1 / 36

Radiation Protection in Radiotherapy

Radiation Protection in Radiotherapy. IAEA Training Material on Radiation Protection in Radiotherapy. Part 1 Aim and Role of Radiotherapy Introductory Lecture. Radiotherapy. One of the main treatment modalities for cancer (often in combination with chemotherapy and surgery)

elroy
Download Presentation

Radiation Protection in Radiotherapy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Radiation Protection inRadiotherapy IAEA Training Material on Radiation Protection in Radiotherapy Part 1 Aim and Role of Radiotherapy Introductory Lecture

  2. 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 Part 1: Introductory lecture

  3. Objectives of the Module • To become familiar with • the principles of radiotherapy • the role of radiotherapy in cancer management • the cost effectiveness of radiotherapy • To appreciate the importance of radiation dose in radiotherapy Part 1: Introductory lecture

  4. Contents of the Lecture 1. Cancer management and radiotherapy 2.Approaches for dose delivery External beam radiotherapy Brachytherapy 3. Features of a radiotherapy department 4.Self test at the end of the lecture ”Quick test” Part 1: Introductory lecture

  5. Cancer incidence (WHO) Part 1: Introductory lecture

  6. Major indications for radiotherapy • Head and neck cancers • Gynaecological cancers (e.g. Cervix) • Prostate cancer • Other pelvic malignancies (rectum, bladder) • Adjuvant breast treatment • Brain cancers • Palliation Part 1: Introductory lecture

  7. Approaches • Palliative radiotherapy to reduce pain and address acute symptoms – e.g. bone metastasis, spinal cord compression, ... • Radical radiotherapy as primary modality for cure – e.g. head and neck • Adjuvant treatment in conjunction with surgery – e.g. breast cancer Part 1: Introductory lecture

  8. 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 Part 1: Introductory lecture

  9. Prognostic Factors • Cancer type and stage • Patient performance • Radiation dose • ... Good prognosis survival Bad prognosis time Part 1: Introductory lecture

  10. Prognostic Factors • Cancer type and stage • Patient performance • Radiation dose • ... Accurate dose delivery matters! Part 1: Introductory lecture

  11. Dose response 100% response means the tumour is cured with certainty (TCP) or unacceptable normal tissue damage (e.g. paralysis) is inevitable Part 1: Introductory lecture

  12. Dose response Therapeutic window: Maximum probability of Complication Free Tumour Control Part 1: Introductory lecture

  13. Dose should be accurate • To target: • 5% too low - may result in clinically detectable reduction in tumour control (e.g. Head and neck cancer: 15%) • To normal tissues: • 5% too high - may lead to significant increase in normal tissue complication probability = morbidity = unacceptable side effects Part 1: Introductory lecture

  14. “Deviations from Prescribed Dose” • May involve severe or even fatal consequences. • IAEA Basic Safety Standards (SS 115): ”…require prompt investigation by licensees in the event of an accidental medical exposure…” Part 1: Introductory lecture

  15. Options for dose delivery • External beam radiotherapy = dose is delivered from outside the patient using X Rays or gamma rays or high energy electrons (refer to part 5 of the course) • Brachytherapy = dose delivered from radioactive sources implanted in the patient close to the target (brachys = Greek for short distance; refer to part 6 of the course) Part 1: Introductory lecture

  16. External beam radiotherapy Part 1: Introductory lecture

  17. External Beam Radiotherapy • Typically fractionated - e.g. 30 daily fractions of 2Gy up to a total dose of 60Gy • Superficial/orthovoltage photons (50 to 400kVp) for skin or superficial lesions • Megavoltage photons (60-Co or linear accelerators = linacs) for deeper lying tumours. • Megavoltage electrons from linacs for more superficial lesions Part 1: Introductory lecture

  18. Superficial/orthovoltage unit Part 1: Introductory lecture

  19. Modern Cobalt 60 unit Part 1: Introductory lecture

  20. Linear accelerator with electron cone Electron applicator Part 1: Introductory lecture

  21. Brachytherapy Interstitial implant for breast radiotherapy Intracavitary gynecological implant Part 1: Introductory lecture

  22. Brachytherapy • Implant of radioactive materials (e.g. 137-Cs, 192-Ir) close to the target area • Intracavitary, interstitial and mould surface applications • Low dose rate, LDR, (60Gy in about 5 days) and high dose rate, HDR, (several fractions of several Gy in few minutes each) applications Part 1: Introductory lecture

  23. Example for HDR Brachytherapy Part 1: Introductory lecture

  24. A radiotherapy department is part of a health system Radiotherapy Department National Cancer System Oncology Host hospital Part 1: Introductory lecture

  25. Patient Flow in Radio-therapy …not necessarily a straightforward process Part 1: Introductory lecture

  26. Patient flow in radiotherapy • Depends on: • disease site and stage • departmental protocols • treating clinician • resources available Part 1: Introductory lecture

  27. Components of a Radiotherapy Department • Diagnostic facilities (CT, MRI, …) • Simulator (refer to part 5 of the course) • Mouldroom • Treatment planning • External beam treatment units (parts 5 and 10) • Brachytherapy equipment (part 6) • Clinic rooms, beds, ... Part 1: Introductory lecture

  28. Layout of a Department Part 1: Introductory lecture

  29. Layout of a Department Physics & workshops Simulator Planning Clinics Two linac bunkers Offices Patient waiting Part 1: Introductory lecture

  30. Professionals in radiotherapy • Radiation oncologists • Other clinicians • Medical radiation physicists • Radiation therapists • Nursing staff • Radiation safety officer • Information technology officer • Administrative staff Part 1: Introductory lecture

  31. Features of Radiotherapy • High and potentially lethal absorbed dose is required to cure cancer • High technology environment • Individualized treatment approach • Complex treatment set-up Part 1: Introductory lecture

  32. Features of Radiotherapy • High and potentially lethal absorbed dose is required to cure cancer • High technology environment • Individualized treatment approach • Complex treatment set-up • Quality assurance, treatment verification and radiation protection essential Part 1: Introductory lecture

  33. Summary • Radiotherapy is an important cancer treatment modality • Accuracy of dose delivery is essential for good outcomes • The complex and high tech environment requires attention to quality assurance and radiation protection Part 1: Introductory lecture

  34. Where to Learn More • Other parts of the course, handouts • References: • Radiotherapy physics textbooks (as per reference list) • IUCC Cancer Statistics • Radiotherapy textbooks (e.g. Perez and Brady 1998) • Site visit of a radiotherapy department (day xxx of the course) Part 1: Introductory lecture

  35. Any questions? Part 1: Introductory lecture

  36. Question: What is the main cancer treated with radiotherapy in your country and what would be a typical treatment approach? (Number of fractions? Total dose?) Part 1: Introductory lecture

More Related