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Tuntipumiamorn L, Tangboonduangjit P, Sanghangthum T, Rangseevijitprapa R, Khamfongkhruea C, Niyomthai T, Vuttiprasertpong B, Supanant S, Chatchaipaiboon N, Iampongpaiboon P, Nakkrasae P, Jaikuna T. Multi-institutional evaluation using the end-to-end test for implementation of dynamic techniques of radiation therapy in Thailand. Rep Pract Oncol Radiother 2019; 24:124-132. [PMID: 30532660 PMCID: PMC6265520 DOI: 10.1016/j.rpor.2018.11.005] [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: 07/10/2018] [Revised: 09/23/2018] [Accepted: 11/10/2018] [Indexed: 10/27/2022] Open
Abstract
AIM In this study, an accuracy survey of intensity-modulated radiation therapy (IMRT) and volumetric arc radiation therapy (VMAT) implementation in radiotherapy centers in Thailand was conducted. BACKGROUND It is well recognized that there is a need for radiotherapy centers to evaluate the accuracy levels of their current practices, and use the related information to identify opportunities for future development. MATERIALS AND METHODS An end-to-end test using a CIRS thorax phantom was carried out at 8 participating centers. Based on each center's protocol for simulation and planning, linac-based IMRT or VMAT plans were generated following the IAEA (CRP E24017) guidelines. Point doses in the region of PTVs and OARs were obtained from 5 ionization chamber readings and the dose distribution from the radiochromic films. The global gamma indices of the measurement doses and the treatment planning system calculation doses were compared. RESULTS The large majority of the RT centers (6/8) fulfilled the dosimetric goals, with the measured and calculated doses at the specification points agreeing within ±3% for PTV and ±5% for OARS. At 2 centers, TPS underestimated the lung doses by about 6% and spinal cord doses by 8%. The mean percentage gamma pass rates for the 8 centers were 98.29 ± 0.67% (for the 3%/3 mm criterion) and 96.72 ± 0.84% (for the 2%/2 mm criterion). CONCLUSIONS The 8 participating RT centers achieved a satisfactory quality level of IMRT/VMAT clinical implementation.
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Affiliation(s)
- Lalida Tuntipumiamorn
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Puangpen Tangboonduangjit
- Department of Diagnostic and Therapeutic Radiology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Taweap Sanghangthum
- Division of Radiation Oncology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Rattapol Rangseevijitprapa
- Division of Radiation Oncology, Faculty of Medicine, Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand
| | | | | | | | | | | | - Porntip Iampongpaiboon
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pitchayut Nakkrasae
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Tanwiwat Jaikuna
- Division of Radiation Oncology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
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Kim JI, Chung JB, Song JY, Kim SK, Choi Y, Choi CH, Choi WH, Cho B, Kim JS, Kim SJ, Ye SJ. Confidence limits for patient-specific IMRT dose QA: a multi-institutional study in Korea. J Appl Clin Med Phys 2016; 17:62-69. [PMID: 26894332 PMCID: PMC5690221 DOI: 10.1120/jacmp.v17i1.5607] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 09/26/2015] [Accepted: 09/23/2015] [Indexed: 11/23/2022] Open
Abstract
This study aims to investigate tolerance levels for patient-specific IMRT dose QA (DQA) using the confidence limits (CL) determined by a multi-institutional study. Eleven institutions participated in the multi-institutional study in Korea. A total of 155 DQA measurements, consisting of point-dose differences (high- and low-dose regions) and gamma passing rates (composite and per-field) for IMRT patients with brain, head and neck (H&N), abdomen, and prostate cancers were examined. The Shapiro-Wilk test was used to evaluate the normality of data grouped by the treatment sites and the DQA methods. The confidence limit coefficients in cases of the normal distribution, and the two-sided Student's t-distribution were applied to determine the confidence limits for the grouped data. The Spearman's test was applied to assess the sensitivity of DQA results within the limited groups. The differences in CLs between the two confidence coefficients based on the normal and t-distributions were negligible for the point-dose data and the gamma passing rates with 3%/3 mm criteria. However, with 2%/2 mm criteria, the difference in CLs were 1.6% and 2.2% for composite and per-field measurements, respectively. This resulted from the large standard deviation and the more sensitive criteria of 2%/2 mm. There was no noticeable correlation among the different QA methods. Our multi-institutional study suggested that the CL was not a suitable metric for defining the tolerance level when the statistics of the sample group did not follow the normality and had a large standard deviation.
