patharakrit teewasutrakul(dvm ) oncology clinics small animal hospital chulalongkorn university...
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PATHARAKRIT TEEWASUTRAKUL(DVM )
ONCOLOGY CLINICS
SMALL ANIMAL HOSPITAL CHULALONGKORN UNIVERSITY
Radiation Therapy
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 1990 3D 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)
What is the Radiation Therapy
รั�งสี�ที่��ใช้รั�กษาได้แก� รั�งสี�เอกซ์� รั�งสี�แกมมา นิ�วตรัอนิ และพวกอนิ�ภาคต�างๆ สี�วนิใหญ่�แลวม�กนิ�ยม ใช้รั�งสี�
แกมมาจากเครั&�องโคบอลต�-60 รั�งสี�เอกซ์�พล�งงานิสี)ง จากเครั&�องเรั�งอนิ�ภาค และนิ�ยมใช้อนิ�ภาคอ�เล+กตรัอนิ รั�กษาบรั�เวณพ&-นิผิ�วต&-นิ ๆ การัเล&อกช้นิ�ด้และพล�งงานิ ของรั�งสี�รั�กษา ตองพ�จารัณาล�กษณะรั)ปรั�าง ตลอด้จนิต1าแหนิ�งที่��ต� -งของกอนิมะเรั+ง
Types of radiation
1. Electromagnetic Radiation 1.1 รั�งสี�เอกซ์� (x-rays) source : high energy x-ray
equipments
1.2 รั�งสี�แกมมา (gamma-rays) :radioactive isotopes nucleus
2. Particle Radiation:Linear Accelerator 2.1 อนิ�ภาคอ�เล+กตรัอนิ (Electrons)
2.2 อนิ�ภาคอ&�นิ ๆ เช้�นิ โปรัตรัอนิ(Photons)
How does radiation kill cells?
Relative radiosensitivity of common animal tumours
response Type of tumors
High Lymphoproliferative disordersMyeloproliferative disordersTransmissible venereal tumourMast cell tumours (variable)
Sensitive Squamous cell carcinomaBasal cell carcinomaAdenocarcinoma (various)
Moderate Oral melanoma
low FibrosarcomaOsteosarcomaChondrosarcomaHaemangiopericytoma
Radiation therapy and Biological response of tumor and normal tissue
Relative radiosensitivity of normal animal tissue
How radiation dose is measured?
The Absorbed dose :Gray(Gy)= SI unit1Gray(Gy)=1joule(j) of energy absorbed by 1
kg tissue1Gray(Gy)=100 Rad1Rad =100ergs/g
1 Fraction =Individual radiation treatment dose
Total dose= Fraction X Time of RT treatment.
Principles of Radiation Oncology
The concept of therapeutic ratio for radiation therapy
Principles of Radiation Oncology
The concept of therapeutic ratio for radiation therapy
Ideal X ORadiosensitive tumor Limited sensitive tumor Radioresistant
tumor
Details Treatment procedure
1.Total dose (Gy)2.Fraction size (Gy)3.Duration of Tx.
Fractionation
Fractionation effect
Radiation dose(Gy)
Cumulation Dose(Gy)
Cells present
Fraction killed
Cell s Remaining
X 1X 1,000,000,000
10% 100,000,000
X 2X 100,000,000 10% 10,000,000
X 3X 10,000,000 10% 1,000,000
X 4X 1,000,000 10% 100,000
X 5X 100,000 10% 10,000
Exponential tumor cell killing by radiation
4R’s radiobiology
1.Repair2.Repopulation3.Redistribution4.Reoxygenation
Fraction ation and Tumor biology
Radiation therapy
Types of Radiation Therapy
1. Teletherapy or External beam therapy
2. Plesiotherapy or Brachytherapy
3. Unsealed source therapy or Nuclear medicine
Model LinacLinear Accelerator
(4-20MeV)
1.Teletherapy or External beam therapy
Stand Mask
Different types of animal immobilization
Tooth block Cat and tooth block
Different type of animal immobilization
Position of dog during RT
Dog and tooth block
Different type of animal immobilization
Animal immobilization
Different types of animal immobilization
Vacuum bag
1.Measures of tumor volume CT scan
Equipment CT or MRI X-rays
Radiotherapy treatment planning
CT &MRI CT&MRI
Radiotherapy treatment planning
Radiotherapy treatment planning
Hand &Computer planning
Radiotherapy treatment planning3D Virtual Simulation
Computer planning
Radiotherapy treatment planning
3D Virtual simulation
Computer planning
Multileaf collimator Other devices
Radiation therapy:Beam control
Virtual Simulation : multiple fields RT
Radiotherapy treatment planning
Monitoring RT procedure
Dog and oronasal mass: canine oral melanoma
Radiation Therapy
multiple fields RT
Cat : CT scan for RT preparation
Cat with nasal lymphoma
Radiation therapy
Common tumours amenable to radiation therapy
Iridium-192 Strontium-90
2. Plesiotherapy or Brachytherapy
Iodine-131
3. Unsealed source therapy or Nuclear medicine
Acute side effects Delay side effects
Common radiation therapy side effects
Common radiation therapy side effects
Acute moist desquamation
Delay effect :Depigmentation
Common radiation therapy side effects
1.Radiation therapy alone
Radiation Therapy in Veterinary Medicine
Curative Treatment Local and small tumor
size Almost radiosensitive
tumor types
Palliative Treatment Reduce cancer pain Destroy cutaneous
metastasis tumor Slowly tumor growth
rate
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
Combined Radiation with Other modalities
Weak point
Radiation Therapy in Veterinary Medicine
IMRT : Intensity modulated RT Rapid Arc : 4D RT
Future Direction of Radiation Therapy
CLINICAL APPLICATION
Radiation Therapy in Veterinary Medicine
Dog and oronasal mass: canine oral melanoma
Radiation Therapy
multiple fields RT
Cat : CT scan for RT preparation
Cat with nasal lymphoma
Radiation therapy
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) 52, 220–223
1.Plasmacytoma
2.cytology
3.Therapeutic Planing
5.Post RT
4.RT 150Gy
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
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
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
Intensity-Modulated and Image-Guided Radiation Therapy forTreatment 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
Intensity-Modulated and Image-Guided Radiation Therapy forTreatment 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
Intensity-Modulated and Image-Guided Radiation Therapy forTreatment of Genitourinary Carcinomas in Dogs
M.W. Nolan, L. Kogan, L.R. Griffin, et al. J Vet Intern Med 2012;26:987–995
Questions