2059 - Spatially Fractionated Radiation Therapy Using Lattice Radiation in Giant Liver Cancer: Dosimetric Advantages of a Novel Multi-Modality Radiotherapy Platform

02:30pm - 04:00pm PT

Hall F

Screen: 9

POSTER

Presenter(s)

Jie Duan, MS - Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi

J. Duan¹, and L. N. Zhao²; ¹Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China, ²Department of radiation oncology, Xijing Hospital, the Fourth Military Medical University, Xi'an, China

Purpose/Objective(s): This study aims to investigate the dosimetric advantages of a novel multi-modality radiotherapy platform, TaiChiB, which integrates a medical linear accelerator (linac) with a focused 60Co ?-ray system. Specifically, the research evaluates the potential benefits of this technique for lattice radiotherapy (LRT) in patients with giant liver cancer.

Materials/Methods: A retrospective analysis was conducted on 10 cases of spatially fractionated radiotherapy for patients with giant liver cancer. Each patient received two treatment plans: a Varian linac x-ray plan (Group A) and a TaiChiB plan combining linac x-rays with focused ?-rays (Group B). In both groups, the prescribed dose to the vertex was 14 Gy, with a primary dose of 40 Gy to the planning target volume (PTV). In the TaiChiB plan, the primary dose was delivered using linac x-rays, while the vertex dose was delivered using ?-rays. Plan quality was evaluated using various criteria, and the results of the two groups were compared through statistical analysis, with p < 0.05 considered statistically significant.

Results:

Both groups' plans met clinical treatment requirements. The TaiChiB plan demonstrated superior dose coverage to the vertex, with a higher mean dose (17.43±0.76 Gy in Group B vs. 15.72±0.41 Gy in Group A, p < 0.01), while maintaining a lower edge dose to the gross tumor volume (GTV) (4.30±0.34 Gy in Group B vs. 5.06±0.19 Gy in Group A, p < 0.01). This resulted in a significantly higher D10/D90 (8.84±5.31 in Group B vs. 4.48±2.03 in Group A). Additionally, the TaiChiB plan showed lower or comparable mean doses to organs-at-risk (OARs). In detail, Live V₁_5Gy (57.84±8.18% (B) vs. 59.96±7.58% (A), p < 0.01), V₃₀_Gy (44.65±5.93% (B) vs. 47.49±5.61% (A), p < 0.01), D_mean_Gy (24.91±2.80 Gy (B) vs. 26.90±2.97 Gy (A), p < 0.01); Lift Kidney V₂₀_Gy (2.06±0.36% (B) vs. 2.33±0.33%(A), p < 0.01); D_mean_Gy (4.57±0.62 Gy (B) vs. 4.98±0.83 Gy (A), p < 0.01); Right Kidney V₂₀_Gy (26.67±5.16% (B) vs. 29.49±2.26%(A), p < 0.01); D_mean_Gy (12.29±1.02% (B) vs. 13.84±0.98% (A), p < 0.01); Intestine D_mean_Gy (6.19±4.75 Gy (B) vs. 6.89±4.99 Gy (A), p < 0.01); Stomach D_mean_Gy (22.88±7.23 Gy (B) vs. 28.80±5.77 Gy (A), p < 0.01); Spinal canal D_max_Gy (29.36±2.89 Gy (B) vs. 35.34±2.89 Gy (A), p < 0.01).

Conclusion: The results demonstrate the dosimetric superiority of the TaiChiB multi-modality radiotherapy platform. By leveraging the physical advantages of ?-rays as a complement to x-rays, TaiChiB offers improved dose distribution for lattice radiotherapy, making it a promising approach for treating patients with giant liver cancer.