Effect of PET before liver resection on surgical management for colorectal adenocarcinoma metastases: a randomized clinical trial.
OBJECTIVE
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.


OBJECTIVE
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.


METHODS
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.


METHODS
Patients were randomized using a 2 to 1 ratio to PET-CT or control.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.


BACKGROUND
clinicaltrials.gov Identifier: NCT00265356.
University Health Network, Toronto, Ontario, Canada.
Carol-Anne
CA
Moulton
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Chu-Shu
CS
Gu
Sunnybrook Health Sciences Centre and Odette Cancer Centre, Toronto, Ontario, Canada.
Calvin H
CH
Law
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Ved R
VR
Tandan
St Joseph's Health Centre, Toronto, Ontario, Canada.
Richard
R
Hart
London Health Sciences Centre, London, Ontario, Canada.
Douglas
D
Quan
Ottawa Hospital, Ottawa, Ontario, Canada.
Robert J
RJ
Fairfull Smith
Cancer Centre of Southeastern Ontario at Kingston General Hospital, Kingston, Canada.
Diederick W
DW
Jalink
Grand River Regional Cancer Centre, Kitchener, Ontario, Canada.
Mohamed
M
Husien
University Health Network, Toronto, Ontario, Canada.
Pablo E
PE
Serrano
University Health Network, Toronto, Ontario, Canada.
Aaron L
AL
Hendler
Sunnybrook Health Sciences Centre and Odette Cancer Centre, Toronto, Ontario, Canada.
Masoom A
MA
Haider
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Leyo
L
Ruo
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Karen Y
KY
Gulenchyn
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Terri
T
Finch
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Jim A
JA
Julian
McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada.
Mark N
MN
Levine
University Health Network, Toronto, Ontario, Canada.
Steven
S
Gallinger
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006498:Hepatectomy / Q000379:methods; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult