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Penoncello GP, Voss MM, Gao Y, Sensoy L, Cao M, Pepin MD, Herchko SM, Benedict SH, DeWees TA, Rong Y. Multicenter Multivendor Evaluation of Dose Volume Histogram Creation Consistencies for 8 Commercial Radiation Therapy Dosimetric Systems. Pract Radiat Oncol 2024; 14:e236-e248. [PMID: 37914082 DOI: 10.1016/j.prro.2023.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/11/2023] [Accepted: 09/26/2023] [Indexed: 11/03/2023]
Abstract
PURPOSE To evaluate dose volume histogram (DVH) construction differences across 8 major commercial treatment planning systems (TPS) and dose reporting systems for clinically treated plans of various anatomic sites and target sizes. METHODS AND MATERIALS Dose files from 10 selected clinically treated plans with a hypofractionation, stereotactic radiation therapy prescription or sharp dose gradients such as head and neck plans ranging from prescription doses of 18 Gy in 1 fraction to 70 Gy in 35 fractions, each calculated at 0.25 and 0.125 cm grid size, were created and anonymized in Eclipse TPS, and exported to 7 other major TPS (Pinnacle, RayStation, and Elements) and dose reporting systems (MIM, Mobius, ProKnow, and Velocity) systems for comparison. Dose-volume constraint points of clinical importance for each plan were collected from each evaluated system (D0.03 cc [Gy], volume, and the mean dose were used for structures without specified constraints). Each reported constraint type and structure volume was normalized to the value from Eclipse for a pairwise comparison. A Wilcoxon rank-sum test was used for statistical significance and a multivariable regression model was evaluated adjusting for plan, grid size, and distance to target center. RESULTS For all DVH points relative to Eclipse, all systems reported median values within 1.0% difference of each other; however, they were all different from Eclipse. Considering mean values, Pinnacle, RayStation, and Elements averaged at 1.038, 1.046, and 1.024, respectively, while MIM, Mobius, ProKnow, and Velocity reported 1.026, 1.050, 1.033, and 1.022, respectively relative to Eclipse. Smaller dose grid size improved agreement between the systems marginally without statistical significance. For structure volumes relative to Eclipse, larger differences are seen across all systems with a range in median values up to 3.0% difference and mean up to 10.1% difference. CONCLUSIONS Large variations were observed between all systems. Eclipse generally reported, at statistically significant levels, lower values than all other evaluated systems. The nonsignificant change resulting from lowering the dose grid resolution indicates that this resolution may be less important than other aspects of calculating DVH curves, such as the 3-dimensional modeling of the structure.
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Affiliation(s)
- Gregory P Penoncello
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona; Department of Radiation Oncology, University of Colorado, Aurora, Colorado
| | - Molly M Voss
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Scottsdale, Arizona
| | - Yu Gao
- Department of Radiation Oncology, Stanford University, Palo Alto, California
| | - Levent Sensoy
- Department of Radiation Oncology, University of Miami, Miami, Florida
| | - Minsong Cao
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Mark D Pepin
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Steven M Herchko
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida
| | - Stanley H Benedict
- Department of Radiation Oncology, University of California Davis, Sacramento, California
| | - Todd A DeWees
- Department of Computational and Quantitative Medicine, City of Hope, Duarte, California; Department of Radiation Oncology, City of Hope, Duarte, California.
| | - Yi Rong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona.
