scholarly journals Dosimetric evaluation of cobalt-60 teletherapy in advanced radiation oncology

2018 ◽  
Vol 18 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Manny Mathuthu ◽  
Nhlakanipho Wisdom Mdziniso ◽  
Yihunie Hibstie Asres
Keyword(s):  
Three Dimensional ◽  
Intensity Modulated Radiotherapy ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Solid State Drives ◽  
Water Phantom ◽  
Intensity Modulated ◽  
Gafchromic Ebt2 Film ◽  
Ebt2 Film

AbstractBackgroundRecent investigations demonstrate a strong potential for cobalt-60 (Co-60)-based teletherapy. The influence of the lower energy and penetration of a cobalt-60 beam compared with linear accelerator beams is negligible for intensity-modulated radiotherapy.PurposeThe aim of this research is to investigate source head fluence modulation in cobalt-60 teletherapy by using a three-dimensional (3D) physical compensator and secondary collimator jaw motion.Materials and methodsThe Oncentra treatment planning system was used to develop three hypothetical plans by secondary collimator jaw motion. A clinical MDS Nordion Equinox 80 cobalt-60 teletherapy unit was used to acquire conventional water phantom beam characteristics. Fluence modulation experiments were executed at 5·0 cm depth in a PTW universal intensity-modulated radiation therapy (IMRT) verification phantom using calibrated Gafchromic external beam therapy 2 (EBT2) and RTQA2-1010 film batches. Gafchromic EBT2 film was used to sample intensity maps generated by secondary collimator jaw motion, yet Gafchromic RTQA2-1010 film sampled maps from the 3D physical compensator. The solid-state drives used were 75·0 and 74·3 cm for the Gafchromic EBT2 and Gafchromic RTQA2-1010 film measurements.ResultsA 2D gamma index analysis was coded to compare EBT2 film measurements with Digital Imaging and Communications in Medicine data. This analysis was also used to verify film measurements versus Monte-Carlo simulations.ConclusionLateral beam profiles generated from water phantom measurements were used to establish source head fluence modulation on the film measurements. The source head fluence of a cobalt-60 teletherapy beam could be modulated by secondary collimator jaw motion and using a 3D physical compensator.

scholarly journals Application of AAPM TG119 to evaluate the Intensity-Modulated radiotherapy (JO-IMRT) plan on the Prowess Panther treatment planning system

2021 ◽  
Vol 5 (2) ◽  
pp. first
Author(s):  
Luong Thi Oanh ◽  
Tai Duong Thanh ◽  
Truong Thi Hong Loan
Keyword(s):  
American Association ◽  
Intensity Modulated Radiotherapy ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Test Cases ◽  
Imrt Plan ◽  
Intensity Modulated ◽  
Higher Doses ◽  
3D Crt

Intensity-modulated radiation therapy (IMRT), one of the modern radiotherapy techniques, is one of the most common treatments for cancer. IMRT technique can deliver higher doses to tumor and reduces the minimum dose to normal tissue. Because IMRT technique is more complex than the 3D-CRT techniques, IMRT is potential to underdose the tumor and overdose the nearby critical structures. The American Association of Physicists in Medicine (AAPM) published the TG119 report, including tests and the quality assurance QA process with the aim of to assessing the overall accuracy of planning and delivery of IMRT treatments. The purpose of this research was to study and apply TG119 to evaluate the Prowess Panther planning (TPS) system for JO-IMRT plan at Dong Nai General Hospital with 4 test cases of TG119. Four test cases of TG119 were carried out on the Prowess Panther planning (TPS) system the obtained results were compared to those results of other authors. The results showed that only the prostate plan met 100% of the dose requirements prescribed by TG119, the other plans were relatively appropriate and still met most of the requirements of TG119. From these results, we concluded that Prowess Panther was a good for JO-IMRT.

