Report from SNM: PET avoids unnecessary liver resection for metastatic colon cancer

Liver resection for metastatic colon cancer is painful and debilitating enough, without a patient's subsequent discovery that the surgery did nothing to halt disease progression. A multicenter prospective trial presented Monday at the Society of Nuclear Medicine conference in New Orleans found that FDG-PET prevents unnecessary surgeries for one of six patients who undergo liver resection based on CT findings.

The possible outcome improvement from PET addresses the 50% of patients who historically experience recurrence in the year after liver resection and the 25% who are found to have unresectable metastatic disease at the time of their laparotomies, according to Dr. W.J.G. Oyen of Radboud University Nijmegen Medical Center in the Netherlands.

The study involved 75 surgical candidates randomly selected for assessment with CT alone and another 75 who were evaluated with CT and FDG-PET.

The departments of nuclear medicine and surgery at VU Medical Center in Amsterdam, the department of surgery at Máxima Medical Center in Veldhoven, and the departments of nuclear medicine and surgery at the University Medical Center in Groningen, the Netherlands, also participated.

All patients were suspected to have up to four potentially resectable colorectal liver metastases but no extrahepatic metastatic disease of the abdomen, pelvis, or chest, with the exception of no more than two resectable lung metastases.

CT was considered the decisive imaging technique for recommending surgical intervention, according to Oyen. No patient received pre- or postsurgical chemotherapy, and all patients were monitored for a year after resection.

All 75 patients who underwent CT workup alone were referred for laparotomy. Eighteen cases were considered nonresectable. Of those who underwent surgery, 16 (28%) experienced recurrent cancer within six months.

Five of 75 patients evaluated with both CT and PET did not undergo surgery because of PET findings. Two had benign disease, and extrahepatic disease was identified in the other three, Oyen said. Of the remaining 70 patients, eight were considered nonresectable at surgery. Of those who received liver resection, 13 (20%) experienced recurrent cancer within six months of their surgeries.

Overall, futile laparoscopies were performed on 34 (45%) patients who received conventional CT workup, Oyen said. Among the patients evaluated with PET as well, 21 (28%) received futile laparotomies. The improvement attributed to PET represented a 38% reduction in the incidence of unnecessary liver resections.

"If you make PET the dominant strategy, which is happening in clinical practice, the number of futile laparotomies goes down. In this study, the percentage of futile laparotomies with PET would be 12%," he said.

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