Radiation treatment monitoring using multimodal functional imaging: PET/CT ((18)F-Fluoromisonidazole & (18)F-Fluorocholine) and DCE-US

• Published in: Journal of translational medicine Vol. 13; p. 383
• Main Authors: Arteaga-Marrero, Natalia, Brekke Rygh, Cecilie, Mainou-Gomez, Jose F, Adamsen, Tom C H, Lutay, Nataliya, Reed, Rolf K, Olsen, Dag R
• Format: Journal Article
• Language: English
• Published: England 18.12.2015
• Subjects: Animals; Choline - administration & dosage; Choline - analogs & derivatives; Male; Mice; Mice, Nude; Misonidazole - administration & dosage; Misonidazole - analogs & derivatives; Monitoring, Physiologic; Multimodal Imaging; Positron-Emission Tomography; Radiotherapy; Tomography, X-Ray Computed
• ISSN: 1479-5876
• DOI: 10.1186/s12967-015-0708-5

This study aims to assess the effect of radiation treatment on the tumour vasculature and its downstream effects on hypoxia and choline metabolism using a multimodal approach in the murine prostate tumour model CWR22. Functional parameters derived from Positron Emission Tomography (PET)/Computer Tomography (CT) with (18)F-Fluoromisonidazole ((18)F-FMISO) and (18)F-Fluorocholine ((18)F-FCH) as well as Dynamic Contrast-Enhanced Ultrasound (DCE-US) were employed to determine the relationship between metabolic parameters and microvascular parameters that reflect the tumour microenvironment. Immunohistochemical analysis was employed for validation. PET/CT and DCE-US were acquired pre- and post-treatment, at day 0 and day 3, respectively. At day 1, radiation treatment was delivered as a single fraction of 10 Gy. Two experimental groups were tested for treatment response with (18)F-FMISO and (18)F-FCH. The maximum Standardized Uptake Values (SUVmax) and the mean SUV (SUVmean) for the (18)F-FMISO group were decreased after treatment, and the SUVmean of the tumour-to-muscle ratio was correlated to microvessel density (MVD) at day 3. The kurtosis of the amplitude of the contrast uptake A was significantly decreased for the control tumours in the (18)F-FCH group. Furthermore, the eliminating rate constant of the contrast agent from the plasma k el derived from DCE-US was negatively correlated to the SUVmean of tumour-to-muscle ratio, necrosis and MVD. The present study suggests that the multimodal approach using (18)F-FMISO PET/CT and DCE-US seems reliable in the assessment of both microvasculature and necrosis as validated by histology. Thus, it has valuable diagnostic and prognostic potential for early non-invasive evaluation of radiotherapy.