EXAM #2: RADIATION ONCOLOGY Flashcards Preview

Hematology and Oncology > EXAM #2: RADIATION ONCOLOGY > Flashcards

Flashcards in EXAM #2: RADIATION ONCOLOGY Deck (46):
1

What is the most fatal cancer in the world?

Lung

2

What are the three most common cancers in men?

Prostate
Lung and bronchus
Colon and rectum

3

What are the three most common cancers in women?

Breast
Lung and bronchus
Colon and rectum

4

What are the four basic patterns of cancer progression?

1) Local-growth
2) Local-extension i.e. tumor invades adjacent organs
3) Lymph node metastases
4) Hematogenous metastases

5

What stage does local tumor growth determine?

T-stage

6

What stage does local extension affect?

Upstaging the T-stage

7

What stage does lymph node metastases affect?

N-stage

8

What stage does hematogenous metastasis affect?

M-stage

9

What cancers does radiation take the place of surgery in?

1) Anal
2) Limited stage small cell lung
3) Esophageal
4) Stage IIIB non-small cell lung cancer

10

What cancers is radiation used as an adjuvant therapy in?

1) Breast
2) Skin with positive margins
3) Prostate
4) Uterine/ endometrial

****Note that radiation is used AFTER the main surgical treatment****

11

What is radiation?

Use of EM and particulate ionizing raidation

12

How is the dose of radiation measured?

Gray

13

What is the most common form of radiation?

Daily external delivery of photons i.e. x-rays over multiple weeks

14

Why is external beam radiation therapy given over time?

This is required for maximal tumor kill and minimal damage to normal tissue damage

15

What does radiosensitive mean?

Tumor melts with radiation

16

What does radioresponsive mean?

Tumor melts quickly with radiation

17

What is Brachytherapy?

Any source that emits a halo of radiation

E.g. prostate seeds

18

What is the most important lesion induced by radiation?

Double strand DNA break

19

What is the most radiosensitive phase of the cell cycle?

M/G2

20

What is the radioresistant phase of the cell cycle?

S

21

What is the RT in radiation therapy? What are the implications?

Theraputic ratio of radiation, like a TI

The bigger the number the more cancerous tissue is specifically targeted

22

Why are hypoxic cells the most radioresistant?

Oxygenation enhances ds-DNA breaks

23

What part of tumors is the most hypoxic?

Central portion

24

What is the standard dose of radation?

180-200 cGy per day

25

What is hypofractionation dose radiation?

Very high dose radiation

26

What types of cancer are typically radiated for palliative reasons?

Brain mets
Bone mets

27

What are the five levels of treatment complexity in radiation?

1) Non-planned
2) 2D
3) 3DCRT
4) IMRT
5) SRS/FSRT/SBRT

28

What is 3D-CRT?

- Computer based treatment plan
- Designs treatment to target the tumor and avoid normal structure

*****Causes a "leaking" or radiation into nearby critical structures*****

29

What is IMRT?

Intensity-modulated radiation therapy (IMRT) is a high-precision radiotherapy that uses computer-controlled linear accelerator to deliver precise radiation doses to a malignant tumor

****This prevents harm to surrounding structures and is at limiting collateral damage than 3D-CRT*****

30

What is SRS?

Stereotactic Radiosurgery

****This creates an x,y, and z axes to localize brain lesions*****

31

What is the cyber knife?

Robot used today for brain tumor localization

32

What is the definition of GTV?

Gross Tumor Volume i.e. the volume of tumor that can be imaged

33

What is the definition of CTV?

Clinical Target Volume, the gross tumor volume plus the margins of assumed sub-clinical disease

34

What is the definition of ITV?

Internal Target Volume,this is a volume that accounts for the movement of the CTV in a patient

35

What is the definition of PTV?

Panning target volume, a volume intended to compensate for errors in planning and set up

36

What does OAR stand for?

Organs at Risk

37

Why is a CT done for every patient?

Planning

38

What is "fusion?"

Fusion of the planning CT and other imaging modalities

39

What are photons best for treating?

Deep lesions

40

What are electrons best for treating?

Superficical lesions

41

What type of beam block is the current standard of care?

Multileaf Collimator (MLC)

42

What is a portal film?

Image used to verify the correct setup for radiation based on bony landmarks

43

What is IGRT?

Image Guided Radiation Therapy

This is a special imaging technology that allows the physician to image the tumor immediately before or during the time radiation is delivered. These images are then compared to the reference images taken during simulation. Any necessary adjustments are then made to the patient's position and/or radiation beams in order to more precisely target radiation at the tumor and avoid healthy surrounding tissue.

44

What is stereoscopic IGRT?

This is an imaging technique, IGRT, that uses bones as landmarks

*****It is difficult to use for deep soft tissue targets are there are no bony landmarks in close proximity******

45

What is stereoscopic IGRT poor for?

Soft tissue targets

46

What is cone beam IGRT best for?

Soft tissue targets