Radiological problems

Question 1

What is classified as an acute side effect of radiotherapy?

Answer 1

Within a few weeks of radiotherapy and is seen in tumours with high cell turnover
Eg. Skin erythema or oral mucositis

Question 2

What is classified as a late side effect of radiotherapy?

Answer 2

Seen months or years after radiotherapy and is seen in tumour with low cell turnover
Eg. fibrosis, loss of function, dry mouth if salivary glands are treated

Question 3

What are some side effects of pelvic radiotherapy?

Answer 3

Skin
- Erythema, desquamation, superficial ulceration

Bladder
- Early: mucositis – causing dysuria and frequency
- Late: chronic cystitis, haematuria

Bowel
- Early: diarrhoea
- Late: rectal bleeding, fibrosis, fistula

Uterus
Late: will not support pregnancy, endometrial lining ablated

Vagina
- Early – mucositis
- Late – stenosis

Ovaries
- Will fail – stop hormone and egg production

Bones
- Bone marrow – OK as not that much irradiated
- Small risk of pathological fracture

Question 4

What are the common sites of bone metastesis?

Answer 4

spine, ribs, pelvis, shoulder girdle

Rare to get them below the knee

Question 5

What are the red-flag symptoms for bone metastasis?

Answer 5

• severe progressive pain which is worse on movement or at night
• inability to bear weight
• signs of hypercalcaemia
• pain on direct palpation

Question 6

What are some investigations for bone metastesis?

Answer 6

-X-ray
- Bone scan: 99mTc-methylene bisphosphonate often detects mets several months before radiological changes are evident
- Serum alkaline phosphatase (ALP) usually raised. It reflects osteoblastic (healing) response to tumour destruction

Question 7

How are bone metastasis treated?

Answer 7

• Analgesia
• Palliative radiotherapy - e.g. 8 Gy in 1#
• Bisphosphonates e.g. Zometa* pyrophosphate analogues → reduce bone turnover → helppain and may slow progression of bony mets
• Hormonal therapy if prostate or breast cancer

Question 8

What medication is used to treat bony metastasis?

Answer 8

• Radioactive 223-Radium
  Used for prostate cancer. It’s similar to Calcium so taken up by bone but emits alpha particles (2 protons/2 neutrons). Has a very short range – a few micrometres (stopped by paper) and a short half-life – 11.4 days so is well tolerated. Given as IV injection every 28 days
• Denosumab
  A monoclonal antibody, SC injection every 28 days. It targets protein called RANKL which controls osteoclast activity

-Chemotherapy

Question 9

what is the treatment of a pathological fracture?

Answer 9

Anticipate and prevent it

If high risk of fracture: arrange prophylactic pinning and post-op RT

Question 10

What is loperamide used for?

Answer 10

An anti-diarrhoea drug used in oncology