SA114350596B1 - Novel 3D Polymer Gel Dosimeters Based on N-(3-Methoxypropyl)acrylamide (NMPAGAT) for Radiation Therapy Treatment Planning System - Google Patents

Abstract

The invention relates to low toxicity trimethoxypropyl acrylamide (PNMPAG) and NMPAGAT polymerized gel dosimeters for use in a radiotherapy planning system. The response of both types of gels was independent of radiation doses and radiation energy and showed a high degree of reliability in repeated measurement after radiation.

Description

_— \ _ Novel 3D Polymer Gel Dosimeters Based on N-(3-Methoxypropyl) acrylamide (NMPAGAT) for Use in Radiotherapy Treatment Planning System Novel 3D Polymer Gel Dosimeters Based on N-( 3-Methoxypropyl) acrylamide (NMPAGAT) for Radiation Therapy Treatment Planning System FULL DESCRIPTION BACKGROUND The present invention relates to normoxic 3-D polymerized gel dosimeters for the radiation treatment planning system 105. Polymeric gels It is a substance similar in texture and upon irradiation it polymerized into a gelatinous mold. Thus, a polymerized gel spectrum can be formed to simulate the patient's body composition for the radiotherapy plan by adding radiation doses to the spectrum. (Sag) Visualizing the complex distribution of doses in terms of the polymer network in a three-dimensional form by magnetic resonance imaging (MRI) to make a planning for radiation treatment J. This was presented 1 to the invention of three-dimensional polymeric gel dosimeters containing DE-methoxy acrylamide Propyl-3)-L8a (NMPAGAT) Methoxypropyl)acrylamide. In a laboratory glove box under 0 nitrogen atmosphere with the symbol (PNMPAG) and under a vacuum wheel under normal atmospheric conditions with the symbol (NMPAGAT). The Division of Radiology in Oncology It is a department for the treatment of malignant tumors in patients with ionizing radiation such as X-rays or electronic rays. ling refers to this treatment as “radiotherapy”; it is a well-established treatment that has developed greatly over recent decades. It offers significant and clear advantages5 to patients in terms of organ preservation, quality of life, effective relief of symptoms, and survival rates in a number of forms of oncological diseases. Radiation therapy is one of the main treatments for tumors or cancer. This includes the use of ionizing radiation to destroy the DNA of tumor cells, but it keeps vy

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on healthy cells and does not damage them. as a therapeutic method; It may be the primary method or as a treatment used

In combination with surgery and chemotherapy provided by medical oncologists. Polymerized gel dosimeters have been shown to; With magnetic resonance imaging (MRI) Resonance Imaging can be used to visualize the three-dimensional spatial distribution of doses for radiometric dalled plotting (Mariansky; ono) Ibot; J S Eastman; with me. lS Reviews J on JC. 1996. Radiotherapy dosimetry using polymeric gel nuclear magnetic resonance imaging. med. Face. 23: 699-705: inl JC; Clark; BG and Arsenault; bad; J. 1998. Experimental Determination of Dosimeter Functions for 2-+ Sources]. med. Face. 25: 2279-87: Dee Dean Y de Wagter C; Van Dieus, by Dierbeck; 0 Es Merciman; with me; de Gersem; W; Voit; T; Ashtin »e; de nef; W. 2000. Evidence of an MRI-based polymer gel dosimeter as a 3D preclinical tool in radiotherapy. magnanimous. Robson. med. 43: 116-25). A polymerized gel is a substance similar in texture and upon irradiation polymerized into a water-based gelatin block. Thus, a polymerized gel spectrum can be formed to simulate the patient's body composition for the radiotherapy plan by adding radiation doses to the spectrum. 5 and the amount of polymer formed allows visualization of the complex radiation dose distribution in 3D by MRI to establish radiotherapy planning; before actual radiation treatments

prepared for the patient in order to destroy the tumor cells. The first suggested therapeutic gel was a ferrous sulfate chemical solution dosimeter. when irradiated; Free radicals arising from radiation and resulting from the radioactive decomposition of water; 0 oxidizes ferrous (Fe+2) ions to ferric 1005 (Fe+3) ions, which changes the magnetic moment of the metal ion. As a result; The spin relaxation time of the water protons in the hydrogel decreases and thus the spin NMR relaxation rate of the protons increases. (de din; gly virgot; AS Claes C; de undre; ou 2006). Basic radioactivity properties of normal oxygenated polymeric gel dosimeters: a comparison of 5 methacrylic acid-based and acrylamide-based gels; Phys.Med.Biol 51:-653

