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Your dog was diagnosed with Chemodectoma (Aortic Body / Heart Base Tumour). Uncommon tumour of chemoreceptor tissue at the heart base. Slow-growing but can cause pericardial effusion and tamponade. Brachycephalic breeds are predisposed (chronic hypoxia theory). Low-moderate metastatic rate (~13%). Compare 3 treatment options for dogs including Toceranib Phosphate (Palladia), Pericardiectomy, Stereotactic Body Radiation Therapy (SBRT) — with survival times, costs, and what to expect during treatment.

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Chemodectoma (Aortic Body / Heart Base Tumour)

BreedsEnglish BulldogFrench BulldogBoston TerrierBoxer
canine

Neuroendocrine

About This Cancer

Chemodectoma (also called aortic body tumour or paraganglioma) arises from chemoreceptor cells at the base of the heart. These specialised cells normally monitor blood oxygen and carbon dioxide levels. The tumour is strongly associated with brachycephalic breeds — Boxers, Bulldogs, and Boston Terriers — and it has been hypothesised that the chronic mild oxygen deficiency associated with their flattened airways may stimulate overgrowth of these monitoring cells. Chemodectomas are generally slow-growing, and many dogs live for extended periods with the tumour. The main clinical problem arises when the tumour causes fluid to accumulate in the pericardial sac, leading to compression of the heart. The tumour has relatively low metastatic potential (about 13%), and treatment focuses on managing complications rather than necessarily removing the tumour itself.

No formal staging system

Assessment based on tumour size, presence of pericardial effusion, arrhythmias, vena caval obstruction, and regional or distant metastasis.

Prognostic Factors(2)
Vena caval obstructionNegatively associated with survival time(Coto et al., 2021)
Arrhythmias at presentationSupraventricular and ventricular arrhythmias negatively associated with survival(Coto et al., 2021)
Minimum Workup(6 steps)
1Echocardiography (heart base mass, pericardial effusion)
2ECG (arrhythmia assessment)
3Thoracic radiographs
4CT angiography (surgical planning, vascular anatomy)
5Pericardiocentesis if tamponade present
6Complete blood count and biochemistry

Median Survival Time Comparison

How long the average patient survives with each treatment

Bar opacity reflects evidence strength
Toceranib Phosphate (Palladia)
~16 mo
Pericardiectomy
See notes
Stereotactic Body Radiation Therapy (SBRT)
~13.5 mo
Reading this page: MST (Median Survival Time) is how long the average patient survives with a given treatment. ORR (Overall Response Rate) is the percentage of patients whose tumour shrank or disappeared. CR = Complete Response (tumour gone); PR = Partial Response (tumour shrank). Hover over any abbreviation for a quick explanation.
Strength of Evidence

Each treatment is rated by how much published research supports its use. Solid bars indicate stronger evidence; dashed bars mean less certainty.

StrongLarge published studies with strong agreement among veterinary oncologists.
ModerateWidely used in clinical practice, but supported by smaller or retrospective studies.
IndirectEvidence comes from a different tumour type or species and has been applied here.
LimitedVery little published data is available for this specific treatment.

Please note: All treatment data is sourced from published peer-reviewed literature. Survival times and cost figures are approximate guides. Your pet's individual factors — including tumour grade, stage, and overall health — will influence outcomes and should guide all treatment decisions. The strength-of-evidence rating reflects how much research exists, not how strongly a treatment is recommended. This tool is designed to help you have informed conversations with your veterinary oncologist, not to replace them. Costs shown are US referral centre estimates and may vary significantly by region.