Feasibility study of functional magnetic resonance imaging-based biologically-guided lattice radiotherapy

Ke Yuan; Xinxiang Zhou; Hao Guo; Yi Peng; Peng Xu; Lintao Li; Jie Li; Heng Li; Shun Lu; Mei Feng; Jinyi Lang; Yuanjie Yang; Xianliang Wang

doi:10.1016/j.ijrobp.2025.06.3901

Feasibility study of functional magnetic resonance imaging-based biologically-guided lattice radiotherapy

Int J Radiat Oncol Biol Phys. 2025 Jul 10:S0360-3016(25)04636-X. doi: 10.1016/j.ijrobp.2025.06.3901. Online ahead of print.

Authors

Ke Yuan¹, Xinxiang Zhou², Hao Guo³, Yi Peng³, Peng Xu⁴, Lintao Li³, Jie Li³, Heng Li⁵, Shun Lu³, Mei Feng³, Jinyi Lang⁶, Yuanjie Yang⁷, Xianliang Wang⁸

Affiliations

¹ School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China; Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu 610042, China. Electronic address: yuanke@scszlyy.org.cn.
² Department of Radiation Oncology, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610042, China.
³ Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu 610042, China.
⁴ Department of Radiation Oncology, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610042, China; Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu 610042, China.
⁵ Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University.
⁶ Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu 610042, China. Electronic address: langjy610@163.com.
⁷ School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China. Electronic address: dr.yang2003@uestc.edu.cn.
⁸ Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Hospital & Institute, Sichuan Cancer Center, University of Electronic Science and Technology of China, Chengdu 610042, China. Electronic address: wangxianliang@scszlyy.org.cn.

PMID: 40651629
DOI: 10.1016/j.ijrobp.2025.06.3901

Abstract

Purpose/objectives: Lattice radiotherapy (LRT) is a promising approach for treating bulky tumors; however, current methods do not consider patient-specific tumor heterogeneity. Low apparent diffusion coefficient (ADC) regions, identified via diffusion-weighted magnetic resonance imaging (DWI), correspond to areas of high cellular density and radioresistance. Targeted dose escalation in these regions may enhance tumor control. Thus, we propose biologically guided lattice radiotherapy (BG-LRT), which optimizes lattice positioning based on ADC map.

Methods: We retrospectively analyzed 20 patients with bulky tumors (>6 cm) who underwent DWI and simulation CT within 3 days. BG-LRT plans were created by aligning high-dose lattice regions with low ADC areas and compared them with hexagonal close-packed lattice radiotherapy (HCP-LRT). Both techniques prescribed 60 Gy in lattice regions and 20 Gy to the gross tumor volume (GTV) over five fractions. The dosimetric evaluation included the peak-valley dose ratio (PVDR) and ablation dose ratio (ADR) within the GTV as well as dose distribution in ADC-defined tumor subregions (R_ADC10-R_ADC50) and organs at risk (OARs).

Results: BG-LRT achieved a higher PVDR (2.7 vs. 2.4) and ADR (2.6% vs. 1.7%) than HCP-LRT. ADR values across all ADC-defined tumor subregions (R_ADC10-R_ADC50) were significantly higher for BG-LRT. OAR doses were comparable between methods, with no significant differences in mean dose (D_mean) to the heart, stomach, esophagus, kidneys, liver, and duodenum as well as the maximum doses (D_max) to the lens, eye, optic nerve, brainstem and optic chiasm. Planning time, delivery time, monitor units, and gamma pass rates were similar between techniques.

Conclusion: BG-LRT improves PVDR and ADR in the GTV while focusing on dose escalation in biologically relevant tumor regions. This technique maintains low OAR doses and represents a promising step toward personalized LRT treatment planning.

Keywords: biological guided radiation therapy; diffusion-weighted MRI; lattice radiation therapy; spatially fractionated radiation therapy.