Radiotherapy in small animals. How is it realized? How does it work? For which patient is it indicated?

Transcription

1 Radiotherapy in small animals How is it realized? How does it work? For which patient is it indicated?

2 Radiotherapy Our linear accelerator can generate photons or electrons. The electron beam is used to treat structures close to the skin surface. Photon radiation is used, in particular, in deeper structures. Tumors are irradiated in several directions to protect surrounding tissues. Electron Photon

3 Manual planning of Radiotherapy Superficial lesions are treated with electrons. In this case, radiotherapy is planned manually.

4 Scanner for Radiotherapy planning Deep tumors, which are not visible from the outside, require planning by computer. For this, a mold with a bite block is made so that the animal can be positioned identically every time and the radiations reach the tumor properly. Scanner planning is designed to plan radiotherapy as precisely as possible. For this, the animal must be under general anesthesia. The molding consists of a special cushion that takes the shape of the animal. The bite block is a dental impression. Molding and bite blick Dental impression for the bite block

5 Scanner for the Radiotherapy planning Example of a bite block for a big dog Scanner Bite block for a small dog or cat

6 Radiotherapy plan The doses and directions of the rays can be precisely adjusted and measured with this software.

7 Radiotherapy planning The doses and directions of the rays can be precisely adjusted and measured with this software.

8 Radiotherapy Each radiotherapy are under general anesthesia. Depending on the number of fields and on the type of radiation, it takes about 5 to 30 minutes.

9 Radiotherapy effects The rays destroy the genetic material (DNA) of the cells. The cells die as they try to divide. Pauses in between radiation sessions allow the irradiated healthy tissue to recover. Tumor cells have a reduced ability to repair damage following radiotherapy. Before Radiotherapy After Radiotherapy

10 Radiotherapy effects The rays destroy the genetic material (DNA) of the cells. The cells die as they try to divide. Pauses in between radiation sessions allow the irradiated healthy tissue to recover. Tumor cells have a reduced ability to repair damage following radiotherapy. Before Radiotherapy After Radiotherapy

11 Side effects to Radiotherapy In superficial tumors (for example skin tumors), radiation therapy causes a transitory Dermatitis. Generally the hair falls out and grows back slowly, most of the time in a different texture and color. In deeper tumors, the extent of the sides effects are often smaller and not visible from the outside. Day 0 Day 21 Day 28 Day 120

12 Side effects to Radiotherapy In superficial tumors (for example skin tumors), radiation therapy causes a transitory Dermatitis. Generally the hair falls out and grows back slowly, most of the time in a different texture and color. In deeper tumors, the extent of the sides effects are often smaller and not visible from the outside. Day 0 Day 120

13 Indications: Tumors Radiotherapy is recommended when a mass can not be (completely) removed surgically. Here is a list of tumors that are most often irradiated; Brain tumor (e.g. meningioma, glioma, ependymoma) Pituitary Tumeurs (e.g.. adenoma, carcinoma) Nasal cavity tumor (e.g. adenocarcinoma, chondrosarcoma, lymphoma) Frontal sinus tumors (e.g. squamous cell carcinoma) Oral cavity tumors (e.g. melanoma, squamous cell carcinoma, fibrosarcoma) Bone tumors (e.g. osteosarcoma, chondrosarcoma, multiple myeloma, synoviosarcoma) Thyroid tumors (carcinoma) Thymus tumors (thymoma, thymic carcinoma) Anal gland tumors (carcinoma) Skin and muscles tumors (e.g. mastocytoma, mélanoma, squamous cell carcinoma, lymphoma, soft tissue sarcoma) Nerve tumors (e.g. schwannoma)

14 Indications: Pain therapy The low dose radiation leads to a regression of inflammatory changes in the diseased area and therefore also of pain symptoms. Good results can be obtained, for example, with osteoarthritis of the elbows, knees and smaller joints or panosteitis. Incurable tumors such as osteosarcoma can also be irradiated to relieve pain.

15 Indications: Papillomatosis Papillomatosis (warts) is a viral disease that usually occurs in young dogs and immunosuppressed animals. This leads to the formation of benign wart (papilloma), a type of cauliflower mass in the oral cavity and on the skin. For single lesions, surgical removal is possible. In case of massive infestation, radiotherapy is recommended. In addition interferon and azithromycin may be administered. Before radiotherapy After radiotherapy

16 In summary: Various tumors can be successfully controlled by radiotherapy. Alone or in combination with surgery and / or chemotherapy, radiotherapy may lead to the healing of certain tumors Radiation can also be used as a pain treatment for nontumor diseases.