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Beltran, C. J.

Publications and source records attributed to Beltran, C. J..

2 recordsLinked to original sources

AI-assisted quantification of the clonogenic assay

The clonogenic assay is the foundational standard for evaluating cellular radiosensitivity, yet its manual quantification is limited by labor-intensive processing, high inter-observer variability, and a reductive binary scoring system. Here, we present and validate a deep learning-based segmentation pipeline for the automated, high-throughput quantification of mammalian cell survival across diverse radiation qualities (photons, protons, and carbon ions). By benchmarking against expert consensus using Bland-Altman analysis, we demonstrate that this AI framework consistently operates within natural human error margins. Crucially, transitioning to automated whole-well image-based analysis enables the extraction of continuous multidimensional data, including colony area, density, and cellularity. This phenotypic profiling successfully identified and quantified high-cellularity colonies formed by radioresistant BxPC-3 cells under particle irradiation. Coupled with rapid image acquisition platforms, this methodology significantly reduces processing bottlenecks while standardizing the derivation of relative biological effectiveness (RBE). By advancing beyond binary survival metrics to continuous morphological profiling, this framework provides a vital new analytical dimension for investigating structural mechanisms of radioresistance.

cell biology↗

Clonogenic survival and relative biological effectiveness of pancreatic ductal adenocarcinoma under pristine and spread-out Bragg peak irradiation with protons and carbon ions.

Biological effectiveness in ion therapy varies with radiation quality and biological context, yet cancer cell response data acquired under well-characterized physical conditions remain limited. We investigated clonogenic survival and relative biological effectiveness (RBE) in PANC-1 and BxPC-3 pancreatic ductal adenocarcinoma (PDAC) cells irradiated at four positions along pristine 180.1 MeV proton and 352.4 MeV/u carbon ion Bragg curves, with 4 cm spread-out Bragg peak (SOBP) irradiation included as a clinically relevant comparison. Cell plane positioning and dose were verified in a water-tank system using an Advanced Markus ionization chamber, and Monte Carlo simulations using TOPAS provided dose-averaged linear energy transfer (LETD) and microdosimetric quantities. RBE was calculated relative to 200 kVp X-rays using the linear-quadratic survival model. Across the sampled pristine beam positions, spanning LETD values of approximately 1-9 keV/m for protons and 12-163 keV/m for carbon ions, RBE increased with LETD. Proton RBE10 exceeded the conventional clinical value of 1.1 at distal positions, whereas carbon ion RBE10 increased from 2.3 to 5.2 in PANC-1 and from 1.3 to 3.7 in BxPC-3, with larger differences between cell lines observed near the Bragg peak. SOBP measurements showed different biological responses across field conditions despite comparable LETD. These physically characterized survival data provide PDAC-relevant benchmarks for evaluating whether RBE models reproduce biological responses across pristine and SOBP irradiation conditions, supporting the future integration of radiation-quality-dependent effects into ion planning.

cancer biology↗