With radiation therapy, the patient is subjected to the selective, slow and gradual action of ionizing radiation produced by machinery called linear accelerators.
Radiation is directed against the tumor mass and causes damage incompatible with cell survival.
Although radiation therapy is a very precise technique, it can happen that healthy cells near the tumor are also affected by radiation. Fortunately, healthy cells can repair radiation damage much better than cancer cells.
The use of radiation in oncology has several purposes:
- Curative
In this case, radiation therapy aimes to get healing the tumor.
- Precautionary
In this case, radiation therapy consists in the irradiation of areas not affected by the neoplasm but which are considered sites of occult locations.
- Symptomatic
In this case, radiation therapy aims to improve the quality of life and increase the survival of the patient.
Radiation therapy can be administered in two ways:
- External
The radiation source is outside the body
- Internal (or brachytherapy)
The radiation source (small radioactive metal probes) is inserted inside the body
In tumor therapy, radiotherapy can be performed alone, as a single therapy, or in association with surgery or chemotherapy. The association can be directed towards the same objective (both therapies act on the primary tumor) or on different objectives (one therapy acts on the primary tumor and the other one on metastases).
- Radiation therapy associated with surgery: it can precede the surgery (to reduce the size of the neoplasm and make it more operable) or follow the surgery (to reduce the risk of local recurrence due to occult micro-foci left after the surgery). Sometimes it can also be intraoperative (in the case of a tumor located deep, surgically exposed and therefore free from the overlap of healthy tissues).
- Radiation therapy associated with chemotherapy: can be performed before or after chemotherapy. In some cases they can be administered, at least in part, simultaneously. The sequence that produced the most promising results was chemotherapy and subsequently radiotherapy. The chemo-radiotherapy association, in turn, may or may not be combined with surgery.
Radiation therapy is not painful even if during the session it is possible to feel a more or less intense sensation of heat in the exposed area. In some cases, a burn on the skin may remain after the session, but it is transient.
