US20050275126A1

US20050275126A1 - Template and method for making a form for casting a radiation treatment block

Info

Publication number: US20050275126A1
Application number: US11/208,352
Authority: US
Inventors: Clifford Merlo
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-10-28
Filing date: 2005-08-19
Publication date: 2005-12-15
Also published as: WO2005044082A2; EP1678726A2; WO2005044082A3; CA2535159A1; US7009194B2; AU2004287447A1; US20050087703A1

Abstract

The present invention provides apparatuses and methods for forming a radiation treatment block using a template with the perimetric outline of different sized radiation treatment blocks with a foam block cutting machine to make a foam mold for casting a radiation treatment block.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of and claims priority from U.S. patent application Ser. No. 10/696,372, filed on Oct. 28, 2003, titled Method for Mounting Radiation Treatment Blocks on a Radiation Treatment Block Mounting Plate, an Adjustable Radiation Treatment Block Mounting Tray and a Template and Method for Making a Form for Casting a Radiation Treatment Block. This application incorporates by reference the aforementioned enumerated patent application and all disclosures therein.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to the area of medicine known as radiation oncology which uses radiation to treat cancer and, more specifically, to a template and method for making a form for casting a radiation treatment block.
2. Description of Related Art and Other Considerations
Radiation produced in a machine and directed towards cancer in humans and animals was found to be effective by the early 1900's. Original machines did not have apertures to control the size of the radiation beam, but later improvements in the form of blocking apertures were placed around the radiation beam to reduce the size of the emanating beam and to provide some protection to uninvolved body structures and anatomy of the patient. The ability to provide protection to uninvolved body structures is highly desirous and allows physicians to increase the radiation dose with the aim of obtaining enhanced results in the treatment of the cancer. To that end, radiation treatment blocks were developed.
Radiation treatment blocks are blocks of metal placed in the path of the radiation beam to shape the radiation beam so that the beam is applied to the prescribed area of treatment for the patient. Historically, radiation blocks were produced in standard shapes without regard to the specific anatomy of a patient. This often required that multiple blocks be utilized to shape the radiation beam to the desired field. This is labor intensive as typically the blocks are heavy. Also, because the blocks were available only in preformed geometric shapes, it also made it difficult to precisely shape the radiation beam to the anatomy of each patient.
More recent technology allows a radiation treatment block to be custom fabricated to precisely shape the radiation beam to a specific patient's anatomy. However, even with the development of custom fabricated radiation treatment blocks, problems with mounting and adjusting the blocks within the radiation beam have persisted. The present methods and apparatuses solve these problems.
Custom blocking structures, or radiation treatment blocks, must be tailored to precisely fit patients and their anatomies. Therefore, for each patient, each block is cut or configured with an aperture which is precisely shaped to “fit” the specific patient's anatomy and is placed in the path of the radiation treatment beam to provide further protection to uninvolved anatomy, thereby allowing even higher doses of radiation to be delivered to the cancer. As higher and higher doses are administered to the patient, the exact position of these blocks in the beam is of paramount importance, because even small deviations of the block aperture and, thus, the beam configuration can lead to permanent, irreversible damage to uninvolved anatomy of the patient.
There are several conventionally employed block positioning techniques and devices for shaping the radiation beam, but all have deficiencies as more fully discussed below, such as block misalignment and inaccurate positioning, the potential for radiation contamination of the treatment facility with toxic and carcinogenic heavy metals, and creating environmentally toxic waste.
A. Misalignment/Inaccuracy Problems
Currently, blocks are typically set on a clear plastic plate known as a block mounting tray or plate, which fits into the radiation treatment machine. The block is typically held in position by gravitational force when the tray is in its horizontal position with respect to the treatment machine. Typically, a radiation technologist, that is the person who administers the radiation to the patient on a day-to-day basis, places and aligns the block each day by hand. This is a tedious, time-consuming procedure, which often results in significant day-to-day variation in positioning the block, all of which are undesirable. Due to the constant handling of radiation treatment blocks by the technologist, there is a potential for the technologist to be exposed to the toxic heavy metals in the block.
An article entitled “Potential Exposure to Metal Fumes, Particulates, and Organic Vapors During Radiotherapy Shielding Block Fabrication” appearing in the September/October 1986 edition of Medical Physics identified potential hazards to block handling personnel as including: (1) bruises to hands or feet from dropped blocks, (2) inhalation of metallic dust particles and fumes, (3) ingestion of metal alloy, (4) skin absorption of metal alloy, and (5) lifting hazards posed by placing very heavy blocks into position.
