OA155] Big data in radiochromic film dosimetry

Abstract

Purpose Radiochromic.com is a web application for radiochromic film dosimetry. Hundreds of users of the application worldwide upload and process film images in the cloud. Once anonymized, these film images, along with sensitometric curves, lateral corrections, etc, form a large sample of data with an enormous potential as a research tool for improving radiochromic film dosimetry. For instance, the development of universal/generic sensitometric curves and lateral corrections, the detection of mistakes made during film measurements, the optimization of dosimetry protocols, the reduction of uncertainties, etc, may be feasible. A comprehensive analysis of the data is a long term project. In this work, the first steps were taken. Methods The sample consisted of 8190 different film images (more than 20 Gb) uploaded by 277 users, as well as 993 calibrations and 748 lateral corrections. A descriptive statistical analysis of the sample was performed. The feasibility of generic lateral corrections was investigated. Results The descriptive analysis of the data offers an approximate picture of the most common dosimetry systems and protocols employed in film dosimetry. Film model, lot, scanner, resolution, dimensions of the scanning area, or post irradiation time were available. As an example, the most common scanner type in the sample was Epson Expression 10000XL-12000XL, with 63% of the users, followed by Epson Perfection V700-V850 scanners with 20%. Generic lateral corrections calculated according to the Absolute correction method proposed by Mendez [Ref:I. Mendez, “Model selection for radiochromic film dosimetry,” Phys. Med. Biol. 60, 4089 (2015)] were found for Epson Expression 10000XL-12000XL and Epson Perfection V700-V850 scanners. At this stage of the research, the generic lateral corrections are considered as gold standards. They are not intended to release from the need of measuring lateral corrections, but to reduce the uncertainty derived from not applying lateral corrections whenever measuring them is not possible. Conclusions A large sample of radiochromic film dosimetry data from hundreds of users worldwide opens up new research areas with many potential applications. In this work, the sample and the first results were presented.