Safe Margin Research Articles

Gustatory interface for operative assessment and taste decoding in patients with tongue cancer

Taste, a pivotal sense modality, plays a fundamental role in discerning flavors and evaluating the potential harm of food, thereby contributing to human survival, physical and mental health. Patients with tongue cancer may experience a loss of taste following extensive surgical resection with flap reconstruction. Here, we designed a gustatory interface that enables the non-invasive detection of tongue electrical activities for a comprehensive operative assessment. Moreover, it decodes gustatory information from the reconstructed tongue without taste buds. Our gustatory interface facilitates the recording and analysis of electrical activities on the tongue, yielding an electrical mapping across the entire tongue surface, which delineates the safe margin for surgical management and assesses flap viability for postoperative structure monitoring and prompt intervention. Furthermore, the gustatory interface helps patients discern tastes with an accuracy of 97.8%. Our invention offers a promising approach to clinical assessment and management and holds potential for improving the quality of life for individuals with tongue cancer.

Anatomical study and clinical outcomes of endoscopic transoral surgery for benign salivary gland tumors in the parapharyngeal space

The existing literature provides little insight into the efficacy of transoral endoscopy in exposing benign tumors originating from salivary glands in the parapharyngeal space at the parotid gland base and resecting part of the deep lobe with a safe margin. This study aims to investigate the efficacy of the endoscopic transoral approach for the visualization and resection of such tumors.Through transoral endoscopic cadaveric dissections and surgical procedures, we examined the anatomical structures of the parapharyngeal space and the deep lobe of the parotid gland, identifying key anatomical landmarks. We conducted a retrospective analysis of 19 patients with benign salivary gland-derived tumors in the parapharyngeal space who underwent transoral endoscopic resection.Intraoperative visualization of the tumor pedicle and the deep lobe of the parotid gland was successfully achieved in all cases, allowing for resection with safe margins. During a median follow-up period of 54.0 months, imaging revealed no signs of recurrence.Endoscopic transoral approach provides effective visualization of the deep lobe of the parotid gland and the medial portion of the parotid bed from the parapharyngeal space. Benign tumors of salivary gland-derived in this area can be well exposed and safely resected with adequate margins.

A new surgical strategy for T4 stage posterior buccal carcinoma: anatomical unit resection

Objective: To investigate the effect of anatomical unit resection on the overall survival rate of patients with T4 stage posterior buccal carcinoma. Methods: We conducted a retrospective study on 79 patients with T4 stage posterior buccal squamous cell carcinoma underwent radical surgery for buccal mucosa cancer and reconstruction with free anterolateral thigh flap in the Department of Oral and Maxillofacial Surgery, the Second Xiangya Hospital, Central South University from March 2014 to December 2019. The 74 patients were males and the 5 patients were females, aged from 28 to 72 years old. The 40 patients in control group underwent traditional extended resection (1.5-2.0 cm safe margin), and 39 patients in the experimental group underwent anatomical unit resection. The clinicopathological parameters of patients were collected and followed up regularly. The overall survival rate was assessed by Log-rank and Cox proportional risk regression model. Multivariate analysis was performed by linear regression model. Results: There were significant differences between experimental group and control group in overall survival rates (61.53% vs 27.50%, χ2=6.624, P=0.010) and local disease control rates (74.36% vs 27.50%, χ2=17.350, P<0.001). Multiple linear regression analysis showed that local disease control rate was significantly correlated with anatomical unit resection (t=3.880, P<0.001) and lymph node metastasis (t=2.619, P=0.011), and also Cox proportional hazards regression model analysis identified that overall survival rate was significantly correlated with anatomical unit resection (Z=2.421, P=0.016) and lymph node metastasis (Z=2.793, P=0.005). Conclusion: For posterior buccal carcinoma with multiple anatomical units involved, anatomical unit resection can significantly reduce local recurrence and improve overall survival rate of patients.

