1. أجهزة العلاج الإشعاعي Clinical Radiation Generator
إعـداد
 م. أنور صلاح عطاالله
September 19, 2018
Clinical Radiation Generator

2. المعالجة الإشعاعية Radiotherapy
استخدام الإشعاع المؤين في معالجة السرطان
Using the ionizing Radiation to treat cancer
معالجة خارجية (عن بعد)
External Beam
Therapy (EBT)
معالجة داخلية (عن قرب)
Brachytherapy
September 19, 2018
Clinical Radiation Generator

3. Clinical Radiation Generator
Radiotherapy
One of the main treatment modalities for cancer (often in combination with chemotherapy and surgery)
It is generally assumed that 50 to 60% of cancer patients will benefit from radiotherapy
Minor role in other diseases
Siemens Oncology
September 19, 2018
Clinical Radiation Generator

4. External Beam Radiotherapy
tumor
patient
September 19, 2018
Clinical Radiation Generator

5. Clinical Radiation Generator
September 19, 2018
Clinical Radiation Generator

6. External Beam Radiotherapy
More than 90% of all radiotherapy patients are treated using EBT
Most of these are treated using X-rays ranging from 20keV to 20MeV in peak-energy
Other EBT treatment options include telecurie units (60-Co and 137-Cs), electrons from linear accelerators and accelerators for heavy charged particles such as protons
September 19, 2018
Clinical Radiation Generator

7. Cancer incidence (WHO)
September 19, 2018
Clinical Radiation Generator

8. Major indications for radiotherapy
Head and neck cancers
Gynaecological cancers (eg. Cervix)
Prostate cancer
Other pelvic malignancies (rectum, bladder)
Adjuvant breast treatment
Brain cancers
Palliation
September 19, 2018
Clinical Radiation Generator

9. Clinical Radiation Generator
Approaches
Palliative radiotherapy to reduce pain and address acute symptoms - eg bone metastasis, spinal cord compression, ...
Radical radiotherapy as primary modality for cure - eg head and neck
Adjuvant treatment in conjunction with surgery - eg breast cancer
September 19, 2018
Clinical Radiation Generator

10. Clinical Radiation Generator
Aim
Patient
Critical
organs
To kill ALL viable cancer cells
To deliver as much dose as possible to the target while minimising the dose to surrounding healthy tissues
target
Beam
directions
September 19, 2018
Clinical Radiation Generator

11. Clinical Radiation Generator
Prognostic Factors
Cancer type and stage
Patient performance
Radiation dose
...
Good prognosis
survival
Bad prognosis
time
September 19, 2018
Clinical Radiation Generator

12. Accurate dose delivery Clinical Radiation Generator
Prognostic Factors
Cancer type and stage
Patient performance
Radiation dose
...
Accurate dose delivery
matters!
September 19, 2018
Clinical Radiation Generator

13. Dose should be accurate
To target:
5% too low - may result in clinically detectable reduction in tumour control (eg. Head and neck cancer: 15%)
To normal tissues:
5% too high - significant increase in normal tissue complication probability = morbidity = unacceptable side effects
September 19, 2018
Clinical Radiation Generator

14. External beam radiotherapy (EBT) treatment approaches
Superficial X-rays
Orthovoltage X-rays
Telecurie units
Megavoltage X-rays
Electrons
Heavy charged particles
Others
September 19, 2018
Clinical Radiation Generator

15. External beam radiotherapy (EBT) treatment approaches
Superficial X-rays
Orthovoltage X-rays
Telecurie units
Megavoltage X-rays
Electrons
Heavy charged particles
Others
40 to 120kVp
150 to 400kVp
137-Cs and 60-Co
Linear accelerators
Protons from cyclotron, C, Ar, ...
Neutrons, pions
September 19, 2018
Clinical Radiation Generator

16. Superficial radiotherapy
50 to 120kVp - similar to diagnostic X-ray qualities
Low penetration
Limited to skin lesions treated with single beam
Typically small field sizes
Applicators required to collimate beam on patient’s skin
Short distance between X-ray focus and skin
September 19, 2018
Clinical Radiation Generator

17. Superficial radiotherapy
Philips RT 100
September 19, 2018
Clinical Radiation Generator

18. Superficial radiotherapy issues
Due to short FSD high output and large influence of inverse square law
Calibration difficult (strong dose gradient, electron contamination)
Dose determined by a timer - on/off effects must be considered
Photon beams may be contaminated with electrons from the applicator
September 19, 2018
Clinical Radiation Generator

19. Orthovoltage radiotherapy
kVp
Penetration sufficient for palliative treatment of bone lesions relatively close to the surface (ribs, spinal cord)
Largely replaced by other treatment modalities
September 19, 2018
Clinical Radiation Generator

20. Clinical Radiation Generator
September 19, 2018
Clinical Radiation Generator

21. Clinical Radiation Generator
September 19, 2018
Clinical Radiation Generator

22. Kilovoltage Equipment (150 - 400 kVp)
Depth dose dramatically affected by the FSD
FSD 6cm,
HVL 6.8mm Cu
FSD 30cm,
HVL 4.4mm Cu
September 19, 2018
Clinical Radiation Generator

23. Orthovoltage patient set-up
Like for superficial irradiation units the beam is set-up with cones directly on the patient’s skin
September 19, 2018
Clinical Radiation Generator

24. Megavoltage radiotherapy
60-Cobalt (energy 1.25MeV)
Linear accelerators (4 to 25MVp)
Skin sparing in photon beams
Typical focus to skin distance 80 to 100cm
Isocentrically mounted
September 19, 2018
Clinical Radiation Generator

25. Clinical Radiation Generator
مع أطيب الأمنيات
September 19, 2018
Clinical Radiation Generator