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Yadav N, Singh M, Mishra A, Mishra SP. Analysis of the gamma index using an indigenously developed anthropomorphic heterogeneous female pelvis (AHFP) phantom. J Cancer Res Ther 2024:01363817-990000000-00097. [PMID: 39207032 DOI: 10.4103/jcrt.jcrt_721_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/14/2023] [Indexed: 09/04/2024]
Abstract
BACKGROUND It is essential in modern radiotherapy treatment practices to evaluate the quality assurance (QA) of the treatment plan prior to the exclusion of patient from treatment. The typical suitable tools used for patient pretreatment QA are phantoms representing the human anatomy. An anthropomorphic heterogeneous female pelvic (AHFP) phantom has been developed to represent the real female pelvic structure. PURPOSE The objective of the current study is to assess the findings of relative dosimetry carried out utilizing an electronic portal imaging device (EPID) on the AHFP phantom fabricated. METHODS The planning target volume (PTV) was created on CT slices of an AHFP phantom to confirm the tool's ability to represent female pelvic anatomy and serve as a QA tool. In order to assess the dose received by healthy organs during radiotherapy, organs at risk such as the bladder and rectum were additionally drawn alongside the PTV. Rapid Arc and Intensity modulated radiation therapy (IMRT) were both used to create the treatment plan on treatment planning system, and the Anisotropic Analytical Algorithm Version 11.0.31 was used to calculate the dose. RESULTS The results obtained for the average gamma value in RapidArc plans are 0.26, 0.27, and 0.28 (g ≤1) and IMRT plans are 0.39, 0.40, and 0.46 (g ≤1) for target 1, target 2, and target 3, respectively. CONCLUSION According to the findings of the current study, the AHFP phantom was used to explore the potential of relative dosimetry using EPID as a QA tool, which was found to be suitable.
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Affiliation(s)
- Neha Yadav
- Department of Applied Physics, Amity School of Engineering and Technology, Amity University, Gwalior, Madhya Pradesh, India
| | - Manisha Singh
- Department of Applied Physics, Amity School of Engineering and Technology, Amity University, Gwalior, Madhya Pradesh, India
| | - Atul Mishra
- Department of Radiation Oncology, Uttar Pradesh University of Medical Sciences, Etawah, Uttar Pradesh, India
| | - Surendra Prasad Mishra
- Department of Radiation Oncology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
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Yadav N, Singh M, Mishra SP, Ansari S. Development of an Anthropomorphic Heterogeneous Female Pelvic Phantom and Its Comparison with a Homogeneous Phantom in Advance Radiation Therapy: Dosimetry Analysis. Med Sci (Basel) 2023; 11:59. [PMID: 37755163 PMCID: PMC10535781 DOI: 10.3390/medsci11030059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND Accurate dosimetry is crucial in radiotherapy to ensure optimal radiation dose delivery to the tumor while sparing healthy tissues. Traditional dosimetry techniques using homogeneous phantoms may not accurately represent the complex anatomical variations in cervical cancer patients, highlighting the need to compare dosimetry results obtained from different phantom models. PURPOSE The aim of this study is to design and evaluate an anthropomorphic heterogeneous female pelvic (AHFP) phantom for radiotherapy quality assurance in cervical cancer treatment. MATERIALS AND METHOD Thirty RapidArc plans designed for cervical cancer patients were exported to both the RW3 homogeneous phantom and the anthropomorphic heterogeneous pelvic phantom. Dose calculations were performed using the anisotropic analytic algorithm (AAA), and the plans were delivered using a linear accelerator (LA). Dose measurements were obtained using a 0.6 cc ion chamber. The percentage (%) variation between planned and measured doses was calculated and analyzed. Additionally, relative dosimetry was performed for various target locations using RapidArc and IMRT treatment techniques. The AHFP phantom demonstrated excellent agreement between measured and expected dose distributions, making it a reliable quality assurance tool in radiotherapy. RESULTS The results reveal that the percentage variation between planned and measured doses for all RapidArc quality assurance (QA) plans using the AHFP phantom is 10.67% (maximum value), 2.31% (minimum value), and 6.89% (average value), with a standard deviation (SD) of 2.565 (t = 3.21604, p = 0.001063). Also, for the percentage of variation between homogeneous and AHFP phantoms, the t-value is -11.17016 and the p-value is <0.00001. The result is thus significant at p < 0.05. We can see that the outcomes differ significantly due to the influence of heterogeneous media. Also, the average gamma values in RapidArc plans are 0.29, 0.32, and 0.35 (g ≤ 1) and IMRT plans are 0.45, 0.44, and 0.42 (g ≤ 1) for targets 1, 2, and 3, respectively. CONCLUSION The AHFP phantom results show more dose variability than homogenous phantom outcomes. Also, the AHFP phantom was found to be suitable for QA evaluation.
