Search

Introduction Contouring has become an increasingly important aspect of radiation therapy due to inverse planning, and yet is extremely time‐consuming. To improve contouring efficiency and reduce potential inter‐observer variation, the atlas‐based auto‐segmentation (ABAS) function in Velocity was introduced to ICON cancer centres (ICC) throughout Australia as a solution for automatic contouring. Methods This paper described the implementation process of the ABAS function and the construction of user‐defined atlas sets and compared the contouring efficiency before and after the introduction of ABAS. Results The results indicate that the main limitation to the ABAS performance was Velocity's sub‐optimal atlas selection method. Three user‐defined atlas sets were constructed. Results suggested that the introduction of the ABAS saved at least 5 minutes of manual contouring time (P, To improve contouring efficiency and reduce potential inter‐observer variation, the atlas‐based auto‐segmentation (ABAS) function was introduced to ICON cancer centres (ICC) throughout Australia. Three user‐defined atlas sets were constructed, which saved at least 5 minutes of manual contouring time.

Studying the interaction between plasma proteins and liposomes is critical, particularly for their use as drug delivery systems. Here, the efficacy of anisotropy resolved multidimensional emission spectroscopy (ARMES) for investigating the interaction of human serum albumin (HSA) with liposomes was explored and compared to conventional spectroscopic techniques. Dynamic Light Scattering (DLS) and absorbance spectroscopy (with Multivariate Curve Resolution (MCR) modeling) indicated that the highest degree of liposome rupturing, and aggregation occurred in water, with less in ammonium bicarbonate buffer (ABC) and phosphate buffered saline (PBS). Fluorescence emission spectra of HSA-liposome mixtures revealed significant hypsochromic shifts for water and ABC, but much less in PBS, where the data suggests a non-penetrating protein layer was formed. Average fluorescence lifetimes decreased upon liposome interaction in water (6.2¿5.2 ns) and ABC buffer (6.3¿5.6 ns) but increased slightly for PBS (5.6¿5.8 ns). ARMES using polarized Total Synchronous Fluorescence Scan measurements with parallel factor (PARAFAC) analysis resolved intrinsic HSA fluorescence into two components for interactions in water and ABC buffer, but only one component for PBS. These components, in water and ABC buffer, corresponded to two different HSA populations, one blue-shifted and penetrating the liposomes (¿ex/em = ~ 280/320 nm) and a second, similar to free HSA in solution (¿ex/em = ~ 282/356 nm). PARAFAC scores for water and ABC buffer suggested that a large proportion of HSA interacted in an end on configuration. ARMES provides a new way for investigating protein-liposome interactions that exploits the full intrinsic emission space of the protein and thus avoids the use of extrinsic labels. The use of multivariate data analysis provided a comprehensive and structured framework to extract a variety of useful information (resolving different fluorescent species, quantifying their signal contribution, and extracting light scatter signals) all of which can be used to discriminate between interaction mechanisms. This publication has emanated from research supported in part by a research grant from Science Foundation Ireland and is co-funded under the European Regional Development Fund under Grant number (14/IA/2282, Advanced Analytics for Biological Therapeutic Manufacture, to AGR). We thank Agilent Technologies (Mulgrave Victoria, Australia) for the loan of a fluorescence spectrometer. The authors also wish to acknowledge and thank the support of Dr. Steven Quinn from the Physics of Life in the University of York who provided guidance on the preparation of the liposome system used in this studied, his help was a key step in the development of this work. peer-reviewed