RT in Dogs

Question 1

Nolan et al. Intensity-Modulated and Image-Guided radiation therapy for treatment of genitourinary carcinomas in dogs

21 dogs

Tumors were located in prostate (10), urinary bladder (9), urethra (2)

Total dose 54-58 Gy delivered in 20 fractions

Acute Toxicities?

Late toxicities?

RR?

Median event free survival?

MST?

Answer 1

Grade 1 and 2 acute genitourinary and grade 1 acute integumentary in 5, 5, 20%

4 dogs had late grade 3 GI and GU toxicosis

60%

317 days (10.6 mo)

654 days (22 mo)

Question 2

Kubicek et al. 2012. Helical tomotherapy setup variation in canine nasal tumor patients immobilized with a bite block

The variation of all parameters were statistically smaller in group immobilized by ___

The mean setup corrections in the mattress and bite block group ranged from 0.91 mm ro 1.59 mm for the translational error and 0.5

Answer 2

mattress and bite block

Question 3

Demetriou et al. 2012. Intentional marginal excision of canine limb STS followed by radiotherapy

Course fractionated protocol of 4 once weekly 8 to 9 Gy by MV x-rays

56 cases

Minor surgical complications?

Tumor recurred locally in?

Death from tumor related causes?

Time from surgery to radiotherapy was only predictor of tumor recurrence

Delaying RT beyond 4 weeks was associated with improved outcome

Answer 3

7%

18%

25%

Question 4

Harmon et al. 2013. Evaluation of canine prostate intrafractionatal motion using serial cone beam computed tomographing imaging

Serial CBCT images taken priot to treatment and during treatment

7 patients

The mean intrafraction movement for the prostate and urethra was <1.60mm and <2.0mm

The maximum variability in intrafraction movement for the prostate and urethra was <1.4mm and <1.5mm

Question 5

Yoshikawa et al. 2012. Repeatability of a planning target volume expansion protocol for RT of regional lymph nodes in canine and feline patients with head tumors

In dogs, the mandibular LNs were positioned more caudally and right mandibular and retropharynngeal LNs were positioned more to the left side of the patient

In cats, the mandibular LN was positioned higher than the planning CT

Question 6

McDonald et al. Response rate and duration associated with 4 Gy 5 fraction palliative radiation protocol

22 cats and 58 dogs

ORR

MPFS

MST

Primary bone tumors ORR? MPFS? MST

Feline oral SCC ORR? MPFS? MST?

STS in dogs ORR? MPFS? MST

Overall toxicity 18.4% with 16.9% acute toxicity (grade I and II)

Answer 6

67%

3. 3 months
4. 2 months

Most common in dogs - 66.6%, 3.5 months, 3 months

54.4%, 1.8 months, 3 months

80%, 5.7 months, 7.9 months

Question 7

Nagata et al. The electron beam attenutating properties of superflab, play-doh, and wet gauze, compared to plastic water

Question 8

Keyerleber et al. 2012. Completeness of reporting of radiaition therapy planning dose, and delivery in veterinary radiation oncology manuscripts from 2005 to 2010

The completeness of reporting was best in regards to statement of prescription radiaiton protocol (91-98% reported) and worse to specifications of absorbed dose within target volumes and surrounding normal tissues (0-6% reported)

Question 9

Erfouth et al. 2012. Use of propofol for induction of anesthesia in dogs undergoing definitve radiation therapy

18 daily treatments M-F

Leukocyte and platelet parameters did not change

Hct, erythrocyte count, Hg concentration, and MCH decreased over time

Dogs receiving propofol for induction had decrease in RBC count

Question 10

Vancil et al. Use of samarium Sm 153 lexidronam for the treatment of dogs with primary tumors of the skull: 20 cases

7 OSA and 13 MLO

20 dogs evaluated 21 days after injection

4 (20%) had subjective improvement, 13 PD, 3 had insufficient follow up

Survival time from injection to death ranged from 3-1314 days (median 144 days)

Question 11

Clermont et al. Radiotherapy induced myelosuppression in dogs: 103 cases

Impact of definitive radiotherapy on hematopoeisis is unknown in tumor bearing dogs

