Application Of PET/CT Imaging In The Diagnosis Of Lung Cancer And Prostate Cancer

Background and Objection:Pulmonary cancer is one of the major malignant tumors which are harmful to human health. The prognosis of pulmonary cancer has a close relationship with earlier diagnosis and earlier treatment. So it is important to provide differential diagnose of pulmonary tumour and also attentioned by clinical doctors all the time. Bronchoscopy and biopsy are invasive examination methods, there is a certain risk, but the test results have a great relationship with the doctor’s operating level and the material parts, or even need to repeatedly check in order to draw firm conclusions, so it is difficult to accept in many patients. Medical imaging plays a very important role in the diagnosis of lung cancer, imaging studies for early diagnosis of lung cancer, treatment options, the observation of the efficacy and prognosis assessment is essential, easy to accept by patients and clinicians. Normal medical imaging is very difficult to differential diagnosing pulmonary tumour. PET/CT, CT and PET integrated with CT to provide precise anatomical localization of lesions, while PET lesions detailed function and metabolism of molecular information, with sensitive, accurate, specific and precise positioning, once available imaging all sectional images of the body, at a glance understanding of the body as a whole situation, to achieve the purpose of early detection of lesions and diagnosis of diseases. PET/CT quantitative observation of the body at the molecular level in the physiological state of dynamic biochemical changes has been recognized and widespread concern of the medical profession, is currently the only functional anatomy, metabolism and receptor imaging technology, with the characteristics of non-invasive, is one of the best means of clinically used for diagnosis and treatment of cancer. PET/CT fusion images can be well described by the role of disease on the biochemical processes, differential diagnosis physiological and pathological uptake, in the disease before anatomical evidence to detect the early onset of signs, or even be able to detect subclinical tumor.18F-fluorodexyglucose [18F-FDG] PET/CT as a special imaging is very widely used for patients and evalute tumors with glucose metabolism, except tumor tissue, many normal tissue and optimum lesion can absorb glucose that is difficult for diagnosing pulmonary tumour. F-fluorothymidine [18F-FLT] as a thymidine ramification can reflect proliferation of tumor cells.18F-FLT can reflect proliferation of tumor cells and differential diagnosis for tumors, but18F-FDG can not substitute the function of that. The preliminary study showed that F-FLT enter into the cell by passive diffusion and Na+-dependent carrier, follow by thymidine kinase1(TK1) Phosphoryl. Hydroxyl on the3position to be replaced by F-18, can not really participate in DNA synthesis, so to achieve imaging purposes such as FDG is the same remain in the cells. Today most studies are following with interest for the relationship with pulmonary tumour size, differentiation of tumour cells and standardized uptake value (SUV) of18F-FLT. Our study aims to investigate the diagnostic performance of dual-tracer (18F-FDG and18F-FLT) PET/CT in pulmonary nodules, to differentiate the malignant tissue from benign pulmonary nodules. Methods and materials:55cases of lung lesions failed to be diagnosed were collected during2010.03to2011.09in our center, including33males and22females, aged from17to82-year-old,28cases for the lungs isolated mass, and the other from2to3tumors, tumor size from0.6to11.0cm. All patients fill in the informed consent of the book before exzaminations, and underwent lung18F-FDG and18F-FLT PET/CT imaging. In order to avoid the two positron drugs interference with each other, there was a intervals for4-7days during two inspection. Surgical resection or biopsy pathologic findings were considered as the basis to judge mass nature. GE medical equipment company of GE the Discovery ST16-row PET/CT scanner imaging equipment,120～140kV,100250mAs,0.8sec rotation speed,1.25mm thickness in3D acquisition of FORE iterative manner image reconstruction, fault resolution4mm FWHM. the synthesis of electronic drug completed by the GE MINI trace system. Medical cyclotron mark to GE Tracerlab FXFN automatic chemical synthesizer. Fasting for more than six hours before the examination, the blood glucose control in less than7.8mmol/L, intravenous dose5MBq/kg, patients are quiet and rest in dark in60mins underwent PET/CT imaging. The image data through a unified treatment of all patients, data analysis, centralized, blinded manner by five doctors with extensive experience in PET/CT diagnosis on the same computer projector film-reading, and independent judgment and analysis of all casesthe imaging findings, conclusions subject to the common opinion of the doctor to read