Outcomes in Patients for Whom Discrepant PET Findings Were Inconsistent with Final Management

Clinical indication and management typePET findings and final validationPET result
New or residual mass
 Surgery as planned (n = 5)Multifocal disease proven inoperable at laparotomy (n = 4)4 T+ve
Suspected granulomatous mediastinal disease in addition to abdominal disease; no progressive abnormality in mediastinum over 1 y (n = 1)F+ve
Rising CEA (n = 5)
 Surgery (n = 1)Presumed physiologic activity in stomach subsequently reinterpreted as metastasis on direct correlation with previously unavailable but reportedly normal CT findings; patient underwent hepatic resection and remained well >12 mo laterInterpretive F−ve
 Diagnostic laparoscopy (n = 1)Prominent bowel activity presumed to be physiologic; small peritoneal metastases identifiedF−ve
 Observation (n = 3)Multiple abnormalities in paraaortic region; multiple metastases confirmed by 6 moT+ve
Local recurrence in pelvis but biopsy-negative; progressive disease confirmedT+ve
Midabdominal uptake on PET, but patient refused follow-upN/E
Symptoms (n = 2)
 ObservationLocal relapse confirmedT+ve
 Diagnostic laparoscopyNo abnormality; multiple tiny peritoneal deposits foundF−ve
Isolated metastases (n = 6)
 Supportive care (n = 2)Isolated liver metastasis; additional disease in liver on CT arterial portography and follow-up CTT+ve*
Isolated liver metastasis; multiple metastases at laparotomyT+ve*
 RadiotherapyBiopsy-proven and apparently isolated liver metastasis on CT not visualized on PET, but poor study because of patient obesity; additional disease in liver on CT arterial portography and follow-up CTF−ve
 Surgery as planned (n = 3)Extrahepatic metastases; inoperable as suspected by PET (n = 2)2 T+ve
Solitary <1-cm liver metastasis on CT not seen on PET; confirmed solitary metastasisF−ve
  • * Underestimated extent of metastatic disease.

  • T+ve = true-positive; F+ve = false-positive; F−ve = false-negative; N/E = not evaluable.