Daily Online Bony Correction is Required for Prostate Patients Without Fiducial Markers or Soft-tissue Imaging

作者：Johnston M L; Vial R; Wiltshire K L; Bell L J; Blome S; Kerestes Z; Morgan G W; O'Driscoll D; Shakespeare T P; Eade T N^*

来源：Clinical Oncology, 2011, 23(7): 454-459.

DOI：10.1016/j.clon.2011.02.013

• Bony anatomy
• fiducial marker
• online correction
• prostate radiotherapy

Aim: To compare online position verification strategies with offline correction protocols for patients undergoing definitive prostate radiotherapy.
Materials and methods: We analysed 50 patients with implanted fiducial markers undergoing curative prostate radiation treatment, all of whom underwent daily kilovoltage imaging using an on-board imager. For each treatment, patients were set-up initially with skin tattoos and in-room lasers. Orthogonal on-board imager images were acquired and the couch shift to match both bony anatomy and the fiducial markers recorded. The set-up error using skin tattoos and offline bone correction was compared with online bone correction. The fiducial markers were used as the reference.
Results: Data from 1923 fractions were analysed. The systematic error was <= 1 mm for all protocols. The average random error was 2-3 mm for online bony correction and 3-5 mm for skin tattoos or offline-bone. Online-bone showed a significant improvement compared with offline-bone in the number of patients with >5 mm set-up errors for >10% (P < 0.001) and >20% (P < 0.003) of their fractions.
Conclusions: Online correction to bony anatomy reduces both systematic and random set-up error in patients undergoing prostate radiotherapy, and is superior to offline correction methods for those patients not suitable for fiducial markers or daily soft-tissue imaging.

• 出版日期2011-9
• 单位河北医科大学