Purpose: To investigate early adoption and potential predictors of postoperative utilization of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in patients who underwent colorectal cancer resection between July 2001 and December 2002 (the first 18 months of Centers for Medicare and Medicaid Services [CMS] coverage for FDG PET) and who were observed for 2 years from the date of surgery.
Materials and methods: This HIPAA-compliant study was exempt from institutional review board approval. Informed consent was waived. This was a retrospective cohort study of FDG PET utilization in patients with colorectal cancer following resection between July 1, 2001 and December 31, 2002. Utilization data were drawn from the Surveillance, Epidemiology and End Results-Medicare files during the first 2 years following colorectal surgery. The primary outcome measure was FDG PET utilization. Covariates included disease-, patient-, and hospital-level characteristics, as well as computed tomography (CT) utilization. Univariate and multiple regression analysis were performed.
Results: Of 10630 patients (mean age, 77.5 years) who underwent resection for colorectal cancer during the study period, 1056 (10%) patients underwent at least one FDG PET examination in the 2-year period following surgery. A 41% relative increase in utilization of FDG PET was found among patients who underwent resection early in the study period compared with those who underwent resection late in the study period; this was a significant difference (P < .001). There was no change in CT utilization between these two groups (P = .302). The highest utilization of FDG PET was during the first 6 months following surgery. Significant predictors of higher FDG PET utilization included rectal cancer, later date of initial surgery, higher disease stage, older age, marital status, and lower comorbidity.
Conclusion: Substantial growth in utilization of FDG PET within 2 years of surgery was found among patients who underwent surgery during the first 18 months of approved CMS coverage, with the highest rates of utilization occurring within 6 months of surgery and lower rates occurring subsequently over the 2-year period following resection.