When the tray is in a more vertical position and, therefore, not supported by the block mounting tray, the block will move or slide off of the tray unless the block is held onto the tray. Accordingly, various methods and devices have been used to mount the block to the tray. The most widely-used method involves the drilling of a hole in the bottom of the block and screwing it to the tray with a simple sheet metal screw. However, many technologists have difficulty in performing this task because it requires a certain degree of skill and careful positioning of the block on the tray, and the effective use of a drill and sheet metal screws. In addition, because the metals and alloys most commonly utilized to form the block are relatively soft, the screw threads in the block can easily be stripped, making it difficult to securely affix the block to the tray. The result is often that the block is poorly secured to the tray, and is loose and slightly misaligned with respect to the beam.
Efforts to correct these problems create further difficulties. When a block is misaligned but fixed to the tray, some technologists often simply compensate for the misalignment by moving the patient, who is already laying or positioned on the treatment machine, with respect to the beam. However, such movement of the patient may create an aberration in the geometry calculated for the treatment and result in a significant change in the dose of radiation delivered to the patient. Furthermore, such compensation may not be communicated to another technologist who provides subsequent treatment. As a result, uninvolved structures or radiation sensitive body parts in the patient may be over-irradiated and permanently damaged.
Other technologists, when confronted with a fixed, but misaligned block, usually elect to cancel treatment on that day and have the patient return for treatment on a subsequent day, after the tray has been dismantled and the block re-affixed to the tray. Such cancellation results in wasted time and effort for both the patient and the technologist, including lost treatment days for the patient. In addition, this subsequent effort to re-affix the block to the tray may also result in a misaligned block. Remounting the block also requires additional handling of the block, which increases the risk that the radiation technologist may be exposed to the toxic metals that are present in the block.
Another method, in an effort to improve the alignment of the block with respect to the tray, involves the milling of slots through the tray. With this method, the sheet metal screw is loosened, the block is slid with respect to the tray, and the screw is then retightened. This procedure allows the block to be adjusted in one direction, with the goal of regaining the proper alignment. Unfortunately, because such milled slots allow an adjustment in only a single direction, their use does not allow the block to be adjusted in a direction perpendicular to that of the slots. Furthermore, the milling of intersecting perpendicular slots in a tray may weaken its structural integrity and, because the blocks are relatively heavy, they can cause the tray to sag, resulting in the misalignment of the block or even fracture, possibly causing injury to the patient or attending personnel.
A less-commonly used system to affix a block to a tray involves the use of a double-sided, adhesive, foam tape. This system suffers from the alignment-of-the-tray-to-block problem described above, as well as from an inability to adjust the block once it is fixed to the tray. In addition, it is possible that a block, which can weigh as much as twenty-five pounds, could fall on a patient or a technologist, which renders this tape-fixing system a less-favored solution due to safety concerns.
B. Contamination of the Radiation Treatment Facility
In addition to the above-described problems, most blocks are formed from an alloy of toxic heavy metals, specifically lead and cadmium, both of which have known health risks. Cadmium is also known to be highly carcinogenic. The repeated handling of these blocks potentially exposes the technologists to these toxic and carcinogenic metals. Additionally, any drilling of them creates an even greater health risk in the form of fine toxic and carcinogenic dust which, without proper handling, can rapidly permeate the radiation treatment facility and, thus, create a hazardous environment for patients and personnel within the facility.
A variation of the sheet-metal-screw method described above is directed to avoid the drilling of the block and, therefore, the contamination of the radiation treatment facility. In this variation, a sheet metal screw is sunk into the alloy while it is still molten to form a properly molded hole. Once the alloy has solidified, the sheet metal screw is removed and replaced by a shorter sheet metal screw for securing the block to the tray. Although this method avoids the generation of fine, toxic dust from drilling, it still suffers from the other disadvantages of the previously-described method, that is, the metal of the block being softer than the metal of the screw creates the chance that the threads produced in the block can become stripped, which can cause misalignment of the block or result in the block falling off the tray and injuring the patient or technologist. Correction of misalignment problems is difficult and time consuming. If the threads become stripped, a new block has to be cast and/or a new hole has to be drilled. If a new hole is drilled, toxic shavings and dust are created.
C. Environmentally Toxic Waste
