| BackgroundNuclide imaging (diagnostic nuclear medicine) belongs to the category of clinical nuclear medicine, the radionuclide is introduced into the body of patients, nuclear medicine instruments detect gamma rays from radionuclide, mainly display function and metabolism of tissues and organs and achieve the purpose of diagnosis of disease. Nuclear medical imaging instrument has experienced scanner, gamma camera to computed tomography scanning, however, which is different from the X-ray tomography instrument (traditional type of scanner transmission computed tomography(CT), nuclear medicine tomography instrument called emission computed tomography(ECT), ECT is divided into single photon emission computed tomography(SPECT) and positron emission computed tomography(PET).Kuhl and Edwards successfully developed the first SPECT in1979, SPECT is a more advanced imaging modality combined with computer technology which was developed on the basis of the gamma camera planar imaging, Application of electronic computer technology increased the function of the tomography imaging, overcome the faults of overview small lesions due to tissue and organ overlapping, improve the positioning accuracy of deep lesions in the planar imaging. However SPECT anatomical structures of tissues and organs and distance relationship shows that still is inferior to CT and MRI. With the rapid development of medical imaging technology, image fusion technology has been widely used in clinical. SPECT/CT is the excellent integrations of functional and metabolic imaging of SPECT with morphologic imaging of CT, realizes the complementary advantages of the two imaging technology, provide more diagnostic information for clinical, also can use X-ray attenuation correction for a CT scan data of SPECT images. Except for diagnosis of nuclear medicine, nuclear medical imaging equipment, radionuclide is another important part of nuclear medicine diagnosis,99mTc-methylene bisphosphonate (MDP) is one of the main bone imaging agent, due to its special physical and chemical properties, although it has the important value of imaging, but as a radionuclide99mT-MDP and it can also be on bone scan client, medical staff and the surrounding radiation, has certain potential hazards, but99mT-methylene bisphosphonate (MDP) caused by the radiation dose size, domestic no research about this aspect of the system, so this subject to the following two parts were retrospectively analyzed and research:1. The diagnostic value of SPECT/CT scanning for bone metastases2. Study on Radiation dose Caused by99mT-MDP and CT in SPECT/CT scanning. PART IThe diagnostic value of SPECT/CT scanning for bone metastases Objective:Investigate diagnostic value of radionuclide imaging/low dose CT imaging in the suspected bone metastases and analysis of related factors for early diagnosis and early reasonable treatment of bone metastases, reduce bone related events (skeletal related events, SREs), improve the quality of life of patients.Materials and methods:This was a retrospective study, from October2008to March2013, There were451patients underwent the whole body bone scan and99mTc-MDP SPECT/CT (German Siemens SymbiaT2type dual probe) scanning of in the nuclear medicine department of Liaocheng people’s hospital (affiliated taishan medical universityl), containing the patients underwent the surgery, radiotherapy or chemotherapy of malignant tumors, it is difficult to determine the nature of the radioactive lesions in the whole body bone scan, such as the number of radioactive lesions≤3, or there is no clear of the multiple primary tumors but radioactive lesions≥4, then SPECT/low dose CT scans was performed in order to make clear nature of the lesions, meanwhile record the patient’s blood tests associated indicators. Image analysis:three nuclear medicine and CT image doctors independently read the imagings, when they did not agree on diagnosis, the other physician need to read the image and discuss the decision. SPECT/low dose CT image:the position of radioactive defection or radioactive lesions in the fusion image is accurate on SPECT CT images, and then determine the structure and density of lesions on low dose CT image characteristic. The final diagnosis was confirmed by the clinical follow-up included telephone and review of diagnostic CT, MRI and biopsy results, etc.Adopts unified image diagnostic criteria of1to4points,1point is chosen as benign,2points is chosen as suspicious benign,3points is chosen as suspicious malignant and four points is rated as malignant, statistics of the whole body bone scan, SPECT CT images, CT, CT image and SPECT/CT fusion image diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy. Application SPSS16.0statistical analysis software for statistical data processing and analysis, the rate of compares the four table chi-square test, ROC curve analysis, one sample t test, All inspection standards are set to0.05, P<0.05for the difference was statistically significant.Results:1. The clinical classification of the patients underwent bone scan.Clinicians for bony metastases of bone scan in order to make clear whether the clinical diagnosis of basically has two kinds, some patients with clear history of malignant tumor,380cases of patients with primary malignant tumor of the top5are lung cancer, breast cancer, prostate cancer, esophageal cancer, gastric cancer; Before67cases,313cases after treatment, including bone pain symptoms in108cases,272cases with no symptoms of bone pain; The type of malignant tumor,135cases of lung cancer,98cases of male and female37cases;177cases of breast cancer, male and female,76cases of lung cancer and breast cancer in male and female ratio is used chi-square test,(chi-square-6.98,6.98; P<0.05, the differences between men’s and women’s disease was statistically significant, other