Radiotherapy

Question 1

Define radiotherapy.

Answer 1

Use of ionizing radiation to induce damage to DNA in cells.

Question 2

What is the target in radiotherapy?

Answer 2

Unrepaired or misrepaired double strand breaks.

Question 3

Define the therapeutic ratio.

Answer 3

The probability of tumour control and the likelihood of normal tissue damage.

Question 4

Define the differential effect.

Answer 4

The effect of applying one treatment in lieu of the other.

Question 5

Define Fractionation.

Answer 5

Aimed at increasing the therapeutic ratio (improve tumour control while sparring normal tissues).

Question 6

What do the 4R’s in Fractionation refer to?

Answer 6

Repair. Repopulation. Redistribution. Reoxygenation.

Question 7

State the the 3 types of Radiotherapy.

Answer 7

External beam. Brachytherapy. Radio-active isotopes.

Question 8

Define Brachytherapy.

Answer 8

Places radioactive sources INSIDE patient to kill cancer cells and shrink tumours.

Question 9

Define External Beam.

Answer 9

Photons - linear accelerators, cyber gamm.

Question 10

Define Radio-active Isotopes.

Answer 10

E.g. iodine in drink form is absorbed into the body and picked up by thyroid cancer cells.

Question 11

Define Stereotactic Radiotherapy.

Answer 11

Radiotherapy from many different angles around the body. Beams meet at the tumour. Tumour receives high does and tissues around receive low dose radiation.

Question 12

State a feature of radiotherapy.

Answer 12

Compared to surgery (organ preservation, no operative risk).
Compared to chemotherapy (no significant haematoloigcal toxicity, infection risk).

Question 13

What are the 2 alternative purposes of radiotherapy?

Answer 13

Radical (cure tumour, high dose, longer course). Palliative (relieve symptoms, lower doses, shorter course.

Question 14

State the stages to Radiotherapy Planning.

Answer 14

Positioning & Immobilisation. CT scanning. Target definition. RT planning.

Question 15

State the Treatment Delivery & Care

Answer 15

Verification. Treatment. Pt care.

Question 16

State the 3 aspects of Radiotherapy Process/Pathway.

Answer 16

Assessment & Consent. Radiotherapy Planning. Treatment Delivery & Care.

Question 17

State 2 acute side effects of Radiotherapy.

Answer 17

General - Fatigue, Skin reaction
Brain - Nausea, Somnolence
Chest - Oesophagitis, Pneumonitis, Rib/chest wall tenderness
Abdomen - Nausea, Diarrhoea
Pelvis - Diarrhoea, cystitis

Question 18

State 2 late side effects of Radiotherapy.

Answer 18

General - second malignancy
Brain - cognitive and memory impairment
Chest - lung fibrosis, cardiac problems
H&N - Dry eye, cataract, dental problems, mandible necrosis
Abdomen - intestinal irritability, kidney damage, liver damage
Pelvis - proctitis, impotence, vaginal dryness, infertility.

Question 19

State the preventative measures after Radiotherapy.

Answer 19

Skin care advice. Anti-emetics. Oral hygiene. Dietary review.

Question 20

State the symptomatic treatment after Radiotherapy.

Answer 20

Loperamide. Analgesia. Nutritional support. Skin reaction treatment. Rest from treatment.

Question 21

State the long term effects after Radiotherapy.

Answer 21

Follow up late effects. Screening for certain late effects e.g. Breast Ca screening after mediastinal RT for lymphoma, TFTs after neck RT, Dental check ups after mouth RT. Treatment e.g. thyroxine replacement.