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Dosimetric analysis of intensity modulated radiotherapy (IMRT) and three dimensional conformal radiotherapy (3DCRT) for treatment of non-small cell lung cancer: A comparative study
Abstract
Purpose: The purpose of this study is to analyze and compare the dosimetric parameters of three dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (IMRT) in selected non-small cell lung cancer (NSCLC) cases.
Methods: Ten patients with inoperable NSCLC were selected for this study. The 3DCRT and IMRT plans were generated for all patients following Radiation Therapy Oncology Group (RTOG) guidelines. Generated plans were then compared on the basis of planning target volume (PTV) coverage, dose delivered to organs at risk, homogeneity index (HI), and conformity index (CI) for the prescribed dose (PD) of 50 Gy in 25 fractions.
Results: The mean D95 and D99 (dose to the 95% and 99% volume) for the PTV were found better in the 3DCRT plans compared to the ones in the IMRT plans. On an average, the volume receiving 20 Gy (V20) of contralateral lung was 2.91% and 3.03% in the 3DCRT and IMRT plans, respectively. The Dmean of contralateral lung was 3.17 Gy (3DCRT) versus 4.2 Gy (IMRT), whereas the Dmean of ipsilateral lung was 12.69 Gy (3DCRT) and 13.82 Gy (IMRT). The V20 of ipsilateral lung was found to be slightly lower in the 3DCRT (25.67%) when compared to the IMRT (30.50%). The dose to the heart was comparable in the 3DCRT and IMRT plans (mean dose: 4.42 Gy versus 4.48 Gy; D33: 3.77 Gy versus and 4.02 Gy). For the spinal cord, the Dmax was found to be lower in the 3DCRT plans (18.40 Gy) when compared to the IMRT plans (25.49 Gy). The HI was 1.08 versus 1.41 in the 3DCRT and IMRT plans, respectively. The CI was identical (1.67) in both sets of plans.
Conclusion: Based on the results of this study, the PTV coverage was found to be slightly better in the 3DCRT plans when compared to the one in the IMRT plans. On average, the dose to the organs at risk were found to be comparable.
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Murshed H, Liu HH, Liao Z, et al. Dose and volume reduction for normal lung using intensity- modulated radiotherapy for advanced-stage non-small- cell lung cancer. Int J Radiat Oncol Biol Phys. 2004; 58:1258-67.
Chapet O, Fraass BA, Haken RK. Multiple fields may offer better esophagus sparing without increased probability of lung toxicity in optimized IMRT of lung tumors. Int J Radiat Oncol Biol Phys. 2006; 65:255-65.
Wu G, Lian J, Shen D. Improving image-guided radiation therapy of lung cancer by reconstructing 4D-CT from a single free-breathing 3D-CT on the treatment day. Med Phys 2012; 39:7694-709.
Balter JM, Ten Haken RK, Lawrence TS, et al. Uncertainties in CT-based radiation therapy treatment planning associated with patient breathing. Int J Radiat Oncol Biol Phys 1996; 36:167-74.
ICRU Report 83. Prescribing, Recording, and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). International Commission on Radiation Units and Measurements, Bethesda; 2010.
Liu HH, Wang X, Dong L, et al. Feasibility of sparing lung and other thoracic structures with intensity-modulated radiotherapy for non-small-cell lung cancer. Int J Radiat Oncol Biol Phys. 2004; 58:1268-79.
Gurjar OP, Mishra SP, Bhandari V, et al. Radiation dose verification using real tissue phantom in modern radiotherapy techniques. J Med Phys 2014; 39:44-9.
Gurjar OP, Mishra SP. Dosimetric analysis of intensity modulated radiotherapy plans having one or more pairs of parallel opposed beams among the set of beams in some special cases. Radiat Prot Environ 2013; 36:138-42.
Rana S, Rogers K, Pokharel S, Cheng C. Evaluation of Acuros XB algorithm based on RTOG 0813 dosimetric criteria for SBRT lung treatment with RapidArc. J Appl Clin Med Phys 2014; 15:4474.
Ojala J. The accuracy of the Acuros XB algorithm in external beam radiotherapy − a comprehensive review. Int J Cancer Ther Oncol 2014; 2:020417.
Sievinen J, Ulmer W, Kaissl W. AAA photon dose calculation model in Eclipse. Palo Alto (CA): Varian Medical Systems, RAD #7170B; 2005.
Gagne IM, Zavgorodni S. Evaluation of the analytical anisotropic algorithm in an extreme water-lung interface phantom using Monte Carlo dose calculations. J Appl Clin Med Phys. 2006; 8:33-46.
Rana S, Pokharel S, Zheng Y, Zhao L, Risalvato D, Vargas C, Cersonsky N. Treatment planning study comparing proton therapy, RapidArc and intensity modulated radiation therapy for a synchronous bilateral lung cancer case. Int J Cancer Ther Oncol 2014; 2):020216.
Nichols RC, Huh SN, Henderson RH, et al. Proton radiation therapy offers reduced normal lung and bone marrow exposure for patients receiving dose-escalated radiation therapy for unresectable stage iii non-small-cell lung cancer: a dosimetric study. Clin Lung Cancer 2011; 12:252-7.
DOI: http://dx.doi.org/10.14319/ijcto.33.23
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International Journal of Cancer Therapy and Oncology (ISSN 2330-4049)
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