Yeh 3). A major drawback of Fricke gel systems is the diffusion of ferric (Fet3) ions within the dosimeter over time; which leads to a change in the distribution of doses with time; Meaning, an MRI should be taken immediately after radiation. This defect has led to the search for alternative gel dosing systems (Sa) to be used with MRI based on a set of simple considerations; for example, the gel must be tissue-like and mechanically strong, and the monomers must be highly reactive in order to form a large amount. of the polymer per concentration of free radical initiators produced by the radioactive decomposition of water A relatively high crosslinking density of the polymer is clearly required to produce a large NMR relaxation effect for the water protons (Mariansky, M; Odette, C and Gorey, JC, 1997). and 0 temperature on the dosing response of a polymeric gel dosimeter BANG (Vs. Med. Biol. 42:303-1).Reported by Mariansky, MJ, Scholes, RJ, Ibott, JS, Gatenby, JC XY, J, Horton, D, Jury, din, C. 1994 (MRI of radiation dose distributions using a polymerized dosimeter; Ph. dm. Biol. 39: 1437-55). He solved this problem by measuring absorbed dose distributions with skepticism l true. ashy The original polymerized gel on high molecular weight compounds consisting of acrylamide monomer (AAM) acrylamide monomer bis-acrylamide as crosslinker(BIS) N,N methyelene-bis--acrylamide dissolved in gelatin. The composition of the auxiliary aqueous monomer solution that was synthesized was 965% of its weight gelatin » 963% of its weight is acrylamide monomer and 963% of its weight is methylene-bis-acrylamide by mass slag. The mixture of gelatin and water was deoxygenated by nitrogen deoxygenation before and during the continuous stirring and mixing of the gel. Gel dosimeters or spectra were sealed and refrigerated prior to irradiation. When irradiated, the water molecules dissociate into hydroxide and hydrogen radicals, which break the chloride 5 0-0 bonds of the auxiliary monomers (acrylamide monomer and somethylene “bis-acrylamide”). And in its turn vy roots interact

They are the resulting copolymers with other copolymers and produce a chain reaction to form spatially preserved three-dimensional polymer aggregates in a gelatin block. The amount of polymer formed is related to the absorbed dose received from the polymerized gel. This polymerized aggregate is assessed as Bale using NMR spectrophotometry and MRI; The contrast in the MR images of radiolabeled PCM dosimeters increases progressively with dose uptake. The first normal concentration gel was proposed; Known as MAGIC methacrylic and ascorbic acid in gelatin initiated by copper (Il) sulphate, ascorbic acid and (MAGIC) hydroquinone in 2001 which can be produced and stored and its irradiation in a normal or normal oxygen environment without nitrogen filtering (Fung; BM; “HS DC; Doss”; DM and Gorey; JC 2001. Polymerized gels for magnetic resonance imaging of radiation dose distributions at normal room temperature; Vis. Med. Biol. 46: 3105-13).

Finning AG, Hill B, Barbanda S, Healy BJ and Baldock C. 2005; investigation of polyacrylamide gel dosimetrics (PAGAT) using magnetic resonance imaging; FacebookMed. . Biol. 503875-88 researched PAGAT polymer gel dosimeters using magnetic resonance imaging. The polyacrylamide gel dosimeter 0 (PAG) is composed of co-monomers (acrylamide monomer and somethylene-bis-acrylamide). and anti-Shas ash (hydroxymethyl) chloride. Phosphonium 1608/65

(THPC) (hydroxymethyl) phosphonium chloride and an inhibitor (HQ) hydroquinone to form a normal pH copolymer gel dosimeter. And he has