Another known method to affix a block to a tray is by sinking a one or more threaded rod into the molten alloy while the alloy is in the block forming mold. After the alloy has cooled a nut can be screwed onto each threaded rod protruding through a hole or slot in the tray in order to affix the block to the tray. This technique again requires an alignment of the tray to the block and can result in possible misalignment inaccuracies due to a single attachment point when one rod is used which can allow the block to shift or rotate on the tray. If more than one rod is used it creates multiple attachment points which makes it difficult to adjust the position of the block on the tray. Furthermore, after the block is no longer needed, the block is melted, whereupon each threaded rod will float to the top of the molten alloy where they can be retrieved. Retrieved threaded rods, however, are usually coated with solidified hazardous alloy or metals and are therefore, unusable. As a result, the rods must be disposed of in accordance with environmental regulations. This creates additional hazardous materials that must be disposed of at licensed disposal facilities. Proper disposal of toxic materials is both costly and time consuming for the facility staff due to the documentation required by environmental regulations. In the past, improper disposal of toxic metals into the general waste system of the local municipality has resulted in toxic pollution to the environment. As an example, many species of trees and the white-tailed ptarmigan of the Rocky Mountains have thereby been exposed to cadmium toxicity as a result of improper disposal or containment of materials containing cadmium.
D. Current Radiation Block Forming Techniques
Currently, radiation treatment blocks are typically prepared by a technologist drawing the perimetric outline of a block around a prescribed treatment area that has been drawn on an x-ray film of a patient by an oncologist. The technologist first draws the outline of the appropriate size radiation treatment block and then traces that pattern on a foam block cutting machine to cut the outline of a radiation treatment block. This procedure is difficult because the technologist has to decide on the correct perimetric outline of a block and oftentimes has no specific guidelines for making the decision. As a result, the sides of a resultant block are oftentimes not square, not properly oriented and of insufficient thickness resulting in the radiation beam spilling over the outer edge of the block. This can result in radiation being applied to uninvolved structures and patient anatomy. The template of the present invention allows a technologist to overlay a template on the marked x-ray film or vice versa. The technologist then can readily observe the appropriate perimetric outline on the template and simply trace the outline using the stylus of the foam block cutting machine. A hot wire present in the machine cuts the perimetric outline of the foam block to correspond with the perimetric outline on the template. A designated beam shaping area can also be cut within the body of the block that will shape the radiation beam for the prescribed treatment. The use of the template saves the technologist time in the preparation of a form for casting a radiation treatment block. The template optionally also provides notches on the sides and corners of the perimetric outlines of the blocks.
Tracing of the notches with the stylus of the foam block cutting machine when the perimetric outline of the block is being cut in the foam block will create notches in the block when it is cast. The notches in the block will accept the shaft of a clamping device as shown in U.S. patent application Ser. No. 10/696,372 to assist in aligning and clamping a block to a mounting tray or plate.
E. Description of the Art
The patent literature includes a description of technology encompassing the above-described problems.
U.S. Pat. No. 5,115,139 (“Cotter patent”) discloses a slotted bracket attached to the underside of a block, through which a connecting bolt passes to run in a slot milled into a tray. The device of the Cotter patent allows the block to be adjusted in a lateral direction and to rotate the block on the tray. However, the device disclosed in the Cotter patent is not applicable to most modem blocks now commonly used, which are specifically cast to match the anatomy of a unique patient undergoing treatment. Furthermore, the device involves only a single point-of-attachment for these heavy blocks that allows for possible unintended rotation or migration of the block on the tray under the influence of gravity. The device also requires that holes be drilled into or cast into the block. If holes are drilled, the Cotter device creates toxic metal dust and particulate matter. If the holes are drilled or cast, they are prone to stripping due to the softness of the metal that is most commonly used to form the blocks.
U.S. Pat. No. 4,266,139 (“'139 patent”) describes a base plate that moves in parallel mounting rails. The device disclosed in the '139 patent allows a plate with a masking overlay to be mounted on a radiation machine. The device, however, does not allow precise multidirectional adjustment of the masking overlay. In addition, the device uses Velcro strips to attach thin metal shield plates thereto. Such a system is incompatible with most custom cast blocks in use today, which can be very heavy and would raise safety concerns if the block fell from the tray.
U.S. Pat. No. 4,472,637 (“'637 patent”) discloses a base plate that can be mounted in slots on a radiation machine. The device allows only bi-directional movement of blocking shields. The '637 patent also discloses a shield with a single attachment point which can be prone to misalignment or rotational movement of the shield on the tray resulting in inaccurate and potentially injurious treatment of the patient.
U.S. Pat. No. 5,056,128 (“'128 patent”) discloses a metal base plate and allows the magnetic mounting of radiation shielding devices. The apparatus would likely not work with the radiation treatment blocks currently in use because: (1) they are not magnetic, and (2) the size and weight of the blocks may make magnetic mounting unsafe.
U.S. Pat. No. 4,700,451 (“'451 patent”) describes a method for indexing a block to a tray. The method, however, uses screws to attach the custom cast block to the tray. This method requires that holes be drilled into the block to secure the screws. This creates toxic dust and particulate matter which exposes technologists to toxic metal. This method also creates the potential for the screws to strip out of the holes resulting in possible misalignment of the block or could result in the block falling off the tray and injuring a patient or technologist.

