Postoperative Verification Research Articles

Case of precise full-mouth occlusal reconstruction guided by digital occlusal function analysis.

The clinical demand for occlusal reconstruction increases rapidly with increasing number of patients who have lost their normal occlusion because of tooth wear and dentition defects. Occlusal reconstruction is a special type of restoration defined as a comprehensive restoration of the function of the stomatognathic system by reestablishing a uniform and stable occlusal relationship between the upper and lower dentitions. Occlusal function analysis is an important part of occlusal reconstruction to achieve accurate restoration design and adjustment. Digital occlusal function analysis was conducted to monitor the movement of the mandible and obtain related data for the parameter design of occlusal reconstruction. Preoperative design, intraoperative adjustment, and postoperative verification were achieved, thereby improving the efficiency and accuracy of occlusal reconstruction.

Usefulness of Preoperative Simulation: Skull Base Approach

Preoperative simulation images creates an accurate visualization of a surgical field. The anatomical relationship of the cranial nerves, arteries, brainstem, and related bony protrusions is important in skull base surgery. However, an operator's intention is unclear for a less experienced neurosurgeon. Three-dimensional(3D)fusion images of computed tomography and magnetic resonance imaging created using a workstation aids precise surgical planning and safety management. Since the simulation images allows to perform virtual surgery, a déjà vu effect for the surgeon can be obtained. Additionally, since 3D surgical images can be used for preoperative consideration and postoperative verification, discussion among the team members is effective from the perspective of surgical education for residents and medical students. Significance of preoperative simulation images will increase eventually.

Enhancing neurosurgical navigation operation flow management through personal digital assistant technology: a prospective cohort study.

This prospective cohort study aims to evaluate the impact of digital health technology especially Personal Digital Assistants (PDA) in neurosurgical procedure management, focusing on surgical safety check accuracy, efficiency, and patient satisfaction. The study included 211 neurosurgical cases from January to December 2022. The control group of 106 patients followed traditional verification methods, while the experimental group of 105 patients used PDA. The PDA system facilitated real-time data collection, verification, and transmission. The study compared both groups in terms of check times, accuracy rates, and patient satisfaction, and used multivariate regression to assess the impact of baseline parameters on these outcomes. The study found that the experimental group using the PDA system reduced the average verification time by approximately 8 min, achieving 100.0% accuracy in preoperative and postoperative checks, significantly better than the control group (91.5% pre- and post-operation). Multivariate regression confirmed a 48.1% reduction in postoperative verification time due to the PDA system (p < 0.001), with the model showing high explanatory power (R2 = 0.911). Other examined factors, including patient age and nurse experience, had no significant effects. Similarly, the PDA's introduction markedly improved verification accuracy, with no significant impact from other variables (p = 0.010). The application of the PDA system in neurosurgical operations significantly enhanced the accuracy and efficiency of surgical safety checks, reduced nursing errors, optimized nursing workflows, and improved patient satisfaction. These results provide valuable insights for the application of PDA technology in high-risk medical fields, demonstrating potential of digital health tools in enhancing surgical safety and efficiency.

EP08.05-003 Evaluation of Dose Changes in Different Periods after 125I Seed Implantation in Lung Cancer

125I seed brachytherapy has the characteristics of sustainable, low dose rate and low damage to peripheral organs in the treatment of non-small cell lung cancer, and it is a better choice for local treatment of lung cancer patients. According to the location and size of the target volume, the preoperative plan simulates the seed implantation situation that achieves the optimal dose, and the postoperative verification plan evaluates the quality of the seed implantation. The number of seeds, the angle of needle insertion and the distribution of seeds in the monolayer implant surface are all determinants of dose.

A Comprehensive Approach for Measuring Spatial Deviations of Computer-Assisted Mandibular Reconstruction.