The polymerized gel showed a high degree of spatial stability over 24 days; good variability in dosing; spatial quality. cola) ka; Sion; any; Ali Muhammad; Iskandar Shahrim; Azhar Abdel Rahman; Hussein. Mohamed 2008 Enhancements in Polymeric Gel 3D Dosimetry and Magnetic Resonance Imaging. Radiometrics. 43; 1377-1382 An investigation into the effect of varying crosslink concentrations; methylene-acrylamide from 762 to 764 and dihydroxyethylacrylate (HEA) monomer 2-hydroxyethylacrylate from 2% to 964 by 905 gelatin on the dosing response of dihydroxyethylacrylate-0-somethylene-bis-acrylamide aqueous polymer gel dosimeters as crosslinker--gelatin (BHEAG) using MRI of the R2 relaxation rate of the LMA proton. It was also found that the PDD deviation between the ionization chamber data and the gel data was less than 965, which indicates that the BHEAG gel dosimeter can be used in planning complex 3D radiotherapy.The first study of the effect of glycerol adjuvant solvent on proportion and shape was conducted. Gel dosing response 5 polymerized by (Jerasik A; Hilts M; Berman A and Macaulay KB 2009. Effects of glycerol cosolvent on the ratio and shape of gel dosing responses; Fis. Med. Biol. 54-9078. Gel formation from iso propyl-acrylamide; double acrylamide; gelatin (965 wt.); Glycerol (weight may vary as needed) and de-ionized water. Tetracycline (hydroxymethyl)phosphonium chloride (5 mM) was used as an oxygen scavenger. The monomer and crosslinker fractions were kept at a ratio of 9650; While the relative amount of total + crosslinked monomer in the gel differed. The completed gel solution was transferred to either 20-mm radial bottles for CT experiments or to 10-mm externally sized NMR sample tubes for [RAMAN] experiments and the gel was irradiated with a longitudinal accelerator using X-ray 6 (MV field size).

1 at a depth of 1.5 cm in water. The gel (sha 400) was irradiated with a dose gap of 0 x 15 cm at five different depths along the central axis of the beam and doses between 3-50 Gray were produced. A significant increase in the dosing sensitivity of the polymerized gel was found with increasing glycerol concentrations. Within the polymerized gel, however, specific changes in the shape of the dose-response curve were observed when the concentration of the co-solvent differed.This change in the shape occurred mainly due to changes in the rate of 5 acrylamide consumption when different concentrations of the co-solvent were used. The optical and NMR dosimetry reports of the focused polymerized gel were examined

N-isopropylacrylamide on normal oxygen isopropylacrylamide for radiotherapy dosimetry. Normoxic optical and magnetic resonance (NIPAM) properties for application in radiotherapy dosimetry. The gel dosimeters contained gelatin (0 wt.); monomer (3% by weight); and crosslinked dimethylene acrylamide (963 by weight) and tetracase 965 (one vial is irradiated to read aly (hydroxymethyl) phosphonium chloride antioxidant) (10 mM). . It showed a longitudinal relationship with the dose from 1.5 to 11 Gy for the dosimeter (pad) each of the 2+ and gel absorption A / 0 / 8 only. Moreover, the response of the absorbed doses varied significantly with 5 different sensitivity to the blue part of the spectrum. mh. zahemtkesh; AS. meguni; ma. Mosleh Shirazi, S. cal Zehtabian, Studying the dependence of the dose rate on the dosimeter 70107. Mahdi Zadeh; s. Sinai S. Bagheri. Low-dose Polymerized Acrylamide Gels. Radiometers. An article published in the journal 0 Radmis investigated the dose rate dependence of a polymerized acrylamide gel dosimeter with low dose rates. A gel dosimeter was used to measure the dosimeter distribution around a 0.97 source for a range of dose rates from 0.06 to LDR from a 117-Moesis 08-7 Gyph source. It was observed that the dose measured by the gel dosimeter was the same at different distances (different dose rates) from the source. The study also concluded that the response of gel 5

_A —_

PAGAT may be affected by oxygen; So it is recommended to use Ya Lala bottles from plastic bottles

For measuring doses from sources with low dose rates.

