1. Introduction to clinical Radiotherapy
Sarah Brothwood
Radiotherapy Practice Educator
Rosemere Cancer Centre

2. Radiotherapy
We have been able to see and document the effects of ionizing radiation

3. Radiotherapy Background
Approximately 50% of cancer patients should receive radiotherapy as part of their treatment [1]
Radiotherapy contributes to cure of 40% of cases, alone or in combination with another modality. [2]
Radiotherapy is prescribed
Radiotherapy uses ionizing radiation which not only effectively cures cancers but can also cause cancer
1. Bentzen et al. towards evidence based guidelines for radiotherapy infrastructure and staffing needs in Europe: the ESTRO QUARTS project. Radiotherapy and Oncology 2005; 75: 355 – 65.
2. Delaney et al. The role of radiotherapy in cancer treatment: estimating optimal utilisation from a review of evidence based clinical guidelines. Cancer 2005; 104:

4. The aim of Radiotherapy
Is to give a maximum dose of ionising radiation to the tumour volume and to minimise the dose given to normal tissue
A successful course of radiotherapy causes lethal damage to tumour cells and sub-lethal damage to normal cells

5. Three Types of Radiotherapy
External Beam Radiotherapy
Brachytherapy- Small sealed sources inserted into the body
Radio-isotopes – e.g. radioactive iodine

6. External Beam Radiotherapy ‘Megavoltage’ X-Rays
Delivered using linear accelerators (linac)
Produces high energy photons between 4MV and 18MV
Can deliver electrons for superficial treatments
Imaging systems used to pinpoint cancers, adapt radiotherapy and ensure accuracy
Very expensive £1.5 - £3 million

7. How we treat the patient

8. Why it works …………

9. Role of Radiotherapy
Radiotherapy is usually required for one of the following reasons:
As a stand-alone treatment to cure cancer;
e.g.T1 larynx
To shrink a cancer before surgery;
e.g.Colo-rectal
To reduce the risk of a cancer coming back after surgery
e.g. Breast following lumpectomy

10. Role of Radiotherapy
Together with chemotherapy or monoclonal antibodies
e.g.Intermediate head and neck cancer with cisplatin or cetuximab
To control symptoms and improve quality of life if a cancer is too advanced to cure
e.g Spinal cord compression

11. To benefit from radiotherapy….
Have disease that is radiosensitive
Localised disease (if radical approach)
Ability to position anatomically to get a high dose to disease and a low dose to critical structures
Compliant patient –
able to keep still!
Consideration of risk
versus benefit – informed consent!

12. Radical or Palliative? Radical Palliative
Patient in good general condition
Limited tumour with some chance of cure
High dose
Inevitable side effects
Palliative
Patient is beyond cure but symptoms can be alleviated
Pain
Obstruction
Bleeding
Ulceration
Pathological fracture
Relief of neurological deficits

13. Sensitivity to Radiotherapy
Radiotherapy works better in some circumstances than in others:
Some tumours more radiosensitive
Radiotherapy works better if tumour is well oxygenated
Cells in a certain phase of the cell cycle are more sensitive to radiation then they are in other phases

14. Radiosensitivity of cell in cell cycle
Relative
Survivability
G S G G1 M
Relative survivability of cells irradiated in different phases of the cell cycle. Synchronised cells in late G2 and in mitosis (M) showed greatest sensitivity to cell killing.

15. Radiotherapy – a targeted treatment
Accuracy is extremely important and more achievable in radiotherapy
This allows treatment areas to be smaller and treatment doses to be higher – sparing normal tissue

16. Common Fractionation Schedules
Single session – (8-10 Gy)
Short course – 4-5Gy per #
Radical course 3-7 weeks – Gy
Hyper or hypo fractionation

17. Side effects from Radiotherapy
General Systemic effects
Malaise
Nausea
Fatigue

18. Radiotherapy Side-effects - Acute
Acute side effects = occur during or immediately after treatment
Can make getting through treatment difficult but usually reversible
Depend on the site of
treatment
Volume of normal tissue
included
Radiotherapy dose given.
Although acute side-effects can make getting through treatment difficult, they are usually completely reversible. The actual side-effects of radiotherapy depend on the site of treatment, the volume of normal tissue included and the radiotherapy dose given.

19. Common Acute Reactions
Skin reaction
Fatigue
Anorexia
Diarrhoea
Cystitis
Nausea/ vomiting
Oesophagitis
Mucositis.
Depression of white cell and platelet count – more prone to infections

20. Radiotherapy Side-effects - Chronic
Late side effects = not apparent for 6 months after RT and can be progressive
careful balance between giving an adequate radiation dose to achieve maximal tumour control and not causing significant late toxicity is required
Late Effects Clinics

21. Late Reactions Fibrosis Necrosis Fistula Cataract Carcinogenesis
Osteoporosis

22. Pelvic Late Effects Bowel Frequency incontinence and/or urgency
adhesions
Bladder frequency
nocturia
Vaginal stenosis
Infertility/early menopause
Erectile dysfunction

23. Breast Late Effects
Fibrosis of breast tissue – change in shape – cosmetic effect
Change in pigmentation
Telangiectasia
Lung Fibrosis
Cardiac toxicity
Suceptability to
rib fractures

24. Head & Neck Late Effects
Cavities and tooth decay
Lack/absence of saliva
Hypothyroidism
Eating & drinking(taste)
Speaking
Hearing
Lymphedeama
Memory problems

25. Conclusion
A large proportion of cancer patients will receive radiotherapy as part of their care
Radiotherapy can be given radically or palliatively
Most patients will experience some side effects, the extent of these depend on area treated and dose and fractionation
Side effects don’t end when treatment finishes. May manifest months/years later
Impact on patients overall wellbeing

26. Any Questions?