Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Onco Board Review 2 > Exotics, RT, Misc. > Flashcards

Exotics, RT, Misc. Flashcards

1
Q

In 64 cats with digital carcinomas, what % represented metastasis from primary lung tumors?

A

87.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What % of dogs with digital SCC will have involvement of other digits?

A

3%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In dogs with digital SCC, __% have metastasis at presentation and __% go on to develop metastasis.

A
  1. 8%

23. 3%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does trastuzumab target?

A

HER2/neu

therapeutic monoclonal antibody –> Herceptin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What do Th1 cells produce?

A

IL-2, IFN-gamma, TNF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do Th2 cells produce?

A

IL-4, IL-5, IL-10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F: Thymomas are a common cause of mediastinal masses in rabbits and can be diagnosed with cytology.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the significance of the shoulder in radiation a survival curve?

A

The shoulder reflects an accumulation of sublethal damage to the cells (can be repaired and lead to an early rise in survival of cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What dose in Gy does alpha/beta ratio represent?

A

The dose in Gy when cell kill from the linear and quadratic components of the cell survival curve is equal.

Linear = # of hits due to one electron is proportional to dose
Quadratic = # of hits due to two separate electrons is proportional to square of dose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the appearance of cells with a high alpha/beta ratio vs. low when plotted?

A

high alpha/beta appears more linear, low has parabolic shape (i.e. greater shoulder)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What dose/fraction is best for low alpha/beta ratio cells?

A

high dose/fraction
(it has been suggested that tissues/cells with low alpha/beta ratios have a greater capacity for repair of sublethal radiation damage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What tumors may have low alpha/beta ratios?

A

melanoma, prostatic tumors, STS, TCC, OSA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which radiation effect is considered the most important for cell kill?

A 
Compton effect
(collision btw photon and electron - transfer of energy to the electron and the photon scatters in new direction; both can undergo further interactions until all energy is dissipated)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the Bragg peak?

A

Localized peak of dose that results from a particle beam.

Particle beam is radiation that uses beams of protons or other charged particles that have different depth-dose distributions compared to photons - they will deposit most of their energy in the last final mm of trajectory = Bragg peak. Treatment with heavy ions takes advantage of the Bragg peak.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is RBE?

A

Relative biological effectiveness – ratio of the dose required to produce a specific biological effect with Co-60 photons (i.e. Co-60 is used as reference radiation) to the charged particle dose that is required to achieve the same biological effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the four R’s of radiation?

A

Repair, Repopulation, Redistribution, Reoxygenation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why is a port film such poor quality?

A

You’re using a therapeutic beam in megavoltage energy to obtain the image - there’re the interactions are occurring mainly by Compton scattering; shows less contrast compared to diagnostic x-rays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a negative of orthovoltage regarding acute side effects?

A

No skin sparing
(produces x-rays but lower voltage than linear accelerator so they don’t go as deep - higher energy goes deeper)

also bad for bone, increased dose to dense tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What kind of rays are produced by Cobalt 60? What is the energy? Is there skin sparing?

A

gamma rays
1.25 MV gamma – energy can’t be changed (comes from radioactive decay, can’t be made by linear accelerator)
Yes - skin sparing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

At what energy range is photoelectric effect dominant? What about Compton?

A

Photoelectric - 10-30 keV (diagnostic range, pretty image)

Compton - 60 keV to 10 MeV (therapeutic range, bad image = port film)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the energy range of electrons? What is removed in the machine to produce electrons?

A

5-20 MeV

Remove Z target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is LET? What has high LET? Low LET?

A

Linear energy transfer -rate of energy loss along a track of an ionizing particle
High LET = neutrons, low energy protons, alphas (i.e. big and bulky and hit everything)
Low LET = X-rays, electrons, gamma (not as biologically damaging per dose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is RBE? If a particle has higher LET, how does that affect RBE?

A

Relative biological effectiveness
Ratio comparing effectiveness of different types of ionizing radiations
Higher LET particles have higher RBE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What causes 2/3 of DNA damage? What causes the other 1/3?

