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Uğurlu BT, Türk A, Celasun MG, Hekimoglu A. Fluence map analyzer reduces low dose volume in locally advanced post mastectomy breast cancer patients. Biomed Phys Eng Express 2022; 8:035003. [PMID: 35203070 DOI: 10.1088/2057-1976/ac584e] [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: 12/17/2021] [Accepted: 02/24/2022] [Indexed: 11/12/2022]
Abstract
Multi-leaf collimator dose leakage in intensity-modulated radiotherapy (IMRT) plans causes higher low dose volume which increases the long-term risks of radiotherapy. We have developed Fluence Map Analyzer (FMA) program that suggests the ideal field geometry to reduce low dose volume in locally advanced breast cancer IMRT plans. In this comparative experimental study, FMA has been applied to standard IMRT plans (STD-IMRT) of randomly selected 15 left and 15 right-sided locally advanced breast cancer patients. All patients underwent a modified radical mastectomy. The chest wall, IMN, axillary, and supraclavicular lymph nodes are included in planning target volume (PTV). The heart, lungs, contralateral breast, and medulla spinalis were delineated as organs at risk (OARs). Two sets of plans, namely STD-IMRT and FMA-IMRT, were generated for each patient. The dosimetric analysis was performed using dose-volume histogram (DVH) and standard evaluation parameters of PTV and OARs. No differences could be observed among the two techniques for PTV coverage. However, FMA-IMRT plans achieved significantly lower V5volumes and mean doses of the heart, lungs, contralateral breast, and body contours. FMA-IMRT used a smaller number of sub-fields and fewer monitor units (MU). FMA automizes the field geometry determination process for locally advanced breast cancer IMRT planning while reducing low dose volume significantly.
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Affiliation(s)
- Berat Tuğrul Uğurlu
- Kutahya Health Science University Medicine Faculty Evliya Celebi Training and Research Hospital, 43040, Kutahya, Turkey
| | - Ali Türk
- Kutahya Health Science University Medicine Faculty Evliya Celebi Training and Research Hospital, 43040, Kutahya, Turkey
| | - Mustafa Gürol Celasun
- Kutahya Health Science University Medicine Faculty Evliya Celebi Training and Research Hospital, 43040, Kutahya, Turkey
| | - Azamat Hekimoglu
- Afyonkarahisar Health Science University, 03200, Afyonkarahisar, Turkey
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Song W, Lu H, Liu J, Zhao D, Ma J, Zhang B, Yu D, Sun X, Li J. Fixed-jaw technique to improve IMRT plan quality for the treatment of cervical and upper thoracic esophageal cancer. J Appl Clin Med Phys 2019; 20:24-32. [PMID: 31460704 PMCID: PMC6806698 DOI: 10.1002/acm2.12704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/30/2019] [Accepted: 07/26/2019] [Indexed: 11/12/2022] Open
Abstract
The purpose of this study was to investigate the potential advantages of the fixed-jaw technique (FJT) over the conventional split-field technique (SFT) for cervical and upper thoracic esophageal cancer (EC) patients treated with intensity-modulated radiotherapy. The SFT and FJT plans were generated for 15 patients with cervical and upper thoracic EC. Dosimetric parameters and delivery efficiency were compared. An area ratio (AR) of the jaw opening to multileaf collimator (MLC) aperture weighted by the number of monitor units (MUs) was defined to evaluate the impact of the transmission through the MLC on the dose gradient outside the PTV50.4, and the correlation between the gradient index (GI) and AR was analyzed. The FJT plans achieved a better GI and AR (P < 0.001). There was a positive correlation between the GI and AR in the FJT (r = 0.883, P < 0.001) and SFT plans (r = 0.836, P < 0.001), respectively. Moreover, the mean dose (Dmean ), V5Gy -V40Gy for the lungs and the Dmean , V5Gy -V50Gy for the body-PTV50.4 in the FJT plans were lower than those in the SFT plans (P < 0.05). The FJT plans demonstrated a reduction trend in the doses to the spinal cord PRV and heart, but only the difference in the heart Dmean reached statistical significance (P < 0.05). The FJT plans reduced the number of MUs and subfields by 5.5% and 17.9% and slightly shortened the delivery time by 0.23 min (P < 0.05). The gamma-index passing rates were above 95% for both plans. The FJT combined with target splitting can provide superior organs at risk sparing and similar target coverage without compromising delivery efficiency and should be a preferred intensity-modulated radiotherapy planning method for cervical and upper thoracic EC patients.