Patient-specific guides for consistently achieving R0 bone margins after resection of primary malignant bone tumors of the pelvis

AimsPrimary malignant bone tumor of the pelvis is an uncommon lesion, the resection of which via freehand osteotomy is subject to inaccuracy due to its three-dimensional anatomy. Patient-Specific Guides (PSG), also called Patient-Specific Instruments (PSI) are essential to ensure surgical planning and resection adequacy. Our aim was to assess their use and effectiveness.MethodsA monocentric retrospective study was conducted on 42 adult patients who underwent PSG-based resection of a primary malignant bone tumor of the pelvis. The primary outcome was the proportion of R0 bone margins. The secondary outcomes were the proportion of overall R0 margins, considering soft-tissue resection, the cumulative incidence of local recurrence, and the time of production for the guides. A comparison to a previous series at our institution was performed regarding histological margins.ResultsUsing PSGs, 100% R0 safe bone margin was achieved, and 88% overall R0 margin due to soft-tissue resection being contaminated, while the comparison to the previous series showed only 80% of R0 safe bone margin. The cumulative incidences of local recurrence were 10% (95% CI: 4–20%) at one year, 15% (95% CI: 6–27%) at two years, and 19% (95% CI: 8–33%) at five years. The median overall duration of the fabrication process of the guide was 35 days (Q1–Q3: 26–47) from the first contact to the surgery date.ConclusionsPatient-Specific Guides can provide a reproducible safe bony margin.

Role of midline raphe in compartmental surgery for squamous cell carcinoma of the tongue.

In the present study, we investigated how tumor distance from midline (TDFM) and depth of invasion (DOI) may affect survival outcomes after compartmental tongue surgery (CTS) for oral tongue squamous cell carcinoma (OTSCC). A retrospective series of cT2-T3 OTSCC treated with upfront CTS at our Department from 2010 to 2021 was evaluated. Radiological and pathological DOI and TDFM were correlated. The main outcomes were overall (OS) and loco-regional recurrence free survival (LRRFS). The linear relationship between DOI and TDFM with 2-year OS and LRRFS was tested. Survival estimates were obtained by the Kaplan-Meier method. Univariate analysis was performed for variables of interest, and results expressed in terms of hazard ratios and 95% confidence intervals. A total of 64 patients underwent CTS and neck dissection. No significant difference was found between pathological (pDOI) and radiological DOI (rDOI) (p = 0.321) or between pathological (pTDFM) and radiological TDFM (p = 0.435). Two- and 5-year OS and LRRFS were 85.7% and 70.4%, 84.3% and 76.1%, respectively. A linear and significant relationship with OS (p = 0.020) and LRRFS (p = 0.013) was found for pDOI; although linear, the relationship between pTDFM was not statistically significant for either survival outcomes. Once categorized, the ideal cut-off for pDOI according to OS was set at 10mm (p = 0.023). In patients undergoing CTS for primary OTSCC, magnetic resonance-derived rDOI represents an accurate estimate of pDOI, In contrast, TDFM was not associated with OS suggesting that the median raphe is a safe deep margin for CTS. BS/231,009 retrospectively registered.

MRI-based assessment of the mylohyoid muscle in oral squamous cell carcinoma, a 7-point scoring method.

To investigate preoperative MRI evaluation of the features of the mylohyoid muscle (MM) predictive of its infiltration in oral squamous cell carcinoma (OSCC) treatment planning, defining the most appropriate sequences to study its deep extension into the floor of the mouth (FOM). We applied a 7-point score to retrospectively evaluate preoperative imaging of patients who underwent surgery for OSCC over 11 years. The results were compared with histopathological findings using Spearman's rank coefficient. Receiver operating characteristic curves were employed to assess the score's ability to predict MM infiltration, determining optimal thresholds for sensitivity, specificity, and predictive values. The Mann-Whitney U-test confirmed that infiltration judgments did not overlap around this threshold. Cohen's K statistical coefficient was used to evaluate the interobserver agreement. Fifty-two patients (mean age 66.4 ± 11.9 years, 36 men) were evaluated. Histopathological examination found MM infiltration in 21% of cases (n = 11), with 90% classified in the highest Score categories. A score > 4 proved to be the best cut-off for predicting the risk of MM infiltration, with a sensitivity of 91% (CI: 0.57-0.99), specificity 61% (CI: 0.45-0.76), PPV 38% (CI: 0.21-0.59), and NPV 96% (CI: 0.78-0.99). At the subsequent single-sequence assessment, the TSE-T2wi had the highest diagnostic accuracy, with sensitivity 90% (CI: 0.57-0.99), specificity 70% (CI: 0.53-0.82), PPV 45% (CI: 0.25-0.67), and NPV 96% (CI: 0.80-0.99). The 7-point score is a promising predictor of safe surgical margins for MM in OSCC treatment, with the particular benefit of T2-weighted sequences. Our scoring system for tumor infiltration of MM, which is easy to use even for less experienced radiologists, allows for uniformity in radiological language, thereby ensuring crucial preoperative information for the surgeon. The relationship of the MM to an oral lesion may impact surgical planning. As the score increases, there is a greater incidence of infiltration in the MM. Our score system improves radiologists' reporting for MM involvement by tumor.

