Preoperative Treatment Planning Research Articles

Total mesorectal excision in MRI-defined low rectal cancer: multicentre study comparing oncological outcomes of robotic, laparoscopic and transanal total mesorectal excision in high-volume centres.

The routine use of MRI in rectal cancer treatment allows the use of a strict definition for low rectal cancer. This study aimed to compare minimally invasive total mesorectal excision in MRI-defined low rectal cancer in expert laparoscopic, transanal and robotic high-volume centres. All MRI-defined low rectal cancer operated on between 2015 and 2017 in 11 Dutch centres were included. Primary outcomes were: R1 rate, total mesorectal excision quality and 3-year local recurrence and survivals (overall and disease free). Secondary outcomes included conversion rate, complications and whether there was a perioperative change in the preoperative treatment plan. Of 1071 eligible rectal cancers, 633 patients with low rectal cancer were identified. Quality of the total mesorectal excision specimen (P = 0.337), R1 rate (P = 0.107), conversion (P = 0.344), anastomotic leakage rate (P = 0.942), local recurrence (P = 0.809), overall survival (P = 0.436) and disease-free survival (P = 0.347) were comparable among the centres. The laparoscopic centre group had the highest rate of perioperative change in the preoperative treatment plan (10.4%), compared with robotic expert centres (5.2%) and transanal centres (2.1%), P = 0.004. The main reason for this change was stapling difficulty (43%), followed by low tumour location (29%). Multivariable analysis showed that laparoscopic surgery was the only independent risk factor for a change in the preoperative planned procedure, P = 0.024. Centres with expertise in all three minimally invasive total mesorectal excision techniques can achieve good oncological resection in the treatment of MRI-defined low rectal cancer. However, compared with robotic expert centres and transanal centres, patients treated in laparoscopic centres have an increased risk of a change in the preoperative intended procedure due to technical limitations.

Opportunities for, and barriers to, uterus-preserving surgical techniques for placenta accreta spectrum.

Placenta accreta spectrum (PAS) can lead to major peripartum morbidity. Appropriate management approaches depend on the clinical severity, each individual's preference, and the treating team's expertise. Peripartum hysterectomy is the most frequently used treatment option. However, it can impact psychological well-being and fertility. We investigated whether conservative treatment with focal resection or leaving the placenta insitu is associated with comparable or lower maternal morbidity than hysterectomy in centers of excellence within the International Society for placenta accreta spectrum (IS-PAS). Furthermore, a survey was conducted to explore potential barriers to conservative management in antenatal counseling and intraoperative decision-making. Confirmed PAS cases in the prospective IS-PAS database from 22 registered centers between January 2020 and June 2022 were included in the analysis. A separate online survey with 21 questions was answered by the IS-PAS center experts about indications, diagnostic criteria, patient counseling, surgical practice, changes from the preoperative treatment plan, and why conservative management may not be offered. A total of 234 cases were included in the analysis: 186 women received hysterectomy and 38 women were treated by focal resection, and 10 by leaving the placenta insitu. Blood loss was lower in the focal resection group and in the placenta insitu group compared to the hysterectomy group (p = 0.04). 46.4% of the women initially planned for focal resection, and 35.7% of those initially planned for leaving the placenta insitu were ultimately treated by hysterectomy. Our survey showed that the IS-PAS centers preferred hysterectomy according to a woman's wishes (64%) and when they expected less blood loss and morbidity (41%). Eighteen percent of centers did not offer focal resection at all due to a lack of experience with this technique. Reasons for not offering to leave the placenta insitu were avoidance of unexpected reoperation (36%), puerperal infection (32%), or skepticism about the method (23%). Uterus-preserving treatment strategies such as focal resection appear to be safe alternatives to peripartum hysterectomy. However, less than half of the IS-PAS centers perform them. Acceptance of conservative treatments could be increased by standardized criteria for their implementation and by systematic training for PAS experts.

SlicerPIT: software development and implementation for planning and image-guided therapy in photoimmunotherapy.

