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"Synthesis and Monte Carlo simulation of improved concrete composites as x-ray/gamma ray shielding materials were performed. Samples of shieldings were synthesized using the base materials of Portland-type cement concrete with fillers of alloy steel, Co, Mn, and Cr, mixed separately as additives. The samples were characterized using Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry (SEM-EDS) to determine the constituent elements quantitatively. Linear attenuation coefficients of the samples were measured in the experiments and also simulated using Monte Carlo transport code MCNP5 in order to evaluate their shielding performance. The results of the experimentation and computer simulation reveal concrete with alloy steel added as having the best shielding properties, although concrete with other fillers added also exhibited enhanced shielding performance. It was demonstrated that 6.06 w% of fillers enhanced the x-ray/gamma ray shielding capability of ordinary concrete composites by improving their attenuation coefficient values by 40–60%."

"In modern medicine, a radiation scans is an very important examination tool for making a diagnosis and subsequent treatment plan. Among the range of medical examinations, Computed tomography (CT) is being performed in an increasing number of cases and a CT scan uses the most radiation of any diagnostic exam. On the other hand, radiation protection during scanning is not typical for bodily regions other than those designated for examination. Therefore, the aim of this study was to develop a lead-free fused radiation shielding fiber (RSF) and to evaluate its effectiveness with a view to reducing radiation exposure to only the effective dose or less in a CT scan by means of a multilayer structural coating. A GE High Speed Advantage Spiral CT was used to conduct measurements using a FH-40G (Eberline, USA) proportional digital counter survey meter. In a brain CT scan, abdominal CT scan, and knee CT scan, two-way ANOVA was used to analyze the changes in radiation dosage and to examine the correlation based on body parts and thickness of the RSF. In addition, when significant results were obtained, a Duncan post hoc test was used to examine the difference depending on each condition. In the brain CT scan, the highest exposure to secondary radiation was measured in the chest, which was closest in distance. The use of a 3- mm shielding fiber resulted in a shielding effect of approximately 65% shielding effect compared to the initial exposure dose. In the abdominal CT scan, no exposure dose was detected in the head area, which had been shielded with the 3-mm shielding fiber. In a knee CT scan, 1-mm shielding fiber was sufficient to demonstrate a shielding effect. The RSF developed in this study may help reduce low-dose exposure to secondary X-rays, such as scattered rays."

"ABSTRAKFilm gafchromic EBT3 merupakan salah satu dosimeter yang paling umum digunakan dalam proses verifikasi dosis pada radioterapi. Hal itu disebabkan oleh karakteristik yang dimiliki oleh gafchromic yaitu memiliki resolusi spasial yang tinggi, ekuivalen dengan jaringan tubuh manusia dan sensitif terhadap dosis. Artefak bergabung dengan kedua orientasi film sehingga menimbulkan fenomena hamburan. Tujuan dilakukannya penelitian ini adalah untuk menganalisis efek dari cahaya terpolarisasi pada respon flatbed scanner yang disebabkan oleh film Gafrchromic EBT3, mengetahui pengaruh dari penambahan polarizer terhadap dosimetri radiasi dan implementasinya pada kasus radioterapi. Penelitian ini menggunakan film gafchromic EBT3 dan scanner Epson V700 dan penggunaan polarizer untuk analisis efek parabola. Film diiradiasi dengan 6 MV foton dari akselerator Varian dengan slab phantom. Kemudian dilakukan scanning dengan penambahan polarizer untuk beberapa konfigurasi. Perangkat lunak yang digunakan dalam penelitian ini adalah image J dan matlab.Hasil dari penelitian ini menunjukkan bahwa polarizer memberikan pengaruh terhadap nilai dmax, dengan nilai tertinggi pada konfigurasi polarizer down dan error sebesar + 14%, sedangkan error terkecil pada konfigurasi Polarizer down sebesar + 1,2%. Selain itu penentuan posisi referensi untuk orientasi sudut menghasilkan nilai maksimum pada sudut 90o. Respon lateral yang diperoleh pada penelitian ini menunjukkan bahwa konfigurasi hanya EBT3 memiliki bentuk parabola negatif dan semakin bertambah dengan kenaikan dosis yang diberikan sampai dengan 8 Gy. Perhitungan gamma index 3% / 3 mm memberikan hasil konfigurasi P0U memiliki nilai yang paling besar dibandingkan dengan konfigurasi yang lainnya yaitu sebesar 86,52%.

