Lichen is the symbiotic association of a fungus (the mycobiont, which provides shelter and structure for the partnership or symbiosis), with an alga or cyanobacterium (the phoâ¦tobiont, also known as the phycobiont, which provides the food for the partnership from photosynthesis).
Some radiation therapy delivery methods include: 1  External beam radiation therapy â radiation is directed from a machine outside the body onto cancerous cells within the body.  Internal radiation therapy â radioactive material is placed (via a catheter or other carrier) directly into or near a tumor.
Patients who receive most types of external-beam radiation therapy usually have to travel to the hospital or an outpatient facility up to 5 days a week for several weeks. One dose (a single fraction) of the total planned dose of radiation is given each day. Occasionally, two treatments a day are given.any other systemic radiation therapy drugs are in clinical trials for different cancer types. Some systemic radiation therapy drugs relieve pain from cancer that has spread to the bone (bone metastases). This is a type of palliative radiation therapy.