Author: Yi Li 👨🔬
Affiliation: Department of Radiation Oncology, the First Affiliated Hospital of Xi'an Jiaotong University 🌍
Purpose: Advances in radiotherapy technology are crucial for improving cervical cancer (CC) treatment. This study explores a novel X-ray and γ-ray dual-modality radiation (TaiChiB) system, comparing its treatment plan quality with that of a conventional LINAC X-ray system for CC patients. The goal is to evaluate whether the dual-modality approach can enhance dose delivery to tumors while better sparing surrounding healthy tissues.
Methods: Retrospective volumetric modulated arc therapy plans for 12 CC patients were analyzed. Dual-modality plans were developed for the same patients, with prescription doses of 50Gy/25 fractions for the planning tumor volume (PTV) and 60Gy/25 fractions for PTV-nd. Dose conformity index (CI) and gradient index (GI) were used to assess target coverage and dose drop. Dose indices (Dmean, Dmax, Dmin) were evaluated for both targets and organs at risk (OARs), including the spinal cord, bladder, and rectum.
Results: Both systems produced dosimetrically acceptable plans. The TaiChiB system showed higher CI values (PTV-nd: 0.68±0.11 vs. 0.57±0.22; PTV: 0.91±0.02 vs. 0.90±0.02) and lower GI values (PTV-nd: 280.62±302.86 vs. 300.65±317.83; PTV: 3.36±0.22 vs. 3.66±0.32) compared to the LINAC system, indicating superior dose conformity and sharper dose gradients. TaiChiB plans also demonstrated higher dosimetric indices (Dmax, Dmean, Dmin) for PTV-nd and PTV, with a notable difference in Dmax. Conversely, TaiChiB plans showed significantly lower dosimetric metrics for OARs, particularly for the spinal cord PRV (23.61±2.80 Gy vs. 29.85±3.23 Gy, P-value=0.0005), indicating better organ protection. Similar improvements were observed for the bladder and rectum.
Conclusion: The dual-modality system offers improved dose distribution within the tumor, sharper dose gradients outside the target, and enhanced protection of adjacent normal tissues. These findings suggest that the dual-modality approach could provide significant clinical benefits for CC patients. Further research and clinical trials are needed to validate and refine this approach for broader clinical use.