Introduction to clinical Radiotherapy Sarah Brothwood Radiotherapy Practice Educator Rosemere Cancer Centre Sarah.brothwood@lthtr.nhs.uk 01772 522694

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

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: 1129 - 37

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

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

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

How we treat the patient

Why it works …………

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

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

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!

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

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

Radiosensitivity of cell in cell cycle Relative Survivability G1 S G2 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.

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

Common Fractionation Schedules Single session – (8-10 Gy) Short course – 4-5Gy per # Radical course 3-7 weeks – 60-70 Gy Hyper or hypo fractionation

Side effects from Radiotherapy General Systemic effects Malaise Nausea Fatigue

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.

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

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

Late Reactions Fibrosis Necrosis Fistula Cataract Carcinogenesis Osteoporosis

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

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

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

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

Any Questions?