Real-time Motion Management During Prostate and Lung Radiotherapy

This study will assess the feasibility of implementing real-time tracking in a clinical setting to account for the relative motion of the moving tumours localised to the prostate or lung. The capability to track the treatment target's motion will ensure that the dose prescribed by the radiation oncologist is the dose delivered to the target and minimises side effects to the critical organs.

During radiation treatment, the target position will be monitored in real-time using built-in imaging technology. The radiation beam shape will be altered to compensate for the moved target positions by the treatment delivery system. The delivered dose to the patient will be calculated after the treatment and compared to the dose without real-time tracking to assess the potential benefit to treatment efficacy, recognising that the radiation dose received by tumour tissue is a very strong biomarker for response.

The estimated dose distributions will be compared to the original plan for non-inferiority using the dose reconstruction method based on the prostate motion trajectory and the logged MLC positions (beam shapes).

Also, the impact on organs at risk doses due to MLC target tracking.

Inclusion criteria

For prostate cancer patients:

• Patients histologically proven prostate adenocarcinoma
• Prostate specific antigen (PSA) obtained within three months prior to enrollment
• Localised prostate cancer at any stage eligible for radiotherapy: i.e. any T- or Gleason stage, but no pelvic lymph nodes can be included within the target to be treated
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2
• Ability to understand and the willingness to sign a written informed consent document.
• Hypofractionated radiation therapy (HYPO) fractionated patients with a prescribed dose of 42.7Gy in 7 fractions.
• MRIOnly workflow meaning synthetic generated CT based on Magnetic resonance imaging (MRI)
• Patients over 40 years old

For lung cancer patients:

• Lung cancer or localised metastatic disease from other cancer diagnoses, accepted for stereotactic radiotherapy to 45Gy in 3 fractions
• Lesion distinguishable on Computer Tomography and where the majority of adjacent tissue is the lung.
• Ability to understand and the willingness to sign a written informed consent document.
• Is able to perform treatment simulation

Exclusion criteria

For prostate cancer patients:

• Patient must have three gold fiducial markers inserted in the prostate
• Patients with artificial Hip(s), lumbar spinal surgical rods or other large metallic pelvic implants
• Patients with overlapping implanted gold fiducials in X-ray imaging
• Unfeasible to track fiducials with kv imaging/existing online imaging systems

For lung cancer patients:

• Previous treatment with radiotherapy for lung cancer or lung metastasis
• Idiopathic lung fibrosis