INTRODUCTION: To evaluate the precision required in dose-escalated IMRT treatment of spinal metastases and paraspinal tumors. METHODS: In IMRT treatment plans of nine patients with spinal metastases (n=7) and paraspinal tumors (n=2) translational patient positioning errors (0-10mm) and rotational errors (0-7.5 degrees ) were simulated. The dose to the spinal cord (D5(spine)) resulting from these simulations was evaluated and NTCP for spinal cord necrosis was calculated. All patient set-up errors observed during treatment were simulated and the influence on D5(spine) was investigated. RESULTS: To keep the dose distribution to the spinal cord within +/-5% (+/-10%) of the prescribed dose, maximum tolerable errors of 1mm (2mm) in the transversal plane, 4mm (7mm) in superior-inferior direction and maximum rotations of 3.5 degrees (5 degrees ) were calculated on average. The translational and rotational component of clinically observed set-up errors increased D5(spine) by 23+/-14% and 3+/-2% on average, respectively. CONCLUSION: Steep dose gradients of IMRT planning require very high precision. In selected patients correction of both translational and rotational errors may be beneficial.
INTRODUCTION: To evaluate the precision required in dose-escalated IMRT treatment of spinal metastases and paraspinal tumors. METHODS: In IMRT treatment plans of nine patients with spinal metastases (n=7) and paraspinal tumors (n=2) translational patient positioning errors (0-10mm) and rotational errors (0-7.5 degrees ) were simulated. The dose to the spinal cord (D5(spine)) resulting from these simulations was evaluated and NTCP for spinal cord necrosis was calculated. All patient set-up errors observed during treatment were simulated and the influence on D5(spine) was investigated. RESULTS: To keep the dose distribution to the spinal cord within +/-5% (+/-10%) of the prescribed dose, maximum tolerable errors of 1mm (2mm) in the transversal plane, 4mm (7mm) in superior-inferior direction and maximum rotations of 3.5 degrees (5 degrees ) were calculated on average. The translational and rotational component of clinically observed set-up errors increased D5(spine) by 23+/-14% and 3+/-2% on average, respectively. CONCLUSION: Steep dose gradients of IMRT planning require very high precision. In selected patients correction of both translational and rotational errors may be beneficial.
Authors: David Y Hu; Yiwen Xu; Yu-Hui Chen; Marjan Khosravi; Yulia Lyatskaya; Jeremy S Bredfeldt; Fred L Hacker; Tracy A Balboni; Alexander Spektor; Daniel Cagney; Raymond Mak; Mai Anh Huynh Journal: Adv Radiat Oncol Date: 2022-04-08
Authors: Orit Gutfeld; Annette E Kretzler; Rojano Kashani; Daniel Tatro; James M Balter Journal: Int J Radiat Oncol Biol Phys Date: 2009-04-01 Impact factor: 7.038
Authors: Jinkoo Kim; Jian-Yue Jin; Ning Wen; Samir H Patel; Benjamin Movsas; Jack Rock; Indrin J Chetty; Samuel Ryu Journal: J Radiosurg SBRT Date: 2012