| Part 1:Experimental study on the factors affecting accuracy of different stereotactic proceduresAim:To measure the target error ranges of different stereotactic procedures and explore their influential factors.Method:A model was designed with a plastic skull model and plastic tubes to simulate intracranial lesion targets. Different puncture operation paths were designed by magnetic resonance imagings (MRI). The target errors, defined as the distance between the needle and the simulation target, were measured in three different kinds of Leksell、 CAS-R-2 and VarioGuide stereotactic procedures. The target errors of the three different operation systems were analyzed by the variance analysis statistical method. Influential factors of target errors in three systems were respectively studied using single factor regression. Influential factors of three systems were respectively analyzed using multiple linear regression. Calculation errors and target errors of CAS-R-2 and VarioGuide systems were analyzed using independent samples t test and Pearson correlation.Results:A total of 61 simulated targets were measured, and 366 target errors were obtained. The average target errors of Leksell, CAS-R-2 and VarioGuide were 3.86mm±1.23 mm,4.15mm±1.47mm and 4.08mm±1.21mm, respectively. There were no statitical differences among target errors of three systems (P=0.186).Effects of angles of ring and arc on target errors in Leksell system had statistical differences (P values were 0.016 and 0.004, respectively), but effects of target positions of X, Y, Z on target errors had no statistical differences (P values were 0.165,0.886 and 0.524, respectively). After data conversions, effects of X-100 value, the space distances between targets and the origins, and the puncture path level angles on target errors had statistical differences (P values were 0.044, <0.001 and <0.001), but the effects of Y-100 and Z-100 values on target errors had no significances (P values were 0.188 and 0.209). Multiple linear regression analyses showed that space distances and horizontal angles were the main influential factors of target errors (P values were 0.001 and <0.001). In CAS-R-2 system, X and Y values, and the joint 1,2,3,5 angles of the mechanical arm had significant effects on target errors (P values were<0.001,0.001,0.002,0.001,<0.001 and 0.001), but Z values and the joint 4 angles had no significant effects on target errors (P values were 0.057 and 0.388). After data conversions, effects of X-100, Y-100, Z-100 values and space distances on target errors had no significant differences (P values were 0.301、0.356、0.128 and 0.276). Multiple linear regression analyses showed that X and Y values were the main influential factors of target errors (P values were<0.001 and 0.001). In VarioGuide system, X、Y and Z values had no significant effects on target errors (P values were 0.272、0.180 and 0.766). After data conversions, X-100、Y-100、Z-100 values and space distances had no significant effects on target errors (P values were 0.307、0.760,0.728 and 0.094). There were significant differences between the average calculation errors and target errors in CAS-R-2 and VarioGuide systems, (P values were<0.001 and<0.001, respectively), and statistical correlations were found between the two groups in the two systems (the correlation coefficients were 0.284 and 0.233, P=0.002 and 0.010, respectively).Conclusions:There was no significant difference between target errors of three systems. Ring angle, arc angle, X-100 value, space distance and horizontal angle had effects on target errors in Leksell system. Especially, space distance and horizontal angle were the main influential factors. X and Y values, and the joint 1,2,3,5 angles of the mechanical arm had effects on target errors in CAS-R-2 system. Especially, X and Y values were the main influential factors. Various factors had no significant effects on target errors in VarioGuide system. The calculation errors were less than target errors, and correlated with each other in CAS-R-2 and VarioGuide systems.Part 2:Clinical study on the factors affecting diagnostic yield, accuracy and safety of stereotactic brain biopsyAim:To explore the diagnostic yield and its influential factors of stereotactic biopsy and analyze the main influential factors of stereotactic biopsy’s safety.Method:A retrospective analysis was applied to stereotactic brain biopsy cases from 2012 January to 2014 June in our hospital. Brain biopsy tissues were obtained and pathological examined in stereotactic operations guided by MRI. Patients’ gerneral information, stereotactic systems, location, number, size, depths, pathological diagnosis of lesions, were collected. Univariate and multivariate analyses were respectively used to found the factors of biopsy diagnostic yield and complication rate with χ2 test and Mann-Whitney U test. Cases diagnosed by second operations were sumerized and diagnosis information of cases undiagnoed