BRIEF SUMMARY OF THE INVENTION

A template of this invention for use with a foam block cutting machine for making a form to cast a radiation treatment block comprises a preferably transparent sheet or plate having perimetric outlines of radiation treatment blocks of varying sizes marked or inscribed thereon. A method of this invention for making a foam form to cast a radiation treatment block comprises using a template with the perimetric outlines of varying sizes of radiation treatment blocks with a foam block cutting machine to cut the perimetric outline of a radiation treatment block.
Other objects and advantages, as well as a more complete understanding of the present invention, will appear from the following explanation of preferred embodiments and the accompanying drawings thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a template of the present invention that can be used with a foam block cutting machine to produce a form to cast a radiation treatment block.
FIG. 2 shows a template of the present invention that is currently in use on a foam block cutting machine.
FIG. 3 shows a ruler of the present invention that can be used to draw perimetric outlines on a template of the invention.
FIG. 4 shows a radiation treatment block fabricated using the devices and methods of the present invention mounted on a radiation treatment block mounting tray.
FIG. 5 shows a radiation treatment block with a ridge protruding from a side of the radiation treatment block. The ridge assists the technologist in the proper positioning and alignment of the radiation treatment block.
Specific apparatuses and methods within the scope of the present invention include, but are not limited to, the apparatuses and methods discussed in detail herein and/or illustrated in the drawings that are present herein.
Contemplated equivalents of the apparatuses and methods described and illustrated herein and/or illustrated in the drawings contained herein include apparatuses and methods which otherwise correspond thereto, and which have the same general properties and/or components thereof, wherein one or more simple or other variations of components, materials or steps are made.
All of the structures and components used in the apparatuses and methods of the current invention and to carry out the methods of the present invention, are commercially-available from sources known by those of ordinary skill in the art.
The different components and structures that may be employed in the methods and apparatuses of the present invention may be generally arranged in the manner shown in the drawings, or described hereinbelow. However, the present invention is not limited to methods and apparatuses shown in the drawings and specifically described herein having the precise arrangements, configurations, dimensions and/or instrumentalities shown in these drawings, or described hereinbelow. These arrangements, configurations, dimensions and instrumentalities may be otherwise, as circumstances require.
Different specific embodiments of that may be employed in the methods and apparatuses of the present invention will now be described with reference to the drawings.

