PURPOSE: Lungs are the major dose-limiting organ during radiotherapy (RT) for non-small-cell lung cancer owing to the development of pneumonitis. This study compared intensity-modulated RT (IMRT) with three-dimensional conformal RT (3D-CRT) in reducing the dose to the lungs. METHODS: Ten patients with localized non-small-cell lung cancer underwent computed tomography (CT). The planning target volume (PTV) was defined and the organs at risk were outlined. An inverse-planning program, AutoPlan, was used to design the beam angle-optimized six-field noncoplanar 3D-CRT plans. Each 3D-CRT plan was compared with a series of five IMRT plans per patient. The IMRT plans were created using a commercial algorithm and consisted of a series of three, five, seven, and nine equidistant coplanar field arrangements and one six-field noncoplanar plan. The planning objectives were to minimize the lung dose while maintaining the dose to the PTV. The percentage of lung volume receiving >20 Gy (V20) and the percentage of the PTV covered by the 90% isodose (PTV90) were the primary endpoints. The PTV90/V20 ratio was used as the parameter accounting for both the reduction in lung volume treated and the PTV coverage. RESULTS: All IMRT plans, except for the three-field coplanar plans, improved the PTV90/V20 ratio significantly compared with the optimized 3D-CRT plan. Nine coplanar IMRT beams were significantly better than five or seven coplanar IMRT beams, with an improved PTV90/V20 ratio. CONCLUSION: The results of our study have shown that IMRT can reduce the dose to the lungs compared with 3D-CRT by improving the conformity of the plan.
PURPOSE: Lungs are the major dose-limiting organ during radiotherapy (RT) for non-small-cell lung cancer owing to the development of pneumonitis. This study compared intensity-modulated RT (IMRT) with three-dimensional conformal RT (3D-CRT) in reducing the dose to the lungs. METHODS: Ten patients with localized non-small-cell lung cancer underwent computed tomography (CT). The planning target volume (PTV) was defined and the organs at risk were outlined. An inverse-planning program, AutoPlan, was used to design the beam angle-optimized six-field noncoplanar 3D-CRT plans. Each 3D-CRT plan was compared with a series of five IMRT plans per patient. The IMRT plans were created using a commercial algorithm and consisted of a series of three, five, seven, and nine equidistant coplanar field arrangements and one six-field noncoplanar plan. The planning objectives were to minimize the lung dose while maintaining the dose to the PTV. The percentage of lung volume receiving >20 Gy (V20) and the percentage of the PTV covered by the 90% isodose (PTV90) were the primary endpoints. The PTV90/V20 ratio was used as the parameter accounting for both the reduction in lung volume treated and the PTV coverage. RESULTS: All IMRT plans, except for the three-field coplanar plans, improved the PTV90/V20 ratio significantly compared with the optimized 3D-CRT plan. Nine coplanar IMRT beams were significantly better than five or seven coplanar IMRT beams, with an improved PTV90/V20 ratio. CONCLUSION: The results of our study have shown that IMRT can reduce the dose to the lungs compared with 3D-CRT by improving the conformity of the plan.
Authors: Y Tajima; H Nakayama; T Itonaga; S Shiraishi; M Okubo; R Mikami; S Sugahara; K Tokuuye Journal: Br J Radiol Date: 2015-05-21 Impact factor: 3.039
Authors: Tejan P Diwanji; Pranshu Mohindra; Melissa Vyfhuis; James W Snider; Chaitanya Kalavagunta; Sina Mossahebi; Jen Yu; Steven Feigenberg; Shahed N Badiyan Journal: Transl Lung Cancer Res Date: 2017-04
Authors: Minal S Kale; Grace Mhango; Marcelo Bonomi; Alex Federman; Keith Sigel; Kenneth E Rosenzweig; Juan P Wisnivesky Journal: Ann Am Thorac Soc Date: 2016-09
Authors: Vasileios Askoxylakis; Julien Dinkel; Monika Eichinger; Bram Stieltjes; Gregor Sommer; Ludwig G Strauss; Antonia Dimitrakopoulou-Strauss; Annette Kopp-Schneider; Uwe Haberkorn; Peter E Huber; Marc Bischof; Jürgen Debus; Christian Thieke Journal: Radiat Oncol Date: 2012-09-14 Impact factor: 3.481