This article is more than 5 years old. Information may no longer be current.
Surgical management of colorectal adenocarcinoma unchanged by PET/CT use
The use of PET/CT vs. CT alone did not significantly change the surgical treatment in patients with potentially resectable hepatic metastases of colorectal adenocarcinoma.
“Some investigators [have] advocated the use of preoperative PET/CT to identify patients with the highest likelihood of long-term survival after surgery based on the results from small studies,” Carol-Anne Moulton, MB, BS, of the University Health Network in Toronto, and colleagues wrote. “We believed that the evidence to support the routine adoption of PET/CT for staging prior to hepatic surgery in patients with colorectal liver metastases was insufficient to inform policy for the Ontario Ministry of Health.”
Carol-Anne Moulton
To evaluate the effect of preoperative PET/CT vs. CT alone on the surgical management of patients and its impact on survival, Moulton and colleagues randomly assigned patients with colorectal cancer treated by surgery with resectable metastases based on CT scans to PET/CT (n=270) or CT only (n=134).
The primary outcome of the study was an alteration in surgical management defined as canceled hepatic surgery, more extensive hepatic surgery or further organ surgery based on PET/CT imaging.
Eligibility criteria for patients included age 18 years or older with histological proof of colorectal cancer treated by R0 resection, resectable colorectal liver metastases based on contrast-enhanced CT scans of the chest, abdomen and pelvis within the preceding 30 days, and a clear colonoscopy within the previous 18 months.
According to study results, of the 263 patients who underwent PET/CT, only 21 exhibited a change in surgical management (8%; 95% CI, 5-11.9). In particular, 2.7% of patients did not undergo laparotomy, 1.5% underwent more extensive hepatic surgery and 3.4% underwent additional organ surgery, consisting primarily of hepatic resection.
Liver resection was performed in 91% of patients in the PET/CT group and 92% of the CT-alone group. After a median follow-up of 36 months, the estimated mortality rate was 11.13 (95% CI, 8.95-13.68) events/1,000 person-months for the PET/CT group and 12.71 (95% CI, 9.4-16.8) events/1,000 person-months for the CT-alone group.
Researchers observed that survival did not differ between the two groups (HR=0.86; 95% CI, 0.6-1.21). The standardized uptake value (SUV) was linked to survival (HR=1.11; 90% CI, 1.07-1.15 per unit increase). The C statistic for the model including the SUV was 0.62 (95% CI, 0.56-0.68); it was 0.5 for the model without SUV (95% CI, 0.44-0.56). The difference in C statistics is 0.12 (95% CI, 0.04-0.21), which suggests that the standard uptake value is not a strong predictor of OS.
“Many countries struggle to maintain quality health care within existing budgets. This is difficult because of increasing health care costs as a result of an aging population and the expense of new therapies and technologies, including diagnostic and functional imaging,” Moulton and colleagues wrote. “These findings raise questions about the value of PET/CT scans in this setting.”
Disclosure: The researchers reported no relevant financial disclosures.