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Chung JB, Kim JS, Eom KY, Kim IA, Kang SW, Lee JW, Kim JY, Suh TS. Comparison of VMAT-SABR treatment plans with flattening filter (FF) and flattening filter-free (FFF) beam for localized prostate cancer. J Appl Clin Med Phys 2015; 16:302–313. [PMID: 26699585 PMCID: PMC5691012 DOI: 10.1120/jacmp.v16i6.5728] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/04/2015] [Accepted: 07/27/2015] [Indexed: 11/25/2022] Open
Abstract
The purpose of this study is to investigate the feasibility of using a flattening filter-free (FFF) beam with an endorectal balloon for stereotactic ablative body radiotherapy (SABR) of clinically localized prostate cancer. We assessed plans of SABR with volumetric-modulated arc therapy (VMAT) that used a flattening filter (FF) beam and an FFF beam and compared the verification results of dosimetric quality assurance for all pretreatment plans. A total of 20 patients with prostate cancer were enrolled in the study. SABR plans using VMAT with two full arcs were optimized in the Eclipse treatment planning system. All plans prescribed 42.7 Gy in 7 fractions of 6.1 Gy each. Four SABR plans were computed for each patient: two with FF beams and two with FFF beams of 6 and 10 MV. For all plans, the cumulative dose-volume histograms (DVHs) for the target volumes and organs at risk (OARs) were recorded and compared. Pretreatment quality assurance (QA) was performed using the I'mRT MatriXX system and radiochromic EBT3 film to verify treatment delivery, and gamma analysis was used to quantify the agreement between calculations and measurements. In addition, total monitor units (MUs) and delivery time were investigated as technical parameters of delivery. All four plans achieved adequate dose conformity to the target volumes and had comparable dosimetric data. The DVHs of all four plans for each patient were very similar. All plans were highly conformal with CI < 1.05 and CN > 0.90, and the doses were homogeneous (HI = 0.08-0.15). Sparing for the bladder and rectum was slightly better with the 10 MV FF and FFF plans than with the 6 MV FF and FFF plans, but the difference was negligible. However, there was no significant difference in sparing for the other OARs. The mean agreement with the 3%/3 mm criterion was higher than 97% for verifying all plans. For the 2%/2 mm criterion, the corresponding agreement values were more than 90%, which showed that the plans were acceptable. The mean MUs and delivery time used were 1701 ± 101 and 3.02 ± 0.17 min for 6 MV FF, 1870 ± 116 and 2.01 ± 0.01 min for 6 MV FFF, 1471 ± 86 and 2.68 ± 0.14 min for 10 MV FF, and 1619 ± 101 and 2.00 ± 0.00 min for 10MV FFF, respectively. In the current study, the dose distributions of the prostate SABR plans using 6 and 10 MV FFF beams were similar to those using 6 and 10 MV FF beams. However, this study confirmed that SABR treatment using an FFF beam had an advantage with respect to delivery time. In addition, all pretreatment plans were verified as acceptable and their results were comparable. Therefore, the results of this study suggest that the use of an FFF beam for prostate SABR is a feasible and efficient technique, if carefully applied.
