Repetitive Painting (REPEAT) Irradiation in Stereotactic Radiotherapy Using Helical Tomotherapy
Y U Ohkubo1, Takuya Kumazawa2, Ryuta Hirai3
1Department of Radiation Oncology, Saku Central Hospital Advanced Care Center, Nagano, Japan; ohkuboy@gmail.com.
In Vivo (Athens, Greece)
|January 1, 2022
Summary
Repetitive Painting (REPEAT) irradiation divides stereotactic radiotherapy fractions into multiple daily sessions. This method shortens treatment time and improves dose accuracy for spine metastases, offering a practical clinical solution.
Area of Science:
- Radiation Oncology
- Medical Physics
Background:
- Stereotactic radiotherapy (SRT) for spine metastases using helical tomotherapy faces challenges due to long irradiation times and intra-fractional motion.
- Current helical tomotherapy limitations prevent real-time position correction during irradiation, impacting treatment accuracy for extended sessions.
Purpose of the Study:
- To introduce and evaluate a novel irradiation method, REPEtitive pAinTing (REPEAT) irradiation, for helical tomotherapy of spine metastases.
- To assess the impact of REPEAT irradiation on irradiation time and dose-volume histogram (DVH) parameters.
Main Methods:
- A planning study was conducted using CT images of a patient with lumbar spine metastasis.
- REPEAT irradiation involves dividing a single fraction into multiple daily sessions with position correction via mega-voltage computed tomography (MVCT) before each session.
- Helical tomotherapy treatment plans were evaluated to compare REPEAT irradiation with conventional methods.
Main Results:
- Dividing 3 irradiation fractions into 3 sessions per day (9 fractions over 3 days) using REPEAT irradiation significantly shortened the irradiation time per session.
- REPEAT irradiation demonstrated improvements in dose-volume histogram (DVH) parameters compared to conventional planning.
Conclusions:
- REPEAT irradiation is a simple, practical treatment method for spine metastases using helical tomotherapy, requiring no special equipment.
- While optimal session parameters may vary, REPEAT irradiation effectively addresses the challenges of long treatment times and intra-fractional motion in SRT.