A

Indirect action = 2/3 = OH radicals (occurs via H2O, requires oxygen to be present - ineffective in hypoxia)
Direct action = 1/2 = direct DNA damage (higher LET/RBE will cause more direct damage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What type of death do most epithelial and mesenchymal tumors undergo after RT? What about lymphoma?
``` epithelial/mesenchymal = mitotic death (die when they try to divide) lymphoma = apoptotic death (aka interphase death), happens within hours ```
26
What is OER? How does higher LET and RBE affect OER?
oxygen enhancement ratio - enhancing therapeutic effects with presence of oxygen Higher LET and RBE decrease OER because bigger, more damaging particles cats more direct DNA damage (and therefore oxygen not as necessary)
27
Which of the R's are used to our advantage with fractionation?
Reoxygenation - well oxygenated cells die, others move closer to blood vessels Redistribution - fractionation allows time for cells to redistribute to more sensitive phase of the cell cycle
28
What do you want dose-response relationship to look like with RT?
Evaluates tumor vs. normal - therapeutic ratio | Want tumor to left of normal (dose on x-axis), reality is there's always overlap
29
What is the single biggest determinant of total radiation dose?
Late side effects
30
What is hyper fractionated dosing?
same total dose over same time | BID treatment - increased fractionations to achieve same dose as conventional
31
What is accelerated dosing?
same total dose but less overall time | severe acute side effects
32
What is the biggest determinant of late side effects?
dose per fraction (i.e. fraction size)
33
What is BED? What is the BED formula?
Biologically equivalent dose - used to see how "hot" different fractionation schemes are in comparison for a specified tissue BED= nd [1+(d/aB)] n=# of fractions d=dose
34
When are cells most sensitive to hyperthermia (which makes it a good candidate to combine with RT)?
Kills in S phase (when most resistant to RT) | Kills hypoxic cells and in acidic environment where radio resistance exists
35
What drug is a radioprotector used in humans for dry mouth?
amifostine
36
What drugs are used as hypoxic radiosensitizers?
nitroimadazoles (etanidazole, nimorazole) - toxicity issues
37
What is radiation recall and what drug is this associated with?
recurrence of RT side effects when you start chemo | doxorubicin
38
What causes delayed acute toxicity of CNS?
transient demyelination due to damaged/lost oligodendrocytes
39
What dose is delivered with Sr90?
100-200 Gy, 1-2 fractions
40
What effect of photon/electron in the MV energy range is eliminated with boluses?
skin sparing effect
41
What is penumbra?
The rapid decrease at the edges of the radiation beam is called the penumbra region. Usually defined as the space between the 80% and 20% isodose lines.
42
What clinical signs are seen in rabbits with thymomas? (Kunzel 2012)
dyspnea (76.9%), exercise intolerance (53.9%) and bilateral exophthalmos (46.2%)
43
How effective was hypofractionated stereotactic RT for rabbit thymomas? (Dolera 2016)
Very! 15 rabbits, all had CR, none died of thymoma. | Tx with 40 Gy in 6 fractions
44
What stains were positive in seminomas from rabbits? Behavior of seminomas? (Banco 2017)
Stains: placental ALP and periodic acid-Schiff (PAS) | Seminomas originate from monocytes - malignant, frequently metastasize
45
What neoplastic process developed in cattle from exposure to bracken fern? (Faccin 2017)
annular esophageal SCC -- consider this ddx for appearance of esophageal scar tissue in cattle
46
What is a diagnostic marker for devil facial tumor disease? What is the origin of the disease?
periaxin is diagnostic marker | peripheral nerve sheath neoplasm of Schwann cell origin
47
Where is bovine LSA found?
HAULS | heart, abomasum, uterus, LN, spine
48
Most common hemostatic alteration in dogs with cancer?
hypercoagulability
49
How many dsDNA breaks are created in each cell after 1 Gy of RT?
40
50
What is gradient index in RT?
evaluates dose falloff - dose outside target volume
51
What is dose conformity index in RT?
evaluates degree to which the dose distribution conforms to the size/shape of the target volume CI = 1 is perfect (no radiation outside PTV), >2 usually acceptable, <1 means less than 100% of PTV covered by Rx
52
What % of dogs with hyperCa have neoplasia?
66% | 33% of cats
53
Which of the following is not a cause of hyperCa in dogs? 1. PTHrp 2. IL-1B 3. TNF-a 4. PGE1 and 2 5. RANKL
TNF-a
54
What is the MOA of Lasix treating hyperCa?
inhibits Ca resorption in the ascending loop of Henle
55
What is the MOA of pred in treating hyperCa?
inhibits PGE, IL-1B, Vit D, and intestinal calcium absorption (also cytotoxic for LSA and MM)
56
What is the most common non-islet cell tumor to cause hypoglycemia?
