Radiotherapy Treatment

Question 1

• Discuss the role radiotherapy plays in treating cancer

Answer 1

Curative - kills all cancer cells & no metastasis
Alternative to surgery if patient not fit
Palliative

Question 2

Describe the differences between external beam radiotherapy and internal radiotherapy

Answer 2

External Beam Radiotherapy:
Radiation beams directed from an external machine
Patient lies on a treatment table
Treatment delivered over multiple sessions
Radiation reaches tumour from outside the body
Radiation source generated externally

Internal Radiotherapy (Brachytherapy):
Radiation source placed directly into or near the tumour
Radiation source inserted using applicators or implants
Treatment delivered in single or multiple sessions
Radiation delivered directly to tumour or specific area
Radiation source located internally in or near the tumour

Question 3

Identify tumours ideally suited to be treated with radiotherapy

Answer 3

Breast cancer
Prostate cancer
Lung cancer - SCLC
Brain tumours - glioma

Question 4

Advantages of RT

Answer 4

Can be used in variety of ways – radical/ palliative
- Wide range of beam energies to suit circumstances
- Typically only affects part of body that is irradiated – side effects limited to treatment area
- Can provide a good alternative to surgery

Question 5

Disadvantage

Answer 5

• Damage to normal tissue
• Long treatment courses
• Some tissues very sensitive to radiation damage – may limit dose that can be given
• Hazard to patients and staff – radiation protection required – cost
• Machinery – expensive (initial and on-going) access to specialist equipment still lacking in research

Question 6

Principles of RT

Answer 6

Pathology - impact on healthy tissue
Location - to avoid sensitive structures
Target volume
Normal structures - tolerant dose
Radiation protection
Treatment prescription