MR-guided daily-adapted stereotactic radiotherapy for ultracentral lung tumours with CBCT delivery

MR-informed Stereotactic Radiotherapy for Treatment of Ultracentral Lung Tumours Utilising a Dedicated MR-simulator for Daily Adaptation Followed by CBCT-guided Treatment Delivery

This study tests whether daily MR-based adaptation followed by CBCT-guided SBRT can safely treat adults with ultracentral primary or metastatic lung tumours.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 11 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: University of Zurich (Academic / other)
• Drugs / interventions: radiation
• Locations: 1 site (Zurich)
• Trial ID: NCT06815289 on ClinicalTrials.gov

What this trial studies

Participants undergo dedicated MR-simulation (0.55 T for daily adaptation and 1.5 T for planning) plus contrast-enhanced 3DCT and 4DCT to define targets and organs at risk. For tumours with breathing motion >5 mm, treatment will use an expiration breath-hold technique; contours from the planning images are propagated to a same-day MRI and edited by the radiation oncologist. A medical physicist will re-optimize the SBRT plan to the day’s anatomy and, after oncologist approval, treatment is delivered with CBCT guidance. The workflow is designed to perform online anatomical adaptation before each fraction to better spare critical central structures while delivering ablative doses.

Who should consider this trial

Good fit: Adults (≥18) with ultracentral primary lung cancer or lung metastases whose planning target volume overlaps the bronchial tree, trachea/carina, or esophagus, who are recommended for SBRT and can undergo MRI and attend daily treatment at the site.

Not a fit: Patients who cannot have MRI (including incompatible implants), are too large for the MR-simulator bore, have prior overlapping radiotherapy, are pregnant or breastfeeding, or whose lesions are not suitable for SBRT are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this approach could reduce severe toxicity and improve local tumor control by tailoring SBRT to daily anatomy for ultracentral lung tumours.

How similar studies have performed: MR-guided online adaptive radiotherapy has demonstrated technical feasibility and promising early results in other disease sites, but clinical evidence specifically showing safety and efficacy for ultracentral lung tumours is limited.

Eligibility criteria

Inclusion Criteria:

* Written informed consent according to Swiss law and ICH/GCP regulations signed and dated by the participant and the investigator before any trial specific procedures (Informed Consent Form);
* Ultracentral (PTV-overlap with bronchial tree, trachea/carina and/or esophagus) primary or secondary lung lesion(s) from a histologically confirmed malignancy, confirmed by imaging and amenable for SBRT;
* Indication for SBRT based on a multidisciplinary tumour board recommendation and / or clinical practice guideline;
* Age≥18 years old;
* Patients who are willing and able to comply with scheduled visits, treatment, and other trial procedures.

Exclusion Criteria:

* Large body size that would not fit the MRI-simulator bore;
* Contraindications for MRI;
* Previous radiation therapy directly overlapping with planned SBRT (type I re-irradiation);
* Women who are pregnant or breast feeding;
* Intention to become pregnant during the trial;
* Lack of safe contraception (Female participants who underwent hysterectomy and/or bilateral oophorectomy or post-menopausal for longer than 2 years are not considered as being of child bearing potential);
* Known or suspected non-compliance, drug or alcohol abuse;
* Inability to follow the procedures of the trial, e.g. due to language problems of the participant;
* Enrolment of the investigator, his/her family members, employees and other dependent persons.

Where this trial is running

Zurich

• University Hospital Zurich — Zurich, Switzerland (Recruiting)

Study contacts

• Study coordinator: Nicolaus Andratschke, Prof. Dr. med.

Conditions Primary Lung Cancer or Secondary Lung Metastases; ultracentral lung tumour