What is Radioresistance cancer?
Radioresistance is a process in which the tumor cells or tissues adapt to the radiotherapy-induced changes and develop resistance to the IR. This is a complex process involving multiple genes, factors, and mechanisms [34, 35].
Which cancer is most radiosensitive?
Two examples of highly radiosensitive cancers are leukemia (cancer of the blood cells) and lymphoma (cancer of the lymphatic system). Radiation therapy is most effective when a tumor is contained, easily accessible, and located away from major organs of the body.
Which Tumours are radiosensitive?
Radiosensitive tumours are tumours which respond well to radiotherapy….This group includes:
- malignant lymphomas.
- seminomas.
- medulloblastoma.
- neuroblastoma.
- Wilm’s tumour.
- early cervical carcinoma.
- vaginal carcinoma.
- most head and neck tumours.
Which cells are radioresistant?
Cells in late G2 and mitosis (M-phase) are the most sensitive to radiation, and cells in late synthesis (S-phase) are the most resistant (Fig. 23.10).
How many stages of cancer are there?
Most types of cancer have 4 stages, numbered from 1 to 4. Doctors often write the stage down in Roman numerals. So they may write stage 4 as stage IV. Stage 3 usually means the cancer is larger.
Can cancer become resistant to radiotherapy?
Many tumors eventually develop resistance Unfortunately, around 40 percent of large tumors that are treated with radiotherapy eventually become resistant, causing significant problems.
Which tumor is least sensitive to radiation?
Amongst the body cells, the most sensitive are spermatogonia and erythroblasts, epidermal stem cells, gastrointestinal stem cells. The least sensitive are nerve cells and muscle fibers.
Which part of the body is 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.
Which organ is 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.
Which of the following are considered to be the most radioresistant?
Essentials of Radiation Biology and Protection 2nd Edition
| Question | Answer |
|---|---|
| What are considered to be the most radioresistant phases of the cell cycle? | Mid-to Late S-phase |
| What is considered to be the most radiosensitive part of a cell? | Nucleus |
| Cell death which occurs before mitosis is termed: | Interphase Death |
What is considered to be radioresistant tissues?
Cells that are mature, differentiated, and not actively dividing (e.g., neurons) are more radioresistant. A cell that is radiosensitive would be more inclined to die after exposure to ionizing radiation than a radioresistant cell (1).
Which organ is most affected by radiation?
The most radiation-sensitive organs include the hematopoietic system [4], the gastrointestinal (GI) system [5], skin [6, 7], vascular system [8, 9], reproductive system, and brain [10–12].
Which organ is least sensitive to radiation?
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.
Which tissue is most radioresistant?
The differentiated fixed postmitotic cells are the most radioresistant. This class includes the long-lived neurons, skeletal muscle cells and erythrocytes.
What is radioresistance in cancer?
Background Radioresistance is a major factor leading to the failure of radiotherapy and poor prognosis in tumor patients. Following the application of radiotherapy, the activity of various metabolic pathways considerably changes, which may result in the development of resistance to radiation. Main body
What is the pathophysiology of radiological resistance?
Radioresistance is a major factor leading to the failure of radiotherapy and poor prognosis in tumor patients. Following the application of radiotherapy, the activity of various metabolic pathways considerably changes, which may result in the development of resistance to radiation. Main body
What is the role of radioresistance in glioma stem cells?
Bao S, Wu Q, McLendon RE, Hao Y, Shi Q, Hjelmeland AB, et al. Glioma stem cells promote radioresistance by preferential activation of the DNA damage response. Nature. 2006;444:756–760.
Does a CAF-rich tumor microenvironment cause radioresistance?
Since the interior region of a tumor rich in fibroblasts is known to contain an abundance of hypoxic regions, a CAF-rich microenvironment is considered to cause radioresistance.