Comparison of Gamma Analyses with using Different Dosimetric Systems for Pre-Treatment Verification of Intensity Modulated Radiation Therapy

2020 ◽  
Author(s):  
Gokcen Inan ◽  
Osman Vefa Gul
Keyword(s):  
Quality Control ◽  
Radiation Therapy ◽  
Linear Accelerator ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Array Detector ◽  
Intensity Modulated ◽  
Treatment Plans ◽  
2D Array

Purpose: The evaluation of the agreement between calculated and measured dose plays an essential role in the quality assurance (QA) procedures of intensity-modulated radiation therapy (IMRT). This study aimed to compare gamma analysis using Portal Dosimetry (PD), Epiqa, and 2D array detector for dose verification of radiotherapy treatment plans. Materials and Methods: Five fields step-and-shoot IMRT plan was used to performed for 20 prostate IMRT patients using the dual-energy DHX linear accelerator (Varian Medical System, Palo Alto, CA, USA). The treatment plans were created using Varian DHX Eclipse treatment planning system (TPS) version 15.1. All measurements were performed by aS500 EPID integrated into Varian DHX linear accelerator and 2D array detector. The dose distribution was evaluated with gamma area histograms (GAHs) generated using different γ criteria (1%/1 mm, 2%/2 mm 3%/2 mm and 3%/3 mm) for dose agreement and distance to agreement parameters. Statistical analyses were evaluated by using Mann Whitney Test and Kruskal-Wallis Test, and p-value of p <0.01 was considered to be significant. Results: The average pass rate for 20 IMRT plans was above 95% for all devices with 2%/2 mm, 3%/2 mm and 3%/3 mm. The mean and standard deviation passing rates (γ ≤1) were found to be 99.80±0.19, 99.35±0.34 and 97.53±0.71 for PD, Epiqa and 2D array respectively. All IMRT plans passed 2%/2 mm, 3%/2 mm and 3%/3 mm gamma by more than 95% of three dosimetric systems. They are all in good agreement with the literature. Conclusion: All three devices are acceptable for quality control of IMRT. Due to the simplicity and fast evaluation process, PD can be preferred for quality control.

scholarly journals PENATALAKSAAN RADIOTERAPI KANKER OVARIUM DENGAN TEKNIK IMRT DI RUMAH SAKIT X

2021 ◽  
Vol 11 (2) ◽  
pp. 22-26
Author(s):  
Diah Novita ◽  
Nursama Heru Apriantoro
Keyword(s):  
Radiation Therapy ◽  
Ct Scan ◽  
Linear Accelerator ◽  
Bone Scan ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Electronic Portal Imaging Device ◽  
Imaging Device ◽  
Intensity Modulated

ABSTRAK Penelitian ini di latar belakangi oleh penyakit keganasan yaitu kanker ovarium yang merupakan kanker ginekologis terbanyak kedua yang diderita dan seringkali baru ditemukan ketika sudah stadium lanjut. Tujuan penelitian ini adalah untuk mengetahui dan mendeskripsikan prosedur penyinaran radioterapi menggunakan teknik IMRT (Intensity Modulated Radiation Therapy) di Instalasi Radioterapi Rumah Sakit X yang merupakan salah satu modalitas pengobatan kanker ovarium. Metode yang digunakan pada penelitian ini adalah kualitatif deskriptif dengan menggunakan satu sampel primer pada kasus kanker ovarium yang menggunakan teknik IMRT (Intensity Modulated Radiation Therapy), sampel ini diambil dari seluruh populasi kanker ovarium di Instalasi Radioterapi Rumah Sakit X. Instrumen penelitian yang digunakan berupa studi kepustakaan, observasi langsung, wawancara serta dokumentasi. Penelitian ini dilakukan pada bulan Mei 2021 di Instalasi Radioterapi Rumah Sakit X. Hasil yang dapat disimpulkan pada penelitian ini adalah prosedur penatalaksanaan radioterapi untuk kasus kanker ovarium menggunakan teknik IMRT (Intensity Modulated Radiation Therapy) di Instalasi Radioterapi Rumah Sakit X meliputi beberapa prosedur yaitu: administrasi dengan membawa dokumen penunjang seperti hasil CT Scan/MRI/Bone Scan/USG, kemudian pasien melakukan konsultasi dengan dokter onkologi radiasi, melakukan persiapan-persiapan pasien, persiapan alat dan bahan, scanning di CT Simulator, proses perencanaan radiasi yang dilakukan di Treatment Planning System (TPS), proses verifikasi menggunakan alat verifikasi yaitu Electronic Portal Imaging Device (EPID) dan yang terakhir adalah penyinaran radiasi di ruang penyinaran dengan menggunakan pesawat radioterapi Linear Accelerator (LINAC) Elekta Synergy Platform.

