Ocular Melanoma

Question 1

What is the goal of ocular brachytherapy?

Answer 1

Treat the tumor (plus a safety margin) to a minimum dose of 70 Gy over 4-7 days

Question 2

What are the critical structures we want to spare with ocular brachytherapy?

Answer 2

• fovea/macula
• optic nerve
• healthy retina
• underlying sclera
• lens
• cornea

Question 3

What’s the planning process for ocular brachytherapy?

Answer 3

• acquire pre-treatment images (fundus photography, ultrasound, orbit CT)
• Planning sheet that communicates other info:
  
  • OD/OS
  • locations (iris, ciliary body, choroid)
  • basal dimensions (longitudinal/transverse)
  • locating distance (to OHN, fovea, limbus)
  • clock hour

Question 4

How is a plaque model chosen?

Answer 4

Based on tumor size and location

Question 5

What’s done after choosing a plaque model?

Answer 5

You plan plaque location and seed positions

Question 6

Explain treatment process

Answer 6

• Patient is anesthetized, prepped and draped
• Eye speculum is inserted
• Conjunctiva is dissected
• if necessary up to two muscles that attach to the eye are removed
• Clock-hours are marked with specialized pen
• Distance to suture locations measured (chord distance)
• Sutures placed, dummy plaque inserted
• Placement checked by a transillumination and/or indirect ophthalmoscope
• Dummy is removed and gold plaque is inserted
• Final check with ophthalmoscope
• Conjunctiva is repaired
• Eye shield is taped on

Question 7

What happens 4-7 days after insertion of plaque?

Answer 7

• patient returns for plaque removal
• therapist checks there is no residual radiation
• eye is repaired
• patient is sent home

Question 8

Acute and chronic side effects of ocular brachytherapy?

Answer 8

• Dryness
• Cataracts
• Retinopathy
• Glaucoma
• Blindness