Photoimmunotherapy is a treatment modality that induces targeted cell death by binding a molecular-targeted drug activated by infrared light to the tumor cells and subsequently illuminating the lesion with infrared light. For deep lesions, a needle catheter is used to puncture the tumor, and an illumination fiber (cylindrical diffuser) is inserted into the catheter lumen for internal illumination. However, it can be challenging to place the cylindrical diffusers in an appropriate position as the deep lesions cannot be often confirmed accurately during surgery. We have developed "SlicerPIT", a planning simulation software for photoimmunotherapy. SlicerPIT allows users to place the cylindrical diffuser with its illumination range on preoperative images in 2D and 3D and export the planning data to external image-guided surgical navigation systems. We performed seven cycles of photoimmunotherapy with SlicerPIT in three patients with recurrent head and neck cancer. Preoperative planning for photoimmunotherapy was conducted using SlicerPIT, which could be imported into the navigation system. During the operation, we punctured the needle catheters along with the treatment plan on the navigation screen. Subsequently, intraoperative CT imaging was performed and overlaid with the preoperative treatment plan to confirm the alignment of the cylindrical diffusers as planned, followed by infrared light illumination. Postoperative imaging showed necrosis and shrinkage of the entire tumor in all cycles. SlicerPIT allows for detailed preoperative treatment planning and accurate puncture. It may be a valuable tool to improve the accuracy of photoimmunotherapy for deep lesions and improve patient outcomes.

Breast edema score at breast MRI: its value in prediction of molecular subtype of breast cancer and its impact on axillary LN metastasis

BackgroundSince many newly diagnosed breast cancer patients have breast MRI, the value of preoperative breast magnetic resonance imaging would improve if molecular subtypes could be consistently identified, and prognostic information provided in addition to diagnostic imaging. Breast edema may improve the ability to predict molecular subtypes and clinical and pathological outcomes in invasive breast cancer patients. The prognosis for breast cancer prognosis based on the findings of breast edema by magnetic resonance imaging will be useful in both pretreatment planning and prognosis. Breast edema on T2-weighted images and STIR was scored on a scale of 1 to 4, as follows: (a) breast edema score (BES) 1, no edema; (b) BES 2, peritumoral edema; (c) BES 3, pre pectoral edema; and (d) BES 4, subcutaneous edema (suspicious for occult inflammatory breast cancer “IBC”). Axillary lymph node status and number were also evaluated in T2 and STIR and after contrast administration. The aim of this work was to assess the role of tumour-related breast edema MRI features in distinguishing molecular subtypes of breast cancer and its effect on pathological axillary lymph nodes in patients with breast cancer.ResultsThere was a highly significant difference between BES with respect to the molecular subtypes of breast cancer, size of the mass, Ki-67 expression, LN status, and LN number (p < 0.0001, 0.045, < 0.0001, < 0.0001, and < 0.0001 respectively). However, there was no significant difference between BES and histopathological grade in studied masses, such as p-value = 0.49.ConclusionsTumour-related breast edema MRI characteristics may be useful in distinguishing molecular subtypes of breast cancer and could be used as a promising feature to improve the predictive performance of pathological axillary lymph nodes in patients with breast cancer, contributing to preoperative treatment planning and prognostic outcome.

Possibilities of Computer Tomography in Preoperative Diagnosis and Surgical Treatment Planning of Juvenile Angiofibroma of the Nasopharynx and Skull Base

The purpose of work was to determine CECT characteristics of primary juvenile angiofibroma of the nasopharynx and skull base (JNA), as well as determination of the paths of spread for the tumor, search for those of them, which are statistically significantly associated with surgical blood loss of subsequent treatment and search for ways to model possible blood loss on their basis.Materials and methods. The data of 60 patients aged from 8 to 17 years were analyzed retrospectively. All patients were boys. The median age was 14 years. The median duration of the disease at the time of surgery was 7 months. The correlation between each of 45 evaluation criteria and intraoperative blood loss was determined for patients in the study group.Results. CT characteristics of JNA were established. The factors, detected by CECT, statistically significantly influencing intraoperative blood loss in angiofibroma treatment were established. A method for modeling intraoperative blood loss based on imaging data was presented.Conclusion. CT with contrast enhancement allows determining of characteristic radiological signs of JNA as well as its characteristics influencing blood loss during surgical treatment. Based on CT data it is possible to model blood loss potential during the JNA treatment.

A sellar-suprasellar malignant optic pathway glioblastoma in the absence of prior radiation therapy: illustrative case.

To date, only a few cases of sellar and suprasellar glioblastomas have been reported even though high-grade glioma constitutes the most common adult brain tumor, commonly arising in the cerebral hemispheres. It arises de novo from astrocytes within the optic nerve, optic chiasm, or optic tracts and is quite challenging to diagnose and treat. To the authors' knowledge, there are 72 cases (including this one) of optic glioma malignancies in the medical literature, 30 corresponding to glioblastomas. The authors present the diagnostic considerations and challenges, management strategies, and clinical course of a very large sellar-suprasellar glioblastoma in a 19-year-female who had never received radiation therapy or prior surgery. Sellar-suprasellar glioblastomas, although extremely rare, are known to occur and pose challenges in their diagnosis and preoperative treatment planning. The presence of diffusion restriction on diffusion-weighted magnetic resonance imaging in a mass lesion that has ring and nodular postcontrast enhancement in addition to absent calcification on computed tomography should be alert to the possibility of a high-grade mass. This is extremely important for preoperative patient counseling and planning for the multimodal treatments, because sellar-suprasellar glioblastomas carry a poorer prognosis than the common benign mass lesions in the region.

