Quizzlet Flashcards
(49 cards)
What are reasons for female dogs presenting with perianal tumors?
Spayed (lack of estrogen)
Hyperadrenocortisicm or testosterone secreting adrenal tumor
What is the expected response of a dog with neurologic signs and increased ACTH secondary to a pituitary macroadenoma treated with radiation therapy?
100% improvement of neuro signs, ACTH increase will persist
What is the MOA of phenoxybenzamine and what effect does it have on vital parameters intraoperatively?
MOA: Nonselective, noncompetitive alpha adrenergic antagonist - (blocks alpha 1 and 2)
- Only significant difference in treated vs non-treated dogs was survival (intraop arrhythmias, BP, hemorrhage etc were not significant (Herrara 2008).
- In dogs undergoing adrenalectomy for pheochromocytoma, phenoxybenzamine pretreatment as administered did not offer any cardiovascular benefits based on the measured variables, and may be associated with more intraoperative hypertensive episodes (Can Vet Journal 2024)
- Phenoxybenzamine pretreatment had no effect on peri-operative mortality (Piegols 2023)
What is the IHC classification for liposarcoma?
MDM2 positive (67-75%, more likely in dedifferentiated)
CDK4 76-100%, variable based on subtype
Ki67 correlates with subtype
(2016 article)
Name IHC for joint tumors: synovial cell, HS, myxosarcoma
Synovial cell: Cytokeratin positive, vimentin positive, CD18 negative
Histiocytic Sarcoma: Cytokeratin negative, vimentin positive, CD18 positive
Myxosarcoma: Cytokeratin negative, Vimentin negative, CD18 (variable 20-40%), Heat shock protein (HSP) positive
What is the appropriate treatment after feline basal cell carcinoma with surgical excision?
Surgery should be curative (RT and doxo reported but benefit is unknown (Withrow p356)
What is the typical feline basal cell tumor location?
They represent 10-26% of feline skin tumors and are located mostly on the head and neck
You have a CT scan of a dog’s leg and there is a mass which looks like fat in between the muscles. The cytology of the mass comes back as fat and blood. What is the next step?
a. surgery
b. amputation
c. MRI
d. biopsy to get the grade
A. Surgical excision if not infiltrative (Spoldi 2017, Vet rad ultra)
Name the tissues that die in interphase via apoptosis rather than mitotic death with radiation therapy?
Lymphoma (note lymphocytes can also die in G0)
Spermocytes, thymocytes, salivary gland epithelium
Dose volume histogram: higher dose to the left eye than the left lens. What would be the possible consequences?
Options included blindness, cataracts
Cataract is a common finding, blindness is very uncommon. If the lens is receiving RT, then KCS is much more common.
Image of RT port films dog getting RT to rostral nose, what will the major side effects be?
A. Dental disease
B. oronasal fistula
c. Ocular
A. Dental disease ( fistulas are more likely with SBRT not port film)
Choose the right answer regarding nasal tumors treated with SRT.
a. Sarcomas did better than carcinomas
b. Most common side effect oronasal fistula
c. IMRT leads to improved ST for stage 1-4 Adams
I think the answer is B
In conclusion, SRT with 3 fractions of 10 Gy provides comparable tumor control to other SRT publication and fractionated IMRT publications and causes minimal acute adverse events. Survival times in dogs with stage 4a and 4b at the time of SRT were not significantly different than dogs with modified Adams stage 1-3. Modified Adams stage alone might not be a reliable prognostic indicator for dogs with stage 4b. (Yoshikawa 2023 J. Vet Int Med)
Median OST and DSST of dogs treated with 1 course of SRT was 441 (95% CI: 389-493 days) and 482 (428-536 days) days, respectively with skin/oral cavity acute morbidities observed in 3% of dogs. DSST in dogs with stage 4 disease showed no statistical difference compared to other stages (P = .64). Oro-nasal (n = 2) or naso-cutaneous (n = 11) fistula development occurred in 7.1% of dogs with median time of 425 days (range: 83-1733 days). Possible chronic rhinitis after SRT was recorded in 54 of 88 dogs (61%) where information was available (Yoshikawa 2023 J. Vet Int Med).
Although previous studies have identified that survival time for dogs with nasal carcinomas treated with conventionally fractionated radiation therapy was shorter than that for treated dogs with nasal sarcomas, we did not find an association between survival time and histologic tumor type in the present study with SRT. (2019, Mayer, Javma)
Clinical signs improved in all cases. Nineteen dogs had CT scans 3-4 months post-SRT and all had partial or complete tumour response. Minimal acute toxicities were detected. Clinically significant late toxicities included oronasal or nasocutaneous fistulas (N = 3) and biopsy-confirmed fungal rhinitis with no evidence of tumour progression (N = 2). The median progression-free survival (PFS) was 354 days, with 49% and 39% progression-free at 1 and 2 years post-SRT, respectively. The median survival time (ST) was 586 days, with 69% and 22% alive 1 and 2 years post-SRT, respectively. Neither the clinical parameters evaluated (modified Adams’ stage, histopathology, presence of intracranial extension of the tumour) nor dosimetric data were predictive for PFS or ST (Geiger 2018 Vet comp onco)
Regarding nasal lymphoma in cats:
Name a negative prognostic factor and discuss differences in survival times between treatment modalities (RT vs CHOP).