patients without malignant tumor but suspected patients in98cases of bone metastases,41cases were male,57cases were female, the whole body bony pain were18cases, thoracic vertebra or ribs were25cases, lumbar vertebra were23cases, vertebral fractures were13cases, fractured ribs were8cases, humerus fracture wasl case, upper limb pain were5cases, hip pain were2cases, lower limb pain were3cases.2.The localization and qualitative value on99mTc-MDP SPECT/CT imaging136cases were no clear malignant tumour history, including1case of parathyroid hormone (PTH) abnormally high levels, early-delay99mTc-MIBI parathyroid imaging and partial SPECT imaging/low dose CT scanning revealed a parathyroid adenoma in the right thyroid lobe under extremely. Among them,95cases of bone scan revealed multiple rib focal radioactive concentration and spine multiple radioactive strong gathering lesions, lumbar significantly, women, the prevalence of osteoporosis is higher than men (chi-square=6.98,6.98; P<0.05difference was statistically significant); And41cases of bone scan showed the axial skeleton and ribs, uneven distribution of radioactive werenot seen abnormal radioactive strong lesios, SPECT/CT scans revealed multiple myeloma was confirmed by clinical materials.Bone scan showed have less radioactive strong subjects,342cases of the oven, radionuclide extremely strong fusion focal a total of657,156cases of benign disease, radioactive thick polyethylene oven302(46.1%), bone benign lesions mainly includes the degeneration of thoracolumbar; Thoracolumbar compression fractures; Lumbar spinal tuberculosis; Joint degeneration. Fracture, bone island; Along they like located.286cases of bone metastases, radioactive strong focal354(53.9%), smaller scope of lesions in CT images generally show partial mind growth, a large patch of irregular bone destruction with strong disease extent in soluble bony destruction, often accompanied by obvious mass lesion. Among them into osseous metastases,216,138dissolved osseous bone metastases.In this study,39cases (3.32%) abnormal bone imaging showed bone soft tissue outside the absorb99mTc-MDP, its parts, respectively, for10cases,9cases of liver and lung7cases, breast muscle tissue and subcutaneous4cases, pleura in3patients, peritoneal in2cases, splenic in2cases, gastric cancer postoperative residual focal sulcus carcinoma, lung and colon cancer in1case. Four of them located in pelvic cavity, a position on the right side of the ovary, biopsy for library kinberg tumor; A location in the right iliac fossa, postoperative pathology for metastases of gastric cancer in2cases located in the right side of the back blind department, after6months follow-up bone scan lesions disappeared.9cases, including13cases of femoral head necrosis, urine pollution.3. Bone scan, SPECT, CT and SPECT/CT diagnostic value.SPECT/CT fusion image diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy were92.8%,100%,100%,97.5%and98.1%, significantly higher than bone scan (chi-square=4.29,4.29,4.20,4.51; P<0.05). Bone scan, SPECT, CT and SPECT/CT using ROC analysis respectively, AUC (area under the ROC curve) are respectively0.747,0.833,0.944,0.833,95%ci respectively is0.653-0.826.0.806-0.937,0.883,0.979,0.909,0.909.4. The analysis of bone metastases and the related clinical factors.In this study,342cases of patients with bone metastases,273casesof which had outside the bone metastasis,131patients of which had sentinel lymph node metastasis and (or) the distance, the pathological changes of bone metastases as the starting69(20.2%) cases. Lung cancer is the most common primary tumor bone, adenocarcinoma of the chance of bone metastases is the largest, small cell lung cancer. Elevated serum alkaline phosphatase (ALP in osseous bone metastases, benign bone lesions and osseous bone metastases increased ALP is not obvious; Combined with the related tumor marker CA125, CEA, CA153, NSE, AFP and elevated PSA, and improves the accuracy of early diagnosis of bone metastases, especially bone scan images were positive, and bone have no obvious change on CT images.Conclusion:1.The characteristics of radionuclide imaging/CT scans and applicants. In this study with bone pain number of applicants for inspectors more women suffer from osteoporosis than man. Malignant breast lesions with metastases, the ribs and sternum were most seen, prostate cancer is more easily transferred to the pelvis, but pelvic malignant tumor metastases, lung cancer was most seen, it is associated with the incidence of lung cancer is higher than prostate cancer, bone malignant lesions in the breast cancer, lung cancer and prostate cancer is more, primary bone tumors occurred in four limbs which is more, the skull more for single lesion, pelvic benign lesions located in the sacroiliac joint, and the superior border of sacral; Acetabulum slightly above the iliac crest is a usual location to osseous bone metastases, radioactive lesions (sometimes less obvious, thus cotyle of radioactive anomalies in don’t easily diagnosed with degenerative diseases; When bone scans found abnormal pelvic cavity radioactive strong stove, and a radioactive concentration degree of poly (before and after the difference is small, lesions located in the pelvic cavity, the mechanism of radioactive concentration needs further research.2. The diagnostic value of low dose CT scans in SPECT/CT. SPECT/low dose CT scanning improved the accuracy of the anatomical location of lesions and bone imaging specificity, not only can be positive lesions of bone imaging for accurate positioning, and CT can show the structure of the bone change, easily confused with bone metastases of common degeneration lesions have better recognition ability, improve the accuracy of bone metastases of bone imaging diagnosis;99mTc-MDP SPECT/low dose CT imaging to reduce the impact of bladder