Superficial Case Studies

Question 1

Name 2 of the most common cancers treated with superficial therapy.

Answer 1

Basal Cell Carcinoma (BCC)
Squamous Cell Carcinoma (SCC)
Cutaneous lymphoma (mycosis fungoides)
Melanomas (Lentigo Maligna)

Question 2

What are the advtanges of using radiotherapy to treat certain cancers with superficial therapy?

Answer 2

• Cosmetic results
• Short term side effects (clear up after treatment stops)
  
  • skin redness
  • blistering similar to mild sunburn
• Long-term side effects (no major)
  
  • Skin lightening or darkening
  • Telangiectasia (reddining of skin due to enlarged capillaries. Spider veins)
  • Skin fibrosis
• Cost of treatment

Question 3

What does the physics support provide in superficial RT?

Answer 3

• Assist in choice of modality
• Advise on acceptable OAR doses
• Design treatment:
  
  • Field size
  • Shielding / collimation
  • Bolus
  • SSD
  • Foils
  • Set-up - gantry angle, collimator angle, …

Question 4

What questions should be asked at the MDT to provide physics support and advice for superficial therapy?

Answer 4

• What dose will be prescribed?
• What % will the treatment be prescribed?
• Is the marked disease field or disease?
  
  • If disease - what margin around disease is required?
  • If field – have they used a correct margin?
• What depth is dose required?
• What dose is required on the surface?
• Are there any critical structures in the vicinity?
• Has the patient had any previous radiotherapy?
• Does the patient have any co-morbidities that might impact on treatment modality / design?