Evaluation and comparison of dose distributions for nasopharyngeal carcinoma patients treated by Jaws-Only IMRT technique and by 3D-CRT technique at Dong Nai General Hospital

The goal of radiation therapy is twofold: maximize the possibility of destroy malignant cells while minimizing the damage to healthy tissue. The introduction of intensity modulated radiation therapy (IMRT) technique has brought improvements in this goal. Multi-leaf collimator (MLC) is a useful tool for IMRT. However, the use of MLC is not necessarily mandatory. The Panther Treatment Planning System version 4.6, Prowess Inc., enables the implementation of this technique for accelerator without MLC (the socalled Jaws-Only IMRT technique). This study aims to evaluate the results of application of Jaws-only IMRT technique for nasopharyngeal carcinoma patients at Dong Nai general hospital. Twenty five patients were randomly selected for this study. For each patient, two plans were generated: 3D-CRT (Three-Dimensional Radiation Treatment) and JO-IMRT. The dose distributions, dose-volume histograms (DVH), conformity indexes (COIN), homogeneity indexes (HI) were used to compare between these two plans and find out the best plan. Pretreatment verifications were performed for all patients' plans using ion chamber (Farmer Type Chamber FC65-P, IBA), detector array (MapCHECK2, Sun Nuclear Corporation and Octavius 4D 1500, PTW). The average deviation between measurement and calculation for point dose was 2.3±1.1 %, within limit dose constraint. For detector array measurements, the gamma index with 3 % dose difference and 3 mm was higher than 95 %. The results showed that the JO-IMRT technique had generated better dose distribution in the target volume and reduced dose to healthy tissues compared to 3D-CRT.

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Verifying the accuracy of 3D-CRT dose distributions calculated by the Prowess Panther treatment planning system (TPS) with Monte Carlo (MC) simulation for head-and-neck (H&N) patients

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v3i2.518 ◽

2019 ◽

Vol 3 (2) ◽

pp. 90-99

Author(s):

Luong Thi Oanh ◽

Duong Thanh Tai ◽

Hoang Duc Tuan ◽

Truong Thi Hong Loan

Keyword(s):

Monte Carlo ◽

Head And Neck ◽

Treatment Planning ◽

Planning System ◽

Treatment Planning System ◽

Average Dose ◽

Monte Carlo Code ◽

Dose Distributions ◽

Mc Simulation ◽

3D Crt

The purpose of this study is to verify and compare the three Dimensional Conformal Radiation Therapy (3D-CRT) dose distributions calculated by the Prowess Panther treatment planning system (TPS) with Monte Carlo (MC) simulation for head-and-neck (H&N) patients. In this study, we used the EGSnrc Monte Carlo code which includes BEAMnrc and DOSXYZnrc programs. Firstly, the clinical 6 MV photon beams form Siemens Primus linear accelerator at Dong Nai General Hospital were simulated using the BEAMnrc. Secondly, the absorbed dose to patients treated by 3D-CRT was computed using the DOSXYZnrc. Finally, the simulated dose distributions were then compared with the ones calculated by the Fast Photon Effective algorithm on the TPS, using the relative dose error comparison and the gamma index using global methods implemented in PTW-VeriSoft with 3%/3 mm. There is a good agreement between the MC and TPS dose. The average gamma passing rates were 92.8% based on the 3%/3 mm. The average dose in the PTV agreed well between the TPS with 0.97% error. MC predict dose was higher than the mean dose to the parotid glands and spinal cord compared to TPS. We have implemented the EGSnrc-based Monte Carlo simulation to verify the 3D-CRT plans generated by Prowess Panther TPS. Our results showed that the TPS agreed with the one of MC.

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Result Analysis Of Treatment Planning System Between 3-Dimensional Conformal Radiation Therapy Technique And Intensity Modulated Radiation Therapy Technique In Nasopharyngeal Cancer Cases

SANITAS : Jurnal Teknologi dan Seni Kesehatan ◽

10.36525/sanitas.2017.5 ◽

2017 ◽

Vol 8 (1) ◽

pp. 29-34

Author(s):

Nursama Heru Apriantoro ◽

Bambang Sutrisno Wibowo ◽

Muhammad Irsal ◽

Prima Chintya Delsi Kasih

Keyword(s):