103 dogs receiving Cobolt teletherapy for cancer over 5. year period

Significant reduction in Hct, total WBC, neutrophils, eosinophils, monocytes, lymphocyes, and Plt

Question 12

Campos et al. 2012. Effect of recombinant human thyrotropin on the uptake of radioactive iodine (¹²³I) in dogs with thyroid tumors

Recombinant human thyrotrpine (rhTSH) enhances radioactive iodine uptake (RAIU)

IV administration of 100ug of rhTSH before 123I has an inconsistent effect on thyroid tumor RAIU

Question 13

Keyerleber et al. Three-dimensional conformal radiation therapy alone or in combination with surgery for treatment of canine intracranial meningioma

MST?

No significant difference in survival between treatment with RT alone versus adjuvant RT

Answer 13

577 days (1.5 yr)

Question 14

Mariani et al. Frameless stereotactic radiosurgery for the treatment of primary intracranial tumors in dogs

Tumors in 51 dogs

38 meningiomas, 4 pituitary tumors, r trigeminal nerve tumors, 3 gliomas, 1 histiocytic sarcoma, 1 choroid plexus tumor

MST

Acute grade III central nervous system toxicity (altered mentation) in 2 dogs

Survival time comparable to conventional RT, but with fewer acute AEs

Answer 14

399 days

Question 15

Bucknoff et al. 2014. Evaluation of thromboelastography for prediction of clinical bleeding in thrombocytopenic dogs after total body irradiation and hematopoeitic cell transplantation

To determine if thromboelastography is more accurate of evaluating hemostasis

Maximum amplitude was on hemostatic variable with significant correlation to bleeding. BMBT had high sensitivity but poor specificity for identifying clinical bleeding.

Compared with BMBT and platetlet count TEG was more reliable at identifying thrombocytopenic dogs with low risk of bleeding

Question 16

Nieset et al. Comparison of adaptive radiotherapy techniques for external radiation therapy of canine bladder cancer

Question 17

Kung et al. 2016. Hypofractionated radiation therapy for the treatment of microscopic canine STS

48 dogs with incompletely or closely resected STS

Local recurrence? Metastasis?

Median PFS? Local failure-free probability at 1 and 3 years?

The 1 and 3 years tumor-specific overall survival was?

Answer 17

21%, 23%

698 days (1.9 yr)

81% and 73%

81% and 61%

Question 18

Griffin et al. Stereotactic radiation therapy for treatment of canine intracranial meningiomas

MST?

Mild to moderate excaerbation of neurologic systems when?

Treatment with steroids and improvement noted in most dogs

Death within 6 months was seen in 13.3%

Volume of normal brain that received full dose of prescription of 8Gy x 3 fractions was predictive of death due to neurologic problems within 6-month period.

Answer 18

561 days (18.7 mo)

3-16 weeks following SRT treatments in 37%

Question 19

Cancedda et al. 2016. Hypofractionated radiotherapy for macroscopic canine STS: a retrospective study of 50 cases treated with 5 x 6Gy protocol with or without metronomic chemotherapy

50 dogs with macroscopic disease, 20 dogs received metronomic chemotherapy

Median PFI and OS

Dogs with tumors on limbs had significantly longer PFI and OS than on head or trunk

Increasing tumor burden decreased OS

Addition of metronomic chemotherapy results in significantly longer OS (757 days) compred to no metronomic (286 days)

No influence of PFI

Answer 19

419 days and 513 days

Question 20

Marcinowska et al. 2015. Comparison of two coarse fractionated RT protocols for the management of canine pituitary macrotumor: an obervational study of 24 dogs

12 dogs treated with 10 fractions of 3.8Gy/fraction on M-W-F vs. 12 treated with once a week protocol (1 x 5Gy followed by 4 x 8.25 Gy) to toal dose of 38 Gy

MST 961 days (32 months) for 10 fractions compared to 182 days (6 months) in 5-fraction group

Question 21

Amores-Fuster et al. 2017. Post-radiatherapy hypothyroidism in dogs treated for thyroid carcinomas

Hypothyroism is common AEs after head and neck RT in humans

How many developed hypothyrodism after RT?