Computer-assisted surgery has become the mainstream in mandibular reconstruction, but the lack of a standard measuring approach for spatial deviations of mandible hinders postoperative verification and the comparison of different subjects. This study aims to set up a comprehensive approach for measuring spatial deviations of computer-assisted mandibular reconstruction. A systematic review was conducted to extract all measurements for computer-assisted mandibular reconstruction. Thereafter, eligible measurements were included in the authors' comprehensive approach, which categorized the measurements according to different anatomical structures and landmarks. A total of 80 studies were included in the authors' systematic review, and 31 measurements were extracted. The authors established a comprehensive panel of anatomical landmarks to facilitate measurement, including parts, points, lines, planes, and angles. These measurements encompassed spatial deviations of the overall mandible, condyle, gonial angle, bone grafts, midline, surgical plate, osteotomy, and miscellaneous indicators. A calculation spreadsheet was developed to collect landmarks and compute deviations automatically with built-in formulas. Finally, a simplified panel of measurements was recommended for spatial deviations of mandibular reconstruction. A comprehensive approach for measuring spatial deviations of computer-assisted mandibular reconstruction was established. Future studies will confirm this approach as an effective and scientific system for postoperative verification of computer-assisted mandibular reconstruction.

Advanced Three-Dimensional Technologies in Craniofacial Reconstruction.

After studying this article, the participant should be able to: 1. Describe the evolution of three-dimensional computer-aided reconstruction and its current applications in craniofacial surgery. 2. Recapitulate virtual surgical planning, or computer-assisted surgical simulation, workflow in craniofacial surgery. 3. Summarize the principles of computer-aided design techniques, such as mirror-imaging and postoperative verification of results. 4. Report the capabilities of computer-aided manufacturing, such as rapid prototyping of three-dimensional models and patient-specific custom implants. 5. Evaluate the advantages and disadvantages of using three-dimensional technology in craniofacial surgery. 6. Critique evidence on advanced three-dimensional technology in craniofacial surgery and identify opportunities for future investigation. Increasingly used in craniofacial surgery, virtual surgical planning is applied to analyze and simulate surgical interventions. Computer-aided design and manufacturing generates models, cutting guides, and custom implants for use in craniofacial surgery. Three-dimensional computer-aided reconstruction may improve results, increase safety, enhance efficiency, augment surgical education, and aid surgeons' ability to execute complex craniofacial operations. Subtopics include image analysis, surgical planning, virtual simulation, custom guides, model or implant generation, and verification of results. Clinical settings for the use of modern three-dimensional technologies include acquired and congenital conditions in both the acute and the elective settings. The aim of these techniques is to achieve superior functional and aesthetic outcomes compared to conventional surgery. Surgeons should understand this evolving technology, its indications, limitations, and future direction to use it optimally for patient care. This article summarizes advanced three-dimensional techniques in craniofacial surgery with cases highlighting clinical concepts.

Dental implant location via surface scanner: a pilot study

PurposeImplant location is performed after placement to verify that the safety of neighboring anatomic structure and the realizability of prosthetic plan. Routine postoperative location is based on radiological scanning and raises the concerns on radiation exposure and inconveniency in practice. In the present study a location method based on surface scanning was introduced and the accuracy of this method was assessed in vitro.Material and methodsA total of 40 implants were placed in 10 resin mandible models. The models were scanned with intraoral scanner (IS group) and extraoral scanner (ES group). The implant position was located with fusing the images of surface scanning and cone beam computerized tomography (CBCT) after implant placement. Deviations were measured between positions located by surface scanner and postoperative CBCT with the parameters: central deviation at apex (cda), central deviation at hex (cdh), horizontal deviation at apex (hda), horizontal deviation at hex (hdh), vertical deviation at apex (vda), vertical deviation at hex (vdh) and angular deviation (ad).ResultsIn IS group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.27 mm, 0.23 mm, 0.12 mm, 0.10 mm, 0.21 mm, 0.19 mm and 0.72°, respectively. In ES group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.28 mm, 0.25 mm 0.14 mm, 0.11 mm, 0.22 mm, 0.20 mm and 0.68°, respectively. The implant deviations in IS and ES groups were of no significant difference for any of the measurements.ConclusionsDental implant can be located via surface scanner with acceptable accuracy for postoperative verification. Further clinical investigation is needed to assess the feasibility of the method.