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Affiliation(s)
- Neha Yadav
- Department of Applied Physics, Amity School of Engineering & Technology, Amity University Madhya Pradesh, Maharajpura Dang, Gwalior 474005, India;
- Department of Medical Physics, Apollo Hospitals Bilaspur, Bilaspur 495006, India;
| | - Manisha Singh
- Department of Applied Physics, Amity School of Engineering & Technology, Amity University Madhya Pradesh, Maharajpura Dang, Gwalior 474005, India;
| | - Surendra P. Mishra
- Department of Radiation Oncology, Dr. Ram Manohar Lohia Institute of Medical Sciences, Lucknow 226010, India;
| | - Shahnawaz Ansari
- Department of Medical Physics, Apollo Hospitals Bilaspur, Bilaspur 495006, India;
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Yasui K, Omi Y, Shimomura A, Muramatsu R, Iwata H, Ogino H, Hayashi N. Dosimetric impact of systematic spot position errors in spot scanning proton therapy of head and neck tumor. J Cancer Res Ther 2023; 19:S0. [PMID: 37147973 DOI: 10.4103/jcrt.jcrt_389_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Purpose The spot position is an important beam parameter in the quality assurance of scanning proton therapy. In this study, we investigated dosimetric impact of systematic 15 spot position errors (SSPE) in spot scanning proton therapy using three types of optimization methods of head and neck tumor. Materials and Methods The planning simulation was performed with ± 2 mm model SSPE in the X and Y directions. Treatment plans were created using intensity-modulated proton therapy (IMPT) and single-field uniform dose (SFUD). IMPT plans were created by two optimization methods: with worst-case optimization (WCO-IMPT) and without (IMPT). For clinical target volume (CTV), D95%, D50%, and D2cc were used for analysis. For organs at risk (OAR), Dmean was used to analyze the brain, cochlea, and parotid, and Dmax was used to analyze brainsetem, chiasm, optic nerve, and cord. Results For CTV, the variation (1 standard deviation) of D95% was ± 0.88%, 0.97% and 0.97% to WCO-IMPT, IMPT, and SFUD plan. The variation of D50% and D2cc of CTV showed <0.5% variation in all plans. The dose variation due to SSPE was larger in OAR, and worst-case optimization reduced the dose variation, especially in Dmax. The analysis results showed that SSPE has little impact on SFUD. Conclusions We clarified the impact of SSPE on dose distribution for three optimization methods. SFUD was shown to be a robust treatment plan for OARs, and the WCO can be used to increase robustness to SSPE in IMPT.
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Yasui K, Muramatsu R, Kamomae T, Toshito T, Kawabata F, Hayashi N. Evaluating the usefulness of the direct density reconstruction algorithm for intensity modulated and passively scattered proton therapy: Validation using an anthropomorphic phantom. Phys Med 2021; 92:95-101. [PMID: 34891108 DOI: 10.1016/j.ejmp.2021.11.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 11/14/2021] [Accepted: 11/20/2021] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Accurate calculation of the proton beam range inside a patient is an important topic in proton therapy. In recent times, a computed tomography (CT) image reconstruction algorithm was developed for treatment planning to reduce the impact of the variation of the CT number with changes in imaging conditions. In this study, we investigated the usefulness of this new reconstruction algorithm (DirectDensity™: DD) in proton therapy based on its comparison with filtered back projection (FBP). METHODS We evaluated the effects of variations in the X-ray tube potential and target size on the FBP- and DD-image values and investigated the usefulness of the DD algorithm based on the range variations and dosimetric quantity variations. RESULTS For X-ray tube potential variations, the range variation in the case of FBP was up to 12.5 mm (20.8%), whereas that of DD was up to 3.3 mm (5.6%). Meanwhile, for target size variations, the range variation in the case of FBP was up to 2.2 mm (2.5%), whereas that of DD was up to 0.9 mm (1.4%). Moreover, the variations observed in the case of DD were smaller than those of FBP for all dosimetric quantities. CONCLUSION The dose distributions obtained using DD were more robust against variations in the CT imaging conditions (X-ray tube potential and target size) than those obtained using FBP, and the range variations were often less than the dose calculation grid (2 mm). Therefore, the DD algorithm is effective in a robust workflow and reduces uncertainty in range calculations.
