Prospective Study on Oncologic Cerebral Imagery Contribution by 18F-FDOPA Position Emission Tomography (PET)
Condition: Glioma; Cerebral Metastases
MeSH terms: Neoplasm Metastasis
Study type: Interventional

Summary: 
      In standard care for patients diagnosed with a primary or secondary (metastasis) cerebral
      tumor, there is currently complex clinical situations in which the clinic and Magnetic
      Resonance Imagery (MRI) do not allow for the medical team to arrive at a conclusive
      diagnosis. The therapeutic proposition requires then a delay in additional follow-up of at
      least 3 months in order to clarify the situation, with a potential delay in diagnosis and
      therefore therapeutic care. The contribution of cerebral molecular imagery could allow for
      new additional information to be brought in or to increase the confidence index in the
      diagnosis in order to comfort the therapeutic collective attitude proposed in the
      multidisciplinary meeting (MM).

      3.4-dihydroxy-6-18F-fluoro-L-phenylalanine (18F-FD0PA), dopamine precursor amino-acid,
      Position Emission Tomography (PET), allows for the studying in vivo of the proteic
      transmembrane transport in gliomatous tissue; active transport happens through a
      sodic-independent canal, increased in malicious transformations, and in which kinetics can
      give an indication regarding the development of the primary tumor.

      In MRIs, tumor tissue growth after injecting the contrast product translates to a rupture in
      the Blood-Brain Barrier (BBB), while tumor extraction from the radiopharmaceutical is
      independent of the state of integrity of the BBB and whose only function is metabolic tissue
      activity. This method of imagery thus appears as a promising contribution to conventional
      imagery.

      Furthermore, different to 18F-FDG (18F-2-fluoro-2-deoxy-D-glucose fluorodeoxyglucose),
      similar to the largely used glucose in oncologic molecular imagery, exploration of harmful
      glioma in 18F-FDOPA, is not compromised by background noise activity, and is almost useless
      in a healthy cerebral cortex, with the exception of striatal physiological fixation used as a
      level of reference. The best performances in terms of positive and negative predictive value
      were defined in the literature with a tumor/striatum threshold of 1.

      According to the latest and current European recommendations, turning to PET when caring for
      high-level gliomas patients can be proposed in the evaluation of therapeutic responses.
      However, very few studies have evaluated the in-practice current clinical contributions of
      PET and put it into perspective with classic clinical radiological data.
    

Detailed description: 
      The primary hypothesis rests on the fact that 18F-FDOPA PET imagery can modify decisions
      regarding the treatment of patients during oncologic neurological MDM. It's a matter of
      measuring the frequency in attitude and situations changes in which these changes most often
      occur.

      Secondly, the study will have the objective, during patient follow-up, to evaluate the
      pertinence of these changes in decisions, as well as the usage of PET in relation to clinical
      situations:

        -  The differential diagnosis between radionecrosis or pseudo-progression and recurrence
           before newly appeared contrast zones in patients diagnosed a high glioma level or
           metastasis and treated by radiotherapy; either with or without chemotherapy.

        -  The evaluation at the end of treatment with introductory level temozolomide (TMZ) (6th
           cycle) after adjuvant radio-chemotherapy of a high-level primary cerebral tumor.

        -  The evaluation of the response under anti-angeogenic treatment

      The expected benefit of this study is an improvement in the patient's care. Indeed, the
      additional information provided by Position Emission Tomography (PET) could allow for
      healthcare professionals to more precociously test for recurrence and thus diminish the delay
      in therapeutic care. Conversely, the PET could allow for healthcare professionals to avoid
      over-treatment of patients for whom the MRI would wrongly indicate a recurrence. Furthermore,
      imagery by PET should bring a new level of additional information allowing for an increase in
      the confidence index when being diagnosed, thus comforting the collective therapeutic
      attitude proposed in the MM.
    

Intervention name(s): PET 18FDOPA
Intervention type(s): Other
Intervention description(s): contribution of PET 18FDOPAimagery in high level glioma diagnosis
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic