The Clinical Value Of ¹⁸F-FDG PET/CT To Diagnosis Of Colorectal Cancer Tumor Lesions

Retrospective analysis of hospital patients with colorectal cancer surgery18F-FDG PET / CTimaging results.Research18F-FDG PET / CT diagnostic colorectal cancer surgery in lymph nodemetastasis, the relationship between serum CEA level in two months before the PET / CTimaging. CEA increased in patients with SUVmax values and the relationship of CEA levels. Toprovide scientific guidance for the clinical application of18F-FDG PET / CT diagnosis ofcolorectal cancer recurrence.MethodsThis was a retrospective study of18F-FDG PET/CT scans obtained from September 2010 toSeptember 2011 in Shanxi Tumor Hospital. Seventy patients（45 men and 25 women） withcolorectal cancer after radical that underwent18F-FDG PET/CT were included in this study. 1lost and 1 patient died .The mean age of the patients was 53±14 Y（range32-84Y）. The use ofAmerica GE Discovery of STE 16 rows of PET / CT scanner to measuring the interested in SUVvalues of recurrent lesions. In this study, grouped according to lymph node metastasis and serumCEA level in patients with colorectal cancer surgery. We calculated after18F-FDG PET/CTdiagnosis of colorectal cancer suspected patients with recurrence. The lymph node metastasis inpatients with increased serum levels of CEA patients and patients with increased TPR and PPV,TNR, PNV. Combined with the gold standard for evaluation colorectal cancer patients / patientswithout lymph node metastasis and postoperative / No recurrence of any correlation between thelevel of CEA level and with / without recurrence, whether there is a correlation. Evaluation of18F-FDG PET/CT diagnosis of elevated serum CEA levels in patients with serum CEA levelswith recurrence of tumor size and SUV values, the recurrence of tumor size and SUV valuesbetween the existence of a correlation. SPSS13.0 software for analysis, all statistical methods is0.05 for the inspection level, P <0.05 was considered statistically significant difference.Results1. 68 cases of colorectal cancer surgery in patients with suspected recurrence underwentconventional imaging review,18F-FDG PET/CT diagnosis of colorectal cancer after surgery withsuspected recurrence in patients with sensitivity of 87% （40/46）, positive predictive value was88.9% （40/45）, specificity was 77.3% （17/22）, negative predictive value of 73.9% （17/23）.2. 49 cases of colorectal cancer surgery with lymph node metastasis in patients with18F-FDGPET/CT imaging, the diagnosis of recurrence in patients with a sensitivity of 97.3% （36/37）,positive predictive value of 97.3% （36/37）,specificity was 91.7% （11/12）, negative predictivevalue of 91.7% （11/12）. 19 cases of colorectal cancer without lymph node metastasis in patients with¹⁸F-FDG PET/CT imaging, the sensitivity of diagnosis of patients with recurrence was44.4% （4/9）, positive predictive value was 50% （4/8）, the specificity was60% （6/10）, negativepredictive value was 54.5% （6/11）.3. 37 cases of colorectal cancer surgery CEA elevated in patients with suspected recurrence of¹⁸F-FDG PET/CT imaging, the diagnosis of recurrence in patients with a sensitivity of 93.3%（28/30）, positive predictive value of 93.3% （28/30）and a specificity of 71.4% （5/7）, negativepredictive value was 71.4% （5/7）. 31 cases of colorectal cancer patients after clinical or routineexamination of suspected recurrence, but the positive predictive value of serum CEA levelswithin the normal range,¹⁸F-FDG PET/CT diagnosis of colorectal cancer postoperativerecurrence in patients with sensitivity of 75% （12/16）,positive predictive value of80% （12/15）,true negative rate of 86.7% （13/15）, negative predictive value75% （12/16）.4. Tumor the size of the lesion SUV was linearly correlated to calculate the Pearson correlationcoefficient r = 0.305 （t = 1.89, P = 0.067> 0.05）. Serum CEA level of lesion SUV was a linearcorrelation, calculation of Pearson correlation coefficient r = .893 （t = 10.49, P <0.001）. Thelongest diameter of the tumor lesions with SUV of lesions was a linear correlation, the Pearsoncorrelation coefficient r = 0.956 （t = 15.67, P <0.001）.Conclusion1.¹⁸F-FDG PET/CT to diagnostic colorectal cancer had lymph node metastasis patients orelevated serum CEA level patients was significantly higher than patients without lymph nodemetastasis in patients with normal serum CEA level.The patients of CRC with elevated serum CEAlevel and lymph node metastasis were priority groups of¹⁸F-FDG PET/CT examination.2.¹⁸F-FDG PET/CT is also valuable to detect tumor recurrence in selected cases who havenormal CEA but clinically and/or radiologically suspicious tumor recurrence. It can be found insmall occult tumor lesions. Colorectal cancer postoperative serum CEA levels increased with thetrue-positive tumor lesions SUVmax value is positively correlated.3. False-positive tumor lesions were mainly seen in inflammation, infection, physiologicaluptake. The false negative tumor lesions were mainly seen in small nodules or some unuptake of¹⁸F-FDG special pathological type. It played a guiding role in clinical and scientific use of¹⁸F-FDG PET/CT diagnosis of postoperative recurrence of colorectal cancer.