scholarly journals Dosimetric Studies of Mixed Energy Intensity Modulated Radiation Therapy for Prostate Cancer Treatments

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
K. Abdul Haneefa ◽  
K. K. Shakir ◽  
A. Siddhartha ◽  
T. Siji Cyriac ◽  
M. M. Musthafa ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radiation Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
High Energy ◽  
Photon Beam ◽  
Planning System ◽  
Treatment Planning System ◽  
Intensity Modulated ◽  
Mixed Beam ◽  
Mixed Field

Dosimetric studies of mixed field photon beam intensity modulated radiation therapy (IMRT) for prostate cancer using pencil beam (PB) and collapsed cone convolution (CCC) algorithms using Oncentra MasterPlan treatment planning system (v. 4.3) are investigated in this study. Three different plans were generated using 6 MV, 15 MV, and mixed beam (both 6 and 15 MV). Fifteen patients with two sets of plans were generated: one by using PB and the other by using CCC for the same planning parameters and constraints except the beam energy. For each patient’s plan of high energy photons, one set of photoneutron measurements using solid state neutron track detector (SSNTD) was taken for this study. Mean percentage of V66 Gy in the rectum is 18.55±2.8, 14.58±2.1, and 16.77±4.7 for 6 MV, 15 MV, and mixed-energy plans, respectively. Mean percentage of V66 Gy in bladder is 16.54±2.1, 17.42±2.1, and 16.94±41.9 for 6 MV, 15 MV, and mixed-energy plans, respectively. Mixed fields neutron contribution at the beam entrance surface is 45.62% less than at 15 MV photon beam. Our result shows that, with negligible neutron contributions, mixed field IMRT has considerable dosimetric advantage.

Dosimetric comparison of intensity-modulated radiation therapy (IMRT) and field-in-field (FIF) technique for head-and-neck cancer

2020 ◽  
pp. 1-6
Author(s):  
Nguyen Thi Lan ◽  
Hoang Dai Viet ◽  
Duong Thanh Tai ◽  
James C. L. Chow
Keyword(s):  
Radiation Therapy ◽  
Head And Neck Cancer ◽  
Head And Neck ◽  
Neck Cancer ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Intensity Modulated ◽  
Target Volumes

Abstract Purpose: This study compared the plan dosimetry between the intensity-modulated radiation therapy (IMRT) and field-in-field (FIF) technique for head-and-neck cancer using the Elekta Monaco treatment planning system (TPS). Materials and methods: A total of 20 head-and-neck cancer patients were selected in this study. IMRT and FIF plans for the patients were created on the Monaco TPS (ver. 5.11.02) using the 6-MV photon beam generated by the Elekta Synergy linear accelerator. The dose–volume histograms, maximum doses, minimum doses, mean doses of the target volumes and organs-at-risk (OARs), conformity index (CI), homogeneity index (HI) and monitor units (MUs) were determined for each IMRT and FIF plan. All IMRT plans passed the patient-specific quality assurance tests from the 2D diode array measurements (MatriXX Evolution System, IBA Dosimetry, Germany). Results: The results showed that the dose distribution to the target volumes of IMRT plans was better than FIF plans, while the dose (mean or max dose) to the OAR was significantly lower than FIF plan, respectively. IMRT and FIF resulted in planning target volume coverage with mean dose of 71·32 ± 0·76 and 73·12 ± 0·62 Gy, respectively, and HI values of 0·08 ± 0·01 (IMRT) and 0·19 ± 0·06 (FIF). The CI for IMRT was 0·98 ± 0·01 and FIF was 0·97 ± 0·01. For the spinal cord tolerance (maximum dose < 45 Gy), IMRT resulted in 39·85 ± 2·04 Gy compared to 41·37 ± 2·42 Gy for FIF. In addition, the mean doses to the parotid grand were 27·27 ± 7·48 and 48·68 ± 1·62 Gy for the IMRT and FIF plans, respectively. Significantly more MUs were required in IMRT plans than FIF plans (on average, 846 ± 100 MU in IMRT and 467 ± 41 MU in FIF). Conclusions: It is concluded that the IMRT technique could provide a better plan dosimetry than the FIF technique for head-and-neck patients.