DERMOID AND EPIDERMOID CYSTS OF THE MAXILLOFACIAL AREA AND THE NECK AMONG CHILDREN

It is generally accepted that dermoid and epidermoid cysts are the result of malformation of the ectoderm. The asymptomatic course, absence of pathognomonic symptoms and similarity of clinical manifestations at separate stages of growth, despite nosological form and place of occurrence, give this pathology of particular relevance in the practice of pediatric maxillofacial surgery.&#x0D; However, if there are no significant issues regarding the etiology and pathogenesis of dermoids and epidermoids, there is a problem of constant monitoring of their prevalence and structure for the formation of administrative organizational measures for the planning of specialized care for this category of patients. Special attention should also be given to the development of new, minimally invasive surgical interventions, given the increasing aesthetic demands and requirements of patients.&#x0D; The aim of the study is to study in a comparative aspect their own experience on the clinical and morphological features and principles of treatment of dermoid and epidermoid cysts of the maxillofacial area and neck in children with the results of scientific studies, covered in literature.&#x0D; A thorough analysis of fundamental scientific works and publications in periodicals devoted to the scientific development of various directions in relation to these issues is carried out.&#x0D; The clinical section of the work concerns 15 children with dermoids and 8 children with epidermoids who have been treated for 8 years in the surgical ward of the children's clinical hospital in Poltava. General clinical, additional, and specific examination methods were used to establish clinical diagnosis, including diagnostic puncture, ultrasound, and MRI examination, which was performed in complex and questionable cases. If it is necessary, the patients are consulted by doctors of related specialties.&#x0D; The microscopic structure of the postoperative material was studied on preparations made by conventional methods.&#x0D; An objective study found that the clinical picture of the dermoid and epidermoid cysts is similar, differing only in slight subjective sensations on palpation.&#x0D; Comparison of clinical diagnosis and results of postoperative morphological verification of removed soft tissue bones showed that in 23.9% of patients the clinical diagnosis did not coincide with pathohistological. The difference in dermoids was the largest (75.0%), which confirms the need for expanded use of additional examination methods both at the pre-hospital stage and under inpatient conditions immediately before surgery.&#x0D; In general, the obtained morphological picture of the postoperative material coincided with the literature data on the classical structure of the dermoid and epidermoid cysts of the soft tissues of the maxillofacial area.&#x0D; Thus, the dermoid and epidermoid cysts of the maxillofacial area in children, having a dysontogenic origin, are most often diagnosed at younger and older school age. Despite their classic clinical picture, a considerable number of discrepancies between clinical and pathohistological diagnoses are traced , requiring a careful examination at both the hospital and hospital stages using modern, informative supplementary and special methods of investigation in complex and doubtful cases of cases and complex cases.&#x0D; These materials may be the basis for further in-depth scientific studies on immunohistochemical structural features dermoids and epidermoids to determine immunocompetence layers cystic membranes and determine their probable role in causing acute inflammation depending on the type of formation.

3D-printing non-coplanar template assisted 125I seed implantation for head and neck tumor: individualized template design and application

Objective To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT)-guided and 3D-printing non-coplanar template-assisted 125I seed implantation for head and neck tumor, aiming to explore the safety, feasibility and accuracy of the individualized template design method. Methods A total of 42 patients with recurrent/metastatic malignant head and neck tumor admitted to Peking University Third Hospital from January to December 2016 were recruited in this study. A prescribed dose of 110-160Gy was adopted.3D-printing non-coplanar templates were designed for 42 cases. The dosimetric parameters including D90, minimum peripheral dose (mPD), V100, V150, V200, conformal index (CI), external index (EI) and homogeneity index (HI) were statistically compared before and after surgery. Results All templates were properly implanted intraoperatively. Compared with preoperative planning, postoperative D90, V100, CI, EI and HI did not significantly differ (P=0.490, 0.407, 0.893, 0.143 and 0.079), whereas mPD, V150 and V200 significantly differed (P=0.036, 0.007 and 0.000). Conclusion After postoperative verification, the main dosimetric parameters have high therapeutic accuracy and properly match with preoperative planning, which can meet clinical requirements. Key words: Three-dimensional printing; Individualized non-coplanar template; Dosimetry; Head and neck neoplasm/radioactive seed implantation

Evaluation of transrectal ultrasound-based dosimetry for brachytherapy of prostate cancer: a single-center experience.

