using Cone Beam CT. Imaging may take place at this time.
4) The brachytherapy stepper (aiming device) can be attached in place of the drop leaf tip extension. At this point, insertion of cannula (i) or catheter can take place. By removing the stepper, one can now take images and Cone Beam CT studies without moving the patient longitudinally down the table top because there is not metal or other artifacting features present at the tip of the table top.
5) Once the medical staff are confident of the treatment plan and positioning of the cannula (i) or catheter, treatment can commence.
The present invention provides a method of adding a variety of useful accessories without introducing any permanent metal components in the imaging/treatment area of the table top. The accessories can include at least one selected from the group consisting of tip extension, a head support board, a head and neck immobilization board, an x-ray phantom, a leg support board, a brachytherapy stepper assembly and a tip extension base stirrup, brachytherapy stepper device, clamps, modular clamps, tip extension base, and drop leaf tip extension. In addition, the design of the present table top system allows a table to be constructed that is uniform in carbon fiber skin thickness so that image artifacting is minimized. In addition, the uniform construction also allows for minimum electron generation when used in high energy radiation therapy.
Furthermore, the present invention provides a method of attaching accessories that is also compatible with adding accessories to the tip of a sliding beam couch top that does not have a permanent connection across the front of the two beams.
The table top and accessories of this invention are designed so that the best possible imaging and treatment configurations are possible. With all accessories removed, the table top is completely metal free in the area of interest.
In a preferred embodiment, it is preferable that the accessory clamps remain flush or below the top surface of the table top. This embodiment is illustrated in
In
This application claims the benefit of U.S. Provisional Application 60/782,033 filed 14 Mar. 2006, entitled “Radiolucent Patent Treatment Table with Removable Tip Extension Base and Accessories.”
Number | Date | Country | |
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60782033 | Mar 2006 | US |