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Gaur G, Dangwal VK, Banipal RPS, Singh R, Kaur G, Grover R, Sachdeva S, Kang MS, Singh S, Garg P, Singh B. Dosimetric Comparison of Different Dose Calculation Algorithms in Postmastectomy Breast Cancer Patients Using Conformal Planning Techniques. J Med Phys 2023; 48:136-145. [PMID: 37576097 PMCID: PMC10419741 DOI: 10.4103/jmp.jmp_28_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/18/2023] [Accepted: 05/24/2023] [Indexed: 08/15/2023] Open
Abstract
Background The aim of the current study was to compare three different dose-calculating algorithms, i.e., superposition (SP), fast SP (FSP), and convolution (CV), for breast cancer patients treated with intensity-modulated radiotherapy (IMRT) and field-in-Field forward plan IMRT (FiF-FP-IMRT). Materials and Methods The current retrospective study involved 100 postmastectomy breast cancer patients who were given radiotherapy using IMRT and FiF-FP-IMRT planning techniques. All the initially SP-calculated plans were recalculated with the same monitor units for FSP and CV algorithm without change in any of the other planning parameters. The isodose distribution and various plan evaluating parameters, for example, conformity index (CI), homogeneity index, and uniformity index target volume and normal structure doses were compared and analyzed for all the different algorithm calculated plans. Results In the IMRT plans, all the target and normal structure dose-volume parameters showed a significant difference between all the three different algorithms with P < 0.05. In the FiF-FP-IMRT plans, CV algorithm showed a significant difference in most of the target and normal structure dose-volume parameters. Among quality indexes, only CI showed a significant difference between all the algorithms in both the planning techniques. R50 showed a significant difference with the CV algorithm in both the planning techniques. Conclusion The change in the dose calculation algorithm resulted in dosimetric changes which must be evaluated by the medical physicists and oncologists while evaluating treatment plans. In the current study with breast patients, the results obtained for target and normal structure doses using the CV algorithm are overestimated as compared to SP and FSP algorithms, producing variable results in air and bony normal structures. However, the ipsilateral lung V5 parameter and the ipsilateral humeral head mean dose were found to be underestimated by the CV algorithm as compared to the SP and FSP algorithm in both the planning techniques.
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Affiliation(s)
- Garima Gaur
- Department of Radiation Oncology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
| | - Vinod Kumar Dangwal
- Department of Radiation Oncology, Government Medical College, Patiala, Punjab, India
| | | | | | - Gurpreet Kaur
- Department of Radiation Oncology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
| | - Romikant Grover
- Department of Radiation Oncology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
| | | | - Manraj Singh Kang
- Department of Radiation Oncology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
| | - Simrandeep Singh
- Department of Radiation Oncology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
| | - Pardeep Garg
- Department of Radiation Oncology, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
| | - Baltej Singh
- Department of Community Medicine, Guru Gobind Singh Medical College and Hospital, Faridkot, Punjab, India
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To segment or not to segment the PTV in SIB-VMAT of head-and-neck cancer: a dosimetric comparison with relevance to clinical practice. JOURNAL OF RADIOTHERAPY IN PRACTICE 2022. [DOI: 10.1017/s146039692100011x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractAim:This study aimed to evaluate and compare simultaneous integrated boost-based volumetric modulated arc therapy (SIB-VMAT) of head-and-neck plans optimised using segmented and non-segmented intermediate-risk target volumes.Materials and methods:CT data of 20 patients with locally advanced laryngeal cancer treated with radical chemoradiation were included retrospectively. Both segmented [planning target volume (PTV) IR!] and non-segmented PTV (PTV IR) volumes were created for the intermediate-risk volume. Correspondingly, two VMAT plans were generated for every CT dataset. Dosimetry parameters obtained from cumulative dose volume histogram and the quality indices such as conformity and homogeneity indices were evaluated for both plans and were statistically analysed.Results:Maximum dose of PTV IR! was observed to be higher in the non-segmented plans (7281·45 versus 7075·75 cGy) and was statistically significant (p = 0·002). Homogeneity index (HI) of PTV IR! in segmented plans fared better compared to non-segmented plans (0·1 versus 0·12, p = 0·01). All other dosimetry parameters were found to be similar in both plans.Conclusion:This study shows that using segmented volumes for planning will lead to more homogenous plans with regard to intermediate- and low-risk volumes, especially under controlled settings.