Quality assurance of intensity-modulated radiotherapy treatment planning: a dosimetric comparison

2018 ◽  
Vol 17 (4) ◽  
pp. 396-402 ◽  
Author(s):  
Saima Altaf ◽  
Khalid Iqbal ◽  
Muhammad Akram ◽  
Saeed A. Buzdar
Keyword(s):  
Quality Assurance ◽  
Radiation Therapy ◽  
Treatment Planning ◽  
Intensity Modulated Radiotherapy ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Imaging Device ◽  
Intensity Modulated ◽  
Passing Rates

AbstractAimThe purpose of this study was to analyse the comparison of intensity-modulated radiation therapy quality assurance (IMRT QA) using Gafchromic® EBT3 film, Electronic portal imaging device (EPID) and MapCHECK®2.BackgroundPretreatment authentication is the main apprehension in advanced radiation therapy treatment plans such as IMRT.Materials and methodsA total of 20 patients were planned on Eclipse treatment planning system using 6 and 15 MV separately.ResultsGamma index of EBT3 film results shows the following average passing rates: 97% for 6 MV and 96·6% for 15 MV using criteria of ±5% of 3 mm, ±3% of 3 mm and ±3% of 2 mm for brain. However, by using ±5% of 3 mm and ±3% of 3 mm criteria, the average passing rates were 95·4% on 6 MV and 95·2% on 15 MV for prostate. For EPID, the results show the average passing rates as 97·8% for 6 MV and 97·2% for 15 MV in for brain. In cases in which ±5% of 3 mm and ±3% of 3 mm were used, the average passing rates were 96·6% for 6 MVand 96·1% for 15 MV for prostate. MapCHECK®2 results show average passing rates of 96·4% for 6 and 96·2% for 15 MV, respectively, for brain using criteria of ±5% of 3 mm, ±3% of 3 mm and ±3% of 2 mm, whereas for ±5% of 3 mm and ±3% of 3 mm the average rates are 95·2% for 6 and 94·7% for 15 MV in prostate.ConclusionsThe EPID results are better than the other methods, and hence EPID can be used effectively for IMRT pretreatment verifications.

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 feasibility of an anthropomorphic three-dimensional PRESAGE® dosimeter for verification of single entry hybrid catheter accelerated partial breast brachytherapy

2018 ◽  
Vol 17 (4) ◽  
pp. 403-410 ◽  
Author(s):  
Khalid Iqbal ◽  
Geoffrey S. Ibbott ◽  
Ryan G. Lafratta ◽  
Kent A. Gifford ◽  
Muhammad Akram ◽  
...  
Keyword(s):  
Dose Distribution ◽  
Three Dimensional ◽  
Target Volume ◽  
Normal Breast ◽  
Planning System ◽  
Treatment Planning System ◽  
Skin Dose ◽  
Line Profiles ◽  
Gamma Analysis ◽  
Ebt2 Film

AbstractPurposeTo determine the feasibility of an anthropomorphic breast polyurethane-based three-dimensional (3D) dosimeter with cavity to measure dose distributions and skin dose for a commercial strut-based applicator strut-adjusted volume implant (SAVI™) 6–1.Materials and methodsAn anthropomorphic breast 3D dosimeter was created with a cavity to accommodate the SAVI™ strut-based device. 2 Gy was prescribed to the breast dosimeter having D95 to planning target volume evaluation (PTV_EVAL) while limiting 125% of the prescribed dose to the skin. Independent dose distribution verification was performed with GAFCHROMIC® EBT2 film. The dose distribution from the 3D dosimeter was compared to the distributions from commercial brachytherapy treatment planning system (TPS) and film. Point skin doses, line profiles and dose–volume histogram (DVHs) for the skin and PTV_EVAL were compared.ResultsThe maximum difference in skin dose for TPS and the 3D dosimeter was 4% whereas 41% between the TPS and EBT2 film. The maximum dose difference for line profiles between TPS, 3D dosimeter, and film was 4·1%. DVHs of skin and PTV_EVAL for TPS and 3D dosimeter differed by a maximum of 4% at 5 mm depth and skin differed by a maximum 1·5% between TPS and 3D dosimeter. The criterion for gamma analysis comparison was 92·5% at ±5%±3 mm criterion. The TPS demonstrated at least ±5% comparability in predicting dose to the skin, PTV_EVAL and normal breast tissue.Conclusions3D anthropomorphic polyurethane dosimeter with cavity gives comparable results to the TPS dose predictions and GAFCHROMIC® EBT2 film results in the context of HDR brachytherapy.