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ABSTRACT

EBT3 gafchromic film is one of the most common dosimeters used in the dose verification process in radiotherapy. This is due to the characteristics possessed by the gafchromic that has a high spatial resolution, equivalent to human body tissue and sensitive to the dose. When scanning films using scanners, light scattering achieves linear CCD cameras causing a non-uniform response. Artifacts join the second film orientation resulting in a scattering phenomenon. The study used EBT3 gafchromic film and Epson V700 scanner and polarizer use for parabolic effect analysis. The film is irradiated with 6 MV photons of the Varian accelerator with a phantom slab. Then scanning with the addition of polarizer for some configuration. The software used in this research is image J and matlab.

The results of this study indicate that the polarizer has an effect on the dmax value, with the highest value in the polarizer down and error configuration of + 14%, while the smallest error in the Polarizer down configuration is + 1.2%. In addition the positioning of the reference for angle orientation gives the maximum value at an angle of 90°. The lateral response obtained in this study indicates that the only configuration of EBT3 has a negative parabolic form and is increasing with increasing doses up to 8 Gy. Calculation of gamma index 3% / 3 mm gives result of configuration P0U has biggest value compared with other configuration that is equal to 86,52%."

"Tujuan : untuk mengetahui waktu terbaik dilakukan adaptasi perencanaan radiasi terhadap kasus kanker nasofaring yang menjalani radiasi di RSCM serta mencari tahu hubungan penurunan berat badan dan pengecilan ukuran tumor terhadap perubahan dosimetri pasien kanker nasofaring serta batasan perubahan separasi leher yang memerlukan tindakan adaptasi perencanaan radiasi. Metode : Dilakukan studi kohort prospektif pada 11 pasien kanker Nasofaring. Dilakukan pengukuran berat badan dengan timbangan dan separasi pada tip mastoid , kelenjar getah bening terlebar menggunakan alat ukur di TPS pada data set CT Simulator dan pada CBCT fraksi 1,6,11,16,21,26,dan 31. Data set hasil CBCT dilakukan fusi terhadap data set CT simulator kemudian dilakukan delineasi dan dilanjutkan rekalkulasi dosis dengan parameter yang sama seperti perencanaan radiasi awal kemudian dilakukan evaluasi dosimetri. Jika terdapat deviasi pada minimal 1 organ normal berisiko atau target volume maka masuk ke kriteria untuk dilakukan adaptasi perencanaan radiasi. Batasan waktu dalam menilai hubungan adaptasi perencanaan radiasi dengan parameter klinis dilakukan menggunakan kurva ROC (Receiving Operator Characteristic) Hasil : Dari 11 pasien yang diteliti,terdapat 10 pasien yang memerlukan adaptasi perencanaan radiasi dikarenakan melewati batas toleransi. Perubahan dosimetri yang menyebabkan adaptasi perencanaan radiasi, terjadi pada fraksi dan struktur organ yang berbeda. Hubungan antara waktu fraksinasi dengan indikasi tindakan adaptasi perencanaan radiasi signifikan mulai fraksi ke 6 sedangkan perubahan relative risk terbesar terdapat pada fraksi 11 ke fraksi 16. Indikasi adaptasi perencanaan radiasi dengan parameter klinis; Δ separasi KGB terlebar (AUC 0.951, 95% CI 0.905-0.996), Δ separasi Tip mastoid (AUC) 0.741, 95% CI 0.631-0.852, Δ persentase berat badan ((AUC) 0.911, 95% CI 0.844-0.978). dengan batas tengah kurva ROC pada Δ separasi KGB terlebar 1,21 cm dan Δ persentase berat badan 4,49 %. Kesimpulan : dari penelitian ini, pasien kanker nasofaring membutuhkan radiasi adaptif untuk memberikan terapeutik ratio yang baik dan didapatkan adanya hubungan antara perubahan separasi dan penurunan berat badan dengan adaptasi perencanaan radiasi.