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Garbacz M, Gajewski J, Durante M, Kisielewicz K, Krah N, Kopeć R, Olko P, Patera V, Rinaldi I, Rydygier M, Schiavi A, Scifoni E, Skóra T, Skrzypek A, Tommasino F, Rucinski A. Quantification of biological range uncertainties in patients treated at the Krakow proton therapy centre. Radiat Oncol 2022; 17:50. [PMID: 35264184 PMCID: PMC8905899 DOI: 10.1186/s13014-022-02022-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 02/28/2022] [Indexed: 12/02/2022] Open
Abstract
Background Variable relative biological effectiveness (vRBE) in proton therapy might significantly modify the prediction of RBE-weighted dose delivered to a patient during proton therapy. In this study we will present a method to quantify the biological range extension of the proton beam, which results from the application of vRBE approach in RBE-weighted dose calculation. Methods and materials The treatment plans of 95 patients (brain and skull base patients) were used for RBE-weighted dose calculation with constant and the McNamara RBE model. For this purpose the Monte Carlo tool FRED was used. The RBE-weighted dose distributions were analysed using indices from dose-volume histograms. We used the volumes receiving at least 95% of the prescribed dose (V95) to estimate the biological range extension resulting from vRBE approach. Results The vRBE model shows higher median value of relative deposited dose and D95 in the planning target volume by around 1% for brain patients and 4% for skull base patients. The maximum doses in organs at risk calculated with vRBE was up to 14 Gy above dose limit. The mean biological range extension was greater than 0.4 cm. Discussion Our method of estimation of biological range extension is insensitive for dose inhomogeneities and can be easily used for different proton plans with intensity-modulated proton therapy (IMPT) optimization. Using volumes instead of dose profiles, which is the common method, is more universal. However it was tested only for IMPT plans on fields arranged around the tumor area. Conclusions Adopting a vRBE model results in an increase in dose and an extension of the beam range, which is especially disadvantageous in cancers close to organs at risk. Our results support the need to re-optimization of proton treatment plans when considering vRBE.
Supplementary Information The online version contains supplementary material available at 10.1186/s13014-022-02022-5.
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Affiliation(s)
- Magdalena Garbacz
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland.
| | - Jan Gajewski
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | - Marco Durante
- GSI Helmholtzzentrum fur Schwerionenforschung, 64291, Darmstadt, Germany.,The Technical University of Darmstadt, 64289, Darmstadt, Germany
| | - Kamil Kisielewicz
- National Oncology Institute, National Research Institute, Krakow Branch, 31115, Kraków, Poland
| | - Nils Krah
- University of Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, France.,University of Lyon, Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822, Villeurbanne, France
| | - Renata Kopeć
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | - Paweł Olko
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | - Vincenzo Patera
- INFN - Section of Rome, 00185, Rome, Italy.,Department of Basic and Applied Sciences for Engineering, Sapienza University of Rome, 00161, Rome, Italy
| | | | - Marzena Rydygier
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
| | | | - Emanuele Scifoni
- Trento Institute for Fundamental Physics and Applications, TIFPA-INFN, 38123, Povo, Trento, Italy
| | - Tomasz Skóra
- National Oncology Institute, National Research Institute, Krakow Branch, 31115, Kraków, Poland
| | | | - Francesco Tommasino
- Trento Institute for Fundamental Physics and Applications, TIFPA-INFN, 38123, Povo, Trento, Italy.,Department of Physics, University of Trento, 38123, Povo, Trento, Italy
| | - Antoni Rucinski
