11/3 - Local Disease Control - Oncology

Staging

Is staging or grading the step done by the vet clinician?

Yes

Should you refer cases with large fixed tumors, large ulcerated cutaneous tumors, large oral tumors, cervical tumors, and tumors within cavities?

Brachytherapy

Which type of radiation therapy is a local therapy, either internal or short distance? An example is the injection of a radioactive isotope directly into the tumor. Strontium 90 radiation is one option. It is rarely done, however.

Radionuclides

One type of radiation therapy is the systemic administration of what? This is commonly done, and can be done for staging (NS, thyroid scan, PET) or as systemic therapy (iodine isotopes for feline hypertyroidism or canine thyroid cancer).

Plesiotherapy

What form of brachytherapy is also called surface contact and uses a Strontium gun to deliver strontium locally and superficially directly to the skin? This can be done for feline nasal planum SCC.

Teletherapy

Which type of radiation therapy is also called external beam radiation therapy, and is the most commonly used radiation treatment in vet med? The patient will not be radioactive, which is not the case in radionucleotide administration. It is localized treatment and can be used on its own, before/after surgery, or in combination with other treatments. Electrons in the beam cause ionization events, leading to DNA damage and apoptosis of cancer cells.

Radiation

What term refers to energy released in the form of a particle or electromagnetic wave that travels through space and matter? The ionizing form is when there is sufficient energy to eject one or more orbital electrons from an atom. A linear accelerator is what delivers this as high energy x-rays.

Gy

What unit is used to describe the dosage of radiation therapy, also called a gray? This refers to the amount of energy absorbed by tissue, and one of these is equal to one joule per kg of tissue. The dose is determined based on whether treatment is meant to be definitive or palliative.

Definitive

Which intent of radiation therapy uses small doses per fraction, has more acute side effects, and is intended for long term tumor control? Often, post-operative margins are incomplete for many tumor types, so this is used to prevent recurrence. It is a primary therapy for many tumors types such as brain and nasal.

Palliative

Which intent of radiation therapy uses large doses per fraction and more late side effects, and is intended for short term pain relief and improvement of quality of life?

SBRT

Which type of radiation therapy (abbreviated) uses stereotactic bodies? It was previously used for more small tumors but is now more commonly used for osteosarcoma, liver tumors, adrenal tumors, and others. It uses very specialized 3D imaging and equipment for precise and targeted large doses. Most modern linear accelerators have the capability for this. It is also used for metastatic disease.

Adenocarcinoma

What tumor is the most common nasal tumor in dogs and can be treated with SBRT as primary treatment? MST is 1 year or longer and QOL can improve.

Lymphoma

A high-grade what is the most common nasal tumor in cats? SBRT can be the primary treatment if it is localized and MST is 1.5 years or longer. QOL will improve.

Acute

Are acute or late radiation therapy side effects more likely to resolve?

Acute

Which side effects of radiation affect rapidly proliferating tissues, such as the oral mucosa, intestinal epithelium, epithelial structures of the eyes, and skin?

Late

Which side effects of radiation therapy affect slowly dividing cells, such as the bone, lung, heart, kidneys, brain, and spinal cord? There can be fibrosis, necrosis, loss of function, death, and development of 2nd malignancies. Long term skin effects can also occur.

CT

What diagnostic technique is required for planning radiation therapy?

Electrochemotherapy

Which type of local cancer treatment is a local therapy which can be done intra-op, post-op, or with measurable disease? Effects are not as well studied as in surgery and radiation therapy.

Stelfonta

What drug is also called tigilanol tiglate, and is contraindicated in metastatic disease or if there are subcutaneous mast cells on the head, body, or trunk? It is indicated for cases of tumor volume of 10 cm3 or less, accessible tumors, non-metastatic dermal tumors, or non-metastatic SC at or distal to the elbow/hock. It causes rapid localized inflammation and necrosis and destruction of tumor vasculature. Supportive medicines can include corticosteroids, H1 blockers, and H2 blockers. A luer-lock syringe is used, small negative pressure is created, and the needle is withdrawn and light pressure is applied. The needle should not be recapped to avoid self-injection. Sloughing occurs by day 7. Second intention wound healing is indicated.