비편평화여과기 빔을 이용한 폐 정위절제방사선치료를 위한 AAA와 Acuros XB 계산 알고리즘의 치료계획 비교 Comparison of Anisotropic Analytic Algorithm Plan and Acuros XB Plan for Lung Stereotactic Ablative Radiotherapy Using Flattening Filter-Free Beams원문보기
이 연구는 비편평화여과기(flattening filter-free, FFF) 빔을 이용한 폐 정위절제방사선치료(stereotactic ablative radiotherapy, SABR)에 대하여 서로 다른 선량계산 알고리즘의 선량적 효과를 조사하였다. SABR를 받은 10명의 폐암 환자를 대상으로하여 평가하였다. 모든 치료계획은 Eclipse 치료계획시스템의 Acuros XB (AXB) 알고리즘을 이용하여 수립되었다. 다른 선량계산 알고리즘과 비교를 위하여, 추가적으로 anisotropic analytic algorithm (AAA) 알고리즘을 적용한 치료계획을 재 수립하였다. 두 알고리즘 평가를 위해서, 치료표적과 손상위험장기의 선량체적히스토그램(dose-volume histogrim, DVH)를 분석하였다. 그리고 기술적 인자로써 계산시간과 총 MU 값을 평가하였다. DVH 비교분석을 통해, PTV의 최대선량은 AXB이 AAA 보다 5.2% 높았으며 최소선량은 4.4% 낮게 나타났다. PTV의 $V_{105%}$에서 7.06%까지 큰 차이를 나타났다. 폐의 최대선량은 AXB 치료계획에서 약간 크게 나타났다. 동측성 폐에 5, 10과 20 Gy 선량이 조사되는 체적은 AAA 보다 AXB에서 더 크게 나타났으나 대측성 폐에 대해서는 거의 비슷하게 나타났다. 척수와 심장에서 최대선량의 차이도 크지 않았다. 계산시간의 경우, AXB가 AAA보다 13.7% 정도 소요시간이 적었고 MU 값은 AXB에서 3.47% 더 많았다. 이 연구의 결과들은 회전조절치료 기법을 포함하여 FFF 빔이 적용된 폐 SABR 치료계획에서 AXB 알고리즘은 선량계산의 정확성과 계산시간의 감소의 장점을 제공할 수 있을 것이다.
이 연구는 비편평화여과기(flattening filter-free, FFF) 빔을 이용한 폐 정위절제방사선치료(stereotactic ablative radiotherapy, SABR)에 대하여 서로 다른 선량계산 알고리즘의 선량적 효과를 조사하였다. SABR를 받은 10명의 폐암 환자를 대상으로하여 평가하였다. 모든 치료계획은 Eclipse 치료계획시스템의 Acuros XB (AXB) 알고리즘을 이용하여 수립되었다. 다른 선량계산 알고리즘과 비교를 위하여, 추가적으로 anisotropic analytic algorithm (AAA) 알고리즘을 적용한 치료계획을 재 수립하였다. 두 알고리즘 평가를 위해서, 치료표적과 손상위험장기의 선량체적히스토그램(dose-volume histogrim, DVH)를 분석하였다. 그리고 기술적 인자로써 계산시간과 총 MU 값을 평가하였다. DVH 비교분석을 통해, PTV의 최대선량은 AXB이 AAA 보다 5.2% 높았으며 최소선량은 4.4% 낮게 나타났다. PTV의 $V_{105%}$에서 7.06%까지 큰 차이를 나타났다. 폐의 최대선량은 AXB 치료계획에서 약간 크게 나타났다. 동측성 폐에 5, 10과 20 Gy 선량이 조사되는 체적은 AAA 보다 AXB에서 더 크게 나타났으나 대측성 폐에 대해서는 거의 비슷하게 나타났다. 척수와 심장에서 최대선량의 차이도 크지 않았다. 계산시간의 경우, AXB가 AAA보다 13.7% 정도 소요시간이 적었고 MU 값은 AXB에서 3.47% 더 많았다. 이 연구의 결과들은 회전조절치료 기법을 포함하여 FFF 빔이 적용된 폐 SABR 치료계획에서 AXB 알고리즘은 선량계산의 정확성과 계산시간의 감소의 장점을 제공할 수 있을 것이다.
This study investigated the dosimetric effects of different dose calculation algorithm for lung stereotactic ablative radiotherapy (SABR) using flattening filter-free (FFF) beams. A total of 10 patients with lung cancer who were treated with SABR were evaluated. All treatment plans were created usin...