Rapid prototyping: A future in orthodontic

&lt;abstract&gt; &lt;p&gt;The term “rapid prototyping” (RP) refers to a variety of methods for creating “physical models based on computer-aided design and computer-aided manufacturing”. With the aid of RP technology, practically any variation of the surface and interior anatomical structure may be replicated in a medical model that is constructed layer by layer. To create the physical model, layer-by-layer construction is carried out using a variety of processes, including stereolithography, selective laser sintering, inkjet printing, and fused deposit modeling. Data for RP is received from magnetic resonance imaging and computed tomography scans, which are then turned into digital images and then into standard triangulation language files. The use of this computerized programming in orthodontics incorporates “diagnosis and treatment planning”, the creation of removable “orthodontic appliances”, “impression trays” for indirect bonding, “3D printed occlusal splints and aligners”, prototype models used in various orthognathic surgeries, and the production of a distractor for distraction osteogenesis. It increases a crucial understanding at the time of preoperative treatment planning and raises the effectiveness of the therapy, yet, clinical judgment is still essential. Applications of RP for an orthodontist vary, and if we utilize it creatively, the future appears more hopeful. This article briefly reviews key advancements, challenges, and prospects in the integration of rapid prototyping and 3D printing, shaping a promising future for orthodontics.&lt;/p&gt; &lt;/abstract&gt;

Associations Between Social Vulnerability Indicators and Pediatric Tonsillectomy Outcomes.

To investigate the impact of neighborhood-level social vulnerability on pediatric tonsillectomy outcomes. This single-center retrospective cohort study included tonsillectomies performed on children aged 1 to 18 between August 2019 and August 2020. Geographic information systems were used to geocode addresses, and spatial overlays were used to assign census-tract level social vulnerability index (SVI) scores to each patient. For categorical variables, two-sided Pearson chi-square tests were used, whereas for continuous variables, paired t-tests, means, and standard deviations were calculated. SVI and its four subthemes were investigated using binomial logistic regressions to determine their impact on post-T&A complications and readmissions. The study included 397 patients, with 52 having complications (13.1%) and 33 (8.3%) requiring readmissions due to their complications. Controlling for age, gender, race, insurance status, surgical indication, comorbidities, obesity, and obstructive sleep apnea, postoperative complications were associated with high overall SVI (odds ratio [OR] 5.086, 95% confidence interval [CI] 1.128-22.938), high socioeconomic vulnerability (SVI theme 1, OR 6.003, 95% CI 1.270-28.385), and high house composition vulnerability (SVI theme 2, OR 6.340, 95% CI 1.275-31.525). Readmissions were also associated with high overall SVI (10.149, 95% CI 1.293-79.647) and high housing/transportation vulnerability (SVI theme 4, OR 5.657, 95% CI 1.089-29.396). Social vulnerability at the neighborhood level is linked to poorer surgical outcomes in otherwise healthy children, suggesting a target for community-based interventions. Because of the increased risk, it may have implications for preoperative decision-making, treatment plans, and clinic follow-ups. Laryngoscope, 134:954-962, 2024.

Evaluation of the accuracy of implants using 3D printed surgical guides in implant placement

Background: The optimal position of the implant in 3 dimensions in space is the most important factor to ensure the long - term success of dental implants. Today, advanced technology can simulate the virtual implant position before surgery. Through 3D printing technology, it is possible to transfer the virtual implant position to the surgical field using a static surgical guide. This study aims to evaluate the accuracy of 3D printed surgical guides when performing implant when performed using 3D printed surgical guides. Methods: The study reports a series of clinical cases with 32 implants placed in the maxilla and mandible. The surgical guide is designed using Blue Sky Implant software. Postoperative CBCT data is combined with preoperative treatment plan data to evaluate deviations in implant position, angle between two implants, and vertical deviation. Results: The study showed implant misalignment when using 3D printed surgical guides: misalignment at the implant neck was 1.11 ± 0.67 mm; at the tip is 1.43 ± 1.053 mm; The angle is 3.01 ± 2.53o and the vertical is 0.71 ± 0.57 mm. The study noted that angular deviations, cervical, apical and vertical deviations were not statistically significant according to gender, parts of dental archs and implant position Conclusion: Using a surgical guide can help the implant to be placed more accurately in all 3 dimensions in the maxilla/ mandible. The 3D printed surgical guide has high precision and can be used to support implant surgery.