PurposeTo explore the possibility of intraoperative transrectal ultrasound (TRUS)-based dose verification in transperineal brachytherapy (BT) with iodine-125 (125I) seeds for prostate cancer.Material and methodsFifteen patients with prostate cancer were treated using BT with 125I seeds. Post-implant TRUS and computed tomography (CT) images were imported into treatment planning system (TPS) for dosimetry. Dosimetry parameters, including minimum dose received by 90% of the volume (D90), percentage of the volume receiving 100% of prescribed dose (V100), and percentage of the volume receiving 200% of prescribed dose (V200) were calculated based on TRUS and CT images, separately. The D90 value of TRUS-based dosimetry was transformed to its expected value. Comparisons of the dosimetric parameters between post-operative verification and preoperative plans were made by paired t-test. One-way ANOVA model was used to assess the differences in preoperative plans. Agreements were evaluated between the preoperative planning and post-operative actual dose parameters using Bland-Altman analysis.ResultsIn total, 825 of 125I seeds were implanted successfully in 15 patients. In TRUS-based dosimetry, 674 seeds (81%) were identified clearly in TRUS-based images, and the expected value of D90 parameter showed no significant differences compared with the preoperative planning and CT post-operation results (p > 0.05). In CT-based dosimetry, 810 seeds (98%) were identified clearly in CT-based images, and there was good consistency of D90, V100, and V200 values (p > 0.05). Post-implant CT-based dosimetry indicated that 125I seed implantation had fulfilled the expected plan.ConclusionsIntraoperative TRUS can be used for dosimetric verification of BT for prostate cancer.

3D printing non-coplanar template-assisted 125-iodine seed implantation for thorax movement tumor: individual template design method

Objective: To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography CT-guided and 3D printing template-assisted 125-iodine ((125)I) seed implantation for thorax movement tumor and to explore the feasibility and accuracy of the individualized template design method. Methods: A total of 35 patients, 20 males and 15 females with median age of 62 (17-87) years old, who registered from January 2016 to December 2017 applied with 3D printing guided template assisted radioactive seed implantations in Peking University Third Hospital were included in this study. (125)I seeds with a prescribed dose of 110-180 Gy were impanted. 3D printing templates were designed and produced for 35 cases. The dosimetric parameters: D(90), minimum peripheral dose (mPD), V(100), V(150), V(200), conformal index (CI), external index (EI), and homogeneity index (HI) were compared between pre-and post-plannings. Statistical method was two group of related non-parameters test. Results: The design and production of 35 cases' templates were in place well. Compared with the preoperative planning, the postoperative D(90), V(100), V(150), V(200), mPD, CI, EI and HI differences were 5.57%, 0.34%, 0.33%, -1.20%, 21%, 2.8%, -14.2%, 4.71%, -10.4%. All the included dosimetry parameters changed slightly after surgery compared with before surgery, but the difference was not statistically significant(all P>0.05). Conclusions: The dosimetric parameters of postoperative verification are consistent well with the preoperative planning and have good accuracy, the results could meet the clinical requirements.

Computed tomography-magnetic resonance imaging fusion-guided iodine-125 seed implantation for single malignant brain tumor: Feasibility and safety

To investigate the feasibility and safety of computed tomography-magnetic resonance imaging (CT-MRI) fusion-guided iodine-125 seed implantation for a single malignant brain tumor. From November 2015 to October 2016, 12 patients with a single malignant brain tumor were treated with permanent iodine-125 seeds implantation. CT-MRI fusion images were used to make the preoperative treatment plan, intraoperative dose optimization, postoperative verification, and tumor response follow-up. The dosimetry parameters of CT-MRI image fusion plans were compared between preprocedures and postprocedures, including plan target volume, V100 (the percentage of the target volume covered by the prescription dose [PD]), D90 (the dose that covers 90% of the target volume), and V200 (the percentage volume of the brain tumor receiving 200% of the PD). Adverse events were graded by the Common Terminology Criteria for Adverse Events. Clinical and radiological follow-ups were performed at a 3-month interval. All the interstitial implantations were completed successfully under the guidance of CT-MRI image fusion. The dosimetry parameters of CT-MRI image fusion postplans did not differ significantly from those of preplans (P > 0.05). No higher than Grade 2 adverse events were observed during the follow-up. Tumor control was achieved in 10 of 12 patients (83.33%). The median overall survival time was 15.05 ± 3.35 months (95% confidence interval 12.99-17.26). CT-MRI image fusion is feasible for the design, optimization, and verification of treatment planning. CT-MRI fusion-based brachytherapy may improve dosimetry of brain tumor while sparing the normal structures, potentially impacting disease control, treatment-related toxicity, and long-term survival.

