Patent Number: 
Section: claims

1. A method of controlling the amount of energy to reach a breast cancer patient undergoing intraoperative electron radiation therapy, comprising:providing an intraoperative electron radiation therapy machine having a head for producing a monoenergetic beam;selecting a bolus made of a material having substantially the same density as human breast tissue and placing the bolus between the head of the machine and the patient to change the energy of a monoenergetic beam after the monoenergetic beam has left the part of the machine that accelerates the electrons to the desired energy, the bolus being chosen to reduce the energy traveling through the tube to a desired amount of energy to treat the patient. 2. The method of claim 1, wherein the bolus is integral with a collimator tube which attaches to the head of the intraoperative electron radiation therapy machine. 3. The method of claim 2, wherein the tube is made of poly(methyl methacrylate). 4. The method of claim 1, wherein the bolus comprises at least one material from the group consisting of isodense materials made up primarily or entirely of carbon, oxygen, and hydrogen, such as PMMA, Delrin brand acetal resin, UHMW (ultra-high molecular weight polyethylene), polyethylene, polypropylene, ABS, acrylic, Bakelite, CPVC, fiberglass, Kynar brand plastic, Lexan brand plastic, Micarta brand plastic, PVC, Ryton brand plastic, and Teflon brand polytetrafluoroethylene. 5. The method of claim 1, wherein the bolus comprises poly(methyl methacrylate). 6. The method of claim 1, further comprising calibrating the intraoperative electron radiation therapy machine after it is moved and before it is used to treat a patient. 7. A method of controlling the amount of energy to reach a breast cancer patient undergoing intraoperative electron radiation therapy, comprising:providing an intraoperative electron radiation therapy machine having a head for producing a beam;controlling the intraoperative electron radiation therapy machine such that the head produces a monoenergetic beam during calibration of the machine and treatment of the patient;calibrating the intraoperative electron radiation therapy machine after it is moved and before it is used to treat a patient;selecting a bolus made of a material having substantially the same density as human breast tissue and placing the bolus between the head of the machine and the patient to change the energy of a monoenergetic beam after it has left the machine, the bolus being chosen to reduce the energy traveling through the tube to a desired amount of energy to treat the patient. 8. The method of claim 7, wherein the bolus is integral with a collimator tube which attaches to the head of the intraoperative electron radiation therapy machine. 9. The method of claim 8, wherein the tube is made of poly(methyl methacrylate). 10. The method of claim 7, wherein the bolus comprises at least one material from the group consisting of isodense materials made up primarily or entirely of carbon, oxygen, and hydrogen, such as poly(methyl methacrylate), Delrin brand acetal resin, UHMW (ultra-high molecular weight polyethylene), polyethylene, polypropylene, ABS, acrylic, Bakelite, CPVC, fiberglass, Kynar brand plastic, Lexan brand plastic, Micarta brand plastic, PVC, Ryton brand plastic, and Teflon brand polytetrafluoroethylene. 11. The method of claim 7, wherein the bolus comprises poly(methyl methacrylate). 12. Apparatus for performing electron radiation therapy on a patient, the apparatus comprising:a plurality of boluses for use with an intraoperative electron radiation therapy machine having a head for producing an energy beam, the boluses made of a material having substantially the same density as human tissue for placement between the head of the machine and the patient to change the energy of a beam after it has left the machine, the bolus being chosen to reduce the energy traveling through the tube to a desired amount of energy to treat the patient. 13. The apparatus of claim 12, wherein the boluses comprise at least one material from the group consisting of isodense materials made up primarily or entirely of carbon, oxygen, and hydrogen, such as poly(methyl methacrylate), Delrin brand acetal resin, UHMW (ultra-high molecular weight polyethylene), polyethylene, polypropylene, ABS, acrylic, Bakelite, CPVC, fiberglass, Kynar brand plastic, Lexan brand plastic, Micarta brand plastic, PVC, Ryton brand plastic, and Teflon brand polytetrafluoroethylene. 14. The apparatus of claim 12, wherein the boluses comprise poly(methyl methacrylate). 15. The apparatus of claim 12, further comprising a collimator tube. 16. The apparatus of claim 15, wherein the tube is made of at least one material from the group consisting of isodense materials made up primarily or entirely of carbon, oxygen, and hydrogen, such as poly(methyl methacrylate), Delrin brand acetal resin, UHMW (ultra-high molecular weight polyethylene), polyethylene, polypropylene, ABS, acrylic, Bakelite, CPVC, fiberglass, Kynar brand plastic, Lexan brand plastic, Micarta brand plastic, PVC, Ryton brand plastic, and Teflon brand polytetrafluoroethylene. 17. The apparatus of claim 15, wherein the tube is made of poly(methyl methacrylate). 18. The apparatus of claim 12, wherein at least some of the boluses are integral with collimator tubes. 19. The apparatus of claim 12, further comprising the intraoperative electron radiation therapy machine. 20. Apparatus for performing electron radiation therapy on a breast cancer patient, the apparatus comprising:an intraoperative electron radiation therapy machine having a head for producing a beam of energy;an intraoperative electron radiation therapy collimator tube connected to the intraoperative electron radiation therapy machine;a plurality of boluses made of a material having substantially the same density as human breast tissue to change the energy of a beam after the beam has left the head of the machine, allowing a bolus to be chosen to reduce the energy traveling from the head to a desired amount of energy to treat the patient. 21. The apparatus of claim 20, wherein the boluses comprise at least one material from the group consisting of isodense materials made up primarily or entirely of carbon, oxygen, and hydrogen, such as poly(methyl methacrylate), Delrin brand acetal resin, UHMW (ultra-high molecular weight polyethylene), polyethylene, polypropylene, ABS, acrylic, Bakelite, CPVC, fiberglass, Kynar brand plastic, Lexan brand plastic, Micarta brand plastic, PVC, Ryton brand plastic, and Teflon brand polytetrafluoroethylene. 22. The apparatus of claim 20, wherein the boluses comprise poly(methyl methacrylate). 23. The apparatus of claim 20, wherein the tube is made of at least one material from the group consisting of isodense materials made up primarily or entirely of carbon, oxygen, and hydrogen, such as poly(methyl methacrylate), Delrin brand acetal resin, UHMW (ultra-high molecular weight polyethylene), polyethylene, polypropylene, ABS, acrylic, Bakelite, CPVC, fiberglass, Kynar brand plastic, Lexan brand plastic, Micarta brand plastic, PVC, Ryton brand plastic, and Teflon brand polytetrafluoroethylene. 24. The apparatus of claim 20, wherein the tube is made of poly(methyl methacrylate). 25. The apparatus of claim 20, wherein at least some of the boluses are integral with collimator tubes. 26. The apparatus of claim 20, wherein the head produces a beam of a single energy. 27. The method of claim 7, wherein the intraoperative electron radiation therapy machine produces a beam of a single energy. 28. The method of claim 7, wherein the intraoperative electron radiation therapy machine produces a beam of about 10 MeV.