PURPOSE: We have used dynamic conformal multiple arc therapy (DCMAT) for stereotactic body radiotherapy (SBRT) since 2001. We investigated the consistency of DCMAT for SBRT using dose-volume histogram analysis. METHODS AND MATERIALS: A total of 50 patients with peripheral lung tumors underwent SBRT. The median tumor diameter was 2.4 cm (range, 0.9-5.9). Treatment planning was performed using a superposition algorithm. The prescribed 50 Gy dose was divided into five fractions. The prescribed dose was defined as 80% of the maximal dose in the planning target volume (PTV), and the leaf margins were modified to ensure the PTV was included in the 80% isodose surface. The dose-volume histogram analysis was used to assess the PTV and normal lung volume. RESULTS: The median dose covering 95% of the PTV was 50.27 Gy (range, 46.14-52.67), essentially consistent with the prescribed dose. The median homogeneity and conformity index was 1.41 (range, 1.31-1.53) and 1.73 (range, 1.41-2.21), respectively. The median volume of lung receiving > or =20 Gy (V(20)) was 4.2% (range, 1.4-10.2%). A linear correlation was found between the tumor diameter and V(20), and an even stronger correlation was found between the PTV/(normal lung volume) and V(20). The estimated V(20) was 7.1% (range, 3.9-10.4%) for a 5-cm-diameter tumor, assumed to be the maximal size limitation for SBRT. CONCLUSION: SBRT with DCMAT achieved high conformity and delivered adequate doses within the PTV. The median dose covering 95% of the PTV was consistent with the prescribed dose. V(20) can be estimated using the tumor diameter and normal lung volume. DCMAT was thus both a feasible and a reproducible method of SBRT delivery.
PURPOSE: We have used dynamic conformal multiple arc therapy (DCMAT) for stereotactic body radiotherapy (SBRT) since 2001. We investigated the consistency of DCMAT for SBRT using dose-volume histogram analysis. METHODS AND MATERIALS: A total of 50 patients with peripheral lung tumors underwent SBRT. The median tumor diameter was 2.4 cm (range, 0.9-5.9). Treatment planning was performed using a superposition algorithm. The prescribed 50 Gy dose was divided into five fractions. The prescribed dose was defined as 80% of the maximal dose in the planning target volume (PTV), and the leaf margins were modified to ensure the PTV was included in the 80% isodose surface. The dose-volume histogram analysis was used to assess the PTV and normal lung volume. RESULTS: The median dose covering 95% of the PTV was 50.27 Gy (range, 46.14-52.67), essentially consistent with the prescribed dose. The median homogeneity and conformity index was 1.41 (range, 1.31-1.53) and 1.73 (range, 1.41-2.21), respectively. The median volume of lung receiving > or =20 Gy (V(20)) was 4.2% (range, 1.4-10.2%). A linear correlation was found between the tumor diameter and V(20), and an even stronger correlation was found between the PTV/(normal lung volume) and V(20). The estimated V(20) was 7.1% (range, 3.9-10.4%) for a 5-cm-diameter tumor, assumed to be the maximal size limitation for SBRT. CONCLUSION: SBRT with DCMAT achieved high conformity and delivered adequate doses within the PTV. The median dose covering 95% of the PTV was consistent with the prescribed dose. V(20) can be estimated using the tumor diameter and normal lung volume. DCMAT was thus both a feasible and a reproducible method of SBRT delivery.
Authors: N Sanuki-Fujimoto; A Takeda; T Ohashi; E Kunieda; S Iwabuchi; K Takatsuka; N Koike; N Shigematsu Journal: Br J Radiol Date: 2010-12 Impact factor: 3.039
Authors: Feng-Ming Spring Kong; Vitali Moiseenko; Jing Zhao; Michael T Milano; Ling Li; Andreas Rimner; Shiva Das; X Allen Li; Moyed Miften; ZhongXing Liao; Mary Martel; Soren M Bentzen; Andrew Jackson; Jimm Grimm; Lawrence B Marks; Ellen Yorke Journal: Int J Radiat Oncol Biol Phys Date: 2018-11-26 Impact factor: 8.013