3D-printing non-coplanar template assisted 125I seed implantation for pelvic tumor: individual template design method

Objective To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT)-guided and 3D-printing non-coplanar template-assisted 125I seed implantation for pelvic tumor, and to explore the feasibility and accuracy of the personalized template designmethod. Methods A total of 51 patients registered from Dec 2015 to Dec 2016 who were applied with 3D-printing guided template assisted radioactive seed implantations in the hospital were included in this study.A prescribed dose of 110-160 Gy was adopted. 3D-printing templates were designed and produced for 51 cases. The dosimetric parameters: D90, minimum peripheral dose (mPD), V100, V150, V200, conformal index (CI), external index (EI), and homogeneity index (HI) were compared between pre-and post-plans. Results 51 cases′ templates were in place well during the operations. Compared with the preoperative planning, the postoperative D90, V100, V150, V200, CI, EI and HI differences had no statistical difference (P>0.05); mPD is larger than before (t=-2.96, P<0.05). Conclusions The main dosimetric parameters of postoperative verification were consistent well with the preoperative planning and have good accuracy, which could meet the clinical requirements. Key words: 3D-printing; Radioactive seed implantation; Personalized non-coplanar template; Dosimetry; Pelvic tumor

Efficacy and dosimetry of computed tomography image-guided 125I radioactive seed implantation for locally recurrent rectal cancer

Objective To evaluate the efficacy of computed tomography (CT) image-guided 125I radioactive seed implantation for locally recurrent rectal cancer (LRRC), and to analyze the relationship between the dosimetry and prognosis. Methods A retrospective analysis was performed on the clinical data of 36 patients with LRRC who received CT image-guided 125I seed implantation in our hospital from 2003 to 2011. Dosimetric verification was performed using CT scan immediately after 125I seed implantation. The D90, D100, V100, and V150 values were evaluated. In all the patients, the median activity of seeds was 0.7 mCi (0.4-0.8 mCi) and the median number of implanted seeds was 74(33-137). The local control (LC) and overall survival (OS) rates were calculated using the Kaplan-Meier method. The log-rank test and Cox regression model were used for the univariate and multivariate analyses, respectively. Results The median OS time was 16.2 months (95% CI=13.5-18.9 months). The median LC time was 10.0 months (95% CI=6.2-13.8 months). The D90 and V100 values were (118.6±25.1) Gy and (90.0±0.3)%, respectively. The univariate analysis suggested that D90 was correlated with the LC time (P=0.048) and V100 was correlated with the OS time (P=0.035). The multivariate analysis showed that a V100 value higher than 90% was a prognostic factor of OS (P=0.044). Conclusions In the treatment of LRRC using CT image-guided 125I radioactive seed implantation, a D90 value larger than 140 Gy and a V100 value higher than 90% in the postoperative verification plan help improve the LC and OS rates. The D90 and V100 values in the postoperative verification plan may predict treatment outcomes in patients. Key words: Neoplasm recurrent, rectal/radioactive seed implantation; Treatment outcome; Dosimetry

Computed tomography image-guided and personalized 3D printed template-assisted 125-iodine seed implantation for recurrent pelvic tumor: a dosimetric study

Objective To compare the dosimetric data between preoperative plans and postoperative verification in computed tomography (CT) image-guided and 3D printed template-assisted 125-iodine (125I) seed implantation for recurrent pelvic tumor, and to explore of the accuracy of the technology in treatment planning. Methods A total of 12 patients with recurrent pelvic tumor who received CT image-guided and 3D printed template-assisted 125I seed implantation in our hospital from 2015 to 2016 were enrolled as subjects. 125I seeds with a prescribed dose of 110-150 Gy were implanted in 15 lesions. Twelve 3D printed templates were designed and produced for 15 treatment areas. Comparison of the dosimetric parameters between postoperative verification and preoperative plans was made by paired t-test. Results The mean D90, mPD, V100, V150, and V200 were 137.4 Gy, 74.4 Gy, 90.1%, 58.7%, and 34.4%, respectively, in postoperative verification and 140.2 Gy, 61.1 Gy, 91.8%, 64.3%, and 36.7%, respectively, in preoperative plans (P=0.153, 0.024, 0.028, 0.003, and 0.302). The conformity index of gross tumor volume was slightly reduced after operation (0.68 vs. 0.69, P=0.437). The external volume index increased after treatment (34.2% vs. 30.5%, P=0.530). Conclusions 3D printed template provides accurate positioning and orientation for treating recurrent pelvic tumor. All main indices of the actual dose distribution in postoperative verification meet the expectation of the preoperative plan, indicating satisfactory treatment accuracy. Key words: Three-dimensional printing; Template; Dosimetry; Neoplasms recurrence, pelvic/seeds implantation