This study investigated the dosimetric effects of different dose calculation algorithm for lung stereotactic ablative radiotherapy (SABR) using flattening filter-free (FFF) beams. A total of 10 patients with lung cancer who were treated with SABR were evaluated. All treatment plans were created using an Acuros XB (AXB) of an Eclipse treatment planning system. An additional plans for comparison of different alagorithm recalcuated with anisotropic analytic algorithm (AAA) algorithm. To address both algorithms, the cumulative dose-volume histogram (DVH) was analyzed for the planning target volume (PTV) and organs at risk (OARs). Technical parameters, such as the computation times and total monitor units (MUs), were also evaluated. A comparison analysis of DVHs from these plans revealed the PTV for AXB estimated a higher maximum dose (5.2%) and lower minimum dose (4.2%) than that of the AAA. The highest dose difference observed 7.06% for the PTV $V_{105%}$. The maximum dose to the lung was also slightly larger in the AXB plans. The percentate volumes of the ipsilateral lung ($V_5$, $V_{10}$, $V_{20}$) receiving 5, 10, and 20 Gy were also larger in AXB plans than for AAA plans. However, these parameters were comparable between both AAA and AXB plans for the contralateral lung. The differences of the maximum dose for the spinal cord and heart were also small. The computation time of AXB plans was 13.7% shorter than that of AAA plans. The average MUs were 3.47% larger for AXB plans than for AAA plans. The results of this study suggest that AXB algorithm can provide advantages such as accurate dose calculations and reduced computation time in lung SABR plan using FFF beams, especially for volumetric modulated arc therapy technique.
This study investigated the dosimetric effects of different dose calculation algorithm for lung stereotactic ablative radiotherapy (SABR) using flattening filter-free (FFF) beams. A total of 10 patients with lung cancer who were treated with SABR were evaluated. All treatment plans were created using an Acuros XB (AXB) of an Eclipse treatment planning system. An additional plans for comparison of different alagorithm recalcuated with anisotropic analytic algorithm (AAA) algorithm. To address both algorithms, the cumulative dose-volume histogram (DVH) was analyzed for the planning target volume (PTV) and organs at risk (OARs). Technical parameters, such as the computation times and total monitor units (MUs), were also evaluated. A comparison analysis of DVHs from these plans revealed the PTV for AXB estimated a higher maximum dose (5.2%) and lower minimum dose (4.2%) than that of the AAA. The highest dose difference observed 7.06% for the PTV $V_{105%}$. The maximum dose to the lung was also slightly larger in the AXB plans. The percentate volumes of the ipsilateral lung ($V_5$, $V_{10}$, $V_{20}$) receiving 5, 10, and 20 Gy were also larger in AXB plans than for AAA plans. However, these parameters were comparable between both AAA and AXB plans for the contralateral lung. The differences of the maximum dose for the spinal cord and heart were also small. The computation time of AXB plans was 13.7% shorter than that of AAA plans. The average MUs were 3.47% larger for AXB plans than for AAA plans. The results of this study suggest that AXB algorithm can provide advantages such as accurate dose calculations and reduced computation time in lung SABR plan using FFF beams, especially for volumetric modulated arc therapy technique.
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문제 정의
The purpose of this study was to evaluate the difference in the dose distribution of AXB and AAA plans implemented in a commercial TPS for lung SABR with an FFF beam. We compared the dosimetric parameters for the target and OARs according to the AAA and AXB plans.
제안 방법
All calculations were performed using a new version of the Eclipse 11.0 TPS with AAA 11.0.34 and AXB 11.0.34 (Varian Medical Systems, Palo Alto, CA). Two dose-reporting modes are available in AXB: dose-to-water and dose-to-medium.
We used the SI to evaluate the detailed dose homogeneity for the PTV and CTV. It qualitatively provided significant information regarding the dosimetric spread across the PTV and CTV. The PTV coverage using the AXB was reduced than that for the AAA, as shown in Fig.
The Digital Imaging and Communications in Medicine (DICOM) CT data were electronically transferred to the Eclipse TPS for contouring and planning. Planning treatment volumes (PTVs) were created by adding 5-mm margins to the clinical treatment volume (CTV) in all directions. The OARs considered were the lungs, heart, and spinal cord.