Was not associated with RT protocol used

Median time to diagnosis was?

Monitoring thyroid function following RT is recommended

Answer 21

48%

6 months

Question 22

Kawabe et al. 2015. Outcomes of dogs undergoing RT for treatment of oral malignant melanoma: 111 cases

Dogs received orthovoltage x-ray (68), megavoltage (39), electron beam RT (4)

Adjunctive tx included debulking surgery, chemotherapy, or both

MST for dogs with stage I, II, III, IV were 758 days, 278, 163, and 80 days and differed significantly with stage I

Dogs with stage III melanoma, risk of death was significantly higher in those that received orthovoltage than those that received megavoltage

Severe AEs in 9 dogs

Question 23

Choy et al. 2016. Tolerability and tumor response of a novel low-dose palliative radiation therapy protocol in dogs with transitional cell carcinoma of the bladder and urethra

10-once daily fractions of 2.7 Gy

Within 6 weeks, 7.6% had CR, 54% PR, 38.5% SD, and none had PD

3 patients with urethral obstruction has micturition restored during the treatment protocol

MST from initial diagnosis was 179 days

MST from start of RT was 150 days

Acute RT side effects in 31% - grade 1 and 2

No significant late AE

Question 24

Magestro et al. 2017. Detection of synchronous primary tumors and previously undetected metastasis in 736 dogs with neoplasia undergoing CT scans for diagnostic, staging, and/or RT treatment planning purposes

Tumor-associated CT abnormalities were detected in 5%

In LNs considered abnormal and were aspirated 23% had metastasis and 6% of normal appearing LNs had metastasis

Question 25

**Zwingenberger et al. Perfusion and volume response of canine brain tumors to stereotactic radiosurgery and radiotherapy** Mean tumor volume significantly declined from baseline to first recheck by -0.826 cm3; recution maintained at second recheck Blood flow and blood volume declined significantly in tumor after treatment Median survival 324 days, and 4 dogs survived longer than 650 days

Question 26

**Hansen et al. 2016. Treatment of MRI-diagnosed trigemminal nerve sheath tumors by stereotactic radiotherapy in dogs** 8 dogs with presumptive PNST Median disease specific survival? No actute AE reported Late radiaiton vs. tumor progression could not be confimred

Answer 26

745 days

Question 27

**Treggiari et al. 2016. Retrospective comparison of 3D conformal RT vs. prednisolone alone in 30 cases of canine infratentorial brain tumors** 15 received RT and GC and 15 GC alone MST 294 days MST for RT group 756 days vs. 89 days **RT provided survival advantage to dogs with infratentorial tumors compared to GC alone**

Question 28

**Dolera et al. 2018. Frameless stereotactic RT alone and combined with temozolomide for presumed canine gliomas** CR and PR in RT and RT +TMZ? Median survival in RT arm and RT + TMZ arm **Combining VMAT with TMZ did not improve survival time**

Answer 28

63.2% vs. 90.9% 383 days and 420 days

Question 29

**Goto et al. 2017. Hypofractionated RT in treatment of canine thymoma: retrospective study of 8 cases** Overall RR was 50% Median time to response was 22 days MST was not reached and 1 year survival rate was 75%

Question 30

**Farelly et al. 2018. Retrospective analysis of nonradiation complications in dogs undergoing radiation therapy** Complications occured in 37% - diarrhea, vomiting, cough, loss of appetite 6% developed severe complications 3% died from complications Dogs that developed complications were younger, received more treatments, had leukocytosis, received steroids, and well less likely to have thrombocytopenia On multivariable analysis, # of treatments and leukocytosis were associated with complications

Question 31

**Poirier et al. 2018. EEfficay of RT for the treatment of sialocele in dogs** 54% achieved a CR and 45% PR with RT 3 dogs developed progression of sialocele at 2, 3, 9 months after RT

Question 32

**Murakami et al. 2017. Interobserver reliability of CT contouring of canine tonsils in RT treatment planning** Discrepancy in tonsillar volumue between groups may affect treatment outcome