Phantom dosimetry and cancer risks estimation undergoing 6 MV photon beam by an Elekta SL-25 linac

Khabaz, Rahim

doi:10.1016/j.apradiso.2020.109232

Cited by 8 publications

(7 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Since the MCNPX outs are per incident neutron, then the neutron source strength in equations (2)-( 4) is equal to one (Q = 1). By having Φ dir from MCNPX and considering d = 100 cm in equation (2), it is quantified a coefficient equal to 0.052696. By fitting fluences of the scattered and thermal neutrons in terms of the internal surface area of rooms based on equations (3) and (4) coefficients α and β were obtained as follows: For example, the fitting of thermal fluences to get coefficient α is shown in figure 8.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of neutron spectra and different fluences inside a radiotherapy room with a modified simple geometry of LINAC head

As-habi¹,

Khabaz²,

Khoshbin-khoshnazar³

2022

Phys. Scr.

Self Cite

View full text Add to dashboard Cite

The photoneutron spectra and ambient dose equivalent were determined in a radiotherapy room with a 15 MV linear accelerator using Monte Carlo simulation. A modified simple geometry of the accelerator's head was modeled by different simulations. Then, by putting it in a radiotherapy room, the photoneutron spectra at different distances from the isocenter and in the maze were determined. The source term spectrum is due to evaporation, and knock-on neutrons. In the presence of the walls, as the distance from isocenter is increased, evaporation and knock-on neutrons are reduced; however, epithermal and thermal neutrons tend to remain constant. The walls also play an influential role in increasing the photoneutron ambient dose equivalent. Subsequently, by placing this modified accelerator's head in the radiotherapy room, the coefficients of scattered and thermal fluences were also estimated.

show abstract

Section: Resultsmentioning

confidence: 99%

“…In the accelerator, electron beams collide with a target (such as tungsten) and produce x-rays. The use of x-ray machines necessitates radiation protection [1,2].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of neutron spectra and different fluences inside a radiotherapy room with a modified simple geometry of LINAC head

As-habi¹,

Khabaz²,

Khoshbin-khoshnazar³

2022

Phys. Scr.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Apabila dibutuhkan satuan dosis dalam Gy maka perlu mengalikan dengan faktor pengali (multiplier). Pada berkas foton 6 MV nilai faktor pengali sebesar 8,93x10 15 untuk mendapatkan dosis yang diterima per 1 Gy (dalam satuan Gy) [15]. Diagram alir dalam penelitian ini ditunjukkan pada Gambar 14.…”

Section: Menjalankan (Running) Program Mcnpxunclassified

Penentuan Faktor Koreksi Dosis Radiasi Sinar-X Linac 6 MV Pada Ketidakhomogenan Jaringan Tubuh dengan MCNPX

Setiawati¹,

Susanto

Arianto

2022

J. Ilmiah Aplikasi Isotop dan Radiasi

View full text Add to dashboard Cite

Salah satu metode untuk menghitung dosis radiasi yang dihasilkan oleh linac adalah dengan menggunakan program simulasi MCNPX. Tujuan penelitian ini adalah untuk menentukan karakteristik kurva Percentage Depth Dose (PDD) untuk berkas sinar-x 6 MV dan faktor koreksi dari distribusi dosis akibat adanya ketidakhomogenan jaringan tubuh. Penelitian ini menggunakan fantom jenis ORNL-MIRD phantom (1996 version) yang telah dimodifikasi. Fantom dibedakan menjadi fantom homogen yaitu dengan komposisi air dan jaringan lunak dan fantom nonhomogen dengan komposisi jaringan lunak yang didalamnya terdapat organ paru-paru pada kedalaman 5-14 cm dan jaringan lunak yang didalamnya terdapat organ tulang belakang pada kedalaman 5-10 cm. Luas lapangan penyinaran radiasi 10 x 10 cm2 dengan arah penyinaran radiasi Anterior-Posterior (AP) serta Posterior-Anterior (PA) dengan SSD 100 cm. Dalam penelitian ini didapatkan karakteristik kurva PDD yang sama antara fantom dengan komposisi air dan fantom dengan komposisi jaringan lunak yaitu dosis maksimum berada pada kedalaman 1,5-2,0 cm. Pada fantom nonhomogen yaitu jaringan lunak yang terdapat organ paru-paru mengalami peningkatan dosis dengan deviasi tertinggi sebesar 49,748 % dan keberadaan organ tulang belakang mengalami penurunan dosis dengan deviasi tertinggi sebesar 31,044 %. Rentang faktor koreksi akibat adanya organ paru-paru adalah 0,701-1,663 sedangkan akibat adanya organ tulang belakang adalah 0,586-0,983.

