Inverse planning of energy-modulated electron beams in radiotherapy. 2006

John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
Department of Human Oncology, Comprehensive Cancer Care Center, University of Wisconsin-Madison, Madison, WI 53792, USA. gentryj@gmh.org

The use of megavoltage electron beams often poses a clinical challenge in that the planning target volume (PTV) is anterior to other radiosensitive structures and has variable depth. To ensure that skin as well as the deepest extent of the PTV receives the prescribed dose entails prescribing to a point beyond the depth of peak dose for a single electron energy. This causes dose inhomogeneities and heightened potential for tissue fibrosis, scarring, and possible soft tissue necrosis. Use of bolus on the skin improves the entrant dose at the cost of decreasing the therapeutic depth that can be treated. Selection of a higher energy to improve dose homogeneity results in increased dose to structures beyond the PTV, as well as enlargement of the volume receiving heightened dose. Measured electron data from a linear accelerator was used as input to create an inverse planning tool employing energy and intensity modulation using bolus (e-IMRT). Using tools readily available in a radiotherapy department, the applications of energy and intensity modulation on the central axis makes it possible to remove hot spots of 115% or more over the depths clinically encountered. The e-IMRT algorithm enables the development of patient-specific dose distributions with user-defined positions of peak dose, range, and reduced dose to points beyond the prescription point.

UI MeSH Term Description Entries
D011879 Radiotherapy Dosage The total amount of radiation absorbed by tissues as a result of radiotherapy. Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D011880 Radiotherapy Planning, Computer-Assisted Computer-assisted mathematical calculations of beam angles, intensities of radiation, and duration of irradiation in radiotherapy. Computer-Assisted Radiotherapy Planning,Dosimetry Calculations, Computer-Assisted,Planning, Computer-Assisted Radiotherapy,Calculation, Computer-Assisted Dosimetry,Calculations, Computer-Assisted Dosimetry,Computer Assisted Radiotherapy Planning,Computer-Assisted Dosimetry Calculation,Computer-Assisted Dosimetry Calculations,Dosimetry Calculation, Computer-Assisted,Dosimetry Calculations, Computer Assisted,Planning, Computer Assisted Radiotherapy,Radiotherapy Planning, Computer Assisted
D001943 Breast Neoplasms Tumors or cancer of the human BREAST. Breast Cancer,Breast Tumors,Cancer of Breast,Breast Carcinoma,Cancer of the Breast,Human Mammary Carcinoma,Malignant Neoplasm of Breast,Malignant Tumor of Breast,Mammary Cancer,Mammary Carcinoma, Human,Mammary Neoplasm, Human,Mammary Neoplasms, Human,Neoplasms, Breast,Tumors, Breast,Breast Carcinomas,Breast Malignant Neoplasm,Breast Malignant Neoplasms,Breast Malignant Tumor,Breast Malignant Tumors,Breast Neoplasm,Breast Tumor,Cancer, Breast,Cancer, Mammary,Cancers, Mammary,Carcinoma, Breast,Carcinoma, Human Mammary,Carcinomas, Breast,Carcinomas, Human Mammary,Human Mammary Carcinomas,Human Mammary Neoplasm,Human Mammary Neoplasms,Mammary Cancers,Mammary Carcinomas, Human,Neoplasm, Breast,Neoplasm, Human Mammary,Neoplasms, Human Mammary,Tumor, Breast
D004583 Electrons Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS. Fast Electrons,Negatrons,Positrons,Electron,Electron, Fast,Electrons, Fast,Fast Electron,Negatron,Positron
D005260 Female Females
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D050397 Radiotherapy, Intensity-Modulated CONFORMAL RADIOTHERAPY that combines several intensity-modulated beams to provide improved dose homogeneity and highly conformal dose distributions. Helical Tomotherapy,Intensity-Modulated Arc Therapy,Volumetric-Modulated Arc Therapy,Arc Therapies, Intensity-Modulated,Arc Therapies, Volumetric-Modulated,Arc Therapy, Intensity-Modulated,Arc Therapy, Volumetric-Modulated,Helical Tomotherapies,Intensity Modulated Arc Therapy,Intensity-Modulated Arc Therapies,Intensity-Modulated Radiotherapies,Intensity-Modulated Radiotherapy,Radiotherapies, Intensity-Modulated,Radiotherapy, Intensity Modulated,Therapies, Intensity-Modulated Arc,Therapies, Volumetric-Modulated Arc,Therapy, Intensity-Modulated Arc,Therapy, Volumetric-Modulated Arc,Tomotherapies, Helical,Tomotherapy, Helical,Volumetric Modulated Arc Therapy,Volumetric-Modulated Arc Therapies

Related Publications

John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
August 2000, Physics in medicine and biology,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
June 2000, Medical physics,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
February 2005, Medical physics,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
October 1998, Physics in medicine and biology,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
March 1998, Der Radiologe,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
May 2010, Medical physics,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
June 2003, Physics in medicine and biology,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
July 1972, Strahlentherapie,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
January 2002, Frontiers of radiation therapy and oncology,
John R Gentry, and Richard Steeves, and Bhudatt A Paliwal
October 2022, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology,
Copied contents to your clipboard!