Alkali Metal Salts of 10,12-Pentacosadiynoic Acid and Their Dosimetry Applications

Hall, Amy V.; Musa, Osama M.; Hood, David K.; Apperley, David C.; Yufit, Dmitry S.; Steed, Jonathan W.

doi:10.1021/acs.cgd.1c00031

Cited by 11 publications

(18 citation statements)

References 46 publications

(111 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The above results strongly suggest that water is integrated into the crystal structure, altering the monomer packing, and removal of it via desiccation has an effect on dosimetric parameters of relevance to traditional and real‐time dosimetry use. This is corroborated by the Fourier transform infrared spectroscopy and thermogravimetric analysis experiments showing that the commercial EBT‐3 film consists of monohydrated form of LiPCDA and dehydration results in the loss of one water molecule per monomer, converting LiPCDA to another form 20 …”

Section: Discussionmentioning

confidence: 57%

Role of water in the crystal structure of LiPCDA monomer and the radiotherapy dose response of EBT‐3 film

et al. 2022

View full text Add to dashboard Cite

Purpose: Radiochromic material used in recent commercial films has been suggested as a candidate for in vivo dosimetry because of its dose sensitivity, real-time response, and atomic composition. It was observed that its sensitive material, lithium pentacosa-10,12-diynoate (LiPCDA), can have two distinct forms, with main absorbance peaks at ∼635 and ∼674 nm. The spectrum of the latter is similar to that of pentacosa-10,12-diynoic acid (PCDA) used in the commercial predecessor, obtained through desiccation of the commercial film. Water was suggested to be a part of the crystal structure and thus its presence or absence would affect dosimetric parameters. The objective of this study is to: (a) investigate how desiccated commercial films compared to the native form in terms of macroscopic crystal structure, dose-response, signal linearity, and post-exposure kinetics; (b) demonstrate proof -of -concept that the two versions can be combined into one optical dosimeter and measured simultaneously. Methods: Commercial radiochromic film, EBT-3, was desiccated for 10 days at 45 • C. Using a 6 MV LINAC beam and standard setup of 100 Source to Axis Distance (SAD), 10 cm × 10 cm field size, and 1.5 cm depth, commercial and desiccated films were irradiated to 50, 100, 200, 500, 1000, 2000, 3000 cGy and the latter to 4000, 5000, and 7000 cGy. A custom phantom equipped with optical fibers for real-time read-out was used for all measurements. Absorbance spectra were collected at ∼1 Hz before, during, and after irradiation. Data were collected for ∼1 h after the end of irradiation for 200 cGy experiments. The radiation-induced change in optical density (∆OD) was calculated with a 10 nm band around the primary absorbance peak. The post-exposure percent optical density change was calculated and compared to ∆OD at the end of irradiation. Both commercial and desiccated films were also irradiated and measured simultaneously as proof -of -concept for using two materials within one optical path. For electron microscopy imaging, active materials from commercial and desiccated films were imaged on a scanning electron microscope at an accelerating voltage of 10 kV. Results: Scanning electron microscope images showed that desiccated film was similar in topographical structure to the commercial EBT-3 form. It maintained a non-linear ∆OD with dose but resulted in ∼1/3 signal compared to the commercial film. Evaluation of post-exposure response showed significantly lower percent increase in ∆OD for desiccated film initially, with no statistically significant difference at 1 h after the end of irradiation. Combining both films andThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

show abstract

Section: Discussionmentioning

confidence: 57%

Role of water in the crystal structure of LiPCDA monomer and the radiotherapy dose response of EBT‐3 film

et al. 2022

View full text Add to dashboard Cite

show abstract

“…38 The anhydrous form displays an enhanced photoresponse in comparison to the monohydrate; however, the anhydrous form is more difficult to process and so the radiochromic films are based on the monohydrate form of Li-PCDA. 38 Heating the films to 100 °C for 1 h can convert the monohydrated form to the anhydrous form. 38 Though no X-ray structures of either Li-PCDA form have been obtained, characterization suggests that the water molecule is coordinated to the lithium ion in the monohydrate, and both forms have a chelating bridging bidentate coordination mode of the carboxylate ligands.…”

