What is cell radiosensitivity?
Radiosensitivity is the relative susceptibility of cells, tissues, organs or organisms to the harmful effect of ionizing radiation.
What determines radiosensitivity?
Radiosensitivity is the relative susceptibility of cells, tissues, organs, organisms, or other substances to the injurious action of radiation. In general, it has been found that cell radiosensitivity is directly proportional to the rate of cell division and inversely proportional to the degree of cell differentiation.
Why the same cell population has different radiosensitivity?
Radiosensitivity depends on several factors. These factors include the ability to repair damage, hypoxia, cell cycle position, and growth fraction. In addition, the volume of the initial tumor has been demonstrated to influence the ability to eradicate tumors.
Which human cells are most sensitive to radiation?
Lymphocytes (white blood cells) and cells which produce blood are constantly regenerating, and are, therefore, the most sensitive. Reproductive and gastrointestinal cells are not regenerating as quickly and are less sensitive. The nerve and muscle cells are the slowest to regenerate and are the least sensitive cells.
What determines high radiosensitivity of cells and tissues?
Actively dividing cells that are less differentiated tend to show higher radiosensitivity. For example, hematopoietic stem cells in bone marrow are differentiated into various blood cells, while dividing actively.
What is the radiosensitive tumor?
Radiosensitive tumours are tumours which respond well to radiotherapy. Radiotherapy may be effective alone, or may require the addition of cytotoxic chemotherapy as in the more advanced stages of a Wilm’s tumour and Hodgkin’s disease. This group includes: malignant lymphomas.
What is individual radiosensitivity?
The term “radiation sensitivity” describes the sensitivity of organisms to the effect of ionising radiation. The cause of radiation sensitivity may be the insufficient repair and/or misrepair of the radiation-damaged genetic material of the cells ( DNA ), for instance due to defective repair mechanisms.
Which organ is the most radiosensitive?
The digestive tract is among the most radiosensitive organs in the body and its function, which is partly regulated by gastrointestinal (GI) peptides, can be affected by radiation exposure.
How does the radiosensitivity of human cells vary with stages of the cell cycle?
How does the radiosensitivity of human cells vary with stages of the cell cycle? The cell is most sensitive during the M phase, and least sensitive during the last S phase. The lethal effects of radiation are determined by observing cell death.
What makes a cell more radiosensitive?
Which organ is most radiosensitive?
digestive tract
The digestive tract is among the most radiosensitive organs in the body and its function, which is partly regulated by gastrointestinal (GI) peptides, can be affected by radiation exposure.
What is the most radiosensitive phase of the cell cycle?
After exposure to low-LET radiations, the most radiosensitive cell stages are mitosis and the G1/S interface.
Which is the best definition of radiosensitivity?
Radiosensitivity is the relative susceptibility of cells, tissues, organs or organisms to the harmful effect of ionizing radiation .
How is the radiosensitivity of a tumor measured?
Radiosensitivity is the response of the tumor to irradiation that can be measured by the extent of regression, rapidity of response, and response durability. Radiosensitivity depends on several factors.
When does the radiosensitivity of a cell change?
Relative sensitivity. This figure illustrates the typical change in the relative radiosensitivity for a biological effect such as cell death when exposed to radiations of low ionizing density (e.g. x-rays).
Can a person with radiosensitivity undergo radiation therapy?
Perhaps a more likely possibility for the future may be to screen patients who are to undergo radiation therapy for the presence of genes that may confer radiosensitivity or radioresistance. Catheryn M. Yashar MD, FACR, FACRO, in Clinical Gynecologic Oncology (Ninth Edition), 2018