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Kim HJ, Kim S, Park YK, Kim JI, Park JM, Ye SJ. Multileaf collimator tongue-and-groove effect on depth and off-axis doses: A comparison of treatment planning data with measurements and Monte Carlo calculations. Med Dosim 2015; 40:271-8. [DOI: 10.1016/j.meddos.2015.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 11/03/2014] [Accepted: 01/22/2015] [Indexed: 10/23/2022]
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Min S, Choi YE, Kwak J, Cho B. Practical approach for pretreatment verification of IMRT with flattening filter free(FFF) beams using Varian Portal Dosimetry. J Appl Clin Med Phys 2014; 16:4934. [PMID: 25679149 PMCID: PMC5689987 DOI: 10.1120/jacmp.v16i1.4934] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 09/05/2014] [Accepted: 09/05/2014] [Indexed: 11/23/2022] Open
Abstract
Patient‐specific pretreatment verification of intensity‐modulated radiation therapy (IMRT) or volumetric‐modulated arc therapy (VMAT) is strongly recommended for all patients in order to detect any potential errors in treatment planning process and machine deliverability, and is thus performed routinely in many clinics. Portal dosimetry is an effective method for this purpose because of its prompt setup, easy data acquisition, and high spatial resolution. However, portal dosimetry cannot be applied to IMRT or VMAT with flattening filter‐free (FFF) beams because of the high dose‐rate saturation effect of the electronic portal imaging device (EPID). In our current report, we suggest a practical QA method of expanding the conventional portal dosimetry to FFF beams with a QA plan generated by the following three steps: 1) replace the FFF beams with flattening filtered (FF) beams of the same nominal energy; 2) reduce the dose rate to avoid the saturation effect of the EPID detector; and 3) adjust the total MU to match the gantry and MLC leaf motions. Two RapidArc plans with 6 and 10 MV FFF beams were selected, and QA plans were created by the aforementioned steps and delivered. The trajectory log files of TrueBeam obtained during the treatment and during the delivery of QA plan were analyzed and compared. The maximum discrepancies in the expected trajectories between the treatment and QA plans were within 0.002 MU for the MU, 0.06° for the motion of gantry rotation, and 0.006 mm for the positions of the MLC leaves, indicating much higher levels of accuracy compared to the mechanical specifications of the machine. For further validation of the method, direct comparisons of the delivered QA FF beam to the treatment FFF beam were performed using film dosimetry and show that gamma passing rates under 2%/2 mm criteria are 99.0%–100% for the all four arc beams. This method can be used on RapidArc plans with FFF beams without any additional procedure or modifications on the conventional portal dosimetry of IMRT and is, therefore, a practical option for routine clinical use. PACS numbers: 87.53.Kn, 87.55.T‐, 87.56.bd, 87.59.‐e
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Affiliation(s)
- Soonki Min
- Asan Medical Center, University of Ulsan College of Medicine.
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Liu FF, Okunieff P, Bernhard EJ, Stone HB, Yoo S, Coleman CN, Vikram B, Brown M, Buatti J, Guha C. Lessons learned from radiation oncology clinical trials. Clin Cancer Res 2013; 19:6089-100. [PMID: 24043463 DOI: 10.1158/1078-0432.ccr-13-1116] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A workshop entitled "Lessons Learned from Radiation Oncology Trials" was held on December 7-8, 2011, in Bethesda, MD, to present and discuss some of the recently conducted radiation oncology clinical trials with a focus on those that failed to refute the null hypothesis. The objectives of this workshop were to summarize and examine the questions that these trials provoked, to assess the quality and limitations of the preclinical data that supported the hypotheses underlying these trials, and to consider possible solutions to these challenges for the design of future clinical trials. Several themes emerged from the discussions: (i) opportunities to learn from null-hypothesis trials through tissue and imaging studies; (ii) value of preclinical data supporting the design of combinatorial therapies; (iii) significance of validated biomarkers; (iv) necessity of quality assurance in radiotherapy delivery; (v) conduct of sufficiently powered studies to address the central hypotheses; and (vi) importance of publishing results of the trials regardless of the outcome. The fact that well-designed hypothesis-driven clinical trials produce null or negative results is expected given the limitations of trial design and complexities of cancer biology. It is important to understand the reasons underlying such null results, however, to effectively merge the technologic innovations with the rapidly evolving biology for maximal patient benefit through the design of future clinical trials.
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Affiliation(s)
- Fei-Fei Liu
- Authors' Affiliations: Department of Radiation Oncology, Princess Margaret Cancer Center, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Florida Shands Cancer Center, Gainesville, Florida; Radiation Research Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda; Molecular Radiation Therapeutics Branch, Division of Cancer Treatment and Diagnosis, and Clinical Radiation Oncology Branch, National Cancer Institute, Rockville, Maryland; Department of Radiation Oncology, Stanford University, Palo Alto, California; Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa; and Department of Radiation Oncology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York
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