Rationale: Non-invasive imaging of hypoxia with the aid of PET-scans could help to select the
patients having a hypoxic tumor, who could be treated with specific anti-hypoxic treatments.
The added value of additional anti-hypoxic treatments depends on the presence of hypoxia and
adequate patient selection. Several 2-nitroimidazoles, labeled with Fluor-18 (18F) have
already been used in patients to identify hypoxia. However, suboptimal image quality and
unpredictable kinetics limit their use. In extensive pre-clinical models and clinical trials
the combination of HX4 labeled with 18F showed to be a promising and non-toxic new probe to
determine hypoxia. With this tracer the proportion of hypoxic tumors in several cancer types
will be verified.
Objective: Determine if tumor hypoxia can be accurately visualized with [18F]HX4 in solid
Study design: Phase II, several solid tumors, single-centre, imaging, non-randomized, open
Main patient characteristics are:
- - Histological/cytological confirmed carcinoma of de esophagus, rectum or prostate or
radiological suspicion for Grade IV glioma (primary brain tumor) or brain metastases.
- - WHO performance status 0 to 2
- Adequate renal function (calculated creatinine clearance at least 60 ml/min).
- - Capable of complying with study procedures
Main intervention: In addition to standard clinical care patients receive two additional PET
scans after injection with the hypoxia tracer [18F]HX4.
Main study parameters/endpoints:
- - Visualization and quantification of tumor hypoxia with [18F] HX4 PET imaging
- Exploring the potential relationship between [18F] HX4 uptake with local and
locoregional tumor recurrence and survival
- Correlation of hypoxia imaging with blood hypoxia markers
- Correlation of hypoxia imaging with tumor tissue biomarkers
- Evaluation of tumor hypoxia changes during treatment.
- - Spatial correlation of [18F] HX4-PET with imaging pre-treatment (if present from routine
- Spatial correlation of [18F] HX4-PET with imaging three months after treatment (if
present from routine clinical practice)
- Quantitative and qualitative correlation of [18F] HX4-PET obtained before treatment and
two weeks into treatment
Nature and extent of the burden and risks associated with participation, benefit and group
The radiation burden due to [18F]HX4 is similar to that encountered in many routine nuclear
medicine procedures e.g. [18F]FDG PET.
Administration of [18F]HX4 presents no known risks. In
previous studies (healthy volunteers, phase I, phase II) no adverse effects were observed.
There are no immediate potential benefits except the satisfaction to participate to improve