radioactive retention, especially for the bone scan unexpectedly found that patients with urinary retention, improve the accuracy of the diagnosis of sacral and pubic bone lesions, also reduced the client for urethral catheterization after rescanning trouble. About bone metastases tumor diagnosis standard, in addition to the typical imaging findings, in atypical lesions, a variety of clinical follow-up imaging methods from each other and also can be used as the "gold standard" diagnosis of bone metastases. Low dose CT image shown in dissolving the bony lesions with local soft tissue mass, diameter greater than2cm, more show the typical "donut", namely the lesion center sparse defect distribution is radioactive, perifocal radioactive concentration. Osteogenesis change early lesions absorb MDP saw no obvious abnormalities.3. Radionuclide imaging/low dose CT scan influenced treatment decisions:23cases of preoperative diagnosis of bone metastases, change treatment;9cases with clear spine of radioactive concentration stove for metastases with degenerative diseases, and selective radiotherapy;3cases in puncture for metastatic lesions, combined with immunohistochemical and tumor marker to find the primary tumor,2cases were obtained the results of osteosarcoma.17cases of preoperative diagnosis of bone metastases, change cure;8cases of clear spine of radioactive concentration stove for metastases with degenerative diseases, so the selective of the radiation;3cases in puncture for metastatic lesions, combined with immunohistochemical and tumor marker to find the primary tumor,1case of targeted biopsy results of ilium inflammatory granuloma. PET/CT scan can find more, more early bone metastases, the discovery of more effective for bone metastases starting symptoms of primary lesions, and can further clarify the diagnosis of multiple myeloma. part ⅡStudy on Radiation dose Caused by99mTc-MDP in SPECT/CT scanningObjective:In recent years, SPECT/CT has gained increasing clinical acceptance as a important hybrid anatomical-functional imaging modality, SPECT/CT allow the acquisition of anatomic(CT) and functional(SPET) information of a patient within a single examination and provides intrinsically coregistered images of the two modalities.99mTc-MDP is the most important bone imaging agent.99mTc-MDP is also grouped to the radioactive drug, in one hand, it conduce to clinical diagnose as a functional imaging-agent, on the other hand,99mTc-MDP can bring about radiation to the patients,the staff and the public, however, a few of documents is about the radiation dose of99mTc-MDP, so that, It is necessary for the health of the staff and the public to study the radiation dose caused by99mTc-MDP in SPET/CT examinations and to implement preferably the theory of radiation optimization.Methods:1. There are160patients who undergoing whole body bone imaging,40of that were selected randomly and the activity of injected99mTc-MDP were recorded,23patients was male,17patients was female, the purity of99mTc-MDP is93%, the activity of99mTc-MDP is23±1.4mCi (870±51.8MBq) according to patients injected99mTc-MDP.Between April to May2013in liaocheng city in shandong province people’s hospital nuclear medicine, the whole body bone scan and locally aged56.6±13.1, weigh72.0±13.9kg t, the nuclear medicine personnel10people,4people, engineer1person, the nurse is responsible for the elution and5people injected with99MTC-MDP1person2. Effective dose of the patients were estimated by dose coefficients and intravenous administration of an activity99mTc-MDP; the doserate from patients was surveyed with the451P-DE-SI Ion Chamber Survey Meter, The time were lOmin, 60min,120min and240min after the patients were injected99mTc-MDP, the distance were0.5m、1.0m and1.5m from the patients. the staffs dose was recorded with TLD and FJ-377thermoluminescence dose reader.3. Statistical analysis. All data were processed and analyzed statistically with Excel2003and SPSS13.0.Results:1. Effective dose of99mTc-MDP is5.23±0.76mSv, compared to the effective dose of the other radionuclide such as18F-FDG, the difference of them was little, however, the effective of125I was evidently higher, It was not evidence of the difference between the radiation dose caused by X-ray scanning and the effective dose of99mTc-MDP, the dose limits of occupational exposure is20mSv and that of public exposure is5mSv, there is statistical significance compared to the dose limits.2. The correlation coefficients of the doserate-distance and doserate-time are-0.994and-0.988respectively, as it can be seen, the influence of the dance is greater than that of the time,2.5μSv/h can be calculated from the basic standards for protection against ionizing radiation and for the safety of radiation sources.3. The overall radiation dose per year received by the staffs was0.873mSv, the overall radiation dose per year received by the injector and the technologist is respectively1.572mSv and1.558mSv, the data were lower than the corresponding dose limit. Total radiation dose per year received by the fingers of the technologist were also lower than the corresponding dose limit.4. Additional radiation dose are smaller (2.3±1.7mSv), diagnostic value are important for patients, conform to the practice of medical radiation legitimacy principle; On the other hand,distance protection and time protection may be reduced the radiation and radiation protection optimization is feasible on SPECT/CT imaging.Conclusions:It is little for patients that dose commitment is caused by99mTc-MDP in SPECT/CT examinations, but the clinician should consider the overall radiation dose received by patients. It is practicable to limit patients’ moving region properly to decrease public radiation from the patients who were injected99mTc-MDP. |
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