P&P LAB

Question 1

what percentage of lung cancer patients are surgical candidates

Answer 1

20%

Question 2

what is the most common single agent chemotherapy used to treat lung cancer

Answer 2

cisplatin

Question 3

what would the current standard therapy regime for lung cancer consist of

Answer 3

concurrent, sequential, or alternation chemo and radiation, using radiation tumor doses 4500-5400 cGy at 180-200 cGy/fraction, 1 fraction/day, 5 fractions/week

Question 4

what is a typical dose/fractionation scheme when treating skeletal mets from lung cancer

Answer 4

3000-4000 cGy in 200-300 cGy daily dose fractions

Question 5

what type of symptoms may a patient who is being treated for lung cancer display if they are beginning to develop brain metastases

Answer 5

seizures, headaches, focal or motor sensory defits, gait disturbance, visual/speech changes, changes in memory, or personality alteration.

Question 6

what is a typical dose/fraction scheme for brain mets

Answer 6

3000-4000 cGy in 10-15 fractions

Question 7

what is superior vena cava syndrome and what doses are typically used to treat it

Answer 7

complete obstruction of the superior vena cava. 3-4 fractions of 300-400 cGy followed by daily dose of 180-250 cGy. total dose of 4500-5000 cGy.

Question 8

identify the critical structures and dose tolerances of any structures that must be considered when planning a lung treatment

Answer 8

spinal cord: 4500-5500 cGy
heart: 4500-5500 cGy
adjacent normal lung: 2000 cGy

Question 9

what is the simplest field used to treat lung cancer

Answer 9

anterior and posterior mediastinal fields-parallel opposed

Question 10

what is the purpose of treating with oblique angles

Answer 10

to miss the spinal cord and heart

Question 11

what is the most radiosensitive gynecological structure

Answer 11

ovary

Question 12

how is dose tolerance of the ovary dependent on age?

Answer 12

65% of women < 40 yrs, 90% 40-44, 100% 50+ produces permanent cessation of menses

Question 13

what is the most radiotolerant gyn structure and what is the dose limit

Answer 13

uterus & cervix (200 Gy)

Question 14

Identify which organs could be included in a gyn treatment field and their dose tolerances

Answer 14

bladder: 75-80 Gy
rectum: 70 Gy
Bowel: 45 Gy

Question 15

what lymph nodes have a probability of being involved in a gyn treatment

Answer 15

inguinal lymph nodes (superficial and deep), pelvic nodes (internal iliac chain), periaortic nodes

Question 16

what is the purpose of midline blocking

Answer 16

to eliminate dose to centrally located anatomy

Question 17

if you were performing a simulation for a whole pelvis cervical treatment, define what the typical borders would be

Answer 17

lower border at inferior aspect of obtorator foramen, upper border at top or bottom of 1.5 or may be extended to L4. lateral borders to 1.5 or 2.0 cm lateral to pelvic sidewall in AP/PA plane

Question 18

define fluoroscopy

Answer 18

the method that provides real-time X ray imaging that is especially useful for guiding a variety of diagnostic and interventional procedures.

Question 19

what is the purpose of the image intensifier

Answer 19

converts the invisible energy of an xray beam into visible light energy.

Question 20

what four components make up the image intensifier

Answer 20

base, reflective layer, phosphor layer, protective coating.

Question 21

what size film cassette can an image intensifier hold

Answer 21

.1 to .5 mm for lead and up to 3 mm for copper

Question 22

what is magnification and how does it apply to simulation?

Answer 22

magnification makes images on a monitor appear larger than they are in reality.

Question 23

what is the formula for magnification factor

Answer 23

image size/object size OR

target to image receptor distance (TID)/target to object distance (TOD)

Question 24

how do kVp and mA affect a simulation? increasing which factor will increase dose to the patient

Answer 24

kVp increases to improve penetrating ability of the beam (larger patients).
mA compensates for contrast loss if kVp is increased
mA increases dose

Question 25

when would it be necessary to utilize a contrast material during a simulation?

Answer 25

shows visual evidence of the differential absorption rates of various body tissues.

Question 26

describe typical epidemiology of skin cancer

Answer 26

most common type of malignancy
50% of people who live to age 65 will develop one skin cancer.
the incidence is rising and continues to grow
BCC>SCC
more young people are affected
geo location, skin types, multiplicity & gender can ^ chances of skin cancer

Question 27

what etiological factors contribute to skin cancer

Answer 27

uv light exposure

exposure to arsenic & therapeutio/occupational exposure to radiation

Question 28

describe basal cell carcinoma

Answer 28

slow growing, does not tend to metastasize, arises from stem cells of the stratum basal, most prevalent in humans, if left untreated can cause extensive damage

Question 29

describe squamous cell carcinoma

Answer 29

faster frowing than BCC & tendency to metastasize, arrises from keratinocytes, common on sunexposed areas

Question 30

describe adenocarcinoma

Answer 30

arises in dermal layer of skin, slow growing lesion, capable of metastasis, radioresistant, treated by surgery.

Question 31

describe cutaneous t cell lymphoma

Answer 31

resembles eczema or other inflammitory diseases. TBI with electrons treatment & topical nitrogen mustard (to control early stages)

Question 32

describe Kaposi’s sarcoma

Answer 32

slow growing, temperate tumor, arises from vascular tissue, surgical removal for individual lesion treatment, RT for multiple lesions

Question 33

describe Merkel’s cell carcinoma

Answer 33

rare tumor, arising from Merkel’s (tactile) calls, high recurrance rates after surgery, frequent involvement in regional lymph nodes and distant metastatic failure, treated with chemo and RT/surgery combination

Question 34

how do most skin cancers present clinically

Answer 34

BCCS-smooth, red or milky lumps and have pearly border, multiple telangiactases
SCC-scaley, crusty, slightly elevated lesion, may have a cutaneous horn
sore that takes 3 weeks to heal, recurrent red patch, may itch/be tender. warts that bleed/scabs

Question 35

what are the ABCD rules for early detection of melanoma?

Answer 35

asymmetry
border
color
diameter

Question 36

in addition to the ABCD rules, what other changes are monitored as possible signs of melanoma?

Answer 36

change in surface, texture, surreounding skin, sensation, previously normal skin

Question 37

describe the treatment methods for melanoma

Answer 37

surgical excision, chemo, immunotherapy, biochemotherapy (to treat metastasized melanomas). rt-adjuvent and primary treatment

Question 38

describe the treatment methods for nonmelanoma

Answer 38

surgery, curettage and electrodesication, cryosurgery, lasers, radiation therapy, 5FU solution/cream, immunotherapy

Question 39

as a general rule what size of a margin should a radiation field treating a skin lesion be

Answer 39

2 cm margin surrounding tumor to cover possible microscopic extension. 1 cm margin for small, superficial BCCs.

Question 40

do we generally treat malignant melanoma with RT? why or why not

Answer 40

no–rt plays the greatest role in the treatment of metastatic/recurrent diseases. malignant melanoma is typically radioresistant.

Question 41

list the typical side effects a patient may experience during RT treatment of the skin

Answer 41

erythema, dry and moist desquamation, darker skin pigmentation, temporary hair loss, necrosis, fibrosis, decreased function of sebaceous and sudoriferous glands.