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Affiliation(s)
- Wei Song
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Hong Lu
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Jie Liu
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Di Zhao
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Jun Ma
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Biyun Zhang
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Dahai Yu
- Department of Radiation Oncology, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Xinchen Sun
- Department of Radiation Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jinkai Li
- Department of Radiation Oncology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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Fu Y, Wang Y, Huang L, Jin Y, Xie C, Jin X. The effect of enforced fixed-field on the delivery accuracy of IMRT in the treatment of cervical cancer patients. Biomed Phys Eng Express 2017. [DOI: 10.1088/2057-1976/aa87b9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mani KR, Upadhayay S, Das KJM. Influence of jaw tracking in intensity-modulated and volumetric-modulated arc radiotherapy for head and neck cancers: a dosimetric study. Radiat Oncol J 2017; 35:90-100. [PMID: 28395504 PMCID: PMC5398351 DOI: 10.3857/roj.2016.02054] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/08/2017] [Accepted: 02/22/2017] [Indexed: 02/03/2023] Open
Abstract
Purpose To Study the dosimetric advantage of the Jaw tracking technique in intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for Head and Neck Cancers. Materials and Methods We retrospectively selected 10 previously treated head and neck cancer patients stage (T1/T2, N1, M0) in this study. All the patients were planned for IMRT and VMAT with simultaneous integrated boost technique. IMRT and VMAT plans were performed with jaw tracking (JT) and with static jaw (SJ) technique by keeping the same constraints and priorities for a particular patient. Target conformity, dose to the critical structures and low dose volumes were recorded and analyzed for IMRT and VMAT plans with and without JT for all the patients. Results The conformity index average of all patients followed by standard deviation (x¯ ± σx¯) of the JT-IMRT, SJ-IMRT, JT-VMAT, and SJ-VMAT were 1.72 ± 0.56, 1.67 ± 0.57, 1.83 ± 0.65, and 1.85 ± 0.64, and homogeneity index were 0.059 ± 0.05, 0.064 ± 0.05, 0.064 ± 0.04, and 0.064 ± 0.05. JT-IMRT shows significant mean reduction in right parotid and left parotid shows of 7.64% (p < 0.001) and 7.45% (p < 0.001) compare to SJ-IMRT. JT-IMRT plans also shows considerable dose reduction to thyroid, inferior constrictors, spinal cord and brainstem compared to the SJ-IMRT plans. Conclusion Significant dose reductions were observed for critical structure in the JT-IMRT compared to SJ-IMRT technique. In JT-VMAT plans dose reduction to the critical structure were not significant compared to the SJ-IMRT due to relatively lesser monitor units.
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Affiliation(s)
- Karthick Raj Mani
- Research and Development Centre, Bharathiar University, Tamilnadu, India
| | - Sagar Upadhayay
- Radiation Oncology, Kathmandu Cancer Center, Bhaktapur, Nepal
| | - K J Maria Das
- Department of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Uttar Pradesh, India
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Hong CS, Ju SG, Kim M, Kim JI, Kim JM, Suh TS, Han Y, Ahn YC, Choi DH, Nam H, Park HC. Dosimetric effects of multileaf collimator leaf width on intensity-modulated radiotherapy for head and neck cancer. Med Phys 2014; 41:021712. [PMID: 24506603 DOI: 10.1118/1.4860155] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The authors evaluated the effects of multileaf collimator (MLC) leaf width (2.5 vs. 5 mm) on dosimetric parameters and delivery efficiencies of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) for head and neck (H&N) cancers. METHODS The authors employed two types of mock phantoms: large-sized head and neck (LH&N) and small-sized C-shape (C-shape) phantoms. Step-and-shoot IMRT (S&S_IMRT) and VMAT treatment plans were designed with 2.5- and 5.0-mm MLC for both C-shape and LH&N phantoms. Their dosimetric characteristics were compared in terms of the conformity index (CI) and homogeneity index (HI) for the planning target volume (PTV), the dose to organs at risk (OARs), and the dose-spillage volume. To analyze the effects of the field and arc numbers, 9-field IMRT (9F-IMRT) and 13-field IMRT (13F-IMRT) plans were established for S&S_IMRT. For VMAT, single arc (VMAT1) and double arc (VMAT2) plans were established. For all plans, dosimetric verification was performed using the phantom to examine the relationship between dosimetric errors and the two leaf widths. Delivery efficiency of the two MLCs was compared in terms of beam delivery times, monitor units (MUs) per fraction, and the number of segments for each plan. RESULTS 2.5-mm MLC showed better dosimetric characteristics in S&S_IMRT and VMAT for C-shape, providing better CI for PTV and lower spinal cord dose and high and intermediate dose-spillage volume as compared with the 5-mm MLC (p < 0.05). However, no significant dosimetric benefits were provided by the 2.5-mm MLC for LH&N (p > 0.05). Further, beam delivery efficiency was not observed to be significantly associated with leaf width for either C-shape or LH&N. However, MUs per fraction were significantly reduced for the 2.5-mm MLC for the LH&N. In dosimetric error analysis, absolute dose evaluations had errors of less than 3%, while the Gamma passing rate was greater than 95% according to the 3%/3 mm criteria. There were no significant differences in dosimetric error between the 2.5- and 5-mm MLCs. CONCLUSIONS As compared with MLC of 5-mm leaf widths, MLC with finer leaf width (2.5-mm) can provide better dosimetric outcomes in IMRT for C-shape. However, the MLC leaf width may only have minor effects on dosimetric characteristics in IMRT for LH&N. The results of the present study will serve as a useful assessment standard when assigning or introducing equipment for the treatment of H&N cancers.
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Affiliation(s)
- Chae-Seon Hong
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Sang Gyu Ju
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Minkyu Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Jung-In Kim
- Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwhan University School of Medicine, Seoul 110-746, South Korea
| | - Jin Man Kim
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Tae-Suk Suh
- Department of Biomedical Engineering and Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul 137-701, South Korea
| | - Youngyih Han
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Yong Chan Ahn
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Doo Ho Choi
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
| | - Heerim Nam
- Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwhan University School of Medicine, Seoul 110-746, South Korea
| | - Hee Chul Park
- Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
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