the piece more than3/5.18F-FDG and18F-FLT SUV in the patient’s gender, age, nodule size, and pathological type of grouping, each group of data expressed in the form of x±s. Analysis of18F-FDG and18F-FLT SUV and lung cancer patients age, tumor size and pathological type of relationship between statistical significance. Comparative analysis of18F-FDG and18F-FLT PET/CT imaging results difference is or not statistically significant, analysis the difference of SUVmax of18F-FDG and 18F-FLT PET/CT imaging between the different pathological types whether there is statistically significant. Statistical analysis using the SPSS version13.0software package, t-test on each set of data using two sets of completely randomized design information. p>0.05no significant difference; p<0.05was considered statistically significant, p<0.01considered significant difference.Results:Pulmonary nodules in55cases, the patients had surgical resection or biopsy of the pathological findings, including16cases of lung cancer,17cases of tuberculosis,22cases of inflammatory lesions.55patients were divided into eight groups according to gender, age, tumor size and pathological type. There were no significant differences between the SUV of18F-FDG and18F-FLT PET/CT imaging and sex, age, diameter of the nodule, type of the pathologic nature of nodule of all fifty-five patients (p>0.05). SUV of18F-FDG PET/CT imaging in patients with the pathological type of had no significant difference (p>0.05). Otherwise there were significant differences between the SUV of18F-FLT and the type of pathologic nature of nodules of all fifty-five patients (p<0.05).18F-FDG SUV was high in patients with pulmonary nodules,18F-FLT SUV was the higher, the vicious was the greater likelihood, the contrary, was a benign tumor possible.Conclusion:Tumor pathological type in patients with lung cancer is an important factor to affect SUV of18F-FLT PET/CT imaging, the SUV of18F-FLT PET/CT imaging has an important value in the differential diagnosis of benign and malignant tumors of the lung.18F-FDG and18F-FLT dual imaging agent of PET/CT joint observation, can significantly improve the performance of the diagnosis of lung tumors. The current lack of diagnosis of lung tumor specificity of positron radiotracers case for the conventional18F-FDG/PET imaging is difficult to identify patients with pulmonary benign and malignant lesions,18F-FDG and18F-FLT combined can compensate for the18F-FDG only reflect cell metabolism, and18F-FLT reflects only the lack of cell proliferation, so that we can from a different perspective for monitoring tumor cell characteristics, so as to improve the purpose of differential diagnosis of lung tumor. Background and Objection:Prostate cancer is the common malignant tumor, and the curative effect is very good for early prostate cancer, most patients can be cured. Early stage prostate cancer have no specificity of clinical situation, that lead to lost treatment opportunity for many patients in the first diagnosis. How to differentiate the prostate cancer from hyperplasia is always puzzled clinicians. Currently18F-FDG PET/CT as an useful imaging technique, can be used as diagnonsis in the early tumor and differential diagnosis of malignant tumor. PET/CT, PET integrated with CT, can provide precise anatomical localization of lesions, function and metabolism of molecular information, once available all sectional images of the body, at a glance understanding of the body as a whole situation, to achieve the purpose of early detection of lesions and diagnosis of diseases. Quantitative observation on PET/CT at the molecular level in the physiological state of dynamic biochemical changes has been recognized and widespread concern of the medical profession. PET/CT is currently the one of functional anatomy, metabolism and receptor imaging technology, with the characteristics of non-invasive, and also one of the best means of clinically used for diagnosis of cancer. PET-CT fusion images can be well described by the role of disease on the biochemical processes, differential diagnosis physiological and pathological uptake, in the disease before anatomical evidence to detect the early onset of signs, or even be able to detect. But18F-FDG drains from the urinary system, that lead to high radioactivity within bladder, intakes very few in prostate tumor, so diagnosis for prostate tumor on18F-FDG PET/CT is difficult.11C-choline have a characteristic of high concentration and no persistence in the bladder, and the level of choline in prostate cancer tissue is hingher than in normal prostate tissue. In our study, we put to use a technology of18F-FDG and11C-Choline PET/CT imaging for diagnosis prostate neoplasm, so that we can provide a valuable non-invasive imaging technology in the diagnosis, staging and detection of recurrent of prostate cancer.Methods and materials:71patients with suspicious prostate lesions and high