1. Patharakrit Teewasutrakul(DVM) Chulalongkorn University
Radiation Therapy
Patharakrit Teewasutrakul(DVM)
Oncology Clinics
SMALL ANIMAL Hospital
Chulalongkorn University

2. Introduction to Radiation Therapy
History
1895 Wilhelm Conrad Röntgen
-Diagnosis &Therapeutic purposes
1902 Radiation induced cancer was reported
1903 suggestion to treat cancer w implanting radium
1930 Initial clinical use of radiation dose fractionation
1972 Computed Tomography and Radiation therapy
D setting w tumor hypoxia and the tumor environment
1994 Am College of Veterinary Radiology
2009 -Currently about 70 board-certified
veterinary radiation oncologists
-Residency programs in USA
-Veterinary Technicians
(Barbara Kaser- Hotz. ,36thWSAVA 2011)
(Elizabeth McNiel.,29th Annual conference of the VCS 2009)

3. What is the Radiation Therapy
รังสีที่ใช้รักษาได้แก่ รังสีเอกซ์ รังสีแกมมา นิวตรอน และพวกอนุภาคต่างๆ ส่วนใหญ่แล้วมักนิยม ใช้รังสีแกมมาจากเครื่องโคบอลต์-60 รังสีเอกซ์พลังงานสูง จากเครื่องเร่งอนุภาค และนิยมใช้อนุภาคอิเล็กตรอน รักษาบริเวณพื้นผิวตื้น ๆ การเลือกชนิดและพลังงาน ของรังสีรักษา ต้องพิจารณาลักษณะรูปร่าง ตลอดจนตำแหน่งที่ตั้งของก้อนมะเร็ง

4. Types of radiation 1. Electromagnetic Radiation
1.1รังสีเอกซ์ (x-rays) source : high energy x-ray equipments
1.2รังสีแกมมา (gamma-rays) :radioactive isotopes nucleus
2.  Particle Radiation:Linear Accelerator
2.1  อนุภาคอิเล็กตรอน (Electrons)
2.2  อนุภาคอื่น ๆ เช่น โปรตรอน(Photons)

5. How does radiation kill cells?

6. Radiation therapy and Biological response of tumor and normal tissue
Relative radiosensitivity of common animal tumours
Relative radiosensitivity of normal animal tissue
response
Type of tumors
High
Lymphoproliferative disorders
Myeloproliferative disorders
Transmissible venereal tumour
Mast cell tumours (variable)
Sensitive
Squamous cell carcinoma
Basal cell carcinoma
Adenocarcinoma (various)
Moderate
Oral melanoma
low
Fibrosarcoma
Osteosarcoma
Chondrosarcoma
Haemangiopericytoma

7. How radiation dose is measured?
The Absorbed dose :Gray(Gy)= SI unit
1Gray(Gy)=1joule(j) of energy absorbed by 1 kg tissue
1Gray(Gy)=100 Rad
1Rad =100ergs/g
1 Fraction =Individual radiation treatment dose
Total dose= Fraction X Time of RT treatment.

8. Principles of Radiation Oncology
The concept of therapeutic ratio for radiation therapy

9. Principles of Radiation Oncology
The concept of therapeutic ratio for radiation therapy
Ideal X O
Radiosensitive tumor
Radioresistant tumor
Limited sensitive tumor

10. Fractionation 1.Total dose (Gy) 2.Fraction size (Gy) 3.Duration of Tx.
Details
Treatment procedure
1.Total dose (Gy)
2.Fraction size (Gy)
3.Duration of Tx.

11. Fractionation effect Exponential tumor cell killing by radiation
dose
(Gy)
Cumulation
Dose
Cells present
Fraction
killed
Cell s Remaining X 1X
1,000,000,000
10%
100,000,000 2X
10,000,000 3X
1,000,000 4X
100,000 5X
10,000

12. Fraction ation and Tumor biology
4R’s radiobiology
1.Repair
2.Repopulation
3.Redistribution
4.Reoxygenation

13. Types of Radiation Therapy
1. Teletherapy or External beam therapy
2. Plesiotherapy or Brachytherapy
3. Unsealed source therapy or Nuclear medicine

14. 1.Teletherapy or External beam therapy
Model Linac
Linear Accelerator
(4-20MeV)