HCC
57
What lab work abnormality is seen with SIADH?
hyponatremia
58
Which chemo agents can cause SIADH?
vincristine, CTX, cisplatin
59
Which tumor type has been linked to ectopic ACTH syndrome in dogs? 1. oral SCC 2. leiomyosarcoma 3. pancreatic tumors 4. primary lung tumors 5. thyroid tumors
primary lung tumors
60
Name 3 tumor types that can result in hypergammaglobulinemia
MM LSA CLL
61
What two repro tumors can cause anemia?
Sertoli cell in males, granulosa cell in females | due to hyperestrogenism
62
Which tumor type has not been reported to cause erythrocytosis: 1. oral melanoma 2. TVT 3. cecal leiomyosarcoma 4. nasal FSA 5. renal LSA
oral melanoma
63
Cutaneous flushing can be associated with what two tumor types?
pheochromocytoma | MCT
64
What PNS can be seen with glucagonoma?
necrolytic migratory erythema/superificial necrolytic dermatitis GI ulceration
65
Which PNS has not been reported with thymoma? 1. exfoliative dermatitis 2. myasthenia gravis 3. polycythemia 4. erythema multiforme 5. polymyositis
polymyositis
66
Which condition has not been associated with HO? 1. perianal adenocarcinoma 2. primary lung tumors 3. pulmonary metastatic disease 4. pregnancy 5. HW disease
perianal adenocarcinoma
67
What are the major cytokines involved in paraneoplastic fever?
IL-1, IL-6, TNF-a, interferons, febrile-promoting prostaglandins
68
What is gadoxetate disodium? What were results using this agent in dogs with HCC? (Constant 2016 - Cannon on paper)
liver-specific contrast agent | hepatic lesions were found in 3/7 patients that were not seen on previous imaging
69
What are effects of CK2 in cancer? (Cannon research)
It is a serine/threonine kinase that causes: suppression of apoptosis activate oncogenic pathways like NFkB, Wnt/B-catenin, PI3K/Akt inactivates tumor suppressors They tested RNAi targeting CK2 in FOSCC - tolerated and there was some efficacy
70
What is the TRAP assay? What were results with TCC? (McCleary-Wheeler 2010)
telomeric repeat amplification protocol | telomerase activity was detected in TCC urine, could be diagnostic test
71
Is immunity from previous vaccinations compromised by chemotherapy? (Henry 2001, Higginbotham on paper)
No
72
What was ORR in horses treated with chemo for LSA? MST? (Luethy 2018)
ORR 93.3% (33.3% CR, 60% PR) MST 8 months 2/3 experienced AE
73
What do red and green mean on gene microarray?
``` red = genes whose expression in tumors is higher than reference sample green = genes whose expression in tumors is lower than reference sample black = no change ```
74
In which canine population can X-chromosome inactivation pattern analysis be useful to assess cell clonality?
female dogs that are heterozygous for the androgen receptor gene (Mochizuki VP 2015)
75
In a recent study on the effects of toceranib in dogs with various neoplasia, which significant changes were seen in systolic blood pressure and/or proteinuria compared to control dogs? (Tjostheim JVIM 2016)
systolic blood pressure was significantly higher in previously normotensive treated dogs after initiation of toceranib as compared to baseline. (proteinuria and BP at baseline were not different from age-matched controls for the dogs with cancer)
76
What are some unusual cancers that have been reported with HO? (Withers 2015)
tumours of the bladder (undifferentiated sarcoma, botryoid rhabdomyosarcoma) or kidney [transitional cell carcinoma (TCC) Other random things: infectious/inflam lung disease, heart worm, Spirocerca lupi esophageal granuloma, bacterial endocarditis, R to L shunting with PDA, congenital megaesophagus
77
Clin path observations with HO (expanded)? (Withers 2015)
haematological and serum biochemical alterations such as anaemia, neutrophillic leukocytosis with or without a left shift, thrombocytosis, thrombocytopaenia, elevated ALKP, hypoalbuminaemia and hyperglobulinaemia are frequently observed
78
What PE abnormality is frequently seen in dogs with HO and is sometimes the presenting complaint? (Withers 2015)
ocular abnormalities
79
How was the anemia most commonly characterized with HO? (Withers 2015)
microcytic
80
Sensitive marker of oxidative DNA damage?
8-oxo-deoxyguanosine
81
What does Comet assay detect?
detects DNA damage at cellular level
82
What does Ames assay detect?
uses bacteria to test whether a given chemical can cause DNA mutation
83
In which DNA repair pathway is the enzyme poly (ADP-ribose) polymerase involved?
Base excision repair
84
Which chemo agents are most likely to cause febrile neutropenia in cats?
lomustine and vinca alkaloids | Pierro febrile neutropenia cats VCO 2017
85
When in the cell cycle are taxanes effective?
metaphase/anaphase junction
86
What is the DLT of docetaxel?
GI upset

Onco Board Review 2 (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions