Generate a palliative whole brain radiotherapy plan

Learning Outcomes

• Knowledge
  • Selection of appropriate patient positioning, technique, and immobilisation equipment.
  • CT Simulation procedure – palliative WBRT
  • ICRU recommendations
  • Prescription from Oncologist/Protocol
  • Planning Target Volume
  • Anatomical borders
  • Organs at Risk/dose tolerance
  • Treatment Planning Software Tools (such as MLCs, field size, collimator position, ICRU ref point etc.)
  • Prescription/protocols
  • Plan optimisation and evaluation knowledge

• Skills
  • Position patient for a CT-simulation of a palliative whole brain  

  • Generate a palliative whole brain radiotherapy treatment plan and DVH using treatment planning software

  • Calculate daily Monitor Units and Daily Absorbed Dose

  • Evaluate the plan

• Attitudes/Behaviours

  • Patient communication, compliance, consen,
    Team communication
    Compassion
    Empathy

  • Accuracy
    Detail

Scenario Environment

Initial Simulation Setup

Step 1: Patient Communication and ID check

• Check patient ID and records
• Check referral and protocols
• Provide instructions to simulated patient
• Re-confirm consent
• Ascertain level of mobility and understanding, and compliance
• Carry out risk assessment (if necessary) - patient is in a wheelchair, moving and handling

Step 2: Positioning technique

• Select patient positioning and immobilisation tools
• Position simulated patient on the couch (in the VERT room)
• Use appropriate moving and handling techniques as per protocol

Step 3: Immobilisation mask (optional step)

• Create a mask using water-bath and thermoplastic mask material on simulated patient

Step 4: CT simulation  

• Explain the procedure

Step 5: Eclipse TPS

• Open whole brain plan
• Create the plan and DVH
• Note the beam parameters
• Calculate the dose and MU

Case Introduction

This patient is in a wheel chair with limited mobility, is able to stand for a short time. He is aged 30 and has good upper body mobility. 

He is accompanied by his husband who is quite chatty and asks lots of questions. The patient understands English well, can communicate well, but does not appear to talk. When you provide initial patient information, his husband responds and continues to disrupt any conversation between you and the patient. Patient records state that he is HIV positive. The primary cancer is unknown. He has brain metastases.

Provide patient information and instructions.

• How would you manage his husband who is talking for the patient?
• What is the risk assessment here?
• Position the patient
• Create a mask (if equipment available)
• Generate a treatment plan
• Note the patient position, immobilisation equipment, and any other relevant information in the computer system
• Technique
• Treatment machine
• Field weighting
• Calculate the dose

Available Collateral Information

• Anatomical landmarks/borders
• Line from outer canthus to the EAM
• Supra orbital ridge to tragus or EAM, coronal base line
• Field size
• MLC
• Inf/lat etc. margins
• OAR dose tolerance - lens, brain stem optic nerve, orbit
• Treatment volume
• Target volume = whole of brain
• Position the ICRU ref point ….
• Gantry angle, coll angle