- Institute of Nuclear Physics Polish Academy of Sciences, 31342, Kraków, Poland
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Dosimetric comparison of intensity-modulated radiotherapy (IMRT) and RapidArc in low grade mucoepidermoid carcinoma of the salivary gland: a single institutional experience. JOURNAL OF RADIOTHERAPY IN PRACTICE 2020. [DOI: 10.1017/s1460396920000643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractPurpose:To report a single-institution experience of intensity-modulated radiotherapy (IMRT) and RapidArc treatment plans for the patients treated with low grade mucoepidermoid carcinoma (MEC) of the salivary gland while sparing the organs at risk (OARs) within tolerance limits.Material and Methods:Twenty-five patients with MEC were selected to develop and analyse the treatment plans using both of the techniques. Dose distributions were calculated using Eclipse treatment planning system (Varian Medical Systems, Palo Alto, CA). Plans were generated to deliver the dose of 6000 cGy in 30 fractions. For IMRT, seven angle plans were used and for RapidArc, two half arcs were used with the same 6 MV photon beam. Quality of treatment plans was evaluated by using parameters such as, coverage, conformity index (CI), homogeneity index (HI), gradient index (GI), unified dosimetry index (UDI), dose volume histogram, delivery time and OARs sparing for IMRT and RapidArc plans.Results:The analysis revealed that IMRT and RapidArc coverages are 0·90 and 0·94, respectively; CIs are 1·15 and 1·10, respectively; HIs are 1·12 and 1·07, respectively; GIs are 0·94 and 0·98, respectively. Average UDI values for RapidArc and IMRT are 1·09 and 1·11, respectively. Integral dose comparison shows better OAR sparing for RapidArc. RapidArc plans have the shorter beam on time (45%) in comparison with IMRT plans.Conclusion:Planning constraints were achieved in both techniques. However, RapidArc showed better quality treatment plan, OARs sparing and shorter delivery time as compared to IMRT.
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Kesen ND, Akbas U, Koksal C, Bilge H. Investigation of AAA dose calculation algorithm accuracy in surface and buildup region for 6MV photon beam using markus parallel-plate ion chamber. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2019; 27:361-369. [PMID: 30856153 DOI: 10.3233/xst-180489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In radiotherapy, dose distributions are obtained by using dose calculation algorithms that are implanted in treatment planning systems (TPS). This study aims to compare the surface doses of separate field sizes calculated by different version of The Analytical Anisotropic Algorithm (AAA) and measured by the parallel-plate ion chamber that is admitted as the most reliable dosimetry system for the surface region dose measurements. In order to measure the near surface dose, water equivalent solid phantom was used and measurements were made for 6MV photon beam at 100 cm source-detector distance for 5×5, 10×10, and 20×20 cm2 field sizes. AAA 8.9 and AAA 15.1 versions of the Varian Eclipse TPS were used for surface dose calculations by generating beams with separate field sizes. The doses were read by considering the effective buildup thickness of Markus parallel-plate ion chamber. The surface doses using 6 MV photon beams for 10×10 cm2 field size at 0.07 mm were found to be 11.04%, 26.25%, and 19.69% for AAA v8.9, AAA v15.1 and Markus chamber, respectively. It was seen that for both of the AAA versions and Markus parallel-plate ion chamber, increasing field sizes also increase surface dose. For all field sizes, surface dose was lowest by using AAA v8.9 at 0.07 mm. The different versions of the same TPS algorithms may calculate the surface doses distinctively. After upgrading of TPS algorithms, surface doses should be calculated and compared by measurements with different dosimetry systems to better understand their calculation behaviors in the near surface region.