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Affiliation(s)
- Keisuke Yasui
- Fujita Health University, Faculty of Radiological Technology, School of Health Sciences, 1-98 Dengakugakubo Kutsukake-cho, Toyoake, Aichi 470-1192, Japan.
| | - Rie Muramatsu
- Nagoya Proton Therapy Center, Nagoya City University West Medical Center, 1-1-1 Hirate-cho Kita-ku, Nagoya, Aichi 462-8508, Japan
| | - Takeshi Kamomae
- Nagoya University Hospital, 65 Tsuruma-cho Shouwa-ku, Nagoya, Aichi 466-8560, Japan
| | - Toshiyuki Toshito
- Nagoya Proton Therapy Center, Nagoya City University West Medical Center, 1-1-1 Hirate-cho Kita-ku, Nagoya, Aichi 462-8508, Japan
| | - Fumitaka Kawabata
- Nagoya University Hospital, 65 Tsuruma-cho Shouwa-ku, Nagoya, Aichi 466-8560, Japan
| | - Naoki Hayashi
- Fujita Health University, Faculty of Radiological Technology, School of Health Sciences, 1-98 Dengakugakubo Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
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Nagata J, Yasui K, Omachi C, Toshiyuki T, Shimizu H, Aoyama T, Hayashi N. Evaluation of radiophotoluminescent glass dosimeter response for therapeutic spot scanning proton beam: suggestion of linear energy transfer-based correction. J Appl Clin Med Phys 2021; 22:265-272. [PMID: 34339583 PMCID: PMC8364267 DOI: 10.1002/acm2.13378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 12/17/2022] Open
Abstract
A radiophotoluminescent glass dosimeter (RGD) is used for a postal audit of a photon beam because of its various excellent characteristics. However, it has not been used for scanning proton beams because its response characteristics have not been verified. In this study, the response of RGD to scanning protons was investigated to develop a dosimetry protocol using the linear energy transfer (LET)‐based correction factor. The responses of RGD to four maximum‐range‐energy‐pattern proton beams were verified by comparing it with ionization chamber (IC) dosimetry. The LET at each measurement depth was calculated via Monte Carlo (MC) simulation. The LET correction factor (kLETRGD) was the ratio between the uncorrected RGD dose (DrawRGD) and the IC dose at each measurement depth. kLETRGD can be represented as a function of LET using the following equation: kLETRGDLET=‐0.035LET+1.090. DrawRGD showed a linear under‐response with increasing LET, and the maximum dose difference between the IC dose and DrawRGD was 15.2% at an LET of 6.07 keV/μm. The LET‐based correction dose (DLETRGD) conformed within 3.6% of the IC dose. The mean dose difference (±SD) of DrawRGD and DLETRGD was –2.5 ± 6.9% and 0.0 ± 1.6%, respectively. To achieve accurate dose verification for scanning proton beams using RGD, we derived a linear regression equation based on LET. The results show that with appropriate LET correction, RGD can be used for dose verification of scanning proton beams.