in first operations were analyzed.Results:A total of 931 cases were retrospectively analysed, including 539 males and 392 females, aged from 1 to 83 years old, with a meidan age of 48 years old.835 cases were confirmly diagnosed, but 96 ones were undignosed. The diagnostic yield was 89.69%. Postoperative complications occurred in 26 cases including 3 deaths, with 2.79% of complication rate. Before biopsy operations,181 patients received treatments, including 87 cases with hormone,48 cases with chemotherapy,74 cases with raiotherapy, and 26 cases with operations. There were 738 cases with tumor lesions,97 cases with nontumor lesions, and 96 cases with undiagnoses in pathological results. There were no significant effects on the diagnostic yield in patients’clinical characteristics, such as gender (P=0.756), preoperative treatment (P=0.104), the application of preoperative hormone (P=0.136), preoperative chemotherapy (P=1.000), preoperative radiotherapy (P=0.883), craniotomy operation history (P=0.333) and biopsy operation method (P=0.424). However, age had significant effects on diagnostic yield (P=0.034), and stratification analysis with cutoff value of 50 years old also showed a statistical significance (P=0.003). there were no significant effects on the diagnostic yield in lesions’ characteristic factors, such as site (P=0.079), number (P=0.723), and lesions which were uniform or not (P=0.060). But significant effects on diagnostic yield were found in depth (P<0.001), lesions which were enhanced or not (P<0.001) and volume (P=0.035). Stratification analysis with cutoff value of 3.52 cm3 also showed a statistical significance (P<0.001). Logistic regression analysis showed that, the main factor affecting the diagnosis rate were patients’age (P=0.060, OR=2.075), focal depth (P=0.060, OR=3.710) and the lesion volume (P=0.060, OR=3.777). Among patients with confirmly pathological diagnoses,40 cases underwent craniotomy operations and 3 cases underwent the second biopsy operations.37 cases had two matched pathological results, and the accuracy rate of diagnosis was 86.05%. Among 96 undiagnosed patients,5 cases underwent craniotomy operations and the pathological results were 1 oligodendroglioma,1 glioblastoma,1 lymphoma,1 tuberculosis, and 1 idiopathic hypertrophic cranial pachymeningitis.9 cases underwent the second biopsy operations and the pathological diagnoses were 1 diffuse astrocytoma,1 less oligodendroglial tumor,1 anaplastic astrocytoma,1 glioblastoma,2 lymphomas,1 Langerhans’cell histiocytosis, and 2 cases of demyelinating.2 cases with first pathological diagnoses of brain tissues were oligodendroglioma and demyelination after second biopsy operations.26 cases with postoperative complications included 21 cases of hemorrhage,2 cases of epilepsy,2 cases of intracranial infection,1 case of cerebral edema. There were no significant effects on complication rate and hemorrhage rate in the clinical factors, such as gender (P1=0.672, P2:=0.335) and patients with symptoms of high intracranial pressure or not (P1=0.957, P2=0.862). History of diabetes had no significant effects on complication rate (P1=0.052), but had statistical effects on hemorrhage rate (P2=0.026). History of hypertension had significant effects on both complication rate (P1=0.026) and hemorrhage rate (P2=0.029). Age also had significant effects on both complication rate (P1=0.015) and hemorrhage rate (P2=0.018). Stratified analysis revealed that age with cutoff value of 55 years old had significant effects on both complication rate (P1=0.024) and hemorrhage rate (P2=0.015). However, there were no significant effects on both complication rate and hemorrhage rate in lesion characteristics, such as lesion location (P1=0.139, P2=0.237), focal depth(P1=1.000, P2=0.697), number of lesions (P1=0.841, P2=1.000), lesions which were uniform or not (P1=0.815, P2=0.793), lesions which were enhanced or not (P1=0.104, P2=0.227), lesion volume (P1=0.898, P2=0.976), and lesions which were tumor or not (P1=0.495, P2=0.400). Multi-factors analysis showed that, the main factor affecting the complication rate was history of hypertension (P=0.020, OR=2.869), and the main factor affecting the hemorrhage rate were history of diabetes (P=0.059, OR=3.077) and patient’s age (P=0.053, OR=2.479).Conclusions:The age of patients, the depth of lesion, lesion enhancement and lesion volume were influential factors of the diagnostic yield of stereotactic biopsy. Especially, patients’age, lesion depth and lesion volume were the main influencial factors. The second biopsies and craniotomy operations can definite pathological diagnoses of lesions which were not confirmed at the first biopsy operations. The main factor affecting the complication rate was history of hypertension, and the main factor affecting the hemorrhage rate were History of diabetes (P=0.059, OR=3.077) and patient’s age (P=0.053, OR=2.479). |
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