Improved stereotactic procedure enhances the accuracy of deep brain stimulation electrode implantation in non-human primates

Purpose: Non-human primate models of deep brain stimulation (DBS) play an increasingly important role in the exploration of DBS mechanisms. The establishment and recognized usefulness of such models depend on the precise positioning of the stimulating targets and electrode implants. The optimal method of targeting remains controversial. Materials and methods: This paper described an improved stereotactic procedure that uses a self-developed adaptor to improve accuracy. This involved: (1) connecting clinical stereotactic devices with the skull of primates using a self-developed adaptor; (2) pre-operation targeting via magnetic resonance imaging (MRI); (3) target re-checking by microelectrode recording (MER); (4) DBS electrode implantation; (5) post-operative MRI verification of electrode placement and (6) positioning confirmation by DBS programming. Results: Use of the adaptor enabled clinical stereotactic surgery, pre-operative MRI targeting, microelectrode mapping and post-operative verification in primate DBS operations. Discrepancies between achieved and predetermined electrode position were around 0.6 mm. DBS programming improved the motor function of the hemiparkinsonism animals and decreased the numbers of rotation induced by apomorphine, indicating the precise positioning of the stimulating target and successful implanting of electrode using this method. Conclusions: An improved stereotactic procedure was performed during a non-human primate DBS operation using a self-developed adaptor. The accuracy of DBS electrode implantation in non-human primates was improved with this method.

Intracochleäre Elektrodenlage

Due to the increasing number of cochlear implantations (CI), postoperative radiological verification of the electrode position, e.g., with respect to quality control, plays a central role. The aim of this study was to evaluate the intracochlear position of deep inserted electrodes by cone beam computed tomography (CBCT). CBCT data sets (Accu-I-tomo, Morita, Kyoto, Japan) of 22 patients (28 ears operated between 2008 and 2011) were retrospectively analyzed. All patients underwent a CI (round window approach) with deep insertion of the electrode (Flex soft or standard electrode from MedEl©). CBCT data were analyzed for intracochlear position of the electrode (scala vestibuli, scala tympani, malposition between the scalae) and the certainty of this evaluation. All ears could be evaluated with the status certain or relatively certain in the basal turn of the cochlea. Thereby, the electrode array was inserted into the scala tympani in 93% (n = 26). Primary insertion into the scala vestibuli and the scala media was observed in 3.5% of the ears, respectively. In the apical part of the cochlea, only 32% (n = 9 ears) could be evaluated with relative certainty. The remaining 68% of cases could not be evaluated. Of the 32% interpretable cases in the apical part of the cochlea, 25% (n = 7) were inserted into the scala tympani, 3.5% (n = 1) into the scala vestibuli, and 3.5% (n = 1) were malpositioned between the scalae. The exact evaluation of the intracochlear position of the electrode by CBCT is only possible in the basal turn of the cochlea. In deep insertion, determination of the position in the medial and apical parts of the cochlea by CBCT is still not possible. Furthermore, the round window approach allows reliable implantation into the scala tympani.

