This trial will investigate the feasibility of the Markerless Tumour Tracking technology.

Markerless Tumour Tracking will be integrated with existing treatment machines to provide real-time monitoring of tumour motion during treatment delivery. Eligible patients will be implanted with fiducial markers, which act as the ground truth for evaluating the accuracy of Markerless Tumour Tracking. The patients will undergo the current standard of care radiotherapy, with the exception that kilovoltage x-ray images will be acquired continuously during treatment delivery to enable Markerless Tumour Tracking.

Inclusion Criteria:

• Is willing to comply with all trial procedures and intends to provide written Informed Consent for participation in this trial.
• Patients undergoing external beam radiotherapy.
• Histologically proven Stage I NSCLC or oligometastatic lung metastases (3 or less).
• MRI/4D-CT prior to insertion of fiducial markers.
• Patient must be able to have fiducial markers placed in the lung (if on anticoagulants, must be cleared by LMO or cardiologist).
• ECOG performance status 0-2.
• A maximum of three metastases to the lung from any non-haematological malignancy. Multiple metastases will be treated separately.
• 1 cm ≤ Tumour diameter in any dimension ≤ = 5 cm.
• The distance between the tumour centroid and the top end of the diaphragm is <=10 cm.

Exclusion Criteria:

• Patient has low respiratory performance as evaluated by the physicians.
• Previous high-dose thoracic radiotherapy.
• Less than one fiducial marker implanted in the lung.
• Fiducial markers are too far from the tumour centroid (>9 cm).
• Cytotoxic chemotherapy within 3 weeks of commencement of treatment, or concurrently with treatment. Hormonal manipulation agents are allowable (e.g. aromatase inhibitors, selective oestrogen receptor modulators, and gonadotropin releasing hormone receptor modulators).
• Targeted agents (such as sunitinib, bevacizumab and tarceva) within 7 days of commencement of treatment, or concurrently with treatment.
• Women who are pregnant or lactating.
• Unwilling or unable to complete quality of life questionnaires.

De-identified participant data and images will be made available for other scientific research.

Data will be made available following publication of the final analysis, and for a minimum of 2 years thereafter.

Requests must be made to the original researchers for access to the data.