General description of the invention

Polymerized gel dosimeters based on the radiation-induced polymerization of acrylamide (tri-

5-methoxypropyl) in a laboratory glovebox under nitrogen atmosphere (PNMPAG) and under a cupboard

Aspiration under normal dog conditions (NMPAGAT) studied as new dosimeter assemblies

Polymerized gels for radiation therapy planning system. The dosimeters were irradiated by Farban systems

medical; United State; In doses absorbed up to 20 Gy. The spin relaxation rate was used

(R2) Water-proton NMR surrounding the polymer formation to check the degree of polymerization for each 0 of the two types of gels. The change in the equivalent amount of polymer formation increases in both types of gels

Gradually increase the absorbed dose up to 20 Gy. It was found that there was no significant effect of rate

Doses and radiation energy on both types of polymer gel dosimeters.

Brief description of the graphics

Figure -1: Relaxation rate (R2) of a gel copolymerized from trimethoxypropyl acrylamide PNMPAG 5 as a function of absorbed dose. The R2 of the gel gradually increases with increasing dose. And can

Longitudinal observation of dose response across the region up to 20 Gy.

Figure 7: Relaxation rate (R2) of PNMPAG-trimethoxypropyl acrylamide copolymer gel

For different dose rates (200 400 600 Gy/min) under 10 MV radiation power as a function

for the absorbed dose. There is no significant effect of dosing rate on the PNMPAG 0.0 polymeric gel dosimeters

Jal “:- Relaxation rate (R2) of the gel copolymerized_ of trimethoxyproyl acrylamide

PNMPAG for different radiation energies (6 5 510 MV 15) at 600 Gy/min as a function of dose

q —_ _ absorbed. There is no significant effect of the radiation dose on the PNMPAG polymeric gel dosimeters. Figure 4:- Dose relaxation rate for irradiated PNMPAG-trimethoxypropyl acrylamide dosimeters up to 2 and 10 Gy as a function of storage time. The results showed no change (<16: +4.996) in the absorption of gel dosimeters up to 180 hours. Figure 5: Dose-response curves for a gel copolymerized from trimethoxypropyl acrylamide (687 M1/0L 2 3) with different concentrations of co-monomers in the dose range of 0 to 20 Gy. The response of the gel to doses increased progressively with increasing dose; Which can be clearly seen from increasing individual dose curves of relative absorption. R2 increases dramatically with increasing concentration of co-monomers. 0 and the longitudinal dosing response can be observed across the region up to 20 Gy. Figure 76: -dad Dose sensitivity for different concentrations of copolymers with the use of 965 by weight gelatin as a function of absorbed dose. The sensitivity value increases gradually with increasing concentrations of co-monomers from 6 to 967.6 wt; Which leads to further polymerization of the gel dosimeters of the tri-methoxyproyl acrylbutylamide NMPAGAT 15 Figure -: 17 Dose response curves for the polymerized gel NMPAGAT with different glycerol concentrations Figure 8:-dad Dose sensitivity to different glycerol concentrations with the use of 965 by weight 0 gelatin as a function of absorbed dose. The sensitivity value increases gradually with increasing glycerol concentrations from 0 to 9610 by weight; resulting in further polymerization of NMPAGAT trimethoxypropyl acrylamide gel dosimeters.