15. Different types of animal immobilization
Stand
Mask

16. Different type of animal immobilization
Tooth block
Cat and tooth block

17. Different type of animal immobilization
Position of dog during RT
Dog and tooth block

18. Different types of animal immobilization
Vacuum bag
Animal immobilization

19. Radiotherapy treatment planning
1.Measures of tumor volume
CT scan
Equipment
CT or MRI
X-rays

20. Radiotherapy treatment planning
CT &MRI
CT&MRI

21. Radiotherapy treatment planning
Hand &Computer planning

22. Radiotherapy treatment planning
3D Virtual Simulation
Computer planning

23. Radiotherapy treatment planning
3D Virtual simulation
Computer planning

24. Radiation therapy:Beam control
Multileaf collimator
Other devices

25. Virtual Simulation : multiple fields RT

26. Radiotherapy treatment planning

27. Monitoring RT procedure

28. Radiation Therapy Dog and oronasal mass: canine oral melanoma
multiple fields RT

29. Cat : CT scan for RT preparation Cat with nasal lymphoma
Radiation therapy
Cat : CT scan for RT preparation
Cat with nasal lymphoma

30. Common tumours amenable to radiation therapy

31. 2. Plesiotherapy or Brachytherapy
Iridium-192
Strontium-90

32. 3. Unsealed source therapy or Nuclear medicine
Iodine-131

33. Common radiation therapy side effects
Acute side effects
Delay side effects

34. Common radiation therapy side effects

35. Common radiation therapy side effects
Acute moist desquamation
Delay effect :Depigmentation

36. Radiation Therapy in Veterinary Medicine
1.Radiation therapy alone
Curative Treatment
Local and small tumor size
Almost radiosensitive tumor types
Palliative Treatment
Reduce cancer pain
Destroy cutaneous metastasis tumor
Slowly tumor growth rate

37. Combined Radiation with Other modalities
1. Combined Radiation and Surgery
2.Combined Radiation and Systemic therapy
Preoperative irradiation
Intraoperative irradiation
Postoperative irradiation
Chemotherapy:
Synergistically improve
Doxorubicin
Carboplatin
Gemcitabine
Paclitaxel
are all shown to improve the effects of radiation
Adjuvant chemotherapy
Neoadjuvant Chemotherapy
Immunotherapy
Melanoma vaccine

38. Radiation Therapy in Veterinary Medicine
Weak point

39. Future Direction of Radiation Therapy
IMRT : Intensity modulated RT
Rapid Arc : 4D RT

40. Radiation Therapy in Veterinary Medicine
Clinical application

41. Radiation Therapy Dog and oronasal mass: canine oral melanoma
multiple fields RT

42. Cat : CT scan for RT preparation Cat with nasal lymphoma
Radiation therapy
Cat : CT scan for RT preparation
Cat with nasal lymphoma

43. Use of strontium-90 plesiotherapy for the treatment of a lingual plasmacytoma in a dog. K. Ware and T. Gieger etal. Journal of Small Animal Practice (2011) , 220–223
1.Plasmacytoma
4.RT 150Gy
3.Therapeutic Planing
2.cytology
5.Post RT

44. Prognostic significance of specific magnetic resonance imaging features in canine nasal tumours treated by radiotherapy . P. AGTHE*, A. R. CAINE, R. N. A. GEAR et al., Journal of Small Animal Practice (2009) 50, 641–648

45. Prognostic significance of specific magnetic resonance imaging features in canine nasal tumours treated by radiotherapy . P. AGTHE*, A. R. CAINE, R. N. A. GEAR et al., Journal of Small Animal Practice (2009) 50, 641–648

46. Prognostic significance of specific magnetic resonance imaging features in canine nasal tumours treated by radiotherapy . P. AGTHE*, A. R. CAINE, R. N. A. GEAR et al., Journal of Small Animal Practice (2009) 50, 641–648

47. Intensity-Modulated and Image-Guided Radiation Therapy for Treatment of Genitourinary Carcinomas in Dogs M.W. Nolan, L. Kogan, L.R. Griffin, et al. J Vet Intern Med 2012;26:987–995
UB target

48. Intensity-Modulated and Image-Guided Radiation Therapy for Treatment of Genitourinary Carcinomas in Dogs M.W. Nolan, L. Kogan, L.R. Griffin, et al. J Vet Intern Med 2012;26:987–995
Colon UB

49. Intensity-Modulated and Image-Guided Radiation Therapy for Treatment of Genitourinary Carcinomas in Dogs M.W. Nolan, L. Kogan, L.R. Griffin, et al. J Vet Intern Med 2012;26:987–995

50. Questions