DETAILED DESCRIPTION

Some Preferred Embodiments
In a first aspect the present invention provides for a template for use with a foam block cutting machine for making a form to cast a radiation treatment block, comprising a sheet, said sheet having marked or inscribed thereon at least one perimetric outline of a radiation treatment block.
In a second aspect the present invention provides for a template for use with a foam block cutting machine for making a form to cast a radiation treatment block, said template comprising a transparent sheet, said sheet having marked or inscribed thereon perimetric outlines of radiation treatment blocks having different sizes, each perimetric outline of a radiation treatment block present on said template having four sides, being rectangular in shape, and having four corners, each of said sides having a rectangular notch positioned thereon, each perimetric outline of a radiation treatment block present on said template having a rectangular notch present on each corner of said perimetric outline, said template further having a horizontal and a vertical line that intersect at a center of said perimetric outlines of said template, said template further having a radiation treatment block alignment line marked or scribed thereon, said radiation treatment block alignment line being positioned such that it intersects with one side of each perimetric outline of a radiation treatment block present on said template, said side having a protrusion thereon extending from said side at the intersection of said side with the radiation treatment block alignment line.
In a third aspect the present invention provides for a method for making a foam form to cast a radiation treatment block comprising:

- (a) providing a foam block cutting machine for making a form to cast a radiation treatment block, said foam block cutting machine having a light table, a hot wire frame, said hot wire frame having an upper hot wire frame member and a lower hot wire frame member, and a hot wire for cutting a foam block, said hot wire being positioned between said upper and lower hot wire frame members, said foam block cutting machine further having a stylus connected to said hot wire frame for tracing a perimetric outline of a radiation treatment block, and a tray for holding a foam block;
- (b) positioning a template for use with a foam block cutting machine for making a form to cast a radiation treatment block on said light table, said template comprising a transparent sheet, said sheet having marked or inscribed thereon a perimetric outline of at least one radiation treatment block;
- (c) placing a foam block for casting a radiation treatment block on said tray;
- (d) tracing a perimetric outline of a radiation treatment block present on said template with said stylus causing said hot wire to cut said foam block in a same perimetric dimension as said perimetric outline of said radiation treatment block on said template.