At Risk ◽

Radiation Therapy ◽

Organs At Risk ◽

Nasopharyngeal Cancer ◽

Target Volume ◽

Planning System ◽

Treatment Planning System ◽

Homogeneity Index ◽

Therapy Technique ◽

3D Crt

This study aims to analyze the difference in results between TPS 3D-CRT radiotherapy irradiation technique and IMRT radiotherapy irradiation technique in nasopharyngeal cancer cases based on the doses received by the target volume and organs at risk and results of isodosis curve which include the value of the index conformity and homogeneity index value. Type of this research is quantitative experimental method. As for the population was taken in 10 patients consisting of 5 male and 5 female patients with nasopharyngeal cancer who received radiation therapy with 3D-CRT irradiation technique and IMRT radiation technique. Meaningfully, the results shows that are no difference in the dose received by the target volume, the dose received by organs at risk, and the curve isodose on these two techniques, including index values of conformity and homogeneity index. In conclusion, IMRT radiotherapy irradiation technique for nasopharyngeal cancer is more prioritized than 3DCRT radiotherapy irradiation technique, as the radiotherapy principle can be achieved by using IMRT radiotherapy irradiation technique.

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Development and evaluation of a Perspex anthropomorphic head and neck phantom for three dimensional conformal radiation therapy (3D-CRT)

Journal of Radiotherapy in Practice ◽

10.1017/s1460396912000453 ◽

2013 ◽

Vol 12 (3) ◽

pp. 272-280 ◽

Cited By ~ 5

Author(s):

Khaldoon M. Radaideh ◽

Laila M. Matalqah ◽

A. A. Tajuddin ◽

W. I. Fabian Lee ◽

S. Bauk ◽

...

Keyword(s):

Radiation Therapy ◽

Head And Neck ◽

Organs At Risk ◽

Radiation Therapy Oncology Group ◽

Repeated Measurements ◽

Planning System ◽

Treatment Planning System ◽

Conformal Radiation Therapy ◽

Good Agreement ◽

3D Crt

AbstractPurposesTo design, construct and evaluate an anthropomorphic head and neck phantom for the dosimetric evaluation of 3D-conformal radiotherapy (3D-CRT) dose planning and delivery, for protocols developed by the Radiation Therapy Oncology Group (RTOG).Materials and methodsAn anthropomorphic head and neck phantom was designed and fabricated using Perspex material with delineated planning target volumes (PTVs) and organs at risk (OARs) regions. The phantom was imaged, planned and irradiated conformally by a 3D-CRT plan. Dosimetry within the phantom was assessed using thermoluminescent dosimeters (TLDs). The reproducibility of phantoms and TLD readings were checked by three repeated identical irradiations. Subsequent three clinical 3D-CRT plans for nasopharyngeal patients have been verified using the phantom. Measured doses from each dosimeter were compared with those acquired from the treatment planning system (TPS).ResultsPhantom's measured doses were reproducible with <3·5% standard deviation between the three TLDs’ repeated measurements. Verification of three head and neck 3D-CRT patients’ plans was implemented, and good agreement between measured values and those predicted by TPS was found. The percentage dose difference for TLD readings matched those corresponding to the calculated dose to within 4%.ConclusionThe good agreement between predicted and measured dose shows that the phantom is a useful and efficient tool for 3D-CRT technique dosimetric verification.

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HUMAN BODY ANTHROPOMORPHIC PHANTOM UTILISATION FOR THE COMPLEX TESTING OF RADIATION THERAPY TECHNOLOGICAL PROCESS

Doklady BGUIR ◽

10.35596/1729-7648-2019-126-8-133-140 ◽

2019 ◽

pp. 133-140

Author(s):

Y. I. Holdman ◽

E. V. Titovich

Keyword(s):

Radiation Therapy ◽

Technological Process ◽

Dose Distribution ◽

Radiation Treatment ◽

Planning System ◽

Treatment Planning System ◽

Therapy Process ◽

Anthropomorphic Phantom ◽

Strict Compliance ◽

End To End

The rapid development of technologies in the field of radiation therapy allows us nowadays to implement precision and most clinically effective radiotherapy techniques for oncological patient’s treatment to minimize the irradiation of normal tissues and improve local tumor control. An important condition for the implementation of the justification principle is strict compliance with the requirements for the accuracy of the dose delivered. High standards of radiation treatments performed are guaranteed by the development and strict compliance with the quality assurance (QA) program in the radiological department. However, due to QA programmes specificity, standardized and worldwide used tests included in the quality management system are trivial mechanical and dosimetric tests that can’t define the presence and magnitude of the integral error in the dose delivered to the patient, which arises as a result of the execution of sophisticated radiation therapy procedures, as well as to take into account the complexity of the implementation of modern methods of treatment. The aim of the work is to develop a method of complex dosimetric testing of the radiation therapy process (end-to-end audit), based on the utilization of the anthropomorphic phantom of the original design. The result of this work is the creation of the modified anthropomorphic phantom for precision dosimetric measurements, designed for testing the following technological procedures of the radiation therapy process: a computer tomography acquisition; a computerized treatment planning system, including a contouring module and dose distribution calculation algorithm; imaging systems integrated with radiation treatment units; dosimetric and technical characteristics of the radiation treatment units. Regular dosimetric testing of the radiation therapy technological process (end-to-end audit) with utilization of the technique proposed by the authors, based on the developed anthropomorphic phantom usage, will allow to assess the accuracy of dose distribution delivered to patients with all major malignant tumors localizations.