show abstract

“…Still, the healthy organs and tissues might be exposed to the unnecessary radiation dose when the radiation beam passes by or because of the scattered radiation. 1 The results of the pretreatment QA are used to predict the treatment outcome on the patient from the alterations in the dose-volume histograms for the contoured planning target volume (PTV) and organs at risk. 2 One of the reasons for this low sensitivity is that the phantom dimension used for the pre-treatment QA is totally different from the real patients.…”

Section: Introductionmentioning

confidence: 99%

Development and dosimetric evaluation of the IMRT prostate at outside-the-irradiated field in a heterogeneity male pelvis phantom

Jayamani

Osman

Tajuddin³

et al. 2022

J Radiother Pract

View full text Add to dashboard Cite

Background: Intensity-modulated radiation therapy (IMRT) treatment delivery requires pre-treatment patient-specific quality assurance (QA) for the dosimetry verification due to its complex multileaf-collimator movement. The prostate target close position between the bladder and rectum requires a tight margin during planning, and mistreatment would have a huge impact on the patient. A commercially available QA tool consists of a homogeneous medium and does not represent an exact photon interaction on the tumour and also on the nearby healthy organ. Objective: A heterogeneous male pelvis phantom was developed and investigated the efficiency of the treatment planning system (TPS) calculation on the off-axis region. Methods: Polymethyl methacrylate was used for the phantom housing, and the material closed to the bladder, rectum and prostate density was chosen to construct the organ models. The phantom was scanned and validated by the computed tomography number and density. An IMRT treatment was planned in the Monaco TPS, and a thermoluminescent dosimeter (TLD-100) was used to validate the point dosimetry. In addition, an EGSnrc Monte Carlo simulation was carried out to validate the phantom dosimetry. Results & Discussion: The dose measurement between TLD-100, TPS, and EGSnrc was compared and validated in the pelvis phantom. In the prostate region, the dose difference was within ± 5%, and the maximum dose difference outside-the-irradiated field was up to 20·07 % and 47·31 % in TPS and TLD-100, respectively. Meanwhile, the measured dose was lower than the calculated dose, and it was apparent for the dose outside-the-irradiated field. Conclusion: The developed heterogeneity male pelvis phantom was validated and verified to be an important QA device for validating radiation dosimetry in the pelvis region. The dose outside-the-irradiated field was underestimated by both TPS and TLD, respectively.

show abstract

Phantom dosimetry and cancer risks estimation undergoing 6 MV photon beam by an Elekta SL-25 linac

Cited by 8 publications

References 41 publications

Evaluation of neutron spectra and different fluences inside a radiotherapy room with a modified simple geometry of LINAC head

Evaluation of neutron spectra and different fluences inside a radiotherapy room with a modified simple geometry of LINAC head

Penentuan Faktor Koreksi Dosis Radiasi Sinar-X Linac 6 MV Pada Ketidakhomogenan Jaringan Tubuh dengan MCNPX

Development and dosimetric evaluation of the IMRT prostate at outside-the-irradiated field in a heterogeneity male pelvis phantom

Contact Info

Product

Resources

About