Primary cutaneous mucinous carcinoma of the cheek: a case report

BackgroundPrimary cutaneous mucinous carcinoma is a rare neoplasia of the sweat gland. The age-adjusted incidence was 0.024 tumors per 100,000 person-years. It is possible that the actual number of tumors may be slightly higher than previously estimated as some cases of primary cutaneous mucinous carcinoma may have been mistaken for benign tumors and removed by laser therapy without histologic examination.Case presentationWe report a 58-year-old Chinese man with primary cutaneous mucinous carcinoma. The patient presented to our care with an indolent nodule on the left cheek, which was proven to be a mucinous adenocarcinoma by excisional biopsy and immunohistochemical staining. Following a comprehensive evaluation, including whole-body computed tomography and positron emission tomography, metastases from other sites were ruled out and the patient was diagnosed with primary cutaneous mucinous carcinoma. The patient underwent an additional wide resection surgery to ensure a safe margin and was then recommended to undergo regular follow-up.ConclusionThis case is one of the few published Chinese cases in literature of primary cutaneous mucinous carcinoma. Diagnosis of primary cutaneous mucinous carcinoma is challenging, and treatment options are limited. Collaboration between clinicians and pathologists is crucial for optimal outcomes. Further studies with longer follow-up periods are necessary to provide evidence for the management of this disease.

Surgery for hepatoblastoma in children with trisomy 18: a monocentric study.

Recently, children with trisomy 18 have been receiving more active treatment for malignancies. We report herein seven cases complete resection was achieved, and discuss multidisciplinary treatment for hepatoblastoma in patients with trisomy 18. The medical records of children with trisomy 18 who were treated at the study center between 2010 and 2023 were reviewed. Six of 69 patients had hepatoblastoma development, and three of these underwent multidisciplinary treatment. In addition, 6 patients had been referred by another hospital for treatment, and four of these underwent multidisciplinary treatment. Among the seven patients who underwent multidisciplinary treatment, three, two, and two were categorized in Pre-treatment Extent of Disease (PRETEXT) classification group I, II, and III, respectively. Neoadjuvant chemotherapy resulting in tumor reduction was performed in three cases. In all the cases, complete resection was achieved with pathologically safe margins. Perioperative complications included circulatory failure in one case and bile leakage in two cases. Adjuvant chemotherapy was administered in four cases. The postoperative observation period ranged from 3months to 11years, and all the patients are recurrence-free. Children with trisomy 18 complicated with hepatoblastoma whose cardiopulmonary conditions are stable may be good candidates for chemotherapy and surgery.

Plexiform Variant of Ameloblastoma in Body of Mandible: Case Report and Review of Literature

Ameloblastoma is a benign but locally aggressive odontogenic epithelial neoplasm arising from remnants of dental lamina and dental organ [1,4]. This neoplasm is more prevalent between 2nd to 4th decade of life and mandible (11%) is more commonly involved than maxilla (1%) [2,5]. It has an aggressive behavior and recurrent course, It is rarely metastatic. Ameloblastoma represents 10% of odontogenic tumors and 1% of all tumors and cysts involving the maxillo mandibular region [1]. The World Health Organization (WHO) classification of 2017 describes ameloblastomas of the following four types: Solid/multicystic ameloblastoma (91%) unicystic ameloblastoma (6%); extraosseous/peripheral ameloblastoma (2%); and metastasizing ameloblastoma (1%). [3,8] A conclusive diagnosis can only be made by histopathology because it has wide range of histologic patterns and has radiographic characteristics with other lesions such the odontogenic keratocyst, giant cell tumour, aneurysmal bone cyst, and renal cell carcinoma metastasis.[5] Treatment for each type of ameloblastoma differs depending on its biological behaviour and rate of recurrence. This report presents a case of ameloblastoma involving the body of mandible with resorption of the root apices of canine, premolars and first molar. The lesion extends till the base of mandible with intact lower border. This was surgically excised preserving the lower border of mandible with safe sound margins of bone.

