Takaki Masanori, Hirose Taka-Aki, Yoshitake Tadamasa, Matsumoto Keiji, Shirakawa Yuko, Wakiyama Hiroaki, Hisano Osamu, Imafuku Hikaru, Ishigami Kousei
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan.
Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku, Fukuoka 812-8582, Japan.
Tech Innov Patient Support Radiat Oncol. 2025 Jun 25;35:100321. doi: 10.1016/j.tipsro.2025.100321. eCollection 2025 Sep.
This study evaluated dosimetric values of cone beam computed tomography (CBCT)-guided online adaptive radiotherapy (oART) in patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, accounting for interfractional and intrafractional motion.
Four patients with stage I gastric MALT lymphoma received CBCT-guided oART. For each of the 60 treatment sessions, scheduled (SCH) and adapted (ADP) plans were generated. Dosimetric evaluation focused on clinical target volume (CTV) and organs at risk (OARs). Metrics included CTV D98 % and D95 %, mean dose to the liver and left and right kidneys, maximum dose to the spinal cord, and V5Gy for bilateral kidneys. Adaptive planning CBCT-based contours were propagated to synthetic CTs of SCH and ADP plans to assess interfractional motion. Post-treatment CBCT-based contours were propagated to synthetic CTs of the ADP plan to evaluate intrafractional motion.
ADP plans significantly improved CTV coverage: mean D98% increased from 94.7 % in the SCH plan to 98.6 %, and D95% from 97.3 % to 99.2 % (p < 0.001). Most OAR doses were reduced in the ADP plans, including bilateral kidney V5Gy (11.3 % vs. 8.3 %, p < 0.001) and spinal cord Dmax (9.8 Gy vs. 7.9 Gy, p < 0.001). Liver Dmean was slightly higher in the ADP plan (11.4 Gy vs. 11.1 Gy, p = 0.002). No significant differences were observed in CTV and OAR dosimetric parameters between adaptive planning and post-treatment CBCTs (e.g., CTV D98%: 98.6 % vs. 98.5 %, p = 0.629).
CBCT-guided oART improved target coverage and maintained post-treatment dosimetric stability in gastric MALT lymphoma, supporting clinical feasibility.
本研究评估了锥形束计算机断层扫描（CBCT）引导下的在线自适应放疗（oART）在胃黏膜相关淋巴组织（MALT）淋巴瘤患者中的剂量学值，同时考虑了分次间和分次内运动。
4例I期胃MALT淋巴瘤患者接受了CBCT引导下的oART。在60次治疗疗程中，每次均生成计划（SCH）和自适应（ADP）计划。剂量学评估集中在临床靶区（CTV）和危及器官（OARs）。指标包括CTV的D98%和D95%、肝脏及左右肾的平均剂量、脊髓的最大剂量以及双侧肾脏的V5Gy。基于CBCT的自适应计划轮廓被传播到SCH和ADP计划的合成CT上，以评估分次间运动。治疗后基于CBCT的轮廓被传播到ADP计划的合成CT上，以评估分次内运动。
ADP计划显著改善了CTV覆盖：平均D98%从SCH计划中的94.7%提高到98.6%，D95%从97.3%提高到99.2%（p < 0.001）。在ADP计划中，大多数OAR剂量降低，包括双侧肾脏的V5Gy（11.3%对8.3%，p < 0.001）和脊髓的Dmax（9.8 Gy对7.9 Gy，p < 0.001）。ADP计划中肝脏的Dmean略高（11.4 Gy对11.1 Gy，p = 0.002）。在自适应计划和治疗后CBCT之间，CTV和OAR剂量学参数未观察到显著差异（例如，CTV D98%：98.6%对98.5%，p = 0.629）。
CBCT引导下的oART改善了胃MALT淋巴瘤的靶区覆盖并维持了治疗后的剂量学稳定性，支持其临床可行性。
