Presurgical diagnostic accuracy of five imaging procedures in chemotherapy-naive (group A) or chemotherapy-pretreated (group B) patients with colorectal liver metastases (Italian PROMETEO Study).

Abstract

3621 Background: The aim of the study was to define the specific diagnostic accuracy of 5 imaging techniques in group A or group B patients (pts) with potentially resectable colorectal cancer liver metastasis (CLMs). Methods: Seventy consecutive CLMs pts referred to the Multidisciplinary Team of Bologna S. Orsola Malpighi Hospital performed computed tomography scan (CT), magnetic resonance (MR), 18F-FDG-PET, and liver contrast-enhanced ultrasonography (CEUS1); CEUS2 was also performed intra-operatively. Every pathological lesion was compared with imaging data. Results: From December 2007 to December 2009, 49/70 pts underwent liver resection. Pt characteristics: 28M/29F; 30(61%) synchronous/19(39%) metachronous metastasis. Twenty-five (51%) pts were in group A, 24 (49%) in group B. Fifty-eight liver lesions were resected in group A (median number per pt 1, range 1-7), 94 in group B (median 2.5, range 1-15). Two lesions at pathological examination were not CLMs (1 giant-cell reaction, 1 cholangiocarcinoma) in group A and 7 (1 hamartoma, 1 steatosis, 3 necrosis, 2 fibrosis) in group B. Conclusions: As compared with pathological evaluation, diagnostic accuracy of all 5 imaging procedures was high in group A, but decreased in group B. This was particularly evident with FDG-PET (p<0.001). CEUS2 presented the higher predictive value. CT % MR % PET % CEUS1 % CEUS2 % Sensitivity Group A 50/56 89 45/49 92 47/56 84 47/54 87 50/51 98 Group B 67/87 77 75/84 89 32/78 41 68/85 80 83/87 95 Positive predictive value Group A 50/52 96 45/47 96 47/48 98 47/49 96 50/53 94 Group B 67/73 92 75/80 94 32/35 91 68/73 93 83/89 93 Specificity Group A 0/2 0 0/2 0 1/2 50 0/2 0 0/3 0 Group B 1/7 14 2/7 29 3/6 50 1/6 17 1/7 14 Negative predictive value Group A 0/6 0 0/4 0 1/10 10 0/7 0 0/1 0 Group B 1/21 5 2/11 18 3/49 6 1/18 5.5 1/5 20 Accuracy Group A 50/58 86 45/51 88 48/58 83 47/56 84 50/54 93 Group B 68/94 72 77/91 85 35/84 42 69/91 76 84/94 89 No significant financial relationships to disclose.