Department of Radiation Medicine and Applied Sciences, School of Medicine, University of California, San Diego, La Jolla, California; Center for Translational Radiation Medicine and Imaging, School of Medicine, University of California, San Diego, La Jolla, California.
Department of Gastroenterology, School of Medicine, University of California, San Diego, La Jolla, California.
Int J Radiat Oncol Biol Phys. 2018 Sep 1;102(1):109-115. doi: 10.1016/j.ijrobp.2018.05.044. Epub 2018 May 23.
Compared with conventional radiation therapy, intensity modulated radiation therapy (IMRT) may reduce acute toxicity from anal cancer treatment, potentially leading to improved long-term outcomes. We analyze the effect of IMRT on short- and long-term outcomes among a large sample of US veterans.
From a national Veterans Affairs database, we identified 779 patients (n = 403 conventional radiation therapy, n = 376 IMRT) with locally advanced anal squamous cell carcinoma diagnosed between 2000 and 2015 and treated with concurrent chemoradiation therapy. Radiation treatment planning and dosimetric constraints were not standardized across patients. We analyzed the effect of IMRT on short-term outcomes (acute toxicity, treatment breaks, and incomplete chemotherapy) and long-term outcomes (survival and ostomy placement) in multivariable logistic regression, Fine-Gray, and frailty models, adjusting for potential confounders.
IMRT was associated with decreased radiation treatment breaks ≥5 days (odds ratio [OR] 0.58; 95% confidence interval [CI] 0.37-0.91; P = .02), increased rates of receiving 2 cycles of mitomycin C chemotherapy (OR 2.04; 95% CI 1.22-3.45; P = .007), increased rates of receiving 2 cycles of any chemotherapy (OR 3.45; 95% CI 1.82-6.25; P < .001), and decreased risk of ostomy related to tumor recurrence or progression (subdistribution hazard ratio 0.60; 95% CI 0.37-0.99; P = .045). IMRT was not associated with a decrease in grade 3 to 4 hematologic toxicity (P = .79), hospitalization for gastrointestinal toxicity (P = .59), or cancer-specific survival (P = 0.18).
Among a large sample of US veterans with anal cancer, IMRT was associated with higher rates of receiving 2 chemotherapy cycles, decreased radiation treatment breaks, and decreased rates of ostomy placement. IMRT appears to offer substantial benefits over conventional radiation therapy for patients undergoing concurrent chemoradiation therapy for anal cancer.
与常规放射治疗相比，调强放射治疗（IMRT）可能会降低肛门癌治疗的急性毒性，从而潜在地改善长期结果。我们分析了大量美国退伍军人样本中 IMRT 对短期和长期结果的影响。
我们从全国退伍军人事务部数据库中确定了 779 名（n = 403 例常规放射治疗，n = 376 例 IMRT）局部晚期肛门鳞癌患者，这些患者在 2000 年至 2015 年间被诊断出患有局部晚期肛门鳞癌，并接受同步放化疗。患者之间的放射治疗计划和剂量学限制没有标准化。我们使用多变量逻辑回归、Fine-Gray 和脆弱模型分析了 IMRT 对短期结果（急性毒性、治疗中断和不完全化疗）和长期结果（生存和造口安置）的影响，调整了潜在混杂因素。
与常规放射治疗相比，IMRT 与放射治疗中断≥5 天的发生率降低（优势比 [OR] 0.58；95%置信区间 [CI] 0.37-0.91；P =.02）、接受 2 周期丝裂霉素 C 化疗的比例增加（OR 2.04；95%CI 1.22-3.45；P =.007）、接受任何 2 周期化疗的比例增加（OR 3.45；95%CI 1.82-6.25；P <.001）以及降低与肿瘤复发或进展相关的造口率（亚分布风险比 0.60；95%CI 0.37-0.99；P =.045）。IMRT 与 3 级至 4 级血液学毒性降低无关（P =.79）、胃肠道毒性住院无关（P =.59）或癌症特异性生存无关（P =.18）。
在大量美国退伍军人肛门癌样本中，IMRT 与接受 2 个化疗周期的比例增加、放射治疗中断减少以及造口率降低有关。IMRT 似乎为接受同步放化疗的肛门癌患者提供了优于常规放射治疗的显著优势。