Locomotion and strike damage of fish passing through a fish friendly tubular pump using computational fluid dynamics and discrete element coupling method

The tubular pump is a typical water transfer apparatus designed for extremely low heads and large flow rates. It serves as the core equipment in pumping stations situated at lakes, rivers, and canals. An adverse effect on the ecological environment stems from fish injury and mortality primarily caused by blade strikes. The present work combines computational fluid dynamics and the discrete element method to simulate the dynamics of fish passing through a simplified blade, allowing us to establish a safe margin of the strike force to further assess fish damage in a more complex tubular pump system. The results indicated that strikes on fish alter their motion state in terms of direction and magnitude, inducing chaotic movements that heighten the risk of subsequent strikes with downstream components. Fish tend to align their velocities with the surrounding fluid due to flow-induced drag after multiple contacts with solid structures. The knife-shaped leading edge, and particularly the blade tip side, emerged as the primary factor in creating strike damage, and the adoption of a slanted and blunt leading edge can effectively reduce fish damage. In addition, decreasing the shaft speed, increasing the flow rate, and restricting the fish size were identified as measures conducive to fish survival in running pumps. The study further suggested that using fewer but larger pumps operating at lower shaft speeds would contribute to better fish friendliness, which can also ensure a sufficient delivery head and mass flow rate.

Complex chest wall reconstruction after failure: a literature review.

Primary and secondary chest wall tumors (bone, breast, and soft tissue), congenital defects, and chest wall osteoradionecrosis often require extensive full-thickness local excisions to guarantee safe oncological margins (in cases of tumors) and complex reconstruction to provide stabilization and good biomechanical results avoiding postoperative respiratory failure. Thus, a personalized approach is required when dealing with chest wall defects, and reconstruction is planned. This review summarizes failed chest wall reconstruction procedures, identifies causes of failure, and highlights principles for complex chest wall reconstruction post-failure. We performed a narrative review of the literature on PubMed, Scopus, ScienceDirect, and Google Scholar, including all the relevant studies published from 1970. The available experiences in literature are only anecdotic and no current guidelines or rules exist on this topic, also given to its rarity. Proper pre-surgical planning and a multidisciplinary team (MDT) discussion are crucial for complex cases such as infections and radiation-induced chest ulcers after previous surgical treatment. Procedures should eventually include thoracic wall debridement, necrotic tissue excision, pulse-jet lavage, prosthesis removal, and vacuum assisted closure (VAC) therapy as a bridge for chest wall re-reconstruction. Sternotomy wounds require wire and prosthesis removal, and the use of meshes or bone allografts. This review aims to summarize experiences and highlight surgical and oncologic principles for complex chest wall reconstruction after failure. This review summarizes literature experiences to identify common key points for chest wall reconstruction after failure and to give some advice to surgeons managing this rare, challenging surgery.

Quench protection for high-temperature superconductor cables using active control of current distribution

Superconducting magnets of future fusion reactors are expected to rely on composite high-temperature superconductor (HTS) cable conductors. In presently used HTS cables, current sharing between components is limited due to poorly defined contact resistances between superconducting tapes or by design. The interplay between contact and termination resistances is the defining factor for power dissipation in these cables and ultimately defines their safe operational margins. However, the current distribution between components along the composite conductor and inside its terminations is a priori unknown, and presently, no means are available to actively tune current flow distribution in real-time to improve margins of quench protection. Also, the lack of ability to electrically probe individual components makes it impossible to identify conductor damage locations within the cable. In this work, we address both problems by introducing active current control of current distribution between components using cryogenically operated metal-oxide-semiconductor-field-effect transistors (MOSFETs). We demonstrate through simulation and experiments how real-time current controls can help to drastically reduce heat dissipation in a developing hot spot in a two-conductor model system and help identify critical current degradation of individual cable components. Prospects of other potential uses of MOSFET devices for improved voltage detection, AC loss-driven active quench protection, and remnant magnetization reduction in HTS magnets are also discussed.