=” \ _ Figure 4:- Relaxation time (RZ) of a polymerized gel of DE-methoxypropyl acrylamide NMPAGAT-6 for different dose rates (200 400 600 Gy/min) under MV radiation energy of 10 as a function of absorbed dose . There was no significant effect of dose rate on NMPAGAT 5 polymer gel dosimeters

Figure -01: Relaxation time (R2) of NMPAGAT-6 polymerized trimethoxypropyl acrylamide gel for different irradiance energies (6 and 10 15 MV) at 600 Gy/min as a function of absorbed dose. There is no significant effect For radiation dose on polymeric gel dosimeters .NMPAGAT

Figure -11: Relaxation time (RZ) of NMPAGAT trimethoxypropyl acrylamide dosimeters irradiated to 6 and 10 Gy as a function of storage time. No change (<196:6) in the absorption of the gel dosimeters was observed up to 108 hours. Detailed description:

5. Polymerized gel containing tri-methoxy acrylamide (PNMPAG) dug ys was set up in a nitrogen atmosphere in a laboratory glove box. FaceMed. Biol and PNMPAG dosimeters consisted of trimethoxypropyl acrylamide monomer at 963.8 percent; crosslinked methylene diacrylamide 963.8%, gelatin (type A mass 300) 9064%; glycerol 9769%. All auxiliary chemicals were obtained from Sigma Chemicals. The room was disinfected.

0 nitrogen for at least 5 hours continuously while mixing the gel to expel the oxygen that inhibits polymerization prior to gamma irradiation. After expelling oxygen from the water for at least two hours; Gelatin was added to deionized ultrapure water and left to saturate for 10 minutes before heating to fifty degrees Celsius for one hour. During continuous stirring, methylene-bis-acrylamide and glycerol were added, respectively, and stirred until complete dissolution. After cooling the solution to 40 °C; Done

-11-

Add trimethoxypropyl acrylamide and stir until completely dissolved. To study the properties; The final polymerized gel was packed into a 10 mm NMR tube and hermetically sealed. All gels were stored in a refrigerator (10°C) overnight prior to irradiation. Irradiations were performed using a 6 million volt MV photon beam of a medical linear accelerator (Varian Medical Systems; USA) at a dose rate of 600 Gy/min and calibrated using an ionization chamber. Each gel-filled sample was placed in a water spectrophotometer with a volume of 30*30*30 cc. The sample was irradiated with a radiation field size of 10*10 cm at different doses at a depth of 5 cm and 100 cm 5500. The sample was transferred back to a refrigerator and kept for approximately 24 hours prior to the NMR measurements of the relaxation rate (42A). Relaxation rate (R2) measurements were performed using a 0 0.5 Tesla NMR (Brücker, Germany). The irradiated PCG sample was placed in NMR NMR tubes (1 cm in size, 20 cm in height) and lowered into a magnetic box (palpation head). A spin-echo multiplier-echo-Gel (CPMG) series was used to measure R2 and three samples were measured at each absorbed dose; However, no significant differences were observed in their properties during the course

measurements. The temperature during the measurements was 0.5 + 22 °C.

Figure 1 shows the change in the relaxation rate of the R2 protons versus the absorbed dose of the 066/000 polymer. The dosing response of the gel increases gradually with increasing dose. Levies dose increases; More radiation-induced free radicals of the monomers are generated by the breaking of the C=C crayon bonds of the co-monomers; resulting in the sal) polymerized gel formed. Longitudinal dosing response can be observed

0 across the area up to 20 Gy. The effect of the energy dose rate on the response of the PNMPAG polymeric gel dosimeters was investigated using 400 and 600 Gy/min under radiation energy of 10 million volts MV, and the samples were irradiated for absorbed doses of 2, 4, 6, 8, 10, 15 and 20 Gy. Three dosimeters were irradiated for each dose point. It was found that there was no significant effect of dose rate on the 5 PNMPAG polymerized gel dosimeters (see Figure 2).

yy Using PNMPAG, the effect of energy on the response of polymer gel dosimeters was verified at 600 Gy/min. The samples were irradiated for absorbed doses of MV 6, 15, and 15 million volts with values of 2, 4, 6, 8, 10, 15, and 20 Gy. Three dosimeters were irradiated for each dose point. It was found that there was no significant effect of radiation dose on the polymerized gel dosimeters (3) (see Figure PHMPAG 5).

The stability and stability of the gel dosimeters were tested by irradiating the PNMPAG dosimeters at 2, 6, and 10 Gy and stored in a refrigerator (at 10°C). A total of three samples were used for each dose. The results showed that there was no change (less than 16: +4.996) in

Absorption of gel dosimeters up to 180 hours (see Figure 4).