A dosimetric study of skin toxicity induced by 3-D conventional and intensity-modulated radiotherapy techniques using immobilization mask for treatment of head-and-neck (nasopharyngeal cancer) carcinoma: a prospective study

2018 ◽  
Vol 18 (02) ◽  
pp. 132-137
Author(s):  
Khaldoon Mahmoud Radaideh
Keyword(s):  
Nasopharyngeal Cancer ◽  
Intensity Modulated Radiotherapy ◽  
Skin Toxicity ◽  
Planning System ◽  
Treatment Planning System ◽  
Skin Dose ◽  
Average Percentage ◽  
Intensity Modulated ◽  
Acute Skin Toxicity ◽  
3D Crt

AbstractBackgroundThe purpose of this study was to investigate variations in surface dose, with and without the use of a Klarity® Mask (Orfit Industries America, Wijnegem, Belgium), using intensity-modulated radiotherapy (IMRT) and 3-D conventional radiotherapy (3D-CRT).Materials and methodsThermoluminescent dosimeters (TLDs) together with a phantom were used to examine acute skin toxicity during nasopharyngeal cancer treatment. These plans were sequentially delivered to the perspex phantom. Dosimeters were placed in five fixed regions over the skin. A Klarity mask for immobilization was used for covering the head, neck, and shoulder. The phantom was irradiated with and without a Klarity Mask, using IMRT and 3D-CRT, respectively.ResultsThe Klarity mask increased the skin doses for IMRT and 3D-CRT approximately 18·6% and 8·6%, respectively, from the prescribed maximum skin dose using treatment planning system (TPS). Additionally, the average percentage dose between IMRT and 3D-CRT received on the surface region was 30·9%, 24·9% with and without Klarity mask respectively. The average percentage dose received on surfaces from the total therapeutic dose 70 Gy, without using the mask was 7·7% and 5·7%, for IMRT and 3D-CRT, respectively. The TPS overestimated the skin dose for IMRT planning by 20%, and for 3D-CRT by 16·6%, compared with TLD measurements.ConclusionsThe results of this study revealed that IMRT significantly increases acute skin toxicity, compared with CRT. Although it is recommended to use Klarity mask as a sparing tool of normal tissue, it increases the risk of skin toxicity. In conclusion, skin dose is an important issue of focus during radiotherapy.

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 Comparison of three film analysis softwares using EBT2 and EBT3 films in radiotherapy

2020 ◽  
Vol 54 (4) ◽  
pp. 505-512
Author(s):  
Tamás Pócza ◽  
Zsuzsánna Zongor ◽  
Barbara Melles-Bencsik ◽  
Dóra Zita Tatai-Szabó ◽  
Tibor Major ◽  
...  
Keyword(s):  
Intensity Modulated Radiotherapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Patient Specific ◽  
Film Analysis ◽  
Intensity Modulated ◽  
Treatment Techniques ◽  
Passing Rate ◽  
Gamma Analysis ◽  
Software Programs

Abstract Introduction The purpose of the study was to compare the results of gamma value based film analysis according to the used type of self-developer film and software product. Material and methods The films were irradiated with different treatment techniques such as 3D conformal and intensity modulated radiotherapy with static and rotational delivery. Stereotactic plans with conformal and intensity modulated arc techniques, using coplanar and non-coplanar beam setup were also evaluated. The data of irradiated film were compared with the planned planar dose distribution exported from the treatment planning system. Three film analysis software programs were evaluated: PTW Mephysto (PTW), FilmQA Pro (FQP) and radiohromic.com(RC). Both EBT2 and EBT3 types of films were examined. The comparisons of dose distributions were performed with gamma analysis using 10% cut-off level. Results The results of the gamma analysis for larger fields were between 78.3% and 98.3%, 75.7% and 100%, 80.2% and 98.8% with PTW, FQP and RC, respectively. The results of evaluation in case of stereotactic measurements were 76.8%–99.2% for PTW, 95.7%–100% for FQP and 91.2%–99.9% for RC. Conclusions All the three software programs are suitable for calibrating and evaluating films, performing gamma analysis, and can be used for patient specific quality assurance measurements. There is no direct connection between gamma passing rate and absolute accuracy or software quality, it is just a feature of the software. The interpretation of own results has to be defined on an institutional level according to given workflow and preliminary results.

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