Magnetic resonance image-based tomotherapy planning for prostate cancer.

To evaluate and compare the feasibilities of magnetic resonance (MR) image-based planning using synthetic computed tomography (sCT) versus CT (pCT)-based planning in helical tomotherapy for prostate cancer.

A retrospective evaluation was performed in 16 patients with prostate cancer who had been treated with helical tomotherapy. MR images were acquired using a dedicated therapy sequence; sCT images were generated using magnetic resonance for calculating attenuation (MRCAT). The three-dimensional dose distribution according to sCT was recalculated using a previously optimized plan and was compared with the doses calculated using pCT.

The mean planning target volume doses calculated by sCT and pCT differed by 0.65% ± 1.11% (p = 0.03). Three-dimensional gamma analysis at a 2%/2 mm dose difference/distance to agreement yielded a pass rate of 0.976 (range, 0.658 to 0.986).

The dose distribution results obtained using tomotherapy from MR-only simulations were in good agreement with the dose distribution results from simulation CT, with mean dose differences of less than 1% for target volume and normal organs in patients with prostate cancer.

Radiation oncology journal. 2020 Mar 27 [Epub]

Sang Hoon Jung, Jinsung Kim, Yoonsun Chung, Bilgin Keserci, Hongryull Pyo, Hee Chul Park, Won Park

Department of Radiation Oncology, Samsung Medical Center, Seoul, Korea., Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea., Department of Nuclear Engineering, Hanyang University, Seoul, Korea., Department of Radiology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia., Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.