Early [18F]-FDG PET Dynamic Analysis in Brain Metastases After Radiotherapy.

N/ARecruitingNCT07632092

Centre Hospitalier Universitaire, Amiens50 enrolled

Overview

Various treatment options are available for brain metastases, depending on factors such as lesion site or number lesions. Radiotherapy is a commonly used treatment. Following stereotactic radiotherapy for brain metastases, a potential complication, namely brain radionecrosis, can occur subsequently. It is essential to differentiate between this radionecrosis and lesion recurrence in order to determine the appropriate treatment approach. Contrast-enhanced magnetic resonance imaging (MRI) is the most widely used technique for monitoring brain metastases. Therefore, patients undergo routine MRI at 3 months and during subsequent follow-ups, but if the lesion evolve and if distinguishing between recurrence and radionecrosis is challenging, an \[18F\]-FDG PET scan is then prescribed by oncologists or radiotherapists during follow-up consultations. As part of the standard patient management protocol, a 10-minute image acquisition begins after a 45-60 minutes wait following the radiotracer injection. A second image acquisition is then conducted 3-4 hours later. For both acquisitions, a low-dose X-ray scanner is synchronously coupled to allow attenuation correction of the PET images. Patient for whom a \[18F\]-FDG PET cerebral examination has been prescribed as part of the usual management of brain metastases will be eligible to the protocol. If the patient agrees to participate, an early imaging session is initiated immediately upon radiotracer injection, lasting 15 minutes in addition to the standard acquisition protocol.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Short Time Examination Brain Metastases Radiation Necrosis

Interventions

CT scanOTHER

The patient is installed in the PET camera as soon as he is injected, so that early fixation of the \[18F\]-FDG radiotracer can be recorded for 15 minutes. As part of this acquisition, a CT scan dedicated for attenuation correction is also performed. Both this scan and the late scan will be carried out at ultra--low dose so that the total dose received by the patient does not exceed what he would have received without this research. The patient's total examination time remains unchanged

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patient referred for cerebral \[18F\]-FDG PET examination prescribed as part of his usual medical care for brain metastasis. * Age ≥ 18 years old * Affiliation to a social security program * Ability of the subject to understand and express his consent Exclusion Criteria: * Age under 18 years old * Person under guardianship or curatorship * Pregnant or breastfeeding woman * Primary brain tumors * Brain metastases from renal, thyroid or other cancers known to have low avidity for \[18F\]-FDG

Outcomes

Primary Outcomes

ratio between lesion maximum activity and controlateral healthy tissue activity

Value of the measurement of the ratio of the maximum activity within the lesion to the average activity within the region of interest of the contralateral healthy tissue.

Time frame: day1

Secondary Outcomes

association between kinetic uptake parameters and diagnosis

association between kinetic uptake parameters from compartmental models and the differential diagnosis of radionecrosis and recurrence of brain metastases treated by radiotherapy

Time frame: 12 months