Section: ■ Introductionmentioning

confidence: 99%

“…38 Heating the films to 100 °C for 1 h can convert the monohydrated form to the anhydrous form. 38 Though no X-ray structures of either Li-PCDA form have been obtained, characterization suggests that the water molecule is coordinated to the lithium ion in the monohydrate, and both forms have a chelating bridging bidentate coordination mode of the carboxylate ligands. 38 Additionally, the two forms must adhere to the postulate due to their obvious photoreactivity.…”

Section: ■ Introductionmentioning

confidence: 99%

“…38 Though no X-ray structures of either Li-PCDA form have been obtained, characterization suggests that the water molecule is coordinated to the lithium ion in the monohydrate, and both forms have a chelating bridging bidentate coordination mode of the carboxylate ligands. 38 Additionally, the two forms must adhere to the postulate due to their obvious photoreactivity. Another alkali-metal salt of PCDA, Na-PCDA, was synthesized by mechanical grinding to give an ionic cocrystal with a formula of Na + PCDA − •3PCDA.…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Properties and Applications of Stimuli-Responsive Diacetylenes

Hall

Musa

Steed

2021

Crystal Growth & Design

Self Cite

View full text Add to dashboard Cite

The topochemical reactivity of diacetylene monomers has long been established and involves the 1,4-addition polymerization reaction. This reaction is governed by well-defined parameters that allow the synthesis of diacetylene polymers. Polydiacetylenes are conjugated polymers that display unique colorimetric and fluorescent transitions when they are exposed to a range of stimuli, allowing them to be easily exploited in biosensors, chemosensors, and radiochromic dosimeters. In this review, we summarize recent work on polydiacetylene systems, focusing on examples involving 10,12-pentacosadiynoic acid (PCDA) that can be structured as polymerized vesicles, films, gels, and powders. Synthetic derivatives of PCDA are also reviewed, along with the effect of incorporating guest molecules to a diacetylene system and establishing the important relationship between reversible thermochromism and noncovalent interactions.

show abstract

“…The other formatted 2D dosimeters that have shown clinical applicability are silver halide-based x-ray film (radiographic film) and the more common Gafchromic ® film containing a diacetylene (e.g., 10,12-pentacosadiynoic acid) active layer; neither format has post-irradiation reusable characteristics [3]. Potentially, a modified polydiacetylene film containing alkali metal salts may have reversible color-changing properties [4,5].…”

Section: Introductionmentioning

confidence: 99%

Feasibility of a Reusable Radiochromic Dosimeter

et al. 2021

View full text Add to dashboard Cite

The current practice for patient-specific quality assurance (QA) uses ion chambers or diode arrays primarily because of their ease of use and reliability. A standard routine compares the dose distribution measured in a phantom with the dose distribution calculated by the treatment planning system for the same experimental conditions. For the particular problems encountered in the treatment planning of complex radiotherapy techniques, such as small fields/segments and dynamic delivery systems, additional tests are required to verify the accuracy of dose calculations. The dose distribution verification should be throughout the total 3D dose distribution for a high dose gradient in a small, irradiated volume, instead of the standard practice of one to several planes with 2D radiochromic (GAFChromic) film. To address this issue, we have developed a 3D radiochromic dosimeter that improves the rigor of current QA techniques by providing high-resolution, complete 3D verification for a wide range of clinical applications. The dosimeter is composed of polyurethane, a radical initiator, and a leuco dye, which is radiolytically oxidized to a dye absorbing at 633 nm. Since this chemical dosimeter is single-use, it represents a significant expense. The purpose of this research is to develop a cost-effective reusable dosimeter formulation. Based on prior reusability studies, three promising dosimeter formulations were studied using small volume optical cuvettes and irradiated to known clinically relevant doses of 0.5–10 Gy. After irradiation, the change in optical density was measured in a spectrophotometer. All three formulations retained linearity of optical density response to radiation upon re-irradiations. However, only one formulation retained dose sensitivity upon at least five re-irradiations, making it ideal for further evaluation as a 3D dosimeter.

show abstract

Alkali Metal Salts of 10,12-Pentacosadiynoic Acid and Their Dosimetry Applications

Cited by 11 publications

References 46 publications

Role of water in the crystal structure of LiPCDA monomer and the radiotherapy dose response of EBT‐3 film

Role of water in the crystal structure of LiPCDA monomer and the radiotherapy dose response of EBT‐3 film

Properties and Applications of Stimuli-Responsive Diacetylenes

Feasibility of a Reusable Radiochromic Dosimeter

Contact Info

Product

Resources

About