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Objectives: to determine appropriate timing for adaptive radiation therapy for nasopharyngeal cancer cases undergoing radiation at the RSCM and to find out the relationship between weight loss and tumor size reduction on dosimetry changes in nasopharyngeal cancer patients and the cut off of changes in neck separation that require adaptive radiation therapy. Methods: A prospective cohort study was conducted on 11 nasopharyngeal cancer patients. Separation measurements were made on the tip mastoid, the widest neck lymph node using a measuring instrument at the treatment planning system (TPS) on the CT Simulator data set and the CBCT data set fractions 1,6,11,16,21,26, and 31. The CBCT data set was fused to the CT data set. The CBCT data set was then delineated and continued with dose recalculation using the same parameters as the initial radiation plan, then dosimetry evaluation was carried out. If there is deviation in at least 1 normal organ at risk or target volume, then it is included in the criteria for adaptive radiation therapy. The time limit in assessing the relationship between adaptive radiation planning adaptive and clinical parameters was carried out using the ROC (Receiving Operator Characteristic) curve. Results: there were 10 out of 11 patients who required adaptive radiation planning due to exceeding the tolerance limit. Dosimetry changes that cause adaptive radiation planning occur in different fractions and organ structures. The relationship between fractionation time and indications of radiation planning adaptative measures is significant starting from the 6th fraction, while the largest relative risk changes are found in fractions 11 to 16. Indications of adaptive radiation planning with clinical parameters; widest lymph node separation (AUC 0.951, 95% CI 0.905-0.996), tip mastoid separation (AUC) 0.741, 95% CI 0.631-0.852, weight percentage ((AUC) 0.911, 95% CI 0.844-0.978). with the middle limit of the ROC curve at the widest KGB separation 1.21 cm and body weight percentage 4.49%. Conclusion: Nasopharyngeal cancer patients require adaptive radiation to provide a good therapeutic ratio and there is relationship between changes in separation and weight loss with adaptive radiation planning"

"Radiografi umum merupakan pelayanan diagnostik yang menggunakan paparan sinar-X, terutama untuk mendeteksi patah tulang, tumor, dan masalah organ internal tubuh. Paparan sinar-X dapat menciptakan citra, memerlukan perlindungan agar area penggunaan radiasi tetap amanbagi pekerja radiasi dan lingkungan. Timbal menjadi pilihan utama saat ini dalam pemilihan material untuk perisai radiasi karena dapat menyerap paparan radiasi sinar-X dengan efektif tetapi kurang efektif dari segi biaya produksi.  Berbeda dengan timbal, beton tidak memiliki kemampuan yang sama dalam menyerap radiasi secara efektif. Namun, produksinya relatif mudah dan biaya produksinya lebih rendah. Salah satu massalah utama terkait dengan penggunaan beton adalah variasi massa jenisnya yang signifikan di berbagai lokasi yang akan diukur terlebih dahulu, disebabkan oleh perbedaan dalam pemilihan material dasarnya. Sehingga pada penelitian ini bertujuan untuk menentukan bentuk kurva antara faktor transmisi dan ketebalan dinding dalam milimeter yang sesuai dengan material beton yang ada di Indonesia hingga membuat perangkat lunak berbasis website untuk mempermudah kalkulasi ketebalan beton yang dibutuhkan. Penelitian ini menggunakan pesawat sinar-X sebagai pemancar radiasi dan beton lokal sebagai perisai radiasi, dilakukan dengan dua percobaan yakni percobaan perisai primer dan percobaan perisai sekunder. Setelah mendapatkan data hasil pengukuran dilakukan pembuatan kurva antara transmisi radiasi dan ketebalan beton,telah didapatkan perbedaan yang cukup besar antara kurva beton lokal dan kurva pada NCRP 147 pada perisai primer maupun perisai sekunder.

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General radiography is a diagnostic service that uses X-ray exposure, primarily to detect fractures, tumors, and internal organ issues. X-ray exposure can create images, requiring protection to ensure the radiation usage area remains safe for radiation workers and the environment. Lead is currently the primary choice for radiation shield material because it can effectively absorb X-ray radiation exposure, though it is less cost-effective to produce. Unlike lead, concrete does not have the same capability to absorb radiation effectively. However, its production is relatively easy and cheaper. One major issue with using concrete is the significant variation in its density across different locations, which must be measured beforehand due to differences in basic material selection. Therefore, this research aims to determine the curve form between the transmission factor and wall thickness in millimeters corresponding to the concrete material available in Indonesia and to develop web-based software to facilitate the calculation of the required concrete thickness. This research uses an X-ray machine as the radiation emitter and local concrete as the radiation shield, conducted through two experiments: primary shield experiment and secondary shield experiment. After obtaining the measurement data, curves were created between radiation transmission and concrete thickness, showing a significant difference between the local concrete curve and the NCRP 147 curve for both primary and secondary shields."

