Dose fall-off during the treatment of thoracic spine metastasis with CyberKnife stereotactic body radiation therapy (SBRT)

Authors

  • Zhongjian Ju Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, China Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
  • Jingyuan Wang Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
  • Huaiwen Zhang Department of Radiotherapy, Jiang-Xi Cancer Hospital, Nanchang, China
  • Lei Du Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, China
  • Wei Xu Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
  • Xiaoshen Wang Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
  • Ruigang Ge Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
  • Jiwei Li Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
  • Qingzeng Zheng Department of Radiotherapy, Beijing Geriatric Hospital, Beijing, China
  • Jianxiong Li Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, China

DOI:

https://doi.org/10.17305/bjbms.2018.3185

Keywords:

CyberKnife, dosage, radiation, stereotactic body radiation therapy, SBRT, thoracic spine metastasis, dose gradient

Abstract

CyberKnife stereotactic body radiation therapy (SBRT) is becoming increasingly used for cancer treatment and, to maximize its clinical application, it is important to define the dosimetric characteristics, optimal dose, and fractionation regimens. The aim of this study was to evaluate the dose fall-off in two fractionated regimens of CyberKnife SBRT during the treatment of thoracic spinal metastasis. Patients with spinal metastasis involving a vertebra and pedicle were treated with 40 Gy in 5 fractions (n = 4), and patients with spinal metastasis involving only a vertebra received 33 Gy in 3 fractions (n = 4). A new approach was used to measure absolute dose fall-off distance, relative dose fall-off distance, and the dose fall-off per unit distance along four reference directions in the axial plane. Patients treated with 33 Gy/3 fractions had a greater absolute dose fall-off distance in direction 1 (from the point with maximum dose [Dmax] towards the spinal cord) and direction 3 (the opposite of direction 1), a greater relative dose fall-off distance in direction 3, and a lower dose fall-off per unit distance in direction 1 and 3 compared to patients treated with 40 Gy/5 fractions (all p < 0.05). Overall, the dose fall-off towards the spinal cord is rapid during the treatment of thoracic spinal metastasis with CyberKnife SBRT, which allows a higher dose of radiation to be delivered to the tumor and, at the same time, better protection of the spinal cord.

Author Biographies

  • Zhongjian Ju, Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, China Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China

    Department of Radiation Oncology

    Department of Radiotherapy

     

  • Jingyuan Wang, Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
    Department of Radiotherapy
  • Huaiwen Zhang, Department of Radiotherapy, Jiang-Xi Cancer Hospital, Nanchang, China
    Department of Radiotherapy
  • Lei Du, Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, China
    Department of Radiation Oncology
  • Wei Xu, Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
    Department of Radiotherapy
  • Xiaoshen Wang, Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
    Department of Radiotherapy
  • Ruigang Ge, Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
    Department of Radiotherapy
  • Jiwei Li, Department of Radiotherapy, Chinese PLA General Hospital, Beijing, China
    Department of Radiotherapy
  • Qingzeng Zheng, Department of Radiotherapy, Beijing Geriatric Hospital, Beijing, China
    Department of Radiotherapy
  • Jianxiong Li, Department of Radiation Oncology, Hainan Branch of Chinese PLA General Hospital, Sanya, China
    Department of Radiation Oncology
Dose fall-off during the treatment of thoracic spine metastasis with CyberKnife stereotactic body radiation therapy (SBRT)

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Published

05-02-2020

How to Cite

1.
Dose fall-off during the treatment of thoracic spine metastasis with CyberKnife stereotactic body radiation therapy (SBRT). Biomol Biomed [Internet]. 2020 Feb. 5 [cited 2024 Mar. 1];20(1):131-9. Available from: https://www.bjbms.org/ojs/index.php/bjbms/article/view/3185