In a fourth aspect the present invention provides for a ruler for use with a template for use with a foam block cutting machine for making a form to cast a radiation treatment block, said ruler having an elongated rectangular shape, said ruler having four sides, two of said sides being elongated, at least one elongated side having a tab protruding from an elongated side.
In a fifth aspect the present invention provides for a ruler for use with a template for use with a foam block cutting machine for making a form to cast a radiation treatment block, said ruler having four sides, two of said sides being elongated, at least one elongated side having a notch present therein.
FIG. 1 shows a template 310 for use with a foam block cutting machine for making a form to cast a radiation treatment block 25. In the embodiment shown, the template 310 is made from a transparent sheet 311. In the embodiment shown, the template 310 is made from a sheet 311 of plastic, however, it is recognized that other materials such as polymers, acrylics and glass would also be suitable. Although it is preferable that the sheet 311 be transparent a non-transparent or translucent sheet can also be suitable. The transparent sheet 311 has marked or scribed thereon perimetric outlines 312 of radiation treatment blocks 25 having different sizes. This allows a radiation technologist or oncologist to select the perimetric outline 312 to correspond with the required size of a radiation treatment block 25 to be fabricated. The template 310 can be provided with a horizontal line 314 and a vertical line 315 that intersect at the center of a perimetric outline 312 present on a template 310. The horizontal and vertical lines 314 and 315 can be utilized to align the template 310 with corresponding horizontal and vertical lines 316, 317 that can be present on a light table 301 of the foam block cutting machine 300 (each shown in FIG. 2).
In the embodiment shown, each side of a perimetric outline 312 has a notch 313 positioned therein. In the embodiment shown, each corner of a plurality of perimetric outlines 312 have a notch 313 positioned therein. In the embodiment shown, the notch 313 is rectangular, however, it is recognized that the notch can also be U-shaped or V-shaped. It is recognized that the perimetric outlines 312 of radiation treatment blocks 25 present on the template 310 can be provided without notches 313 positioned therein.
The template 310 can optionally have a radiation treatment block alignment line 32 scribed or marked thereon. At an intersection of the radiation treatment block alignment line 32 with a side of a perimetric outline 312 of a radiation treatment block 25, a ridge 325 is marked or scribed on the template 310. The ridge 325 protrudes from a side of a perimetric outline 312 of a radiation treatment block 25. When a radiation technologist traces over a ridge 325 present on a perimetric outline 312 of a radiation treatment block 25, a ridge 325 will be formed in foam block 307 form that can be used to cast a radiation treatment block 25. When the radiation treatment block 25 is cast in the foam block 307 form a ridge 31 will protrude from a side surface 28 of the radiation treatment block 25. The ridge 31 allows the radiation treatment block 25 to be accurately aligned and positioned on a radiation block mounting tray.
FIG. 2 shows a foam block cutting machine 300 for cutting a foam form for casting a radiation treatment block 25. A template 310 for tracing a perimetric outline 312 of a radiation treatment block 25 can be placed on a light table 301 of a foam block cutting machine 300. A radiation technologist can trace a selected perimetric outline 312 of a radiation treatment block 25 on the template 310 with a stylus 302 present on the foam block cutting machine 300. The stylus 302 is connected to a hot wire frame 303 that has a hot wire 304 positioned between an upper hot wire frame member 305 and a lower hot wire frame member 306. A foam block 307 is positioned in a foam block mounting tray 308. As a radiation technologist traces a perimetric outline 312 of a radiation treatment block 25 on the template 310 the hot wire 304 cuts the foam block 307 to the same perimetric outline 312 of the radiation treatment block 25 on the template. 310. If required by the prescribed treatment, the technologist can also cut the foam block 307 to create an opening in the foam block 307 that will create a beam shaping opening in the radiation treatment block 25 when a radiation treatment block 25 is cast in the foam block 307 form.
FIG. 3 shows two embodiments of a ruler 400 and 401. One embodiment of a ruler 400 has a notch 402 present therein. An alternative embodiment of a rule 401 has a tab 403 present thereon. The rulers 400 and 401 can be used by a technologist to guide a stylus 302 of a foam block cutting machine 300 while tracing a perimetric outline 312 of a radiation treatment block 25 on the template 310. The notch 402 and the tab 403 facilitate the tracing of one or more notches 313 present on a template 310. It is also recognized that a ruler 400 or 401 can have both a notch 402 and a tab 403 present therein.