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Affiliation(s)
- Nazmiye Donmez Kesen
- Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey
| | - Ugur Akbas
- Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey
| | - Canan Koksal
- Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey
| | - Hatice Bilge
- Division of Medical Physics, Istanbul University Oncology Institute, Istanbul, Turkey
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Evaluation of various dose homogeneity indices for treatment of patients with cervix cancer using intensity-modulated radiation therapy technique. JOURNAL OF RADIOTHERAPY IN PRACTICE 2018. [DOI: 10.1017/s1460396918000249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractAimThis study is primarily aimed at the analysis of various dose homogeneity indices (HIs) essential for the evaluation of therapeutic plans by employing intensity-modulated radiation therapy (IMRT) on patients with cervix cancer. Also integral dose (ID) to healthy surrounding organs is computed.Materials and methodsEffectiveness of different HIs (A, B, C, D) was explored for IMRT plans using 15 MV photon beam. In total, 18 patients were selected at random for treatment of cervix cancer, and dose of 5,040 cGy was delivered in 28 equal fractions.ResultsThe study was undertaken to compare four HI formulas and coefficient of determination between each set of HI was known by calculating R2 value. Mean±SD of HI A, HI B, HI C and HI D were 1·12±0·02, 0·13±0·04, 0·10±0·02 and 0·99±0·03, respectively. Mean value of ID for rectum is 3·16 and for bladder is 10·3.FindingsOur data suggested that HI calculated using four formulas provided good plan quality. The results advocate that all the studied HIs can be effectively used for assessment of uniformity inside the target volume. However, values of HI C were closest to ideal value as compared with other three formulas; hence, it is considered a better measure to compute homogeneity of dose within target volume. The ID gives satisfactory results for surrounding normal tissues such as rectum and bladder and significant critical tissue sparing was achieved by using IMRT technique.
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Study of dosimetric indices and dose constraints to critical organs for head and neck tumours treated with inverse planned simultaneous integrated boost intensity-modulated radiotherapy. JOURNAL OF RADIOTHERAPY IN PRACTICE 2018. [DOI: 10.1017/s1460396917000668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
AbstractAimThis study aimed to investigate tolerance dose to organs at risk (OARs) as well as degree of conformity and homogeneity for head and neck cancer patients by using simultaneous integrated boost intensity-modulated radiotherapy technique (SIB IMRT).Materials and methodsThis study analysed 15 head and neck cancer patients receiving treatment using inverse planned SIB IMRT technique. Using a beam energy of 6 MV, two dose levels of 70 and 55·4 Gy were used to treat the tumour. Doses of 2 Gy in 35 fractions and 1·68 Gy in 33 fractions were simultaneously delivered for effective planning target volume (PTV1) and boost planning target volume (PTV2), respectively.ResultsDose distribution in PTV and critical organs lies within tolerance dose guidelines protecting spinal cord, brain stem, optic chiasm, optic nerve, thus reducing the risk of damage to normal tissues. Minor deviation from tolerance limit was observed for parotid glands. This technique provided highly conformal and homogenous dose distribution as well as better sparing of OARs, hence verifying quality assurance results to be satisfactory.FindingsSIB IMRT technique offers best solution for preserving organ function by keeping dose below tolerance level. Treatment of head and neck carcinoma using SIB IMRT is feasible, more efficient, and dose escalation is achieved in a single plan.
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Mohandass P, Khanna D, Manigandan D, Bhalla NK, Puri A. Validation of a Software Upgrade in a Monte Carlo Treatment Planning System by Comparison of Plans in Different Versions. J Med Phys 2018; 43:93-99. [PMID: 29962686 PMCID: PMC6020620 DOI: 10.4103/jmp.jmp_7_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Validation of a new software version of a Monte Carlo treatment planning system through comparing plans generated by two software versions in volumetric-modulated arc therapy (VMAT) for lung cancer. MATERIALS AND METHODS Three patients who were treated with 60 Gy/30 fractions in Elekta Synergy™ linear accelerator by VMAT technique with 2% statistical uncertainty (SU) were chosen for the study. Multiple VMAT plans were generated using two different software versions of Monaco treatment planning system TPS (V5.10.02 and V5.11). By keeping all other parameters constant, originally accepted plans were recalculated for the SUs of 0.5%, 1%, 2%, 3%, 4%, and 5%. For plan evaluation, the metrics compared were conformity Index (CI), homogeneity Index (HI), dose coverage to planning target volume (PTV), organ at risk (OAR) doses to spinal cord, pericardium, bilateral lungs-PTV, esophagus, liver, normal tissue integral dose (NTID), volumes receiving dose >5 and >10 Gy, calculation time (tCT), and gamma pass rates. RESULTS In both versions, CI and HI improved as the SU increased from 0.5% to 5%. No significant dose difference was observed in Dmean to PTV, bilateral lungs-PTV, pericardium, esophagus, liver, normal tissue volume receiving >5, and >10 Gy and NTID. It was observed that while the tCT and gamma pass rates decreased, the maximum dose to PTV increased as the SU increased. No other significant dose differences were observed between the two MC versions compared. CONCLUSION For lung VMAT plans, in both versions, SU could be accepted up to 3% per plan with reduced tCT without compromising plan quality and deliverability by accepting variations in point dose and an inhomogeneous dose within the target. The plan quality of Monaco™V5.10.02 was similar to Monaco™TPS-V5.11 except for tCT.