Role of TPS in 125I brachytherapy for orbital tumors

Objective To investigate the role of TPS in 125I brachytherapy for orbital tumors.Methods Sixty-six patients with orbital tumor treated with 125I seeds from 2005 to 2009 were retrospectively analyzed.Forty-three patients were treated using TPS guided brachytherapy and the prescribed dose was 140 Gy.Other 23 patients were treated without TPS but simply implanted with 125I seeds at 1 cm intervals in parallelwith each other intraoperatively.CT and TPS quality verification were performed postoperatively in all patients.Also,CT and (or) MRI examination were performed at 3,6,12 and 24 months after brachytherapy for follow-up.x2 test and Kaplan-Meier survival analysis with log-rank significance test were used with SPSS 17.0.Results A total of 1070 125 I seeds were implanted in 66 cases,on average,( 16.2 ± 7.3) seeds for each patient.The satisfaction rates of postoperative quality verification in patients with and without TPS preplans were 79.07％ (34/43) and 43.48％ (10/23) respectively (x2 =8.542,P =0.003 ).Ten patients were lost in follow-up.Local recurrence rates in patients with favorable postoperative quality verification were 0(0/37) in 3 months,6.25％ (2/32) in 6 months,13.64％ (3/22) in 12 months and 3/9 in 24 months respectively,which were significantly different from those (5.26％ (1/19),16.67％ (3/18),30.77％ (4/13),6/6 )in the patients with inferior postoperative quality verification (x2 =9.017,P =0.0003).Conclusions TPS plays an important role in 125I brachytherapy for orbital tumors.Also,postoperative quality verification by TPS may help predict the local recurrence after brachytherapy. Key words: Orbital neoplasms; Brachytherapy; Iodine radioisotopes; Radiotherapy planning,computer-assissted

Navigation endoscopique et transparences corporelles par scanner à RX, une étape en imagerie in vivo

Progress in HR-CTdata processing has led to lower X-ray exposure and to better diagnostic performance. We describe 19 adult patients (among 5000) examined by HR CT with 64 detectors, acquisition and exposure protocols in mSv, spiral, 0.6-mm slices, 5To PACS. After the two usual processing steps (60 gray values, 5122 and 10242 matrices, dedicated workstations for coronaroscopy and virtual coloscopy, 2D multiplanar reformation, surfacic, 3D volumes with dissection and navigation), a third original data processing step on additional workstations was added. Variable matrix extrapolated images, flexible colored curves (different from anatomical conventions), lighting (sources) and transparencies (unavailable with traditional endoscopy) were used. The digital film is a 16-minute "journey "consisting of 19 endo-body navigations in 5 regions, from the head to the bronchi, from the heart to the coronary arteries, and from the digestive tract to the abdomen and pelvis. One possible application is post-operative verification of an aortic graft. The movie is illustrated here with ten plates. This new approach is cost-effective and beneficial for the patient, in terms of early diagnosis and therapeutic follow-up. Ethical issues are also examined.

Inter- and intraobserver variability in the postoperative evaluation of transpedicular stabilization: computed tomography versus magnetic resonance imaging

Background context Computed tomography (CT) represents the state of the art for the postoperative verification of the implant position after transpedicular stabilizations. Magnetic resonance imaging (MRI) has not challenged the CT, yet, because of susceptibility artifacts but would be favorable as a diagnostic tool for its excellent soft-tissue qualities. Purpose A study that analyzed if an artifact-reduced MRI could overcome this problem and provide sufficient data for the postoperative assessment was conducted. Study design The study design was a radiologic comparison of CT and MRI techniques evaluating pedicle screw placement after spinal fusion. Patient sample Fifty consecutive patients were given an MRI and a CT after a transpedicular stabilization surgery. Thirty-eight patients suffered from degenerative spinal disorders; three surgeries had become necessary because of spondylodiscitis, eight patients suffered from metastatic vertebrae destruction, and one patient experienced a fracture. Outcome measures Any contact of a malpositioned pedicle screw with the dura and/or radicular structures was identified as an implant-associated complication and was compared with postoperative clinical patient findings. Methods In total, 338 pedicular screws were analyzed in regard to their intrapedicular position. The double-blind evaluation of MRI and CT data was carried out by two radiologists and two spine surgeons. Accuracy of the CT analysis was calculated based on the interobserver agreement of 100%. Magnetic resonance imaging accuracy was calculated. Results The interobserver accuracy of the CT data amounted to a median of 89.8% and in the MRI data of 86.7%. Intraobserver comparisons showed a significant difference between CT and magnetic resonance evaluations in one observer (κ=0.293). In all other observers, the results were concordant with kappa values from κ=0.328 to κ=0.702. There was a high degree of agreement regarding the diagnosis of malpositioned pedicle screw and corresponding clinical symptoms between both techniques. Conclusions The presented data show that artifact-reduced MRI is equivalent to CT imaging in the postoperative evaluation of titanium spinal rod-screw systems. We therefore conclude that MRI should be considered as an alternative tool for the golden standard CT for postoperative imaging controls for its advantages in soft-tissue analysis.