Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

PURPOSE: A challenge for single-cell dosimetry of internalized Auger electron-emitting (AE) radiopharmaceuticals remains how best to elucidate their spatial distribution. To this end, a method, photoresist autoradiography (PAR), was previously developed to identify the lateral spatial distribution of AE-emitting radionuclides internalized in single cancer cells. In this paper, we present a simple mathematical model based on the radius and depth of radiation-induced patterns in photoresist material to identify the location in the z-plane of an 111In source capable of generating the pattern. MATERIALS AND METHODS: SQ20B cells, derived from a head and neck squamous cell carcinoma, were exposed to 111In-labeled epidermal growth factor (EGF) (8 MBq/μg). The integrated electron fluence after four half-lives from the internalized radionuclide-containing construct was detected by a photoresist layer that was placed in close proximity to the cells. The resultant latent patterns were chemically developed and analyzed by atomic force microscopy (AFM). The features in the patterns were matched to locations of electrons emitted from simulated point sources, thereby determining the likely locations of internalized radionuclides. RESULTS: The modeling procedure was validated using simple patterns. The model relates the depth and radius (in the x-y plane) of a pattern to the location and fluence of the source giving rise to the pattern. This point source modeling method provided a good fit to experimental data and can be expanded to analyze more complex patterns. CONCLUSIONS: We have demonstrated the utility of the modelling technique to identify the location of internalized AE-emitting radionuclides. This methodology now needs to be extended to predict the source positions in more complex PAR patterns.

Original publication

DOI

10.1080/09553002.2016.1233369

Type

Conference paper

Publication Date

11/2016

Volume

92

Pages

633 - 640

Keywords

AFM, Auger electron-emitters, autoradiography, micro-dosimetry, photoresist, Autoradiography, Carcinoma, Squamous Cell, Cell Line, Tumor, Computer Simulation, Electrons, Head and Neck Neoplasms, Humans, Indium Radioisotopes, Models, Biological, Radiometry, Radiotherapy Dosage, Reproducibility of Results, Sensitivity and Specificity, Squamous Cell Carcinoma of Head and Neck, Tissue Distribution