Long-Term Follow-Up of Computer-Assisted Microvascular Mandibular Reconstruction: A Retrospective Study.

Background: Virtual surgical planning has become a well-established practice in head and neck surgery. In oncological surgery, it permits the achievement of safe margins resections and ensures functional reconstructions and optimal esthetic outcomes. This study aimed to evaluate the long-term outcomes after virtually planned mandibular microvascular reconstruction, focusing on functional and esthetic results, as well as health-related quality of life. Methods: A long-term retrospective evaluation of 17 patients with oral cavity malignancy who underwent computer-assisted mandibular resection and reconstruction was performed. Functional and esthetic outcomes were analyzed using the EORTC, QLQ-C30, H&N35, and FACE-Q questionnaires. Results: Time since reconstruction ranged from 7 to 14 years. Patients reported high functional levels on the QLQ-C30 functional scales but lower scores on H&N35. On FACE-Q, patients demonstrated higher appraisal and satisfaction with their smiles compared to their overall facial appearance. Conclusions: In this retrospective case series, patients undergoing computer-assisted mandibular reconstruction for oral malignancies achieved good long-term functional and esthetic outcomes. Although limited by the small sample size, these results support the enduring benefits of virtual planning for mandibular reconstruction. To minimize declines in function and appearance, considerations should include immediate dental implants, enhanced reconstruction of the temporomandibular joint, newer methods of radiotherapy to minimize xerostomia, and oral exercises to prevent trismus.

The effect of narrow band imaging in CO2 laser therapy in early-stage glottic cancer

Objective:To explore efficacy of narrow band imaging（NBI） technique in CO2laser therapy in Early-Stage Glottic cancer. Methods:The clinical data of patients with Early-Stage Glottic cancer who underwent CO2laser vocal cord resection from June 2011 to August 2022 were retrospectively analyzed. Among these, 27 patients who underwent surgery assisted by NBI were assigned to the observation group, while 25 patients who underwent conventional CO2 laser microsurgery with a suspension laryngoscope were assigned to the control group. The differences between the two groups were analyzed in terms of intraoperative frozen pathology results, postoperative recurrence rates, 5-year cumulative disease-free survival rates, complications, and voice recovery. Results:All 52 patients were operated successfully. Temporary tracheostomy and serious complications did not occur during the operation. The postoperative patient's pronunciation was satisfactory. One patient experienced vocal cord adhesion, but there were no severe complications such as breathing difficulties or bleeding, with an overall complication rate of 1.92%. Postoperative follow-up was 1-5 years. The 5 years recurrence free survival in the general group was 77.90％, and the 5 years recurrence free survival in the NBI group was 100％, the difference was statistically significant（P<0.05）. NBI endoscopy is safer and more accurate than the general group in determining the safe margin of tumor mucosal resection（P<0.05）. Among the patients who accepted the voice analysis, the difference was no statistically significant（P>0.05）. Conclusion:Compared with conventional CO2laser surgery under microscope, NBI guided laser resection of Early-Stage Glottic cancer is more accurate. NBI guided laser resection could improve 5 years recurrence free survival rate. In a word, narrow-band imaging endoscopy can has very high value in clinical application.

Risk of fracture in massive cultural objects made of lime wood: a case study of Veit Stoss’ altarpiece

Massive cultural objects made of wood are often situated in historic interiors in which they experience uncontrolled dynamic variations of relative humidity (RH). Although the objects usually have acclimatized to the natural climate variability, preventing risks related to any kind of modification of their environment requires an understanding of the object’s response to the expected changes. In the present study, an analysis of the risk of cracking related to continuous or intermittent heating, or the transfer to hypothetically ideal conditions in a conservation studio was performed for the case of elements of Veit Stoss’ altarpiece (1477–1489) preserved in St. Mary’s Basilica in Krakow, Poland. Massive sculptures carved in lime wood and approximately one meter in diameter were analysed. The study aimed at determining safe margins of environment modifications that would not cause propagation of cracks that are known to have accumulated in wood during centuries of the altarpiece’s existence. The mechanical properties of lime wood were determined experimentally to feed the numerical model. The energy release rates around the tips of cracks of various depths in a wooden sculpture were calculated using the finite element analysis and compared with the critical value of the parameter triggering the fracture propagation in the material, derived from the fracture energy measurement. It was shown that the church interior housing the altarpiece can be heated to 11 °C during the cold season to provide human comfort. The allowable duration of intermittent heating events to more comfortable 18 °C that would induce drops in RH of up to 40% was assessed as 12 h. The study demonstrated that moving the sculptures to the conservation studio would have to be done with extreme caution as it would be connected with risks depending on the depth of existing cracks and the duration of the RH change.

