Objective: We demonstrated for the first time the safety and feasibility of escalating up to 55 Gy/11 Gy/fr/5fr in borderline (BRPC)/unresectable locally advanced pancreatic cancer (LAPC), using the standard LINAC platform. The aim of the present study is to assess for the first time the impact of this high-dose neoadjuvant stereotactic ablative radiotherapy (SABRT) protocol on tumor resectability and pathological responses. Materials/Methods: From June 2017 to December 2022, patients with BRPC/LAPC were treated with neoadjuvant chemotherapy (ChT) and SABRT-escalated doses of SIB at 45 Gy, 50 Gy, and up to 55 Gy (BED ≥ 100). Radiological evaluation was conducted with a CT scan 6-8 weeks post-treatment to determine resectability status based on established criteria (SAR/APA2014). Surgical decisions were made by the multidisciplinary tumor board of the participating institutions. Pathological assessments post-surgery used criteria from the College of American Pathologists (CAP), categorizing resection status as R0 (negative margins), R1 (microscopic tumor margins), and R2 (macroscopic tumor margins). Tumor response was evaluated with the Tumor Response Scoring (TRS) system, as G0 (no viable cancer cells), G1 (single cells or rare small groups), G2 (residual cancer with evident regression), and G3 (extensive residual cancer). Results: Thirty-three patients (p) were included: 39.4% (13p) BRPC/60.6% (20p) LAPC. After ChT-SABRT, 45.5% (15p) were considered resectable, with 11/13 (84.6%) BRPC and 4/20 (20%) LAPC (p< 0.0001). One patient refused surgery and other patient died of COVID sepsis. Two more patients had disseminated disease at surgery. Among the 11 patients who underwent full surgery, all patients achieved either clean margins R0: 72.7% (8p) or microscopic affected margins R1: 27.3% (3p). TRS scores were G1: 27.3% (3p), G2: 54.5% (6p), and G3: 18.2% (2p). The present follow-up (FUP) was closed on 1 November 2024 (23.55 months, range: 6–71 months). The mean freedom from local progression as the first cause of disease failure was 43.30 ± 3.09 (37.23–49.38), and the median was not reached. The actuarial 1- and 2-year rates for freedom from local relapse as a first cause of disease failure were 92.3% (87.7–93.3%) and 79.7% (79.7–87.7%), respectively. Conclusions: Neoadjuvant ChT-SABRT in LAPC improves resectability rates and induces relevant tumor regression. These promising findings should be validated by larger sample sizes and extended follow-up.
目的：本研究首次证明了在标准直线加速器平台上，对临界可切除/不可切除局部晚期胰腺癌患者实施最高达55 Gy/11 Gy/次/5次分割的剂量递增方案的安全性与可行性。本研究旨在首次评估这种高剂量新辅助立体定向消融放疗方案对肿瘤可切除性及病理反应的影响。 材料与方法：2017年6月至2022年12月期间，临界可切除/不可切除局部晚期胰腺癌患者接受新辅助化疗联合剂量递增的立体定向消融放疗（同步推量剂量分别为45 Gy、50 Gy及最高55 Gy，生物有效剂量≥100）。治疗后6-8周进行CT影像学评估，依据既定标准判断可切除性。手术决策由参与机构的多学科肿瘤委员会制定。术后病理评估采用美国病理学家学会标准，将切除状态分为R0（切缘阴性）、R1（切缘显微镜下阳性）和R2（切缘肉眼阳性）。肿瘤反应采用肿瘤反应评分系统评估，分为G0（无存活癌细胞）、G1（单个或罕见小簇癌细胞）、G2（存在明显退变的残留癌）和G3（广泛残留癌）。 结果：共纳入33例患者，其中临界可切除胰腺癌占39.4%（13例），不可切除局部晚期胰腺癌占60.6%（20例）。新辅助放化疗后，45.5%（15例）患者评估为可切除，包括11/13例（84.6%）临界可切除患者和4/20例（20%）不可切除局部晚期患者。1例患者拒绝手术，1例因COVID脓毒症死亡，另有2例术中发现播散性疾病。在11例接受根治手术的患者中，所有患者均达到R0切缘（72.7%，8例）或R1切缘（27.3%，3例）。肿瘤反应评分分布为G1级27.3%（3例）、G2级54.5%（6例）、G3级18.2%（2例）。截至2024年11月1日，中位随访时间为23.55个月（范围6-71个月）。首次疾病失败原因中位无局部进展时间未达到，平均时间为43.30±3.09个月。首次疾病失败原因的无局部复发生存率：1年为92.3%，2年为79.7%。 结论：新辅助放化疗可提高不可切除局部晚期胰腺癌的切除率并诱导显著肿瘤消退。这些具有前景的发现需通过更大样本量和更长期随访进行验证。
肿瘤(癌症)患者之家