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Affiliation(s)
- Junya Nagata
- Graduate School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Keisuke Yasui
- Faculty of Radiological Technology, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Chihiro Omachi
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Toshito Toshiyuki
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan
| | - Takahiro Aoyama
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan
| | - Naoki Hayashi
- Faculty of Radiological Technology, School of Health Sciences, Fujita Health University, Toyoake, Japan
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Omi Y, Yasui K, Shimomura A, Muramatsu R, Iwata H, Ogino H, Furukawa A, Hayashi N. Dosimetric effects of quality assurance-related setup errors in passive proton therapy for prostate cancer with and without a hydrogel spacer. Radiol Phys Technol 2021; 14:328-335. [PMID: 34313911 DOI: 10.1007/s12194-021-00632-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 07/20/2021] [Accepted: 07/21/2021] [Indexed: 11/30/2022]
Abstract
The purpose of this study was to evaluate the effect of quality assurance (QA)-related setup errors in passive proton therapy for prostate cancer with and without a hydrogel spacer. We used 20 typical computed tomography (CT) images of prostate cancer: 10 patients with and 10 patients without spacers. The following 12 model errors were assumed: output error ± 2%, range error ± 1 mm, setup error ± 1 mm for three directions, and multileaf collimator (MLC) position error ± 1 mm. We created verification plans with model errors and compared the prostate-rectal (PR) distance and dose indices with and without the spacer. The mean PR distance at the isocenter was 1.1 ± 1.3 mm without the spacer and 12.9 ± 2.9 mm with the spacer (P < 0.001). The mean rectum V53.5 GyE, V50 GyE, and V34.5 GyE in the original plan were 2.3%, 4.1%, and 12.1% without the spacer and 0.1%, 0.4%, and 3.3% with the spacer (P = 0.0011, < 0.001, and < 0.001). The effects of the range and lateral setup errors were small; however, the effects of the vertical/long setup and MLC error were significant in the cases without the spacer. The means of the maximum absolute change from original plans across all scenarios in the rectum V53.5 GyE, V50 GyE, and V34.5 GyE were 1.3%, 1.5%, and 2.3% without the spacer, and 0.2%, 0.4%, and 1.3% with the spacer (P < 0.001, < 0.001, and = 0.0019). This study indicated that spacer injections were also effective in reducing the change in the rectal dose due to setup errors.
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Affiliation(s)
- Yuta Omi
- Anjo Kosei Hospital, 28 Higashi-Hirokute, Anjo-cho, Anjo, Aichi, 446-8602, Japan
| | - Keisuke Yasui
- Faculty of Radiological Technology, School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
| | - Akira Shimomura
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya, Aichi, 462-8508, Japan
| | - Rie Muramatsu
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya, Aichi, 462-8508, Japan
| | - Hiromitsu Iwata
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya, Aichi, 462-8508, Japan
| | - Hiroyuki Ogino
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, 1-1-1, Hirate-cho, Kita-ku, Nagoya, Aichi, 462-8508, Japan
| | - Akari Furukawa
- Faculty of Radiological Technology, School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Naoki Hayashi
- Faculty of Radiological Technology, School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
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Yasui K, Omachi C, Nagata J, Toshito T, Shimizu H, Aoyama T, Hayashi N. Dosimetric response of a glass dosimeter in proton beams: LET-dependence and correction factor. Phys Med 2021; 81:147-154. [PMID: 33461027 DOI: 10.1016/j.ejmp.2020.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 11/09/2020] [Accepted: 12/01/2020] [Indexed: 10/22/2022] Open
Abstract
A radiophotoluminescent glass dosimeter (RGD) is widely used in postal audit system for photon beams in Japan. However, proton dosimetry in RGDs is scarcely used owing to a lack of clarity in their response to beam quality. In this study, we investigated RGD response to beam quality for establishing a suitable linear energy transfer (LET)-corrected dosimetry protocol in a therapeutic proton beam. The RGD response was compared with ionization chamber measurement for a 100-225 MeV passive proton beam. LET of the measurement points was calculated by the Monte Carlo method. An LET-correction factor, defined as a ratio between the non-corrected RGD dose and ionization chamber dose, of 1.226×(LET)-0.171 was derived for the RGD response. The magnitude of the LET-dependence of RGD increased with LET; for an LET of 8.2 keV/μm, the RGD under-response was up to 16%. The coefficient of determination, mean difference ± SD of non-corrected RGD dose, residual range-corrected RGD dose, and LET-corrected RGD dose to the ionization chamber are 0.923, 3.7 ± 4.2%, -2.4 ± 7.5%, and 0.04 ± 2.1%, respectively. The LET-corrected RGD dose was within 5% of the corresponding ionization chamber dose at all energies until 200 MeV, where it was 5.3% lower than the ionization chamber dose. A corrected LET-dependence of RGD using a correction factor based on a power function of LET and precise dosimetric verification close to the maximum LET were realized here. We further confirmed establishment of an accurate postal audit under various irradiation conditions.
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Affiliation(s)
- Keisuke Yasui
- Fujita Health University, Faculty of Radiological Technology, School of Health Sciences, Japan.
| | - Chihiro Omachi
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Japan
| | - Junya Nagata
- Graduate School of Health Sciences, Fujita Health University, Japan
| | - Toshiyuki Toshito
- Nagoya Proton Therapy Center, Nagoya City West Medical Center, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Japan
| | - Takahiro Aoyama
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Japan
| | - Naoki Hayashi
- Fujita Health University, Faculty of Radiological Technology, School of Health Sciences, Japan
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