"Latar belakang: Kanker nasofaring menempati urutan ke lima kanker yang paling sering diderita di Indonesia hingga tahun 2020. Terapi pilihan yang menjadi pilihan tata laksana kanker nasofaring adalah terapi radiasi dengan teknik Intensity Modulated Radiation Therapy (IMRT) karena dapat mengurangi kejadian xerostomia. Namun sekalipun dengan teknik IMRT cedera pada kelenjar saliva pasca terapi radiasi masih sering terjadi. Penilaian cedera kelenjar saliva pasca radiasi menggunakan klasifikasi Radiation Therapy Oncology Group (RTOG) di mana penilaian derajat keparahan berdasarkan gejala klinis pasien sehingga MRI yang mempunyai kelebihan dalam menilai jaringan lunak dapat membantu penilaian derajat xerostomia secara objektif dengan melihat perubahan volume dan perubahan intensitas kelenjar parotis.Metode: Dilakukan pengumpulan data dosis radiasi dan derajat xerostomia dari 30 pasien kanker nasofaring yang menjalani terapi radiasi serta dilakukan pengukuran perubahan volume serta rasio intensitas kelenjar parotis terhadap otot temporalis dari data MRI nasofaring pasien sebelum dilakukannya radiasi, 3 bulan sesudah radiasi dan 12 bulan sesudah radiasi.Hasil: Xerostomia derajat 1 memiliki perubahan rasio intensitas sebesar 0.9 pada  3 bulan sesudah radiasi dan sebesar 2.0 pada 12 bulan sesudah radiasi serta perubahan volume sebesar 4.0 ml pada 3 bulan dan 7.9 ml pada 12 bulan sesudah radiasi. Sedangkan xerostomia derajat 2 memiliki perubahan rasio intensitas sebesar 1.0 pada 3 bulan sesudah radiasi dan 2.0 pada 12 bulan sesudah radiasi serta perubahan volume sebesar 7.3 ml pada 3 bulan dan 9.5 ml pada 12 bulan. Hubungan korelasi dosis radiasi dengan  perubahan intensitas 12 bulan memiliki nilai P 0.002 dan nilai R 0.54, sedangkan hubungan dosis radiasi dengan perubahan volume 3 bulan memiliki nilai P sebesar 0.000 serta nilai R 0.9 dan dengan perubahan volume 12 bulan memiliki nilai P sebesar 0.000 dan nilai R 0.9.Kesimpulan: Penelitian ini menunjukkan perubahan intensitas kelenjar parotis lebih besar pada bulan ke 12 dibandingkan dengan bulan ke 3 setelah radiasi serta pada xerostomia derajat 2. Semakin besar dosis radiasi maka semakin besar pula perubahan volume kelenjar parotis.

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Background: Nasopharyngeal cancer ranks as the fifth most common cancer in Indonesia until 2020. The treatment of choice for nasopharyngeal cancer is Intensity Modulated Radiation Therapy (IMRT) because it can reduce the incidence of xerostomia. However, even with the IMRT technique, injuries to the salivary glands after radiation therapy still occur frequently. Assessment of post-radiation saliva gland injury using classification Radiation Therapy Oncology Group (RTOG) where the assessment of the degree of severity is based on the patient's clinical symptoms so that MRI which has advantages in assessing soft tissue can help assess the degree of xerostomia objectively by looking at volume changes and parotid gland intensity changes. .

Method: Data were collected on radiation dose and degree of xerostomia from 30 nasopharyngeal cancer patients undergoing radiation therapy and measurements of changes in volume and intensity ratio of the parotid gland to the temporalis muscle were taken from nasopharyngeal MRI data before radiation, 3 months after radiation and 12 months after radiation.

Results: Grade 1 xerostomia had an intensity change of 0.9 at 3 months and 2.0 at 12 months and a volume change of 4.0 ml at 3 months and 7.9 ml at 12 months while grade 2 xerostomia had an intensity change of 1.0 at 3 months and 2.0 at 12 months and a change volume of 7.3 ml at 3 months and 9.5 ml at 12 months. The correlation between radiation dose and intensity change for 12 months has a P value of 0.002 and an R value of 0.54, while the relationship between radiation dose and volume change for 3 months has a P value of 0.000, an R value of 0.9 and a 12 month volume change with a P value of 0.000 and an R value of 0.9l.

Conclusion: This study showed that the change in the intensity of the parotid gland was greater at 12 months than at 3 months after radiation and at grade 2 xersotomia. The greater the radiation dose, the greater the parotid gland volume change."