University Health Network, Toronto, Ontario, Canada.
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
JAMA. 2014 May 14;311(18):1863-9. doi: 10.1001/jama.2014.3740.
Patients with colorectal cancer with liver metastases undergo hepatic resection with curative intent. Positron emission tomography combined with computed tomography (PET-CT) could help avoid noncurative surgery by identifying patients with occult metastases.
To determine the effect of preoperative PET-CT vs no PET-CT (control) on the surgical management of patients with resectable metastases and to investigate the effect of PET-CT on survival and the association between the standardized uptake value (ratio of tissue radioactivity to injected radioactivity adjusted by weight) and survival.
DESIGN, SETTING, AND PARTICIPANTS: A randomized trial of patients older than 18 years with colorectal cancer treated by surgery, with resectable metastases based on CT scans of the chest, abdomen, and pelvis within the previous 30 days, and with a clear colonoscopy within the previous 18 months was conducted between 2005 and 2013, involving 21 surgeons at 9 hospitals in Ontario, Canada, with PET-CT scanners at 5 academic institutions.
Patients were randomized using a 2 to 1 ratio to PET-CT or control.
The primary outcome was a change in surgical management defined as canceled hepatic surgery, more extensive hepatic surgery, or additional organ surgery based on the PET-CT. Survival was a secondary outcome.
Of the 263 patients who underwent PET-CT, 21 had a change in surgical management (8.0%; 95% CI, 5.0%-11.9%). Specifically, 7 patients (2.7%) did not undergo laparotomy, 4 (1.5%) had more extensive hepatic surgery, 9 (3.4%) had additional organ surgery (8 of whom had hepatic resection), and the abdominal cavity was opened in 1 patient but hepatic surgery was not performed and the cavity was closed. Liver resection was performed in 91% of patients in the PET-CT group and 92% of the control group. After a median follow-up of 36 months, the estimated mortality rate was 11.13 (95% CI, 8.95-13.68) events/1000 person-months for the PET-CT group and 12.71 (95% CI, 9.40-16.80) events/1000 person-months for the control group. Survival did not differ between the 2 groups (hazard ratio, 0.86 [95% CI, 0.60-1.21]; P = .38). The standardized uptake value was associated with survival (hazard ratio, 1.11 [90% CI, 1.07-1.15] per unit increase; P < .001). The C statistic for the model including the standardized uptake value was 0.62 (95% CI, 0.56-0.68) and without it was 0.50 (95% CI, 0.44-0.56). The difference in C statistics is 0.12 (95% CI, 0.04-0.21). The low C statistic suggests that the standard uptake value is not a strong predictor of overall survival.
Among patients with potentially resectable hepatic metastases of colorectal adenocarcinoma, the use of PET-CT compared with CT alone did not result in frequent change in surgical management. These findings raise questions about the value of PET-CT scans in this setting.
clinicaltrials.gov Identifier: NCT00265356.
重要性：患有结直肠癌伴肝转移的患者接受有治愈意图的肝切除术。正电子发射断层扫描（PET-CT）可以通过识别隐匿性转移来帮助避免非治愈性手术。
目的：确定术前 PET-CT 与无 PET-CT（对照组）对比对可切除转移灶患者手术管理的影响，并研究 PET-CT 对生存率的影响，以及标准化摄取值（组织放射性与注射放射性之比，经体重校正）与生存率之间的关系。
设计、地点和参与者：这是一项随机试验，纳入了 2005 年至 2013 年间在加拿大安大略省 9 家医院接受手术治疗、基于胸部、腹部和骨盆 CT 扫描（在之前 30 天内进行）且结肠镜检查在之前 18 个月内进行的 18 岁以上结直肠癌患者，且有可切除转移灶，共有 21 名外科医生参与，在 5 所学术机构有 PET-CT 扫描仪。
干预措施：患者按照 2:1 的比例随机分配到 PET-CT 组或对照组。
主要结果和测量指标：主要结局是基于 PET-CT 而改变的手术管理，定义为取消肝切除术、更广泛的肝切除术或额外的器官切除术。次要结局是生存率。
结果：在接受 PET-CT 的 263 名患者中，21 名患者（8.0%；95% CI，5.0%-11.9%）的手术管理发生改变。具体来说，7 名患者（2.7%）未行剖腹手术，4 名患者（1.5%）行更广泛的肝切除术，9 名患者（3.4%）行额外器官手术（其中 8 名患者行肝切除术），1 名患者开腹但未行肝切除术并关闭腹腔。PET-CT 组 91%的患者行肝切除术，对照组 92%的患者行肝切除术。中位随访 36 个月后，PET-CT 组的估计死亡率为 11.13（95% CI，8.95-13.68）/1000 人-月，对照组为 12.71（95% CI，9.40-16.80）/1000 人-月。两组的生存率无差异（风险比，0.86 [95% CI，0.60-1.21]；P = .38）。标准化摄取值与生存率相关（风险比，每单位增加 1.11 [90% CI，1.07-1.15]；P < .001）。纳入标准化摄取值的模型的 C 统计量为 0.62（95% CI，0.56-0.68），不纳入的为 0.50（95% CI，0.44-0.56）。C 统计量的差异为 0.12（95% CI，0.04-0.21）。低 C 统计量表明，标准摄取值不是总生存率的有力预测指标。
结论和相关性：在结直肠腺癌伴肝转移有潜在可切除性的患者中，与单独使用 CT 相比，使用 PET-CT 并未导致手术管理的频繁改变。这些发现对该环境中 PET-CT 扫描的价值提出了质疑。
试验注册：clinicaltrials.gov 标识符：NCT00265356。
