Handbook of Radiotherapy Physics - Theory and Practice - Taylor & Francis ( ) In order to cover in detail all aspects of radiotherapy physics and biology , Publishing, Madison, WI, , musicmarkup.info . Handbook of Radiotherapy Physics Theory and Practice - Ebook download as PDF File .pdf), Text File .txt) or read book online. radiotherapy physics. From background physics and biological models to the latest imaging and treatment modalities, the Handbook of Radiotherapy Physics: Theory and Practice covers. DownloadPDF MB Read online. From background.
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HANDBOOK OF RADIOTHERAPY PHYSICS: THEORY AND PRACTICE IAEA, Vienna, (musicmarkup.info Handbook of Radiotherapy Physics, Theory and Practice CRC Press This Document PDF may be used for research, teaching and private. Handbook of Radiotherapy Physics: Theory and Practice | 𝗥𝗲𝗾𝘂𝗲𝘀𝘁 𝗣𝗗𝗙 on ResearchGate | On Jan 1, , P. Mayles and others published Handbook of.
Radiation therapy for a patient with a diffuse intrinsic pontine glioma , with radiation dose color-coded. Different cancers respond to radiation therapy in different ways. Highly radiosensitive cancer cells are rapidly killed by modest doses of radiation. These include leukemias , most lymphomas and germ cell tumors. Some types of cancer are notably radioresistant, that is, much higher doses are required to produce a radical cure than may be safe in clinical practice.
Radiation therapy is also used post surgery in some cases to prevent the disease continuing to progress. Low doses of radiation are used typically three gray of radiation for five days, with a break of three months followed by another phase of three gray of radiation for five days.
This DNA damage is caused by one of two types of energy, photon or charged particle. This damage is either direct or indirect ionization of the atoms which make up the DNA chain.
Indirect ionization happens as a result of the ionization of water, forming free radicals , notably hydroxyl radicals, which then damage the DNA. In photon therapy, most of the radiation effect is through free radicals. However, double-stranded DNA breaks are much more difficult to repair, and can lead to dramatic chromosomal abnormalities and genetic deletions.
Targeting double-stranded breaks increases the probability that cells will undergo cell death.
Cancer cells are generally less differentiated and more stem cell -like; they reproduce more than most healthy differentiated cells, and have a diminished ability to repair sub-lethal damage. Single-strand DNA damage is then passed on through cell division; damage to the cancer cells' DNA accumulates, causing them to die or reproduce more slowly. One of the major limitations of photon radiation therapy is that the cells of solid tumors become deficient in oxygen.
Solid tumors can outgrow their blood supply, causing a low-oxygen state known as hypoxia.
Oxygen is a potent radiosensitizer , increasing the effectiveness of a given dose of radiation by forming DNA-damaging free radicals. Tumor cells in a hypoxic environment may be as much as 2 to 3 times more resistant to radiation damage than those in a normal oxygen environment.
Newer research approaches are currently being studied, including preclinical and clinical investigations into the use of an oxygen diffusion-enhancing compound such as trans sodium crocetinate TSC as a radiosensitizer.
Due to their relatively large mass, protons and other charged particles have little lateral side scatter in the tissue—the beam does not broaden much, stays focused on the tumor shape, and delivers small dose side-effects to surrounding tissue.
They also more precisely target the tumor using the Bragg peak effect. See proton therapy for a good example of the different effects of intensity-modulated radiation therapy IMRT vs.
This procedure reduces damage to healthy tissue between the charged particle radiation source and the tumor and sets a finite range for tissue damage after the tumor has been reached. In contrast, IMRT's use of uncharged particles causes its energy to damage healthy cells when it exits the body.
This exiting damage is not therapeutic, can increase treatment side effects, and increases the probability of secondary cancer induction. Many other factors are considered by radiation oncologists when selecting a dose, including whether the patient is receiving chemotherapy, patient comorbidities, whether radiation therapy is being administered before or after surgery, and the degree of success of surgery.
Delivery parameters of a prescribed dose are determined during treatment planning part of dosimetry. Treatment planning is generally performed on dedicated computers using specialized treatment planning software. Depending on the radiation delivery method, several angles or sources may be used to sum to the total necessary dose. The planner will try to design a plan that delivers a uniform prescription dose to the tumor and minimizes dose to surrounding healthy tissues.
In radiation therapy, three-dimensional dose distributions may be evaluated using the dosimetry technique known as gel dosimetry. Fractionation allows normal cells time to recover, while tumor cells are generally less efficient in repair between fractions.
Fractionation also allows tumor cells that were in a relatively radio-resistant phase of the cell cycle during one treatment to cycle into a sensitive phase of the cycle before the next fraction is given. Similarly, tumor cells that were chronically or acutely hypoxic and therefore more radioresistant may reoxygenate between fractions, improving the tumor cell kill.
In North America, Australia, and Europe, the typical fractionation schedule for adults is 1. In some cancer types, prolongation of the fraction schedule over too long can allow for the tumor to begin repopulating, and for these tumor types, including head-and-neck and cervical squamous cell cancers, radiation treatment is preferably completed within a certain amount of time. For children, a typical fraction size may be 1.
In some cases, two fractions per day are used near the end of a course of treatment. This schedule, known as a concomitant boost regimen or hyperfractionation, is used on tumors that regenerate more quickly when they are smaller. In particular, tumors in the head-and-neck demonstrate this behavior. Patients receiving palliative radiation to treat uncomplicated painful bone metastasis should not receive more than a single fraction of radiation.
This is a radiation treatment in which the total dose of radiation is divided into large doses. Typical doses vary significantly by cancer type, from 2. Subsequent sections examine brachytherapy using sealed and unsealed sources and provide the framework of radiation protection, including an appendix that describes the detailed application of UK legislation. The final part contains handy tables of both physical constants and attenuation data.
To achieve safe and effective radiotherapy, there needs to be a close understanding among various disciplines. With contributions from renowned specialists, the Handbook of Radiotherapy Physics: Theory and Practice provides essential theoretical and practical knowledge for medical physicists, researchers, radiation oncologists, and radiation technologists. Reviews "… Due to the broad range of topics covered and the clear, concise explanations, this text would be ideal for anyone wishing to study or refresh their knowledge of any central area of radiotherapy physics.
Request an e-inspection copy. Share this Title. Recommend to Librarian. Related Titles. Pediatric Radiotherapy Planning and Treatment.
Image-Guided Radiation Therapy. Radioimmunotherapy of Cancer. Contemporary IMRT: Developing Physics and Clinical Implementation.
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Linear Accelerators. Handbook of Radiotherapy Physics: Theory and Practice. Radiol Phys Technol, 7, Ottawa: National Research Council of Canada, Medical Physics, 33 4 , Medical Physics, 34 2 , Tese de Doutorado.