Sudo Shuou, Kita Nozomi, Tomita Natsuo, Takaoka Taiki, Okazaki Dai, Niwa Masanari, Torii Akira, Takano Seiya, Oguri Masanosuke, Matsuura Akane, Ukai Machiko, Niimi Akio, Hiwatashi Akio
Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho, Mizuho-Ku, Nagoya, Aichi, 467-8601, Japan.
Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-Cho, Mizuho-Ku, Nagoya, Aichi, 467-8601, Japan.
Jpn J Radiol. 2025 Jun;43(6):1036-1043. doi: 10.1007/s11604-025-01749-x. Epub 2025 Feb 22.
This study investigated effects of target coverage on local recurrence (LR) in stereotactic body radiotherapy (SBRT) for early-stage lung squamous cell carcinoma (SCC).
Patients with clinical stage IA1-IIA lung SCC treated with SBRT were included in the analysis. Doses of 48-52 Gy were prescribed to the isocenter of the planning target volume according to the tumor diameter. The primary endpoint was LR. To examine the independent effects of dosimetric factors on LR after adjustment for clinical factors, Fine-Gray model with death as a competing risk was used for evaluation.
Among all 59 patients analyzed, the median follow-up was 42 months. The 3-year LR rate was 24.0%. Univariate analysis of clinical factors showed that biologically effective dose calculated with an α/β value of 10 (BED) was associated with LR (p = 0.033). After adjustment for clinical factors, internal target volume (ITV) Dmean was associated with LR (p = 0.049). Subgroup analysis was performed for each prescribed dose group. The results of Fine-Gray model and receiver operating characteristic curve analysis showed that ITV Dmean > 100% of the prescribed dose was the best indicator of preventing LR.
ITV coverage may be particularly important in SBRT for early-stage lung SCC.
本研究探讨立体定向体部放疗（SBRT）治疗早期肺鳞状细胞癌（SCC）时靶区覆盖对局部复发（LR）的影响。
分析接受SBRT治疗的临床ⅠA1 - ⅡA期肺SCC患者。根据肿瘤直径，计划靶区等中心的处方剂量为48 - 52 Gy。主要终点为LR。为了在调整临床因素后检验剂量学因素对LR的独立影响，采用以死亡作为竞争风险的Fine - Gray模型进行评估。
在分析的所有59例患者中，中位随访时间为42个月。3年LR率为24.0%。临床因素的单因素分析显示，用α/β值为10计算的生物等效剂量（BED）与LR相关（p = 0.033）。调整临床因素后，内靶区（ITV）平均剂量与LR相关（p = 0.049）。对每个处方剂量组进行亚组分析。Fine - Gray模型和受试者工作特征曲线分析结果显示，ITV平均剂量>处方剂量的100%是预防LR的最佳指标。
在SBRT治疗早期肺SCC中，ITV覆盖可能尤为重要。
