直肠癌新辅助治疗中盆腔骨髓保护调强放疗与病理反应的相关性

Correlation between pelvic bone marrow-sparing IMRT and pathological response in neoadjuvant chemoradiotherapy for rectal cancer

目的:探讨直肠癌新辅助治疗中盆腔骨髓保护调强放疗与病理反应的相关性。方法:回顾性分析2017年01月至2020年12月于我院接受新辅助放化疗及根治性手术的192例Ⅱ、Ⅲ期直肠癌患者的临床病理资料,其中95例为接受盆腔骨髓保护调强放疗的患者(淋巴细胞保护组),余97例患者来源于本单位回顾性数据库(对照组)。比较两组患者淋巴细胞绝对计数最低值、淋巴细胞下降程度及肿瘤病理反应率差异,分析直肠癌新辅助治疗中盆腔骨髓保护调强放疗与病理反应的相关性。结果:淋巴细胞保护组患者放化疗期间最低淋巴细胞计数、放化疗后淋巴细胞计数及病理反应率均高于对照组,差异有统计学意义。淋巴细胞保护组3-4级淋巴细胞减少症发生率为38.9%,低于对照组的56.8%(P=0.034)。多因素Logistic回归分析结果显示3-4级淋巴细胞减少症、淋巴细胞保护、临床分期及等待手术期间化疗是肿瘤病理反应状态的独立影响因素。结论:直肠癌患者新辅助放化疗期间3-4级淋巴细胞减少症与治疗后肿瘤病理反应状态密切相关,通过盆腔骨髓保护调强放疗可有效保护患者的淋巴细胞,减轻3-4级淋巴细胞减少症发生率,提高肿瘤病理反应。

Objective:To explore the correlation between pelvic bone marrow-sparing IMRT and pathological response in neoadjuvant chemoradiotherapy(nCRT)for rectal cancer.Methods:Clinical and pathological data of 192 stage II,III rectal cancer patients treated with nCRT and subsequent surgery in our hospital from January 2017 to December 2020 were retrospectively analyzed.Among these patients,95 patients who have underwent pelvic bone marrow-sparing IMRT were selected as the research group(lymphocyte-sparing group),and the remaining 97 patients who came from the established retrospective database were selected as the control group.The lymphocyte nadirs,lymphopenia,and the rate of pathological response between the two groups were compared and correlation between pelvic bone marrow-sparing IMRT and pathological response in nCRT for rectal cancer was evaluated.Results:The lymphocyte nadirs during the nCRT,the lymphocyte count after treatment,and pathological response rate in the lymphocyte-sparing group were higher than those in the control group with statistically significant respectively.The incidence rate of grade 3-4 lymphopenia in the lymphocyte-sparing group was 38.9%,which was lower than that 56.8%in the control group(P=0.034).Multivariate Logistic regression analysis results identified that grade 3-4 lymphopenia,lymphocyte-sparing,clinical stage,and chemotherapy during the interval between nCRT and surgery were independent predictive factors for response to nCRT.Conclusion:The incidence rate of grade 3-4 lymphopenia is associated with pathologic response in rectal cancer patients undergoing nCRT.The bone marrow-sparing IMRT will effectively protect the lymphocytes of rectal cancer patients and reduce the incidence rate of grade 3-4 lymphopenia,thus improve pathologic response to nCRT.