PSA level were selected during March,2010to September,2011period for the study (average of4cases/per month), the age from51to82years, mean age of71.6years. All the prostate lesions were confirmed by biopsy or surgical resection specimens on pathology immunohistochemistry, among them,39cases of prostate cancer, metastasis to varying degrees, the remaining32cases as benign prostatic hyperplasia lesions. All patients underwent whole body18F-FDG and11C-choline. Equipment and technique:PET/CT imaging, GE medical equipment company of GE the Discovery ST16-row PET/CT scanner imaging equipment,120-140kV,100250mAs,0.8sec rotation speed,1.25mm thickness in3D acquisition of FORE iterative manner image reconstruction, resolution4mm FWHM, the synthesis of electronic drug completed by the GE MINItrace system. Medical cyclotron mark to GE Tracerlab FXFN automatic chemical synthesizer.18F-FDG PET/CT examination after fasting for more than six hours, blood glucose control in less than7.8mmol/L, drinking500ml to a full bladder before the examination0.5h, intravenous injection of18F-FDG dose of5MBq/kg, then the patients underwent PET/CT imaging after60mins quiet rest. The patients need not fast on11C-choline PET/CT scan, blood sugar level not regulate, drinking500ml to a full bladder before the examination0.5h, quiet rest lOmins, and underwent PET/CT scan5mins after intravenous injection of 11C-choline, dose7.4MBq/kg. A centralized data analysis, blinded manner by five doctor with rich experience in PET/CT diagnosis on the same computer projector and film-reading, and independent judgment and analysis of the image results in all cases, the conclusion of more than3/5film-reading the doctor views prevail. SUV of18F-FDG and11C-choline in the patient’s age and pathological type divided into two groups, each group of data representation of the form x±s. Analysis SUV of18F-FDG and11C-choline, lesions of prostate tissue and normal tissue of the P/M and prostate lesions in patients with age and pathological type of mutual relations and meaning. Comparative analysis the diagnostic value of18F-FDG and "C-choline PET/CT imaging in prostate lesions, evaluate the reliability and relevance of two different positron drugs in the diagnosis of prostate lesions, investigate the performance of joint movement two positron drugs of PET/CT imaging in the diagnosis of prostate lesions. Statistical SPSS13.0software package, Quantitative data were expressed as mean and standard deviation (x±s), using two sets of completely randomized design information on each group of data t-test, p>0.05that no significant difference; p<0.05was considered statistically significant, p<0.01was considered significant difference.Results:In71cases of suspicious prostate lesions,52cases were confirmed surgiccaly and pathologically, the other19cases by aspiration biopsy. Of them, there was prostate cancer in39cases, including7cases of well differentiated adenocarcinoma,14cases of moderately differentiated adenocarcinoma,18cases of poorly differentiated adenocarcinoma,and benign prostatic hyperplasia in32cases, associated with chronic inflammation in11cases of them. SUV on18F-FDG PET imaging ranged from4to32, average11.05.11C-choline PET imaging SUV values ranged3to12, an average of6.68. There were no ststistics difference in the SUV of18F-FDG and11C-choline with age (p>0.05), pathological type of prostate neoplasms (p>0.05), and clearly ststistics difference in the SUV of11C-choline with pathological type prostate neoplasms (p<0.05). For the SUV of11C-choline, the higher the vicious the greater the likelihood, on the contrary, may be benign prostatic hyperplasia.Conclusion:The different pathological type of prostate lesions is an important factor in the standard uptake value of11C-choline. PET/CT imaging in the differential diagnosis of benign and malignant prostatic lesions has an important value and significance.11C-choline PET/CT imaging is a good noninvasive method for diagnosis of prostate cancer, especially for patients with suspected prostate cancer at an elevated PSA. PET/CT imaging, the precise positioning of the CT is of great significance, the radioactive concentration in the prostatic central zone and the symmetry is more suggestive of benign prostatic hyperplasia, radioactivity accumulation point located outside the peripheral zone and showed a solitary nodule is highly vigilant against prostate cancer.11C-choline PET/CT imaging for whole body can be found in the partial transferation of lymph node and distant metastases, and contribute to an accurate clinical staging.11C-choline PET/CT imaging is of great significance for the evaluation of treatment efficacy, monitoring residual tumor and recurrence, and can find that part of the PSA did not significantly elevated in patients with tumor recurrence, and the detection rate is high in patients with PSA significantly increased of residual tumor and recurrence.