FIG. 4 shows an adjustable radiation treatment block mounting tray 1 having a radiation treatment block 25 fabricated using the devices and methods of the present invention mounted on an upper face 14 of the plate 12. The block 25 is compressibly secured to the upper face 14 of the plate 12 of the adjustable radiation block mounting tray 1 using a plurality of external clamping devices 40. The threaded end portion 44 of the rod 41 that is present on the external clamping device 40 can be inserted through a block mounting hole 15 or slot 16 positioned proximate a groove 29 in a side surface 28 of the block 25, and a threaded nut 43 can be attached to the threaded end portion 44 of the rod 41 (see FIG. 5). An opposite hingeable connection end portion 45 of the rod 41 is hingeably connected to the hingeable connection end portion 46 of the shaft 42 present on the clamping device 40 (see FIG. 5). The shaft 42 is pivoted until an opposite substantially hook shaped end portion 47 present on the shaft 42 is positioned above a top surface 26 of the radiation treatment block 25 and the shaft 42 is at least partially in the groove 29 (FIG. 5). The threaded nut 43 present on the threaded end 44 portion of the rod 41 of the clamping device 40 can be adjusted so that at least part of the substantially hook shaped end portion 47 of the shaft 42 engages the top surface 26 of the block 25 to compressibly secure the block 25 to the upper face 14 of the plate 12 (shown in FIG. 5).
The lower face (not shown) of the plate 12 is positioned on a top face of the substantially rigid frame body 2. The frame body 2 has one or more bores 6 (not shown) to receive a releasable fastener 13 therein. A releasable fastener 13 is positioned through at least one orifice 17 present in the plate 12 and inserted into a bore. The releasable fastener 13 can be adjusted to a fastened position until the plate 12 is compressibly secured to the frame body 2. The releasable fastener 13 can be adjusted to a released position to allow the plate 12 to be moved relative to the frame body 2. This allows a radiation technologist to adjust and align the position of a radiation treatment block 25 for use in a radiation beam 90 by moving the plate 12 relative to the frame body 2. Once the correct alignment of the block 25 is achieved within the radiation beam, the releasable fasteners 13 can be adjusted to a fastened position to compressibly secure the plate 12 to the frame body 2 and fix the block 25 in a correct position. The bores can either be threaded or non-threaded, but are preferably threaded.
In the embodiment shown in FIG. 4 a side frame body member 5 has a slotted orifice 8 that forms a handle portion 9 in a side frame body member 5. A handle fitting 38 can optionally be affixed to the handle portion 9.
In the embodiment shown in FIG. 4, a compressible washer 49 is positioned on the threaded end portion 44 of the rod 41 and is positioned at least partially between the upper face 14 of the plate 12 and the bottom surface 27 of the block 25.
In the embodiment shown, the adjustable radiation block mounting tray 1 has one or more spring mounting fitting 20 affixed to both a top face 102 of an upper frame body member 3 and to the upper face 14 of the plate 12. The plate 12 has notches 19 that extend from an outer edge 18 of the plate 12 into the plate 12. The notches 19 are positioned to align over a spring attachment fitting 20 affixed to a top face 102 of an upper frame body member 3. A spring mounting fitting 20 affixed to a top face 102 of an upper frame body member 3 is connected to a spring attachment fitting 20 affixed to the upper face 14 of the plate 12 by a spring 21. The spring 21 absorbs some of the weight of the block 25 when the adjustable radiation treatment block mounting tray 1 is installed in a radiation treatment machine and the releasable fasteners 13 are in a released position. This allows a radiation technologist to more easily move the plate 12 relative to the frame body 2 and align the position of the block 25. It is recognized by those skilled in the art that various types of springs 21 are suitable, for this purpose, including but not limited to coiled springs and elastomeric bands or strips.
Although the embodiment in FIG. 4 shows that the lower face (not shown) of the plate 12 is positioned on a top face 102 of a substantially rigid frame body 2, other embodiments of the invention are also suitable. In an alternative embodiment, the bottom face (not shown) of the frame body 2 can be positioned on the upper face 14 of the plate 12.
FIG. 5 shows an embodiment of a radiation treatment block 25 fabricated using the device and method of the present invention. In the embodiment shown, the radiation treatment block 25 further comprises a ridge 31 protruding from a side surface 28 of a radiation treatment block 25. The ridge 31 extends from the top surface 26 to the bottom surface 27 of a radiation treatment block 25. The ridge 31 can be positioned on a side surface 28 of a radiation treatment block 25 so that it is aligned over a radiation treatment block alignment line 32 that is marked or scribed on an upper face 14 of a plate 12 of an adjustable radiation treatment block mounting tray 1 or a radiation treatment block mounting plate. The ridge 31 and the radiation treatment block alignment line 32 can assist a radiation technologist to correctly position and orient a radiation treatment block 25 on the plate 12.
The methods and apparatuses of the present invention allow radiation blocks of varying sizes to be quickly and accurately prepared using a template in conjunction with a foam block cutting machine to cut the perimetric outline of a form for casting a radiation treatment block.
Upon completion of the treatment of a patient, the radiation block can be melted and used to cast another block. This eliminates the creation of hazardous materials and waste.

