FDG PET Imaging for Colorectal Cancer

PET/CT is approved by Medicare for us in staging, restaging and detecting recurrence in colorectal cancer.

2004 Colorectal Statistics:

Estimated New Cases

  • Colon 106,370
  • Rectal 40,570

Estimated New Deaths

  • Colon 56,730

*All cancer statistics obtained from the American Cancer Society’s Cancer Facts and Figures available at www.cancer.org.

Colorectal Cancer and FDG PET Imaging Statistics**

Table 1: Utility of PET Imaging in Colorectal Cancer Diagnosis/Staging (N=134)

  PET CT
Sensitivity 85% 34%
Specificity 71% 92%
PPV 95% 50%
NPV 99% 86%
Accuracy 94% 81%
  PET CT
Sensitivity 96% N/A

For this patient population there was a 37% change in the way the physician managed the patients based upon the PET scan.

Table 3: Utility of PET Imaging in Colorectal Cancer Recurrence (N=2244)

  PET CT
Sensitivity 91% 63%
Specificity 88% 96%
PPV 76% 74%
NPV 97% 92%
Accuracy 90% 90%

For this patient population there was a 24% change in the way the physician managed the patient’s disease based upon the results of the PET scan.

Table 3: Utility of PET Imaging in Breast Cancer Diagnosis/Staging (N=65)

  PET CT
Sensitivity 94% 79%
Specificity 87% 73%
PPV 93% N/A
NPV 88% N/A
Accuracy 94% 80%

For this patient population there was a 32% change in the way the physician managed the patient based upon the PET scan.

** Reprinted by permission of the Society of Nuclear Medicine from: Gambhir, Sanjiv S., Czernin, Johannes, Schwimmer, Judy, Silverman, Daniel H.S., Coleman, R. Edward, Phelps, Michael E. “A Tabulated Summary of the FDG PET Literature” J Nucl Med 2001 42: 1-93.

Case Study
Patient: 68yo male initially diagnosed with colon cancer three years prior. The patient underwent surgery and chemotherapy. Patient now with rising CEA and CT with a solitary liver lesion in the right lobe Patient being considered for surgery. PET/CT was ordered to restage the patient.

Results: PET/CT revealed multiple tumors within the bones, liver and abdominal lymph nodes that were not seen with CT. PET/CT helped the patient avoid a futile surgery, and directed the patient to a more appropriate therapy