1. Changes in Tumor Biology During Chemoradiation of Cervix Cancer Assessed by Multiparametric MRI and Hypoxia PET.
- Author
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Georg P, Andrzejewski P, Baltzer P, Daniel M, Wadsak W, Mitterhauser M, Sturdza A, Majercakova K, Karanikas G, Pötter R, Hacker M, Helbich T, Georg D, and Pinker K
- Subjects
- Adult, Aged, Diffusion Magnetic Resonance Imaging, Female, Humans, Middle Aged, Misonidazole analogs & derivatives, Misonidazole chemistry, Tumor Burden, Chemoradiotherapy, Hypoxia pathology, Magnetic Resonance Imaging, Positron-Emission Tomography, Uterine Cervical Neoplasms pathology, Uterine Cervical Neoplasms therapy
- Abstract
Purpose: Imaging biomarkers assessed with magnetic resonance imaging (MRI) and/or positron emission tomography (PET) enable non-invasive tumor characterization in cervix cancer patients. We investigated the spatio-temporal stability of hypoxia, perfusion, and the cell density of tumors over time by repetitive imaging prior to, during, and after radio-chemotherapy., Procedures: Thirteen patients were included in this prospective study. The imaging protocol included the following: [
18 F]fluoromisonidazole ([18 F]FMISO)-PET/x-ray computed tomography (CT) and multiparametric (mp)-MRI at four time-points (TP): baseline (BL); and weeks 2 (TP1), 5 (TP2), and 19 after treatment start (follow-up FU). Complete datasets for six patients could be assessed for tumor volume, enhancement kinetics, diffusivity, and [18 F]FMISO-avidity (P1-P6). In addition, two patients completed all PET/CT examinations (P7-P8) but not all MR scans; however, one of them had no hypoxia (P8). Descriptive statistics, correlations, and voxel-by-voxel analysis were performed. For various, independent reasons, five patients could not complete the study according to the protocol with all imaging sequences., Results: Median tumor ADCs (in ×10-3 mm2 /s) were 0.99 ± 0.10 at BL, 1.20 ± 0.12 at TP1, 1.33 ± 0.14 at TP2, and 1.38 ± 0.21 at FU. The median TBRpeak (tumor-to-background) was 2.7 ± 0.8 at BL, 1.6 ± 0.2 at TP1, 1.8 ± 0.3 at TP2, and 1.7 ± 0.3 at FU. The voxel-by-voxel analysis of the [18 F]FMISO uptake at BL and TP1 showed no correlation. Between TP2 and TP1 and FU and TP2, weak correlations were found for two patients., Conclusions: Longitudinal mp-MR and PET imaging enables the in vivo tumor characterization over time. While perfusion and cell density decreased, there was a non-uniform change of hypoxia observed during radiotherapy. To assess the potential impact with regard to more personalized treatment approaches, hypoxia imaging-based dose painting for cervix cancer requires further research.- Published
- 2018
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