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HYBRID IMRT RADIATION TECHNIQUE COMPARISON WITH 3D-CRT FOR LEFT-SIDED WHOLE BREAST CANCER

10.46793/iccbi21.153p ◽

2021 ◽

Author(s):

Nina Pavlović ◽

◽

Tatjana Miladinović ◽

Darko Stojanović ◽

Aleksandar Miladinović ◽

...

Keyword(s):

Breast Cancer ◽

Radiation Therapy ◽

Target Volume ◽

Planning System ◽

Treatment Planning System ◽

Conformity Index ◽

Treatment Technique ◽

Dose Ratio ◽

Conformal Radiation Therapy ◽

3D Crt

To identify the best treatment technique for patients with left-sided breast cancer, we compared plans obtained with a hybrid intensity-modulated radiation therapy (hIMRT) and conventional three- dimensional conformal radiation therapy (3D-CRT). Dosimetric indices for PTVs and OARs were calculated. Also, the dose coverage, homogeneity index, conformity index of the target, and the dose volumes of critical structures were analyzed. A sample of seven patients who were selected randomly treated in University Clinical Center Kragujevac between 2019 and 2020 was selected for the study. Therapy plans for both techniques were made with an ECLIPSE treatment planning system for each patient based on the same images and contours. The hybrid IMRT technique consists of two static opposed tangential fields and four optimized IMRT fields (dose ratio 70:30). For 3D-CRT planning, one isocenter with half-beam blocked tangential fields with wedges was used. All treatment plans were generated with 6 MV photon beam. Hybrid IMRT plans compared to the 3D-CRT resulted in better dose delivered to 95% (D95) of the planning target volume (PTV) and better heterogeneity HI and conformity CI. Protection for critical organs such as the heart, lungs, and contralateral breast is slightly worse than those obtained by 3D-CRT.

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Validation of a Monte Carlo simulation for Microbeam Radiation Therapy on the Imaging and Medical Beamline at the Australian Synchrotron

Scientific Reports ◽

10.1038/s41598-019-53991-9 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Andrew Dipuglia ◽

Matthew Cameron ◽

Jeremy A. Davis ◽

Iwan M. Cornelius ◽

Andrew W. Stevenson ◽

...

Keyword(s):

Magnetic Field ◽

Monte Carlo ◽

Radiation Therapy ◽

Planning System ◽

Treatment Planning System ◽

Photon Flux ◽

X Rays ◽

Dose Distributions ◽

Microbeam Radiation Therapy ◽

Independent Verification

AbstractMicrobeam Radiation Therapy (MRT) is an emerging cancer treatment modality characterised by the use of high-intensity synchrotron-generated x-rays, spatially fractionated by a multi-slit collimator (MSC), to ablate target tumours. The implementation of an accurate treatment planning system, coupled with simulation tools that allow for independent verification of calculated dose distributions are required to ensure optimal treatment outcomes via reliable dose delivery. In this article we present data from the first Geant4 Monte Carlo radiation transport model of the Imaging and Medical Beamline at the Australian Synchrotron. We have developed the model for use as an independent verification tool for experiments in one of three MRT delivery rooms and therefore compare simulation results with equivalent experimental data. The normalised x-ray spectra produced by the Geant4 model and a previously validated analytical model, SPEC, showed very good agreement using wiggler magnetic field strengths of 2 and 3 T. However, the validity of absolute photon flux at the plane of the Phase Space File (PSF) for a fixed number of simulated electrons was unable to be established. This work shows a possible limitation of the G4SynchrotronRadiation process to model synchrotron radiation when using a variable magnetic field. To account for this limitation, experimentally derived normalisation factors for each wiggler field strength determined under reference conditions were implemented. Experimentally measured broadbeam and microbeam dose distributions within a Gammex RMI457 Solid Water® phantom were compared to simulated distributions generated by the Geant4 model. Simulated and measured broadbeam dose distributions agreed within 3% for all investigated configurations and measured depths. Agreement between the simulated and measured microbeam dose distributions agreed within 5% for all investigated configurations and measured depths.

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