The beam parameters of the clinical treatment plans in this study were set up in the Eclipse TPS, and the treatment plans were calculated using a volumetric modulated arc therapy (VMAT) technique with two partial arcs allowing the optimizer to use a maximum dose rate of 1400 monitor units (MUs)/min for a 6-MV FFF beam. The dose calculations were performed with inhomogeneity correction and 2.
The SABR immobilization platform (Body Pro-Lok, CIVCO, Orange City, IA, USA) was used to fix the thoracic and abdominal regions and reduce residual body motion. The computed tomography (CT) data of these patients with lung tumors who underwent SABR were used, and the scans were acquired with 2-mm slice spacing on the flat table top of a Philips Big-bore CT scanner. The treatment plans were created using different dose calculation algorithms in this study.
The beam parameters of the clinical treatment plans in this study were set up in the Eclipse TPS, and the treatment plans were calculated using a volumetric modulated arc therapy (VMAT) technique with two partial arcs allowing the optimizer to use a maximum dose rate of 1400 monitor units (MUs)/min for a 6-MV FFF beam. The dose calculations were performed with inhomogeneity correction and 2.5-mm grid resolution in all plans. In all plans, 48 Gy of radiation were delivered in four equal fractions to deliver a biological equivalent dose exceeding 100 Gy.
The computed tomography (CT) data of these patients with lung tumors who underwent SABR were used, and the scans were acquired with 2-mm slice spacing on the flat table top of a Philips Big-bore CT scanner. The treatment plans were created using different dose calculation algorithms in this study. The Digital Imaging and Communications in Medicine (DICOM) CT data were electronically transferred to the Eclipse TPS for contouring and planning.
대상 데이터
The dose-volume histogram (DVH) of the calculated SABR plans for lung cancer was generated in the Eclipse TPS. The average DVH of the PTV was generated for the AAA and AXB plans by averaging the data for the 10 analyzed patients. For the PTV and CTV, the mean dose, minimum dose, maximum dose (high point dose), and homogeneity were compared.
성능/효과
HI: homogeneity indices, CI: conformity indices, LCF: lesion coverage factor, HTCI: health tissue conformity index, CN: conformity number V95%, V100%, V105%: the volumes receiving 95%, 100%, and 105% of the prescribed dose, respectively.
37 Gy, respectively. Regarding the different calculation algorithms, the mean V95%, V100%, and V105% for the PTV displayed large differences, with the largest difference (7.06%) observed for the PTV V105%. However, V95% and V100% differed by no more than 0.
The optimization goals were to ensure that the entire CTV received 95% of the prescribed dose and for the PTV to cover 95% of the volume that received 95% of the prescribed dose, with no PTV hot spot receiving 107% or more of the prescribed dose. Doses exceeding 107% were permitted only inside the target.
These results mean that 95% (2 standard deviations) and 99% (3 standard devations) of PTV using the AXB is encompassed 44.11∼51.89 to 42.83∼53.17 Gy, and that using the AAA is encompassed 45.48∼50.52 to 44.43∼51.57 Gy, respectively.
참고문헌 (29)
Boyer AL and Schultheiss T: Effects of dosimetric and clinical uncertainty on complication-free local tumor control. Radiother Oncol 11(1):65-71 (1988)
Park BD, Jung SH, Park S, et al: Comparison of dose distributions calculated by anisotropic analytical algorithm and pencil beam convolution algorithm at tumors located in liver dome site. Progress in Medical Physics. 23(2):106-113 (2012)
Robinson D: Inhomogeneity correction and the analytic anisotropic algorithm J Appl Clin Med Phys 9(2):112-122 (2008)
Gagne IM and Zavgordoni S: Evaluation of the analytical anisotropic algorithm in an extreme water-lung interface phantom using Monte Carlo dose calculations. J Appl Clin Med Phys 8(1):33-46 (2007)
Tillikainen L, Helminnen H, Torsti T, et al: A 3D pencil-beam-based superposition algorithm for photon dose calculation in heterogeneous media. Phys Med Biol 53(14):3821-3839 (2008)
