Background: Lattice Radiation Therapy (LRT), a spatially fractionated stereotactic radiotherapy (SBRT) technique, has shown promising results in the palliative treatment of large tumors. The focus of our first analysis of 56 lesions ≥7 cm was on the extent of shrinkage following palliative LRT (mean 50%) and assessment of its effect duration (: mean 6 months). Herewith we present an updated analysis of our single-center LRT cohort, with a focus on LRT outcome across diagnoses and applied LRT regimens. Methods: We assessed the clinical outcome following LRT in 66 patients treated for 81 lesions between 01.2022 and 05.2025. LRT protocols included simultaneous integrated boost (sib-) LRT in 49 lesions (5 × 4–5 Gy to the entire mass with sib of 9–13 Gy to lattice vertices). Alternatively mainly in pre-irradiated and/or very large lesions—a single-fraction stereotactic LRT (SBRT-LRT) of 1 × 20 Gy to vertices only was delivered to 26 lesions. In six cases with modest response to single fraction SBRT-LRT, the sib-LRT schedule was added 4–8 weeks later. Results: The median age was 68 years (18–93). Main tumor locations were abdomino-pelvic (n= 34) and thoracic (n= 17). Histopathological diagnoses included carcinoma (n= 34), sarcoma (n= 31), and melanoma (n= 16). 31% of all lesions have been previously irradiated. 73% of cases underwent concurrent or peri-LRT systemic therapy. The mean/median overall survival (OS) time of the cohort was 7.6/4.6 months (0.4–40.2), 11.9/5.8 months in 16/66 alive, and 6.4/4.3 months in deceased patients, respectively. 82% of symptomatic patients reported immediate subjective improvement (PROM), with a lifelong response duration in most cases. Progressive disease (PD: >10% increase in initial volume) was found in 9%, stable disease (SD +/−10% of initial volume) in 19% of scanned lesions, and shrinkage (>10% reduction in initial volume) in 75%, with a mean/median tumor volume reduction of 51/60%. The extent of shrinkage was found to be 11–30%/31–60%/61–100% in 38/24/38% of lesions. Response rates (PD, SD, shrinkage) following the two applied LRT regimens, as well as those related to sarcoma and carcinoma diagnoses, were found to be comparable. Treatment tolerance was excellent (G0-1). Conclusions: Palliative LRT provides rapid subjective relief in ~80% of symptomatic patients. Radiologic shrinkage was stated in 75% of FU-scanned lesions, with a lifelong effect duration in most patients. LRT was found effective across histologies, with a similar extent of shrinkage in carcinoma and sarcoma following 1F SBRT- and 5F sib-LRT regimens, respectively.
背景：格栅放射治疗（LRT）作为一种空间分割立体定向放射治疗技术，在大型肿瘤的姑息治疗中已显示出良好前景。我们前期对56个≥7 cm病灶的分析聚焦于姑息性LRT后的肿瘤退缩程度（平均50%）及其疗效持续时间评估（平均6个月）。本文现对我们单中心LRT队列进行更新分析，重点探讨不同诊断类型及应用LRT方案的治疗结局。 方法：我们评估了2022年1月至2025年5月期间接受LRT治疗的66例患者（共81个病灶）的临床结局。LRT方案包括：49个病灶采用同步整合推量LRT（全瘤区5×4-5 Gy，格栅顶点同步推量9-13 Gy）；另对26个病灶（主要为既往放疗和/或巨大肿瘤）采用单次立体定向LRT（仅对格栅顶点实施1×20 Gy）。6例对单次SBRT-LRT反应欠佳的患者，在4-8周后追加了sib-LRT方案。 结果：患者中位年龄68岁（范围18-93岁）。主要肿瘤部位为腹盆腔（34例）和胸部（17例）。组织病理学诊断包括癌（34例）、肉瘤（31例）和黑色素瘤（16例）。31%的病灶既往接受过放疗。73%的病例在LRT期间或围治疗期接受了全身治疗。队列总生存期（OS）平均/中位时间为7.6/4.6个月（范围0.4-40.2），其中16/66例存活患者为11.9/5.8个月，死亡患者为6.4/4.3个月。82%的有症状患者报告即刻主观症状改善（患者报告结局），且多数患者疗效持续终生。影像学评估显示：9%的病灶出现疾病进展（PD：体积较基线增加>10%），19%疾病稳定（SD：体积变化在基线±10%内），75%出现肿瘤退缩（体积较基线减少>10%），肿瘤体积平均/中位缩小幅度达51%/60%。肿瘤退缩程度分级显示：38%病灶缩小11-30%，24%缩小31-60%，38%缩小61-100%。两种LRT方案的治疗反应率（PD、SD、退缩）以及肉瘤与癌的诊断亚组间反应率具有可比性。治疗耐受性良好（G0-1级）。 结论：姑息性LRT可为约80%的有症状患者提供快速主观症状缓解。75%的随访影像学病灶出现放射学退缩，且多数患者疗效持续终生。LRT在不同组织学类型中均显示有效，单次SBRT-LRT与5次sib-LRT方案分别在癌和肉瘤中产生相似的肿瘤退缩程度。
肿瘤(癌症)患者之家