The Application Of PET/CT In Clinical Diagnosis Of Prostate Cancer

Background: Prostate Cancer is found in older men. With the elongation of the lives, the incidence of prostate cancer is increasing ,and seriously affects the lives of men. Prostate cancer is detected by DRE or high PSA value. The most important examination is histopathologic using TURS. When Prostate Cancer is final diagnosis, the treament and prognosis depend on the tumor histology and clinical staging. The tumor stage is very important in deciding operation, choosing treament method and predicting prognosis. The image examination is also important to the pathological changes ,diagnosis and staging. But the traditional image examination has high misdiagnosis rate and missed diagnosis rate, which severely affected the early diagnosis of prostate cancer.Recently, nuclear medicine has developed quickly ,which is responsible for the appearance of PET-CT, a milestone in the image examination. PET/CT fixes PET and CT to the same frame, one scaning can obtain the picture of PET and CT. The anatomy picture of CT can match the function and metabolism picture of PET and together they can provide the installation and function message in a tumor. PET-CT is the new device in diagnosis and staging of a tumor.Purpose: To evaluate the clinical application of positron emission tomography - computed tomography (PET/CT) in Prostate Cancer, initially to get the message in a different imaging agent for prostate cancer diagnosis, sensitivity and specificity。Method: All twenty-eight patients undergoing PET-CT scaning of possible Pea or health examination in our PET center during March, 2004 to January , 2005. All those patients undergoing PET/CT scanning when there was a corresponding symptom in themselves, and by reading the scaning, get the results. Ten patients firstly undergoing the 18F-FDG PET/CT imaging and secondly got the llC-choline PET/CT scaning ,and then obtained the different clinical and staging results. We used paired-samples T test to compare different imaging agents, which was completed in spsslO.O. Thus P values less than 0.05 were considered as stastistical significance.Result: 18F-FDG PET-CT scans were taken in twenty-eight patients with suspect prostate cancer resulting in nineteen cases with a final pathology diagnosis of prostate cancer, and carried out the precise fixing and the qualitaty diagnosis of the focus infection? By visual inspection, FDG accumulation was positive in fourteen patients with prostate cancer (SUV>2.5) , twelve cases of final pathology diagnosis is prostate cancer (five pou is well-differentiated adenocarinoma cancer of prostate, three pou is moderately differentiated adenocarinoma cancer of prostate, four pou is poorly differentiated adenocarinoma cancer of prostate undifferentiation adenocarinoma cancer of prostate) , seven cases have meta- peritoneum and cavitas pelvis lymphaden transfuse (the smallest node is 0.7cm><0.5cm), six cases have multi-place osseous metastasis o Two of nine cases of BPH are positive? FDGPET-CT evaluation index in prostate cancer sensitivity is 63.1%. specificity 77.7%, positive predictive value 85.1%, negative predictive value 50% , a degree of accuracy of 67.8%.CT evaluation index in prostate cancer sensitivity is 47.3%, FDGPET evaluation index in prostate cancer sensitivity is 52.6%, specificity 77.7%, positive predictive value 83.3%, negative predictive value43.7% , a degree of accuracy of 60.7%. PET scaning cued the high FDG changes in fourteen pou positive patient, SUV value is 2.7~11.4, radioactivity five gather focus is distribute nodosity, five pou has nodus lymphatic metabasis in pelvic and back membrana. The largest nodus lymphatic is 2.4cmx 1.2cm, the smallest nodus lymphatic is 0.7cm><0.5cm.7 pou with bone metastasis. The smallest noduslymphatic and bone metabasis are tested by PET-CT. Through the PET/CT scaning, we can detect the initial stage of prostate cancer: 2 Pou are located A stage, 2 Pou are located B stage, 1 Pou is located C stage, 7 Pou are located D stage. Three patients take the radical correction through abdominoscope. One patient took radical correction. The post-operation pathology is coincidental for the pre-operation. Two false positive patients' pathology were found with benign prostate hyperplasia. The scaning of PET-CT discloses high radioaction, no local nodus, and blurred borderline. The value of SUV is 3.1,4.2. Fourteen negative patients disclose the normal FDG metabolism. The highest value of SUV is 1.8.7 pou and tested as malignant by pathology and follow-up.nC-choline and 18F-FDG were used for ten patientSo In the primary focus, Seven patients were positive in 18F-FDG PET/CT, nine patients were positive in nC-choline PET/CTo In the bone metabasis, four patients were positive in 18F-FDG PET/CT, six patients were positive in uC-choline PET-CT. hi the nodus lymphatic metabasis, five patients were positive in 18F-FDG PET/CT, five patients were positive in nC-choline PET/CT. Through PET/CT scaning, we can detect the initial stage of prostate cancer: Two Pou are located A stage, two Pou are located B stage, one Pou is located C stage, five Pou are located D stage.Conclution: Dual — modality PET/CT can disclose the location of tumors, preciselydiscriminate the borderline, size, morphous and peplos encroachmant, nodus lymphatic metabasis,and distant metabasis.hi the different imaging agent for monitoring the primary location, nC-choline is superior to the18F-FDGohi the bone metabasis, nC-choline is superior to the 18F-FDG. But in nodus lymphatic metabasis,they have no variability. Once PET/CT becomes more widely available, it may become a newStandard approach to staging in patients with prostate cancer.