scholarly journals A comparison of the quality assurance of four dosimetric tools for intensity modulated radiation therapy

2015 ◽  
Vol 49 (3) ◽  
pp. 307-313 ◽  
Author(s):  
Jaeman Son ◽  
Taesung Baek ◽  
Boram Lee ◽  
Dongho Shin ◽  
Sung Yong Park ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Radiation Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Intensity Modulated ◽  
Passing Rates ◽  
Passing Rate ◽  
Patient Specific Qa

Abstract Background. This study was designed to compare the quality assurance (QA) results of four dosimetric tools used for intensity modulated radiation therapy (IMRT) and to suggest universal criteria for the passing rate in QA, irrespective of the dosimetric tool used. Materials and methods. Thirty fields of IMRT plans from five patients were selected, followed by irradiation onto radiochromic film, a diode array (Mapcheck), an ion chamber array (MatriXX) and an electronic portal imaging device (EPID) for patient-specific QA. The measured doses from the four dosimetric tools were compared with the dose calculated by the treatment planning system. The passing rates of the four dosimetric tools were calculated using the gamma index method, using as criteria a dose difference of 3% and a distance-to-agreement of 3 mm. Results. The QA results based on Mapcheck, MatriXX and EPID showed good agreement, with average passing rates of 99.61%, 99.04% and 99.29%, respectively. However, the average passing rate based on film measurement was significantly lower, 95.88%. The average uncertainty (1 standard deviation) of passing rates for 6 intensity modulated fields was around 0.31 for film measurement, larger than those of the other three dosimetric tools. Conclusions. QA results and consistencies depend on the choice of dosimetric tool. Universal passing rates should depend on the normalization or inter-comparisons of dosimetric tools if more than one dosimetric tool is used for patient specific QA.

scholarly journals Dosimetric effects of supine immobilization devices on the skin in intensity-modulated radiation therapy for breast cancer: a retrospective study

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ran Lv ◽  
Guangyi Yang ◽  
Yongzhi Huang ◽  
Yanhong Wang
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Retrospective Study ◽  
Intensity Modulated Radiation Therapy ◽  
Radical Mastectomy ◽  
Planning System ◽  
Treatment Planning System ◽  
Skin Dose ◽  
Intensity Modulated ◽  
Left And Right

Abstract Background The dose perturbation effect of immobilization devices is often overlooked in intensity-modulated radiation therapy (IMRT) for breast cancer (BC). This retrospective study assessed the dosimetric effects of supine immobilization devices on the skin using a commercial treatment planning system. Methods Forty women with BC were divided into four groups according to the type of primary surgery: groups A and B included patients with left and right BC, respectively, who received 50 Gy radiotherapy in 25 fractions after radical mastectomy, while groups C and D included patients with left and right BC, respectively, who received breast-conservation surgery (BCS) and 40.05 Gy in 15 fractions as well as a tumor bed simultaneous integrated boost to 45 Gy. A 0.2-cm thick skin contour and two sets of body contours were outlined for each patient. Dose calculations were conducted for the two sets of contours using the same plan. The dose differences were assessed by comparing the dose-volume histogram parameter results and by plan subtraction. Results The supine immobilization devices for BC resulted in significantly increased skin doses, which may ultimately lead to skin toxicity. The mean dose increased by approximately 0.5 and 0.45 Gy in groups A and B after radical mastectomy and by 2.7 and 3.25 Gy in groups C and D after BCS; in groups A–D, the percentages of total normal skin volume receiving equal to or greater than 5 Gy (V5) increased by 0.54, 1.15, 2.67, and 1.94%, respectively, while the V10 increased by 1.27, 1.83, 1.36, and 2.88%; the V20 by 0.85, 1.87, 2.76, and 4.86%; the V30 by 1.3, 1.24, 10.58, and 11.91%; and the V40 by 1.29, 0.65, 10, and 10.51%. The dose encompassing the planning target volume and other organs at risk, showed little distinction between IMRT plans without and with consideration of immobilization devices. Conclusions The supine immobilization devices significantly increased the dose to the skin, especially for patients with BCS. Thus, immobilization devices should be included in the external contour to account for dose attenuation and skin dose increment. Trial registration This study does not report on interventions in human health care.

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