Comparaison Between MRI Alone or Combined With Positron Emission Tomography for Brain Metastasis Diagnosis

Study Overview
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Brief Summary
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During gamma scalpel treatment of brain tumors and metastases, a follow-up magnetic resonance imaging (MRI) scan is performed. The radiologist who reviews the MRI assesses whether there is an increase in signal at the tumor site. This increase potentially indicates that the treatment was not effective. However, in 25% of cases (one in four people), this signal enhancement is not due to ineffective treatment, but to inflammation (swelling/damage) and tissue death around the tumor. This is why when an increase in signal is detected, additional follow-up is essential. The standard additional follow-up has an accuracy of about 83%. This is an observational study on patients with brain metastatis comparing MRI alone or combined to PET-FET to improve accuracy of diagnosis of metastasis recurrence.

Official Title
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Differentiation Between Radionecrosis and Tumor Recurrence for Post-stereotactic Radiosurgery Follow-up by Pharmacokinetic Analyses in Perfusion MRI and Positron Emission Tomography

Conditions
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Brain Metastases, Adult

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or female over 18 years of age; Having undergone gamma knife radiosurgery for brain metastasis; Presenting for a first MRI follow-up (Cohort C1); Presence of one or more brain metastases with increased enhancement on follow-up MRI (Cohort C2.1 and C2.2); A participant recruited for Cohort C1 could be recruited for follow-up in Cohort C2.1 or C2.2 if the MRI result is ambiguous. Exclusion Criteria: Pregnancy or breastfeeding; Other condition that may influence the imaging result; Renal impairment (<30 mL/min/1.73 m2). This threshold is consistent with recent RAC recommendations; Note: For participants with intermediate renal clearance (30-60 mL/min/1.73 m2), the total gadobutrol dose injected is set at the manufacturer's recommended clinical dose. For patients with renal clearance greater than 60 mL/min/1.73 m2, a dose of 1.5x the normal dose is used. These dose values have been approved by Dr. Chénard and are consistent with the RAC recommendations. Inability to maintain supine position for the required duration (variable, depending on the sequence); Patients who have previously received full brain irradiation; Patients who are claustrophobic and cannot tolerate insertion into the MRI scanner;

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of novel MRI method with current MRI exam method | In the context of differentiating radionecrosis and recurrence of metastasis: Is our new method better than the actual standard of care in Sherbrooke? | Following MRI exam | 
| Comparison of DCE-MRI method with FET PET | In the context of differentiating radionecrosis and recurrence of metastasis: is one better than the other? And Can DCE-MRI and FET PET be combined to differentiate between recurrence/radionecrosis? | Following MRI exam | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Radiofrequency, CT scan, Radionecrosis, Tumor recurrence, Post-stereotactic surgery, Positron emission tomography, 18F-fluoroethyl-tyrosine, Perfusion MRI, Magnetic resonance imaging