Vassiliev ON, Wareing TA, Davis IM, et al: Feasibility of a multigroup deterministic solution method for three-dimensional radiotherapy dose calculations.Int J Radiat Oncol Biol Phys 72(1):220-227 (2008)
Vassiliev ON, Wareing TA, McGhee J, Failla G, Salehpour MR, Mourtada F: Validation of a new grid-based Boltzmann equation solver for dose calculation in radiotherapy with photon beams. Phys Med Biol 55(3):581-598 (2010)
Gifford KA, Horton JL, Jr., Wareing TA, Failla G, Mourtada F: Comparison of a finite-element multigroup discrete-ordinates code with Monte Carlo for radiotherapy calculations. Phys Med Biol 51(9):2253-2265 (2006)
Han T, Mikell JK, Salehpour M, Mourtada F: Dosimetric comparison of Acuros XB deterministic radiation transport method with Monte Carlo and model-based convolution methods in heterogeneous media. Med Phys 38(5):2651-2664 (2011)
Bush K, Gagne IM, Zavgorodni S, Ansbacher W, Beckham W: Dosimetric validation of Acuros XB with Monte Carlo methods for photon dose calculations Med Phys 38(4):2208-2221 (2011)
Kan WK, Leung L, Yu P: Verification and dosimetric impact of Acuros XB algorithm on intensity modulated stereotactic radiotherapy for locally persistent nasopharyngeal carcinoma. Med Phys 39(8):4705-4714 (2012)
Fogliata A, Nicolini G, Clivio A, Vanetti E, Cozzi L. Dosimetric evaluation of Acuros XB Advanced Dose Calculation algorithm in heterogeneous media. Radiation Oncology 6:82 (2011)
Esch AV, Tillikainen L, Pyykkonen J, et al: Testing of the analytical anisotropic algorithm for photon dose calculation. Medical Physics Med Phys 33(11):4130-4148 (2006)
Breitman K, Rathee S, Newcomb C, et al: Experimental Validation of the Eclipse AAA Algorithm. J Appl Clin Med Phys 8(2):76-92 (2007)
Fogliata A, Vanetti E, Albers D, et al: On the dosimetric behaviour of photon dose calculation algorithms in the presence of simple geometric heterogeneities: comparison with Monte Carlo calculations. Phys Med Biol 52(5):1363-1385 (2007)
Han T, Mourtada F, Kisling K, et al: Experimental validation of deterministic Acuros XB algorithm for IMRT and VMAT dose calculations with the Radiological Physics Center's head and neck phantom. Med Phys 39(4):2193-2202 (2012)
Teh B, Mai WY, Uhl BM, et al: Intensity-modulated radiation therapy for prostate cancer with the use of a rectal balloon for prostate immobilization: acute toxicity and dose-volume analysis. Int J Radiat Oncol Biol Phys 49(3):705-712 (2001)
Kim JS, Chung JB, Kim IA, Eom KY: Dosimetric effects of endorectal balloons on intensity-modulated radation therapy plans for prostate cancer. J Korean Phys Soc 63(8):1637-1643 (2013)
Stanley J, Breitman K, Dunscombe P, Spencer D, Lau H: Evaluation of stereotactic radiosurgery conformity indices for 170 target volumes in patients with brain metastases. J Appl Clin Med Phys 12(2):245-253 (2011)
Yoon M, Park SY, Shin D, et al: A new homogeneity index based on statistical analysis of the dose-volume histogram. J Appl Clin Med Phys 8(2):9-17(2007)
Hinnen KA, Monninkhof EM, Battermann JJ, et al: Prostate specific antigen bounce is related to overall survival in prostate brachytherapy. Int J Radiat Oncol Biol Phys 82(2):883 (2012)
Scorsetti M, Alongi F, Castiglioni S, et al: Feasibility and early clinical assessment of flattening filter free (FFF) based stereotactic body radiotherapy (SBRT) treatments. Radiation Oncology 6:113 (2011)
Vassiliev ON, Kry SF, Chang JY, et al: Stereotactic radiotherapy for lung cancer using a flattening filter free Clinac. J Appl Clin Med Phys 10(1):14-21 (2009)
Mancosu P, Castiglioni S, Reggiori G, et al: Stereotactic body radiation therapy for liver tumours using flattening filter free beam: dosimetric and technical considerations. Radiation Oncology 7:16 (2012)
Fogliata A, Nicolini G, Clivio A, et al: Accuracy of Acuros XB and AAA dose calculation for small fields with reference to RapidArc((R)) stereotactic treatments. Med Phys 38(11):6228-6237 (2011)
Narabayashi M, Mizowaki T, Matsuo Y, et al: Dosimetric evaluation of the impacts of different heterogeneity correction algorithms on target doses in stereotactic body radiation therapy for lung tumors. J Radiat Research 53(5):777-784 (2012)
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