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Diagnosticaccuracy of colorectal cancer staging with whole-body PET/CTcolonography.Veit-Haibach P, Kuehle CA, Beyer T, Stergar H, Kuehl H, Schmidt J,Borsch G, Dahmen G, Barkhausen J, Bockisch A, Antoch G. JAMA. 2006 Dec6;296(21):2590-600.
CONTEXT:Staging of patients with colorectal cancer often requires a multimodality,multistep imaging approach. Colonography composed of a combined modality ofpositron emission tomography (PET) and computed tomography (CT) provideswhole-body tumor staging in a single session. OBJECTIVES: To determine thestaging accuracy of whole-body PET/CT colonography compared with the stagingaccuracies of CT followed by PET (CT + PET) and CT alone and to evaluate theeffect of PET/CT colonography on therapy planning compared with conventionalstaging (CT of the abdomen and thorax and optical colonoscopy). DESIGN,SETTING, AND PATIENTS: Prospective study of 47 patients enrolled between May2004 and June 2006 with clinical findings and optical colonoscopy thatsuggested primary colorectal cancer (mean [SD] age, 71 ù years; range, 47-92years). Patients underwent whole-body PET/CT colonography 1 day aftercolonoscopy. The study was conducted at a university hospital with a mean (SD)follow-up of 447 (140) days (range, 232-653 days). MAIN OUTCOME MEASURES:Correct classification of overall TNM stage using PET/CT colonography comparedwith CT + PET and CT alone. Secondary outcome measures were the accurateassessment of T-stage, N-stage, and M-stage by PET/CT colonography comparedwith CT + PET and CT alone and the effect of PET/CT colonography on therapy planning.RESULTS: Of the 47 patients with a total of 50 lesions, the overall TNM stagewas correctly determined for 37 lesions with PET/CT colonography (74%; 95%confidence interval [CI], 60%-85%), 32 lesions with CT + PET (64%; 95% CI,49%-77%), and 26 lesions with CT alone with a 0.7-cm node threshold (52%; 95%CI, 37%-66%). Compared with optimized abdominal CT staging alone, PET/CTcolonography was significantly more accurate in defining TNM stage (difference,22%; 95% CI, 9%-36%; P=.003), which was mainly based on a more accuratedefinition of the T-stage. Differences were not detected for defining N-stagebetween PET/CT colonography and CT alone with a threshold of 0.7 cm formalignant nodes but were detected with a threshold of 1 cm. Differences werenot detected in defining M-stage separately or when comparing the accuracies ofPET/CT colonography with CT + PET. PET/CT colonography affected consecutivetherapy decisions in 4 patients (9%; 95% CI, 2.4%-20.4%) compared withconventional staging (CT alone and colonoscopy). CONCLUSIONS: In thispreliminary study, PET/CT colonography is at least equivalent to CT + PET fortumor staging in patients with colorectal cancer. Thus, PET/CT colonography inconjunction with optical colonoscopy may be a suitable concept of tumor stagingfor patients with colorectal cancer. Leggil'articolo