Simulation of hypoxia PET-tracer uptake in tumours: Dependence of clinical uptake-values on transport parameters and arterial input functionParedes-Cisneros, I., Karger, C. P., Caprile, P., Nolte, D., Espinoza, I. & Gago-Arias, A., Feb-2020, In : Physica medica-European journal of medical physics. 70, p. 109-117 9 p.
Research output: Contribution to journal › Article › Academic › peer-review
Poor radiotherapy outcome is in many cases related to hypoxia, due to the increased radioresistance of hypoxic tumour cells. Positron emission tomography may be used to non-invasively assess the oxygenation status of the tumour using hypoxia-specific radiotracers. Quantification and interpretation of these images remains challenging, since radiotracer binding and oxygen tension are not uniquely related. Computer simulation is a useful tool to improve the understanding of tracer dynamics and its relation to clinical uptake parameters currently used to quantify hypoxia. In this study, a model for simulating oxygen and radiotracer distribution in tumours was implemented to analyse the impact of physiological transport parameters and of the arterial input function (AIF) on: oxygenation histograms, time-activity curves, tracer binding and clinical uptake-values (tissue-to-blood ratio, TBR, and a composed hypoxia-perfusion metric, FHP). Results were obtained for parallel and orthogonal vessel architectures and for vascular fractions (VFs) of 1% and 3%. The most sensitive parameters were the AIF and the maximum binding rate (K-max). TBR allowed discriminating VF for different AIF, and FHP for different K-max, but neither TBR nor FHP were unbiased in all cases. Biases may especially occur in the comparison of TBR- or FHP-values between different tumours, where the relation between measured and actual AIF may vary. Thus, these parameters represent only surrogates rather than absolute measurements of hypoxia in tumours.
|Number of pages||9|
|Journal||Physica medica-European journal of medical physics|
|Publication status||Published - Feb-2020|
- Hypoxia tracer uptake, Positron-emission-tomography (PET), Radiotherapy, Computer simulation, SQUAMOUS-CELL CARCINOMA, OXYGENATION, HEAD, MODEL, FLUOROMISONIDAZOLE, FMISO, FAZA