Helou Joelle, Thibault Isabelle, Poon Ian, Chiang Andrew, Jain Suneil, Soliman Hany, Erler Darby, Yeung Latifa, Cheung Patrick
Department of Radiation Oncology, Sunnybrook Odette Cancer Centre, University of Toronto, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec City, Québec, Canada.
Int J Radiat Oncol Biol Phys. 2017 Jun 1;98(2):419-427. doi: 10.1016/j.ijrobp.2017.02.093. Epub 2017 Feb 28.
To assess the association between colorectal cancer (CRC) histology, dose, and local failure (LF) after stereotactic ablative radiation therapy (SABR) for pulmonary metastases, and to describe subsequent cancer progression, change of systemic therapy (CST), survival, and their association with treatment indications.
From a prospective SABR cohort, 180 pulmonary metastases in 120 patients were identified. Treatment indications were single metastasis, oligometastases, oligoprogression, and dominant areas of progression. Doses of 48 to 52 Gy/4 to 5 fractions were delivered. Since 2010 the dose for peripheral CRC metastases was increased to 60 Gy/4 fractions. Cumulative incidence function (CIF) was used to report LF, progression probability, and CST. The Kaplan-Meier method estimated overall survival (OS). Univariate and multivariable analyses to assess variable associations were conducted.
Median follow-up was 22 months (interquartile range, 14-33 months). At 24 months, the CIF of LF was 23.6% (95% confidence interval [CI] 15.1%-33.3%) and 8.3% (95% CI 2.6%-18.6%), respectively, for CRC and non-CRC metastases (P<.001). This association remained significant after adjusting for confounders (subdistribution hazard ratio [SHR] 13.6, 95% CI 4.2-44.1, P<.001). Among CRC metastases, 56 and 45 received <60 Gy and 60 Gy, respectively. Delivering 60 Gy was independently associated with a lower hazard of LF (SHR 0.271, 95% CI 0.078-0.940, P=.040). At 12 months the CIF of progression was 41.67% (95% CI 21.69%-60.56%), 42.51% (95% CI 29.09%-55.29%), 62.96% (95% CI 41.25%-78.53%), and 78.57% (95% CI 42.20%-93.48%), respectively, for patients treated for single metastasis, oligometastases, oligoprogression, and dominant area of progression (P<.001). A CST was observed, respectively, in 4 (17%), 17 (31%), 12 (44%), and 10 (71%) patients with a median time of 13.1, 11.1, 8.4, and 8.4 months.
Colorectal cancer lung metastases are associated with a higher hazard of LF and require higher SABR doses. Outcomes for patients with oligometastases and oligoprogression treated with SABR seem favorable. Prospective clinical trials are needed to confirm these benefits.
评估立体定向消融放疗（SABR）治疗肺转移瘤后结直肠癌（CRC）组织学、剂量与局部失败（LF）之间的关联，并描述后续癌症进展、全身治疗变化（CST）、生存率及其与治疗指征的关联。
从一个前瞻性SABR队列中，识别出120例患者的180个肺转移瘤。治疗指征为单发转移瘤、寡转移瘤、寡进展和主要进展区域。给予48至52 Gy/4至5次分割的剂量。自2010年起，外周CRC转移瘤的剂量增加至60 Gy/4次分割。累积发病率函数（CIF）用于报告LF、进展概率和CST。采用Kaplan-Meier方法估计总生存期（OS）。进行单因素和多因素分析以评估变量之间的关联。
中位随访时间为22个月（四分位间距，14 - 33个月）。在24个月时，CRC转移瘤和非CRC转移瘤的LF的CIF分别为23.6%（95%置信区间[CI] 15.1% - 33.3%）和8.3%（95% CI 2.6% - 18.6%）（P <.001）。在对混杂因素进行调整后，这种关联仍然显著（亚分布风险比[SHR] 13.6，95% CI 4.2 - 44.1，P <.001）。在CRC转移瘤中，分别有56个和45个接受了<60 Gy和60 Gy的剂量。给予60 Gy与较低的LF风险独立相关（SHR 0.271，95% CI 0.078 - 0.940，P =.040）。在12个月时，单发转移瘤、寡转移瘤、寡进展和主要进展区域患者的进展CIF分别为41.67%（95% CI 21.69% - 60.56%）、42.51%（95% CI 29.09% - 55.29%）、62.96%（95% CI 41.25% - 78.53%）和78.57%（95% CI 42.20% - 93.48%）（P <.001）。分别有4例（17%）、17例（31%）、12例（44%）和10例（71%）患者出现CST，中位时间分别为13.1、11.1、8.4和8.4个月。
结直肠癌肺转移瘤与较高的LF风险相关，需要更高的SABR剂量。SABR治疗寡转移瘤和寡进展患者的结局似乎较好。需要进行前瞻性临床试验来证实这些益处。