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Affiliation(s)
- P. Mohandass
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India,Department of Physics, School of Engineering and Technology, Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu, India,Address for correspondence: Mr. P. Mohandass, Department of Radiation Oncology, Fortis Hospital, Sector-62, Phase 8, SAS Nagar, Mohali - 160 062, Punjab, India. E-mail:
| | - D. Khanna
- Department of Physics, School of Engineering and Technology, Karunya Institute of Technology and Sciences, Coimbatore, Tamil Nadu, India
| | - D. Manigandan
- Department of Radiotherapy, Medanta The Medicity Hospital, Gurgaon, Haryana, India
| | - Narendra Kumar Bhalla
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
| | - Abhishek Puri
- Department of Radiation Oncology, Fortis Cancer Institute, Fortis Hospital, Mohali, Punjab, India
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Atiq M, Atiq A, Iqbal K, Shamsi Q, Andleeb F, Buzdar SA. Evaluation of dose conformity and coverage of target volume for intensity-modulated radiotherapy of pelvic cancer treatment. Indian J Cancer 2017; 54:379-384. [PMID: 29199727 DOI: 10.4103/ijc.ijc_80_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Better conformity may help in delivering minimum dose to organs at risk (OARs) and maximum dose to planning target volume (PTV). As per the requirements of modern radiotherapy, 95% isodose should cover the PTV, so conformity indices (CIs) are used for evaluating quality of conformation of treatment plans. AIM This study aimed to investigate degree of conformity for pelvic patients using intensity-modulated radiotherapy (IMRT) technique. Three formulas of CIs described in literature were analyzed in this study. SETTINGS AND DESIGN This study was performed to evaluate degree of conformity of 18 patients treated with radiotherapy treatment plan using cumulative dose volume histogram. Effectiveness of different CIs was explored for IMRT plans using 15 MV photon beam. Doses delivered to OAR were also studied. STATISTICAL ANALYSIS USED CI suggested by the International Commission on Radiation Units and Measurements, radiation CI and CI prescription isodose to target volume (PITV) had mean ± standard deviation values of 1.02 ± 0.018, 0.98 ± 0.017, and 1.63 ± 0.333, respectively. RESULTS AND CONCLUSION Dose distribution for all patients was highly conformal and clinically acceptable. Values of CI PITV exceeded acceptable value for 27% patients with minor deviation. No statistically significant differences were observed for three CIs reported. Target volume lies between 95% and 107% of prescribed dose which shows ideal target coverage. This simple parameter is advantageous since it is easy to interpret and helped determine quality of treatment plan. This study clearly demonstrated that favorable dose distribution in PTV and OARs is achieved using IMRT technique, and hence, the risk of damage to normal tissues is reduced.
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Affiliation(s)
- M Atiq
- Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - A Atiq
- Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - K Iqbal
- Shaukat Khanum Cancer Hospital & Research Center, Lahore, Pakistan
| | - Q Shamsi
- Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - F Andleeb
- Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - S A Buzdar
- Department of Physics, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
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