Claims

1. A template for use with a foam block cutting machine for making a form to cast a radiation treatment block, comprising a sheet, said sheet having marked or inscribed thereon at least one perimetric outline of a radiation treatment block.

2. The template as in claim 1 wherein said template further comprises at least one horizontal line and at least one vertical line inscribed or marked thereon, said horizontal and vertical lines intersecting at a center of at least one perimetric outline of a radiation treatment block present on said template.

3. The template as in claim 1 wherein said sheet is transparent.

4. The template as in claim 1 wherein said sheet is marked or scribed with perimetric outlines of radiation treatment blocks having different sizes.

5. The template as in claim 1 wherein each perimetric outline of a radiation treatment block present on said template has four sides and is rectangular in shape.

6. The template as in claim 5 wherein said template further comprises a radiation treatment block alignment line marked or scribed thereon, said radiation treatment block alignment line being positioned such that it intersects with one side of each perimetric outline of a radiation treatment block present on said template, said side having a protrusion thereon extending from said side at the intersection of said side with the radiation treatment block alignment line.

7. The template as in claim 1 wherein at least one perimetric outline of a radiation treatment block present on said template has a notch present on at least one side of said perimetric outline, said notch projecting inward towards an interior of said radiation treatment block.

8. The template as in claim 1 wherein each side of at least one perimetric outline of said radiation treatment block present on said template has a notch present therein, each notch projecting inward towards an interior of said perimetric outline of said radiation treatment block.

9. The template as in claim 8 wherein said notch is rectangular.

10. The template as in claim 8 wherein said notch is U-shaped or V-shaped.

11. A template for use with a foam block cutting machine for making a form to cast a radiation treatment block, said template comprising a transparent sheet, said sheet having marked or inscribed thereon perimetric outlines of radiation treatment blocks having different sizes, each perimetric outline of a radiation treatment block present on said template having four sides, being rectangular in shape, and having four corners, each of said sides having a rectangular notch positioned thereon, each perimetric outline of a radiation treatment block present on said template having a rectangular notch present on each corner of said perimetric outline, said template further having a horizontal and a vertical line that intersect at a center of said perimetric outlines of said template, said template further having a radiation treatment block alignment line marked or scribed thereon, said radiation treatment block alignment line being positioned such that it intersects with one side of each perimetric outline of a radiation treatment block present on said template, said side having a protrusion thereon extending from said side at the intersection of said side with the radiation treatment block alignment line.

12. A method for making a foam form to cast a radiation treatment block comprising:

(a) providing a foam block cutting machine for making a form to cast a radiation treatment block, said foam block cutting machine having a light table, a hot wire frame, said hot wire frame having an upper hot wire frame member and a lower hot wire frame member, and a hot wire for cutting a foam block, said hot wire being positioned between said upper and lower hot wire frame members, said foam block cutting machine further having a stylus connected to said hot wire frame for tracing a perimetric outline of a radiation treatment block, and a tray for holding a foam block;

(b) positioning a template for use with a foam block cutting machine for making a form to cast a radiation treatment block on said light table, said template comprising a transparent sheet, said sheet having marked or inscribed thereon a perimetric outline of at least one radiation treatment block;

(c) placing a foam block for casting a radiation treatment block on said tray;

(d) tracing a perimetric outline of a radiation treatment block present on said template with said stylus causing said hot wire to cut said foam block in a same perimetric dimension as said perimetric outline of said radiation treatment block on said template.

13. The method as in claim 12 wherein the light table has a vertical and horizontal line marked thereon, the vertical and horizontal lines of the light table intersecting at the center of the light table.

14. The method as in claim 12 wherein said foam block can be further cut with said hot wire to create an opening in said foam block that will form a field shaping opening in a radiation treatment block when a radiation treatment block is cast in said foam block form.

15. A ruler for use with a template for use with a foam block cutting machine for making a form to cast a radiation treatment block, said ruler having an elongated rectangular shape, said ruler having four sides, two of said sides being elongated, at least one elongated side having a tab protruding from an elongated side.

16. The ruler as in claim 15 wherein said ruler further comprises a notch present in at least one elongated side of said ruler.

17. A ruler for use with a template for use with a foam block cutting machine for making a form to cast a radiation treatment block, said ruler having four sides, two of said sides being elongated, at least one elongated side having a notch present therein.

18. The ruler as in claim 17 wherein said ruler further comprises a tab protruding from an elongated side of said ruler.