42 Result(s)
within
Chapter
Indra J Das
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Chapter and Conference Paper
Factors Affecting Accuracy in Proton Therapy
Introduction: To examine the various processes involved and to assess their effects on the accuracy of proton therapy. Materials and methods: Proton therapy involves several processes: (1) Beam commissioning. ...
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Chapter and Conference Paper
Temporal Response of Gafchromic EBT2 Radiochromic Film in Proton Beam Irradiation
Introduction: Gafchromic EBT2 is being used for radiation dosimetry including photon, electrons and recently in proton beams, based on its color changes from transparent to blue due to polymerization. It is cr...
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Chapter and Conference Paper
Quality Assurance of Proton Compensators
Distal dose conformity to a target volume is achieved by choosing proper range of the proton beam and modifying it by custom designed compensator. The voxel of the compensator is milled precisely using a compu...
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Chapter
Normal Tissue Radiation Response
Radiation toxicity in normal tissues can be classified as early effects, late effects, and consequential late effects. These effects vary based on the tissue type, radiation dose, fractionation, and the volume...
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Chapter
Characteristics of Photon Beams
Photon beams are characterized by their intensity and energy. The attenuation coefficient measures the rate at which the beam is attenuated (loses intensity) at depth. A half-value layer is a thickness of mate...
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Chapter
Cell and Tissue Kinetics
The response of cells to low LET radiation is often dependent upon phase of the cell cycle at the time of irradiation, but the response of tumors and normal tissue is dependent on other additional parameters s...
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Chapter
Chemotherapy, Chemomodulation, and Immunomodulation of Radiation Therapy
Radiation therapy can be modified by increasing the effectiveness of radiation on tumors (radiosensitizers), protecting normal tissues (radioprotectors), increasing oxygen concentration, or by using systemic t...
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Chapter
Dosimetry of Photon Beams in a Patient
Simple dose calculations are based on photon dose to water. When treating patients, dose corrections must be introduced to account for anatomic variations in shape and density. These dose correction techniques...
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Chapter
Time Dose and Fractionation Effects
The linear-quadratic (LQ) model utilizes the terms α (single-hit kill) and β (two-hit kill) which correlate with low-dose killing and high-dose killing, respectively. Fractionation experiments with normal tiss...
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Chapter
Hyperthermia
Though its use has waned and conventional heat treatments alone are only used to treat some types of cancer at a few clinics in the United States, there is still some interest in the use of hyperthermia as an ...
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Chapter
Radiation Effects in the Embryo and Fetus
The severity of the effects of ionizing radiation on the pre- and postimplantation embryo/fetus is dependent upon the dose, dose rate, and stage of gestation. In the preimplantation (conceptus) stage, relative...
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Chapter
Dosimetry of Electron Beams
The electron is a charged particle with a finite range directly proportional to its energy. Electrons are limited to more superficial depths than photons. Surface dose increases with energy, unlike photons. Si...
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Chapter
Advanced Treatment Planning for EBRT
Treatment planning techniques include patient immobilization, imaging, radiation field design, verification, and evaluation. Modern radiotherapy takes advantage of many different imaging modalities, including ...
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Chapter
Radiation Protection and Safety
Radiation protection is a necessary process to reduce dose to radiation workers and the general public. There are multiple bodies that regulate various aspects of radiation protection including the Internation...
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Chapter
Special Topics: Computers
With the advent of computers and especially with 3D conformal radiotherapy, the use of Patient Archiving and Communication System and common Digital Imaging and Communications in Medicine files has become incr...
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Chapter
Cancer Biology
Cancer results from an accumulation of multiple mutations in cellular genes that regulate cell growth/life span, death, and migration, immune response, telomere length, genomic instability, invasion, and metas...
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Chapter
Radioactive Decay
When atoms become unstable, they undergo changes called radioactive decay. If the nucleus is very heavy and has too many protons, it may undergo alpha decay (release a helium nucleus). If a nucleus is very lig...
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Chapter
Protons
Proton beams offer a therapeutic advantage of having a steep dose falloff at the end of their path. While a proton is moving fast, it typically has a small sphere of influence as a charged particle and has a r...
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Chapter
Modes of Cell Death and Survival Assays
There are many ways that normal and tumor cells can die from radiation injury. Extensive DNA damage may result in mitotic catastrophe or senescence, or necrosis with corresponding inflammation. Alternatively, ...
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Chapter
Interactions of Electromagnetic Radiation with Matter
Photons are a type of boson that carries electromagnetic energy. They have no charge and are therefore an indirectly ionizing particle. At lower energies, they predominantly interact with matter through cohere...