Anemia
No differences in MST between RT or CHOP (Haney JVIM 2009).
Other papers show no difference in MST based on anemia.
***Cat with unilateral nasal tumor. RT plan shows GTV is it okay or need new CT, lead bite plate to reduce dose to palate, bolus for head, GTV looks great.
Yes - need bite plate, sometimes bolus (not pRT), if strong PR may need new CT if GTV is much smaller.
You have a cat with an invasive nasal SCC that measures 3 cm and is suspected to invade bone (based on physical exam). The owner declines surgical excision and external beam RT, what other options can you discuss and which would be best suited for this patient.
Electrochemotherapy is likely best option.
Others include curettage (appropriate for tumors that affect less than 50% of the nasal planum), Strontium 90 (only for superficial tumors, penetrates up to 3 mm), imiquimod (again, only for superficial tumors, used in Bowen’s carcinoma (pg 494 withrow)
Mandibular OSA has a lower metastatic rate and a higher 1 year survival rate but many still metastasize. How much does chemotherapy increase survival time?
Metastasis free interveral increases from 535d to 911 d (ie more than 2 years)
What would you recommend for a patient with an incompletely excised GIST?
Largely unknown, clinical benefit noted for gross disease - what to do next (Palladia, no tx)
What percentage of GISTS have mutation in exon 11?
Human 50-80%, c-kit exon 11 mutations in 32.6% by conventional PCR and 73.9% by RT-PCR (Takanousu Vet J 2016).
2010 study showed 35% (BMJ 2010)
Mutations of c-KIT were detected in 47% of cases (Vet sciences morini 2022)
Dog with cutaneous T cell LSA treated with Elspar, vincristine, and CCNU goes into remission for 5 months without treatment. Develops a mediastinal mass and cytology results are consistent with LSA. How do you treat?
Restart protocol
Which protocol has the longest survival time for T cell LSA?
LOPP (323d, Brown 2018)vs Modified LOPP (507d, Morgan 2018)
One retrospective report of 50 dogs with T cell lymphoma treated with L-asparaginase and mechlorethamine, prednisone, procarbazine and vincristine (L-MOPP) found superior response rate and survival compared to historical data for dogs with T cell lymphoma treated with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) based protocols. The CR rate was 78% and the median progression-free survival (PFS) was 189 days (Brodsky et al., 2009).
In another retrospective study of 24 dogs with T cell lymphoma treated with a CHOP-based protocol, a higher proportion of dogs had CR (88%), although the PFS period was shorter at 104 days (Rebhun et al., 2011). A third study found only 10/25 (40%) of 25 dogs with T cell lymphoma treated with CHOP achieved CR for a median PFS of 105 days (Curran and Thamm, 2015).
This study represents the largest group of dogs with T cell lymphoma treated with a specific chemotherapy protocol yet reported. The median PFS of 175 days (95% CI, 119–231 days) and the median OST of 237 days (95% CI, 186–288 days) in this study were similar to those reported in two previous studies of canine T cell lymphoma: (1) median PFS of 189 days (95% CI, 99–278 days) (Brodsky et al., 2009);(2) median OST of 270 days (95% CI, 206–333 days) (Brodsky et al., 2009); and (3) median OST of 235 days (95% CI, 164–244 days) (Rebhun et al., 2011). The 1 and 2 year survival rates in the dogs reported in the present study (31% and 20%, respectively) are higher than those in the L-CHOP-based study (1 and 2 year survival rates 14% and 5%, respectively) of Rebhun et al. (2011), but less than the 25% of dogs still alive after 2.6 years in the L-MOPP-based study of Brodsky et al. (2009). (goodman 2016 vet journal)
Modified LOPP Median survival time (MST) was 507 days (Morgan 2018 vet comp onc)
Boxer with T cell LSA. What are flow results.
CD 3+ and CD 4+
Cats with LSA that receive vinblastine rather than vincristine in a CHOP-based protocol show what changes in SE and overall prognosis?
Decreased GI side effects and similar RR, PFI and ST. Cats in both arms had similar response rates, PFS, and LSS (48 versus 64 days, P = .87; 139 versus 136 days, P = .96). (Krick 2013 JVIM)
Incompletely excised STS grade II owner cannot afford definitive RT.
Metronomic chemotherapy (emslie 2008)
Benign neglect
Palliative RT - the median progression free survival was 698 days (all grades of STS)
A canine patient with pericardial effusion has a fluid analysis that returns as not definite for neoplasia. What might increase the likelihood of diagnostic effusion and what are your differentials for this patient?
Diagnostic fluid analysis increased from 7.7 to >20% if hct of fluid <10%. (Cagle JVIM 2014)
Septic pericarditis, coagulopathies, left atrial rupture, neoplasia, idiopathic. Most common are idiopathic and cardiac HSA with heart base tumors, mesothelioma and lymphoma occuring less frequently.
