PET scans often lead to treatment changes for recurrent colorectal cancer

NEW YORK (Reuters Health) - Positron emission tomography (PET) scans revealed additional sites of disease in nearly half of patients with possible recurrent colorectal cancer (CRC), and additional information provided by these scans led to changes in planned treatment for a majority of the patients, according to a study by Australian researchers.

The study, the largest prospective trial of its kind to date, is published in the September issue of The Journal of Nuclear Medicine.

"In our study, PET was able to identify more appropriate and effective treatment for patients with suspected recurrent colon cancer," Dr. Andrew M. Scott of the Ludwig Centre for Cancer Research, Melbourne, told Reuters Health, "and management decisions were made that led to potentially curative treatment, as well as avoiding unnecessary treatment, including major surgery."

All 191 patients in the study had a previous diagnosis of CRC. As determined by conventional imaging, 93 patients (group A) had residual lesions equivocal for recurrent tumor, and 98 patients (group B) had potentially resectable liver or lung metastases.

Pre-PET management plans (for surgery, radiotherapy and/or chemotherapy) were obtained for all patients, and a 12-month follow-up determined both the changes to those plans as the result of PET and the outcomes of treatment.

PET detected additional sites of disease in 48.4% of group A patients and 43.9% of group B patients. In group A, 61 patients (65.6%) had their treatment plans changed on the basis of PET results, and this was true of 48 patients (49.0%) in group B as well.

"These data show the value of PET in the stratification of patients into curative or palliative and surgical or nonsurgical groups," the researchers write.

This study, as well as earlier research, Dr. Scott said, "provides definitive information on the role of PET in patients with suspected recurrent colon cancer, and its impact on patient management. The role of PET in this clinical scenario has therefore been firmly established."

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