10 and complicates handling of a normal gel dosimeter (PNMPAG) in a nitrogen atmosphere in a laboratory glove box; Normal oxygen concentration polymerized gel dosimeters containing different concentrations of trimethoxypropyl acrylamide were used in this invention. The polymeric gel containing trimethoxypropyl acrylamide was mounted under a vacuum wheel under normal atmospheric conditions. The NMPAGAT dosimeters consisted of trimethoxypropyl acrylamide; crosslinked methylene diacrylamide; gelatin (type A; block 300); Glycerol and Tetracycline (hydroxymethyl)phosphonium chloride. All auxiliary chemicals were obtained from Sigma Chemicals. Gelatin was added to deionized ultrapure water and left to saturate for 10 minutes before heating to fifty degrees Celsius for one hour. during continuous 0 flipping; BIS and glycerol were added respectively and stirred until completely dissolved. After the solution was cooled to 40 degrees gia, trimethoxypropyl acrylamide was added and stirred until complete dissolution. After the solution cooled down to 35°C; Phosphonium chloride tetracase has been added as an antioxidant. The final polymerized gel was packed into 10 mm NMR tubes and sealed. All gels were stored in a refrigerator (10°C) overnight prior to irradiation. 5 NMPAGAT dosimeters were performed as previously mentioned for [PNMPAG] dosimeters.

Ad —_ \ _ measure three samples at each absorbed dose; However, no significant differences were observed in their properties during the measurements. The effect of total concentrations of the copolymers (tri-methoxy-proyl acrylamide and somethylene-bis-acrylamide) on the response of the gel dosimeter was examined by preparing different formulations of NMPAGAT dosimeters as shown in Table 1 and in Figure 5f. and b) the change in the relaxation rate of R2 protons versus the adsorbed dose of NMPAGAT polymerization for the total concentration of copolymers from 6 to 967.6 wt. The response of the gel to doses increased progressively with increasing dose; which can be clearly seen from increasing individual dose curves with 0 relative absorption (see Figure 5). And when the dose increases; More radiation-induced free radicals of the monomers are generated by the breaking of the C=C crayon bonds of the co-monomers; Which leads to thickening of the formed polymerized gel. The results show that the rate of relaxation 42 increases significantly with an increase in the concentration of co-monomers. (Sarg longitudinal view of dose response across the region up to 20 Gy (Fig. 5(a)) with the exception of the lowest concentration of copolymers. 5 Table 1: NMPAGAT polymerized gel formulations based on 965 wt. Weight Auxiliary Monomers NMPA BIS THPC Agheilatin Water of Formula mM Weight Percentage | Weight Percentage | Weight Percentage | Weight Percentage

_— ¢ \ _ The dose sensitivity was taken from the slope of the longitudinal position of the dose D (up to 10 (sha) versus 42 in Fig. 5. The results show that the sensitivity value increases gradually with increasing concentrations of copolymers from 6 to 967.6 wt; which leads to NMPAGAT gel dosimeters further polymerized as shown in Figure 6. The effect of glycerol concentrations on the response of the gel dosimeter was examined by preparing different formulations

for NMPAGAT dosimeters as shown in Table 2. Table 2: Polymerized NMPAGAT gel formulations based on 965 by weight gelatin and 0-0 by weight glycerol.

NMPA BIS | THPC Gelatin | Glycerol 1 water symbol

mM is the percentage of weight | weight ratio ratio weight ratio | Weight ratio 1 formulation

weight

10 Figure 7 shows the dosing response of different concentrations of glycerol in the dose range 0-20 Gy. Effects of a glycerol adjuvant on the proportion and shape of gel dosing response. A significant increase in the dosing sensitivity of the polymerized gel was found by increasing the concentrations of glycerol D within the polymerized gel. The results show that the sensitivity value increases gradually with increasing concentrations of co-monomers from 6 to 967.6

5 1 wt » leading to further polymerization of the NMPAGAT gel dosimeters as shown in Figure 6.

