Lesson 2 (PRELIMS) Flashcards
(46 cards)
The medical specialty of radiation therapy is often confused with that of _____. In diagnostic radiology, it uses X-ray (CT), sound waves (ultrasound), radio frequencies ( MRI) and gamma rays in nuclear medicine, are used to produce images of certain parts of the body.
Radiology
_____ is a clinical specialty dealing with the use of ionizing radiation in the treatment of patients with malignant neoplasia.
Radiation Therapy
In radiation therapy, _____ radiations (x-rays/gamma rays) are used to kill abnormally growing cells and tissues. This radiation is thousands of times more powerful than the radiation used in taking a diagnostic xray.
Ionizing
The objective or aim of radiation therapy is to deliver a _____ measured dose of radiation to a defined tumor volume with _____ damage to the surrounding healthy tissues, resulting in _____ of tumor and a high _____.
Precisely
minimal
eradication
high quality of life
Standard practice is to deliver small doses of radiation over a period of ___ to ___ weeks. This technique is called _____ and yields more effective results over administration of a single large dose of radiation.
4 to 8
Fractionation
About _____% of all cancer patients in the United States receive radiation during the management of their disease. Half of these patients are given radiation with the intent to cure (curative treatment) while the other half receive radiation to reduce or relieve pain in cases where prognosis is terminal (palliative treatment).
60
On the other hand, _____ is a clinical and scientific endeavor devoted to the management of patients with cancer and other neoplasm by ionizing radiation alone or combined with other modalities and to the investigation of application of radiation therapy and the training of personnel in the field.
Radiation Oncology
Enumerate major forms of cancer treatment
- Surgery
- Chemotherapy
- Radiation Therapy
- Electron Therapy
- Bone Marrow Transplantation
- Stereotactic Radiosurgery (SRS)
Major forms of cancer treatment: Involves the removal of the tumor plus some surrounding normal tissues.
- Surgery
Major forms of cancer treatment: Is the use of drugs, taken by mouth or injected into a patient’s vein. These drugs travel throughout the body working to destroy cancer cells.
- Chemotherapy
Major forms of cancer treatment: Uses photons, electrons and other sources of radiation, to deliver radiation treatment and destroy cancer cells. Treatment can be delivered locally, or in special instances, can be given to the whole body.
- Radiation Therapy
Major forms of cancer treatment: Or on other occasions low voltage x-rays, are used to treat benign skin or superficial soft tissue disorders.
- Electron Therapy
Major forms of cancer treatment: Can be performed for some malignant diseases and radiation therapy is delivered as a part of the procedure. While this is also helps to suppress the patient’s immunologic responses for improve acceptance of the donor bone marrow, it is primarily used to fully cradicate the patient’s diseased bone marrow prior to transplantation.
- Bone Marrow Transplantation
Major forms of cancer treatment: Can be performed on benign nous malformation (AVM) in the brain that are surgically unresectable.
- Stereotactic Radiosurgery (SRS)
Two types of administration of radiation therapy
External Beam Radiation Therapy
Brachytherapy
A radiation beam comes from an outside source directed towards the tumor sites. Machines used are either Cobalt 60 (Co60) or a Linear Accelerator (LINAC).
Conventionally:
● Daily treatment takes ___to___ min /field, with daily dose of 180-200 cGy/fraction.
● Usually 5 days a week, with a total dose ranges from 50-70 Gy.
● Treatment lasts for 4-7 weeks depends on type of tumor and other factors.
External Beam Radiation Therapy
2-8
Involves the application of radioactive source directly to the tumor site.
● Radioactive sources are Cobalt 60, Iridium 192, Cesium 137, Gold 198 etc.
● It can be applied Intracavitary, Interstitial, Intraluminal, contact or surface application.
● Treatment is given once a week for a period of 3- 4 weeks.
● With a prescribed dose of ___ gray/fraction.
Brachytherapy
7
1 Rad = ___ cGya For every Gy there is _____ Rad
1
100
Inside / Outside of Cavity.
Intracavitary
In between of Muscles.
Interstitial
Pathways of the Lumen.
Intraluminal
Direct to the Skin
Contact or surface
2 intentions or aims of radiotherapy
- Curative treatment
- Palliative treatment
Intentions or aims of radiotherapy: Refer to the health care practices that treat patient with the intent of curing them, to overcome disease and promote recovery.
Curative Treatment
