FET PET 2010 is a prospective, multicentre trial aiming to evaluate the additional benefit of FET PET in the assessment of remission after first line therapy and during follow-up

2.1 Primary objective The main objective is to evaluate the relative benefit of FET PET in comparison to the MRI in differentiating biologically active tumour tissue from therapy-related changes in paediatric brain tumours after first line therapy (Δ specificityFET PET to specificityMRT) 2.2 Secondary Objectives To assess sensitivity of FET PET in comparison with the sensitivity of MRI (Δ sensitivityFET PET to sensitivityMRT) To assess the positive and negative predictive values (PPV, NPV) of FET PET in comparison with the PPV and NPV of MRI (Δ PPVFET PET to PPVMRT, Δ NPVFET PET to NPVMRT) To evaluate specificity, sensitivity, PPV, and NPV by SUVratio analyses of FET PET data To evaluate the potential of FET PET for non-invasive tumour grading (WHO I/II vs. III/IV) by kinetic studies when histology is available To assess adverse events and toxicity profile

2.3 Endpoints (Standard of truth1) 2.3.1 Primary Endpoint The primary endpoint is an event free survival of the follow-up period of 24 (12) months after first line therapy (confirmed by clinical and neuroradiological assessment) or the confirmed diagnosis of progression or recurrence of brain tumour tissue (confirmed by histology or clinical and neuroradiological assessment).

The follow-up period for patients with a low risk of tumour recurrence after first line therapy, i.e. astrocytoma WHO grade I-II, oligodendroglioma WHO grade I-II, germ cell tumour, choroid plexus tumour, craniopharyngioma will be 24 months.

The follow-up period for patients with a high risk of tumour recurrence after first line therapy, i.e. astrocytoma WHO grade III-IV, oligodendroglioma WHO grade III-IV, medulloblastoma, supratentorial PNET, AT/RT and other high-grade tumour lesions will be 12 months.

2.3.2 Secondary Endpoints To assess the secondary objectives of the FET PET 2010 study, the investigators will determine event free survival of the follow-up period of 24 (12) months after first line therapy (confirmed by clinical and neuroradiological assessment) or the confirmed diagnosis of progression or recurrence of brain tumour tissue (confirmed by histology or clinical and neuroradiological assessment).

Histopathological characteristics of recurrent tumours (WHO grade I-IV) Safety and Toxicity (evolution according to CTCEA v3.0 criteria): the NCI Common Terminology Criteria for Adverse Events v3.0 is a descriptive terminology, that is used for Adverse Event (AE) reporting. A grading scale is provided for each AE term. Attached is a selection of categories, which are required to assess safety and toxicity of FET PET examinations.

Inclusion Criteria:

• Written informed consent (given by the parents as legal representatives of the patients and given by the patients)
• Completion of the first line therapy according to the current HIT-protocols (Current and subsequent paediatric primary brain tumour treatment studies approved by GPOH)
• Fully evaluable MRI at the end of first line therapy as confirmed by the reference centre of neuroradiology (Prof. Dr. M. Warmuth-Metz, Würzburg)
• Histology of primary brain tumour confirmed by local and reference centre of Neuropathology (Prof. Dr. T. Pietsch) except for patients where tumour diagnosis is confirmed by the reference centre of neuroradiology, i.e. NF-1 and confirmed LGG or patient with diffuse intrinsic pontine glioma
• Laboratory requirements prior to enrolment: Serum creatinine: within normal limits; AST, ALT: not more than 10 x above normal limits
• Age at inclusion: 1 year to 17 years
• Children below the age of 12 years are included as 2 of 3 paediatric patients with a brain tumour are younger than 12 years. Furthermore, young age is a known negative risk factor for different histological entities. Thus, this group is the most likely to benefit from the results of this study
• In all patients with reproductive potential, a pregnancy must be excluded by a pregnancy test before FET PET investigation
• Highly effective contraception in women with reproductive potential (defined as pearl index < 1) during study participation and follow up time
• No participation in other clinical trials according to AMG with the same clinical indication over the course of the FET PET 2010 study

Exclusion Criteria:

• Presence of solid non-CNS tumours or leukaemia
• MRI at completion of first line therapy that does not meet standard quality criteria for evaluation as defined by the reference centre for neuroradiology of the HITNetzwerk (Würzburg, Prof. Warmuth-Metz);
• Known allergic reactions or drug intolerance to contrast agents
• Patients according to § 88 StrhlSchV
• Pregnancy or breast-feeding
• Women (adolescents) of childbearing potential without highly effective contraception (PEARL-Index < 1%), for example ParaGard IntraUterineDevice (IUD), Mirena IUD, Implants, Depo Provera Injections;
• Persons who are detained officially or legally to an official institute