A\_ and three dosimeters were irradiated for each dose point. It was found that there was no significant effect of dose rate on the dosimeters of polymerized gel 0110/0/65 (see Figure 2).

The effect of energy on the response of polymer gel dosimeters 0110/0/6 was verified using 1551056 million volts MV at 600 Gy/min. ADU was dosed dosimetrically for each dose point. It was found that there was no significant effect of radiation dose on the PHMPAG polymerized gel dosimeters (see Figure 3). up to 2, 6 and 10 Gy and store in a refrigerator (at 10°C). A total of three samples were used for each dose. The results showed no change (<16: +4.996) in the absorption of gel dosimeters up to 180 hours (see Figure 4).

Claims (1)

-?1- Claims - 1 Composition for gel dosimeters of tri-methoxypropylacrylamide (NMPA) N-(3-Methoxypropyl)acrylamide in nitrogen atmosphere in a laboratory glovebox with symbol ((PNMPAG) containing Composition on: Gelatin (Type A; Mass 300): 96 .101 9 5 - 2 : nly Trimethoxypropyl (NMPA) N-(3-Methoxypropyl)acrylamide Jug wt.% : 1-8 : –bis— (pling acrylamide (BIS) N,N’ methyelene-bis—acrylamide wt.% : 1-4 : 0 and glycerol : 1001.96 1-50. ultrapure de-ionized water for use as a solvent; “- The process for preparing polymerized gel dosimeters PNMPAG involves saturating the chamber with nitrogen for at least 5 hours continuously while mixing the gel to expel the oxygen that inhibits polymerization prior to 5 gamma irradiation. After oxygen has been expelled from the water for at least 2 hours; gelatin is added to the water Ultra-pure, deionized and left to saturate for 10 minutes before heating to fifty degrees Celsius for an hour.During continuous stirring, NUN” (BIS) methyelene-bis-acrylamide and glycerol are added, respectively, and stirred until complete dissolution. dang the solution is cooled to 40 °C; SUE cudally methoxypropyl acrylamide (NMPA) N-(3-Methoxypropyl)acrylamide | 0 is added until complete dissolution. To study the properties, the finished polymerized gel is packed in an NMR tube 10 mm and hermetically sealed”; store all gels in a refrigerator (10°C) overnight prior to irradiation.*- Polymerized gel dosimeter formulation containing N=trimethoxypropylacrylamide -117- cua ((NMPAGAT) NPC with symbol (3-Methoxypropyl)acrylamide The composition includes: Gelatin (Type A mass 300): 96 No and 5 - 2. (NMPA) N-(3- Methoxypropyl)acrylamide Jug nly 1-8wt% : 5 .1-4 wt.% : (BIS) N,N' methyelene-bis-acrylamide Acrylamide -515- (lig) and glycerol: 1001.96 1-50. Tetrakis (hydroxymethyl) phosphonium and Tetrakis (hydroxymethyl) phosphonium chloride. 1-50 mM: (THPC) chloride 0 and de-ionized ultrapure water as solvent. ;?