Evaluation of Safe Margins Using Immunohistochemistry in Oral Squamous Cell Carcinoma.

Hematoxylin & Eosin (H & E) stains have been conventionally used to establish the status of safe margins following resection of primary Oral Squamous Cell Carcinoma. Due to non-specificity of this stain, there is a possibility of false negative results. In this study, we have assessed the role of Immunohistochemistry (IHC) in establishing the status of safe margins. To compare Hematoxylin & Eosin (H & E) and Immunohistochemistry (IHC) staining in identification of tumor cells in establishing the status of safe margins. This study included 14 cases diagnosed with OSCC. Following resection, the primary lesion was subjected to Histopathological analysis. 2 sets of HP slides were prepared from serial sectioning of the wax block prepared for each of the four margins. Both sets of slides were stained with H &E stain. One set of these slides was further stained with Pan CK marker (IHC) which is a cytokeratin marker to identify tumour cells. All the slides with H & E staining reported negative for tumor infiltration and 4 slides (3 patients) out of 56 were reported positive with PanCK marker. There was a statistically significant difference in the number of patients with positive margins using IHC as compared to H & E stain. Immunohistochemistry using PanCK marker proved to be more efficient in the determination of status of safe margins than routine H & E staining.

Early stage thymoma and the surgical extent paradigm.

The recommended treatment for early stage thymoma without myasthenia gravis is complete thymectomy (CT). Limited thymectomy (LT) (simply resecting the thymoma with safe surgical margins) is gaining popularity. In this study, we compared the surgical and oncological results of complete and limited thymectomy in non-myasthenic patients with early stage thymoma. Non-myasthenic, Masaoka stage I-II, 86 patients who underwent surgical resection for thymoma were included in the study. Complete thymectomy (n:44) included patients who had resection of the thymoma together with the entire thymus and limited thymectomy (n:42) included patients who had resection of the thymoma without remaining thymus. The surgical approach, tumor size, histological type, pathological stage, adjuvant therapy, complications, postop myasthenia gravis, recurrence and death were recorded and compared between groups. Complete thymectomy group had more WHO type B1-3 tumors, more complications and more deaths than patients in the limited thymectomy group (p = 0.03, 0.018 and 0.023 respectively). Although statistically not significant CT group had more recurrences than LT group (11.4%/4.8%, p = 0.43). The 10-year freedom from recurrence (FFR) rate in the CT group was 84.8% and in the LT group ıt was 97.6%, the difference was not statistically significant (p = 0.15). None of the factors including surgical extent analysed with univariate and multivariate analysis had a significant effect on FFR. Limited thymectomy may be a good treatment option for non-myasthenic early stage thymoma patients but randomized controlled trials with long follow-up periods, ideally comparing patients operated with minimally invasive surgery are necessary.

Therapeutic management of malignant tumors of the auricle – comments on a clinical case

Basal cell carcinoma is one of the most common malig­nan­cies located in the auricle. It is an aggressive tumor due to the local evolution, being able to invade adjacent tissues, but with a low rate of metastasis. Establishing a correct histological diagnosis is essential for proper the­ra­peu­tic management and for the patient’s prognosis. The au­thors present the clinical case of a 74-year-old patient ad­mit­ted to our clinic for a tumor of the left auricle. The pro­blems encountered in establishing a correct histological diag­no­sis, the particularities of the complete sur­gi­cal abla­tion of the tumor and the aspects related to the post-re­sec­tion auricle remodelling technique are presented, exem­pli­fied and commented, considering the practice of a sur­gi­cal in­ter­ven­tion in an area with profound esthetic im­pli­ca­tions. The short-term and medium-term results highlight the lack of tumor residue, the successful coverage of the post­abla­tive skin defect and a satisfactory local appearance in the left ear and face in general. The diagnostic and the­ra­peu­tic management of ear malignancies involves a num­ber of difficulties and must be established through inter­dis­ci­pli­­nary collaboration within a specialized oncology com­mis­sion. Complete ablation of the tumor and obtaining safe negative margin, together with the reconstructive technique used after resection allowed good results in the short and medium term from an oncological, functional and esthetic point of view. The surgical treatment is the only therapeutic means used in this case.

