title: Dosimetric comparison of three-dimensional conformal radiotherapy, intensity modulated radiotherapy, and helical tomotherapy for lung stereotactic body radiotherapy.
abstract: To compare the treatment plans generated with three-dimensional conformal radiation therapy (3DCRT), intensity modulated radiotherapy (IMRT), and helical tomotherapy (HT) for stereotactic body radiotherapy of lung, twenty patients with medically inoperable (early nonsmall cell lung cancer) were retrospectively reviewed for dosimetric evaluation of treatment delivery techniques (3DCRT, IMRT, and HT). A dose of 6 Gy per fraction in 8 fractions was prescribed to deliver 95% of the prescription dose to 95% volume of planning target volume (PTV). Plan quality was assessed using conformity index (CI) and homogeneity index (HI). Doses to critical organs were assessed. Mean CI with 3DCRT, IMRT, and HT was 1.19 (standard deviation [SD] 0.13), 1.18 (SD 0.11), and 1.08 (SD 0.04), respectively. Mean HI with 3DCRT, IMRT, and HT was 1.14 (SD 0.05), 1.08 (SD 0.02), and 1.07 (SD 0.04), respectively. Mean R50% values for 3DCRT, IMRT, and HT was 8.5 (SD 0.35), 7.04 (SD 0.45), and 5.43 (SD 0.29), respectively. D2cm was found superior with IMRT and HT. Significant sparing of critical organs can be achieved with highly conformal techniques (IMRT and HT) without compromising the PTV conformity and homogeneity.
authors: Department of Medical Physics, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Rajesh Ashok
authors: RA
authors: Kinhikar
authors: Department of Medical Physics, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Yogesh G
authors: YG
authors: Ghadi
authors: Department of Medical Physics, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Priyadarshini
authors: P
authors: Sahoo
authors: Department of Radiation Oncology, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Sarbani Ghosh
authors: SG
authors: Laskar
authors: Department of Medical Physics, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Deepak D
authors: DD
authors: Deshpande
authors: Department of Radiation Oncology, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Shyam K
authors: SK
authors: Shrivastava
authors: Department of Radiation Oncology, Tata Memorial Centre, Mumbai, Maharashtra, India.
authors: Jaiprakash
authors: J
authors: Agarwal
keywords: Helical tomotherapy; intensity modulated radiotherapy; lung stereotactic body radiotherapy; three-dimensional conformal radiation therapy; treatment planning