Radiation Therapy Lecture Powerpoint

Question 1

Radiation therapy definition

Answer 1

Cancer treatment that uses high doses of radiation to kill cancer cells and stop them from spreading, up to 1/2 of cancer patients receive it at some point, can be used alone or alongside surgery or chemo

Question 2

Photons energy rating scale

Answer 2

• Gamma rays
• x rays
• uv
• visible
• infared
• radio

Question 3

Radiation therapy mech of action

Answer 3

Damages DNA directly or creates free radicals in cell that damage DNA of both cancer cells resulting in their death as well as host cells

Question 4

Radiation can be both used as curative therapy as well as…

Answer 4

….palliative care

Question 5

Preoperative radiation is known as ___, during surgery is ____, and post op therapy is ____

Answer 5

neoadjuvant, intraoperative, adjuvant

Question 6

Considerations made in a radiation oncologist’s plan (therapeutic ratio) include (5)

Answer 6

• type of cancer
• size and location
• how close to normal tissue it is
• how far into the body it needs to travel
• age

Question 7

Measure of radiation energy absorbed by 1kg of human tissue is a…

Answer 7

…gray (Gy)

Question 8

Tattoo/body molds/mask use by radiation therapist

Answer 8

Ensure a patient is in correct position throughout treatment, permanent markings in the case of tattoos and potentially claustrophobic in the case of masks

Question 9

Brachytherapy

Answer 9

Internal radiation where radioactive material is placed in the body near cancer cells typically in seeds

Question 10

Systemic radiation

Answer 10

A radioactive substance is given by mouth or vein and travels into the blood to tissues thru the body

Question 11

3D conformational radiation therapy (3D-CRT)

Answer 11

Most common type of external radiation therapy, computer software allows delivery at precisely shaped areas

Question 12

Intensity modulated radiation therapy (IMRT)

Answer 12

A type of external radiation therapy that allows for different areas of a tumor or space nearby to receive varying doses of radiation allowing for less side effects than 3D-CRT

Question 13

Gamma knife/stereotactic radiosurgery

Answer 13

A device for external radiation therapy for small tumors of the brain with well defined edges

Question 14

Cyberknife/sterotactic body radiation therapy

Answer 14

A device for external radiation therapy of small tumors outside the brain and spinal cord

Question 15

Total body irradation

Answer 15

Most commonly used for hematopoietic cell transplantation for leukemias and lymphomas, used as part of cytoreductive regimen

Question 16

Proton therapy vs Electron therapy

Answer 16

Proton deposited energy is mostly delivered at the end of the path and less along the way (go thru tissue and not effect it until hitting the target tissue)

Electron beams can be used on superficial tumors (skin or surface of breast) that cannot travel very far thru tissue

Question 17

Internal radiation therapy can be temporary or…

Answer 17

…permanent

Question 18

During permanent brachytherapy, it is advised to limit contact with children and pregnant women because…

Answer 18

….the patient is slightly radioactive despite the amount reaching the skin is minimal

Question 19

Zevalin

Answer 19

A monoclonal antibiody with radioactive substance bound to it used in treatment of B cell non hodgkin lymphoma to bind a protein found on surface of B lymphocytes

Question 20

Often radiation therapy is given multiple times a week 2 treatments a day. Why?

Answer 20

Smaller doses minimize damage to normal tissue and by varying the time we increase chances the cells are being exposed at critical time of cell cycle when they are vulnerable to DNA damage

Question 21

What stage of cell cylce are cells most radiosensitive? What is least?

Answer 21

G2 and M are most, S is least

Question 22

Some cancers are very susceptible to radiation, while some are….

Answer 22

….radioresistant

Question 23

Radiation acute side effects (5, one important one to note)

Answer 23

• diarrhea
• hair loss
• sexual changes
• fatigue
• VERY DEPENDENT on location of the treatment

Question 24

Radiation chronic side effects (5)

Answer 24

• fibrosis and limited movement
• memory loss
• infertility
• mouth problems
• 2ndary cancers in children or adolescents

Question 25

Radiation pneumonitis

Answer 25

A condition occurring 4-12 weeks after chest radiation (lung, breast, mediastinal) that presents with cough, dyspnea, chest pain, low grade fever that can be treated with steroids but can cause lung fibrosis

Question 26

Radiosensitizers and radioprotectors (and an example of each)

Answer 26

• Drugs that make the cancer cells more sensitive to radiation therapy, developing field such as cisplatin
• Protect normal cells from damage caused by radiation therapy in areas where it is hard not to expose vital tissues to radiation such as amifostine