A framework for developing an attitude determination and control system simulator for Cubesats: Processor-in-loop testing approach

The outbreak of miniaturized satellites is increasingly demanding well-performing attitude determination and control systems (ADCS). Testing an ADCS directly using hardware is extremely costly and risky, whereas testing it using only computer simulation does not yield realistic enough results. Therefore, a detailed framework for developing an ADCS simulator with processor-in-the-loop testing for low-earth orbit Cubesats is established in this paper. In particular, the study focuses on the implementation of the algorithms on a STM32 with ARM Cortex CPU for efficient testing and prototyping. This is done by formulating a quaternion-based satellite dynamic model equiped with a three-axis magnetorquers and a set of pyramidal cluster of reaction wheels for high pointing capabilities. Prominently used sensors are modeled so that the attitude can be estimated using a multiplicative extended Kalman filter. For attitude control, several modes are developed based on different mission stages, and a simplified less burdensome control switching strategy is proposed to maintain stability with minimal computation and energy resources. To test the applicability of the simulator, an ADCS is designed to meet the requirements of the recent low-atmosphere measurement missions. The results are analyzed in accordance with the ESA ECSS standards, and the assessment shows that the specifications can be met with a safe margin, leaving room for unmodeled errors to be taken into account in later stages of the design. Additionally, the proposed control strategy gives various possibilities for missions with different types of objectives, furthermore the framework's flexibility provides easy modification of any part for the user's specific needs.

Analysis of factors influencing the efficacy and prognosis of surgical treatment for primary malignant pelvic bone tumors

Objective: To analyze the prognostic factors and the influence of surgical margin to prognosis. Methods: A retrospective analysis was performed for 208 pelvic tumors who received surgical treatment from January 2000 to December 2017 in our instituition. Survival analysis was performed using the Kaplan-Meier method and Log rank test, and impact factor analysis was performed using Cox regression models. Results: There were 183 initial patients and 25 recurrent cases. According to Enneking staging, 110 cases were stage ⅠB and 98 cases were stage ⅡB. 19 lesions were in zone Ⅰ, 1 in zone Ⅱ, 15 in zone Ⅲ, 29 in zone Ⅰ+Ⅱ, 71 in zone Ⅱ+Ⅲ, 29 in zone Ⅰ+Ⅳ, 35 in zone Ⅰ+Ⅱ+Ⅲ, 3 in zone Ⅰ+Ⅱ+Ⅳ, and 6 in zone Ⅰ+Ⅱ+Ⅲ+Ⅳ. Surgical margins including Intralesional excision in 7 cases, contaminated margin in 21 cases, marginal resection in 67 cases, and wide resection in 113 cases. Local recurrence occurred in 37 cases (17.8%), 25 cases were performed by reoperation and 12 cases received amputation finally. The 5-year recurrence rate of marginal resection was higher than wide resection (P＜0.05), and the recurrence-free survival rate of marginal resection was lower than wide resection (P＜0.05). There was significant differences in recurrence rate and recurrence-free survival rate between R0 and R1 resection (P＜0.05). 92 cases were not reconstructed and 116 cases were reconstructed after pelvic surgery. At the last follow-up, 63 patients (30.3%) died, and the 5-year, 10-year and 15-year survival rates were 70.4%, 66.8% and 61.3%, respectively. The 5-year survival rate of stage ⅠB and ⅡB tumor was 90.4% and 46.8%, respectively. There were 29 cases had postoperative wound complications (13.8%), 1 case with pelvic organ injury. The final function was evaluated in 132 patients, with an average MSTS score of 25.1±3.6. Cox multivariate analysis showed that surgical staging, R0/R1 margin and metastasis were independent prognostic factors for pelvic tumors. Conclusions: The safe surgical margin is the key factor for recurrence-free of pelvic tumor. The survival rate of stage ⅡB pelvic tumors was significantly lower than that of stage ⅠB tumors. Wound infection is the main postoperative complication. Surgical staging, R0/R1 margin and metastasis were independent prognostic factors of pelvic tumors.