- The process for preparing the NMPAGAT polymeric gel dosimeters involves adding gelatin to deionized ultrapure water and allowing it to saturate for 10 minutes before heating to 50°C for 24 hours. During continuous stirring, methylene (N,N' methyelene—.L SI) —bis— (BIS) 015-56 and glycerol are added, respectively, and stirred until complete dissolution. aang cooling of the solution to 40 °C; Add N-(3-Methoxypropyl)acrylamide (NMPA) and stir until completely dissolved. Once the solution is cooled to 35 °C; Tetrakis (hydroxymethyl) phosphonium chloride 0 210006 sla (1100) is added for oxidation. The final polymerized gel is packed into 10 mm nuclear magnetic resonance (NMR) tubes and closed. The gel is stored in a refrigerator (10 °C) overnight before irradiation. b oh a rl _ d ad 2 1 Fe 1 » 6 a 3 s1 1 > * Ne. YY 058 ..y YY ve dala A 1 - 0 effluent dose Gray VS ivy — A q BN ; > , A 8 , i Eas MV A ee i pe SR ae ~ a et 5 aa) ِ Ss . : l A k m ee 8 b oR = i : Eu os = x os 6 ni N E a. * amai, > wo X nb: ss i lin ab a a 0 & aa wa yawa yawa yawa yawa yawa yawa oh yo wo oh yo wo yawa wo oh yo wo ya moa wa ya Wa wa ya moa wa ya la wam ya la wa um yam laa um yam lee lam yalla ee ma wa wa maya wa wa wa wa ee imama wa wa ma wa wa wa | 1 ¥ % 1 1 ¥ : * 3 a , ¥ ¥ ' 7 Lod _ \ «= Asah Gy Xo | = Gy a l a l a a a q s a s a s ary ary SAN 4 Su | Tins JV SEA SRR = WHE PUREE? A SU L 4 L + oe * [+23 Yun AF EL storage time; Hour + hour format -?1-£ + 4 MV Ye id a1 MV : which pra eR 7 8 ss 3 a] 1 PB NA : i LEN = ¥ 3 4 A Yo iy ye 34 3A rc a gh maxed dose £ form b except vo 3 i he pain os h 75 a lac i m ® N 3 b e 3 a ra 3 the 01 oy < mg e ma 5 ~ 3 a 1 @cliyAmin a | Yo an 8 a 1:. 1 _ Heb 1 . hae 3 re i.e. | # m=a 3 sj e 3 1 1 i SE of 1 yo | aa 4 net i 7 »m od & b: 1 and b EE 1 3 i a La: suck and ENE 1 1 1 1 a a a a a a a a a a a a a a a a a a a * A Ya 3 YE 3 YA 5 ** 4 £ ¥ + Alu Tb Absorbent Dose Gy m ~ > ods ivy mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm Gy [PRR a SHS : : XY te : ' - i. | 3 had k 1 1 1 rll ) SSE——— SE Sr StH | for : } 3« z vo Y.O. Yaa. D 3 - x Oy storage time; JS ivy watch ¥ + NMPAGAT-Y ol Xoo Min: « NMPAGAT-Y B A 1 D Ha Lajd Pa en ¥ & NMPAGAT-} M Ce B AT wT = Ye A — + 3 J ven J ee 1 3 deme A «} m a ki £ 1 & ?? aj \ _ l i % «7 JN | ee | 3 z and b ? «« 3. A A bd 0 34 Mammary Concentration Weight 96 ASKS Tivy — \ a — ve — bblllllll 2 NMPAGAT- oe SNMPAGAT-° a 1 Ye PE a ANMPAGAT-t oa iv 3 | es ea Ae god died 0 alive: mother 0 we RE «3 A I 3 ] ed «XE UA Ye 51# YE gla 5 a wy absorbed dose» gray shape blowing —Yv- s ye To H H H H H H 1 1 bs * “5 a 1 i 1 | to JE NE ay RE JE NE ay RE ¥ 1 pe 1 bs LIER I Ô A 1 2 4] : J 1 2 EI *a ¥ 1 i 1 i 1 i 1 A Low A AAA AAA AAA A AS 0 3 ¥ ¥ £ o& 1 v 1 : glycerol concentration. Weight Bh 3.3 oi 8 solution concentration q ? xy a —YA- Te Y Ss olyimin A N fxn ovina : The A 3 La & Vee 4 3737 Aa oe Love ' oF 3 a to 0 3 @ a 3 A : 4 WR a3 43 a & * 0 * 1 4 A Ys vy : a . z the absorbed dose; Drag $4 1 1 1 a The validity period of this patent is twenty years from the date of filing the application, provided that the annual financial fee is paid for the patent and that it is not invalid or forfeited for violating any of the provisions of the patent system, layout designs of integrated circuits, plant varieties, and industrial designs, or its executive regulations issued by King Abdulaziz City for Science and Technology; Saudi Patent Office P.O. Box TAT Riyadh 57??11 ¢ Kingdom of Saudi Arabia Email: Patents @kacst.edu.sa