N V N Madhusudhana Sresty1,2, Deleep Gudipudi3, A Krishnam Raju3, T Anil Kumar3, V R P Lakshmi3, G Srikanth3, M Narasimha3. 1. Department of Radiotherapy, Basavatarakam Indo American Cancer Hospital & Research Institute, Hyderabad, India. srestybarc@gmail.com. 2. Head-Medical Physics, Department of Radiotherapy, Basavatarakam Indo American Cancer Hospital & Research Institute, Road No: 14, 500034, Hyderabad, Banjara Hills, India. srestybarc@gmail.com. 3. Department of Radiotherapy, Basavatarakam Indo American Cancer Hospital & Research Institute, Hyderabad, India.
Abstract
PURPOSE: Total body irradiation (TBI) can be safely delivered on TomoTherapy (Accuray, Sunnyvale, CA, USA) in both pediatric and adult patients with proper imaging and planning despite the length constraint of 135 cm. To overcome this limitation, two CT (Computed Tomography) scans (CT1& CT2) are taken in patients above 135 cm in height. Adequate junction dose coverage is important in TBI. Presently, there is no clinical report with a focus on the quality of dose distribution at the CT junction in view of the guidelines on quality of coverage from the RTOG. Hence, our main objectives were to evaluate the dose distribution and quality of coverage at the junction in 16 patients who received TBI using TomoTherapy. METHODS: PTV(upper) and PTV(lower) along with a junction were created on CT1 and CT2, respectively. Subsequently, the 10 cm junction in the thigh region was divided into five target volumes of 2 cm thickness with dose prescription ranging from 10 to 90% to deliver a total dose equal to 100% when fused. RESULTS: The D50 was equal to the prescribed dose in most of the cases ranging from 99.5 to 104% for PTV(upper), 100-103% for PTV(lower), and 99.5-108% for junctional PTVs (1PTV, 2PTV, 3PTV, 4PTV, and 5PTV). The average D95 doses from PTV(upper) and PTV(lower) were 97 ± 1.4% and 96.7 ± 1.08%, respectively. The average D95 doses for 1PTV, 2PTV, 3PTV, 4PTV, and 5PTV were 96.1 ± 1.88%, 91.6 ± 1.82%, 87.3 ± 1.5%, 91.6 ± 1.4%, and 96.2 ± 1.5% respectively. QRTOG values ranged between 0.85 and 1.05 and were in concordance with RTOG guidelines. CONCLUSION: Since junction-based planning was required for most TBI patients, it is essential to evaluate the quality of dose coverage in the junction for better TBI plans.
PURPOSE: Total body irradiation (TBI) can be safely delivered on TomoTherapy (Accuray, Sunnyvale, CA, USA) in both pediatric and adult patients with proper imaging and planning despite the length constraint of 135 cm. To overcome this limitation, two CT (Computed Tomography) scans (CT1& CT2) are taken in patients above 135 cm in height. Adequate junction dose coverage is important in TBI. Presently, there is no clinical report with a focus on the quality of dose distribution at the CT junction in view of the guidelines on quality of coverage from the RTOG. Hence, our main objectives were to evaluate the dose distribution and quality of coverage at the junction in 16 patients who received TBI using TomoTherapy. METHODS: PTV(upper) and PTV(lower) along with a junction were created on CT1 and CT2, respectively. Subsequently, the 10 cm junction in the thigh region was divided into five target volumes of 2 cm thickness with dose prescription ranging from 10 to 90% to deliver a total dose equal to 100% when fused. RESULTS: The D50 was equal to the prescribed dose in most of the cases ranging from 99.5 to 104% for PTV(upper), 100-103% for PTV(lower), and 99.5-108% for junctional PTVs (1PTV, 2PTV, 3PTV, 4PTV, and 5PTV). The average D95 doses from PTV(upper) and PTV(lower) were 97 ± 1.4% and 96.7 ± 1.08%, respectively. The average D95 doses for 1PTV, 2PTV, 3PTV, 4PTV, and 5PTV were 96.1 ± 1.88%, 91.6 ± 1.82%, 87.3 ± 1.5%, 91.6 ± 1.4%, and 96.2 ± 1.5% respectively. QRTOG values ranged between 0.85 and 1.05 and were in concordance with RTOG guidelines. CONCLUSION: Since junction-based planning was required for most TBI patients, it is essential to evaluate the quality of dose coverage in the junction for better TBI plans.
Authors: J A Peñagarícano; M Chao; F Van Rhee; E G Moros; P M Corry; V Ratanatharathorn Journal: Bone Marrow Transplant Date: 2010-10-11 Impact factor: 5.483
Authors: Jeffrey Y C Wong; Andrea Riccardo Filippi; Bouthaina Shbib Dabaja; Joachim Yahalom; Lena Specht Journal: Int J Radiat Oncol Biol Phys Date: 2018-05-02 Impact factor: 7.038
Authors: Mustafa Abugideiri; Ronica H Nanda; Charlotte Butker; Chao Zhang; Sungjin Kim; Kuang-Yueh Chiang; Elizabeth Butker; Mohammad K Khan; Ann E Haight; Zhengjia Chen; Natia Esiashvili Journal: Int J Radiat Oncol Biol Phys Date: 2015-10-31 Impact factor: 7.038