Breast Edema of Early-stage Invasive Ductal Carcinoma: Correlation with Axillary Lymph Node Metastasis and Clinical-pathological Characteristics.

This study aimed to evaluate the association of different patterns of breast edema and clinical-pathological features and axillary lymph node (ALN) status in early invasive ductal carcinoma (IDC) for simple and readily available assessment and to guide surgeons to perform sentinel lymph node biopsy for selected patients. This retrospective analysis involved 207 individuals with clinical T1-T2 stage IDC. The clinical-pathological features of the patients were compared with different breast edema and ALN statuses. Independent risk factors for ALN metastasis were verified using multivariate logistic regression analysis. ALN metastasis was confirmed in 100 of 207 patients (48.3%) with early-stage IDC. Significant differences were found between different ALN states for tumour size, clinical T stage, and breast edema (P <0.05). The clinical T2 stage (odds ratio-1.882, p=0.043) and moderate to severe edema (odds ratio-10.869, p=0.004) were independent risk factors for ALN metastasis. Moreover, better prognostic factors, including smaller tumour size, lower Ki-67 index and histologic grade, luminal A subtype, and lower incidence of lymph node metastasis, were more frequently found in patients with no breast edema (p<0.05). Breast edema can be considered a promising feature to improve the predictive performance of pathological ALN status in patients with early-stage breast cancer and thus may contribute to preoperative treatment planning.

P19.06.B T2/FLAIR MISMATCH, SPECIFIC RADIOGENOMIC MARKER FOR A DIFFUSE LOW GRADE ASTROCYTOMA

Abstract A 36-year-old woman presented with recurring episodes of generalized tonic clonic seizures. An MRI from an outside institution demonstrated an intra-axial brain mass suspicious for a primary brain tumor. Repeat conventional and advanced MRI imaging revealed a primary brain mass centred on the left postcentral gyrus involving cortex and subcortical white matter. The lesion was homogenously hyperintense on T2-weighted imaging, and centrally iso-to hypointense on FLAIR with a rim of hyperintense signal on the FLAIR sequence. There was no significant peritumoral edema or minimal effacement of the central sulcus. No abnormal enhancement was seen post-contrast. The lesion demonstrated no reduced diffusivity on diffusion-weighted imaging. MR perfusion showed no elevation in regional cerebral blood volume or flow. Findings are most compatible with a low grade glioma. Patient underwent total surgical resection and biopsy for histopathology. Genetic sequencing revealed an IDH mutant, non 1P,19q codeleted grade II astrocytoma. The diagnosis of adult infiltrating gliomas is predicted using imaging, and confirmed by histopathology, and molecular diagnostic methods. Regardless of grade the 1st phase in glioma diagnosis and management is IDH status. A multidisciplinary approach to the diagnosis of low grade and high grade glioma including genetic and molecular analysis is essential, as different genetic and molecular subtypes have different management and prognostic implications. Conventional MRI still represents a mandatory and extremely important step in the diagnostic workflow of neuro oncological patients for preoperative diagnosis, treatment planning, and subsequent follow up. The T2/FLAIR mismatch sign describes the MRI appearance of an IDH-mutant astrocytoma that is non 1p19q codeleted, and it is considered a preoperative novel specific MRI marker for this type of diffuse astrocytoma. In this case, the MRI findings were used preoperatively as a noninvasive tool to diagnose the patient`s low grade glioma which was confirmed by subsequent histological and genetic analysis. TEACHING POINTS1. T2/FLAIR mismatch allows for pre-operative diagnosis of IDH-mutant astrocytomas with a high level of specificity.2. It is particularly helpful in distinguishing diffuse astrocytoma from an oligodendroglioma3. Conventional MR sequences can suggest the diagnosis of IDH mutant gliomas which can assist neurosurgeons in presurgical planning and can help neuro-oncologists with treatment planning including potential clinical trials.

Classification of the implant-ridge relationship utilizing the MobileNet architecture

Background/purposeProper implant-ridge classification is crucial for developing a dental implant treatment plan. This study aimed to verify the ability of MobileNet, an advanced deep learning model characterized by a lightweight architecture that allows for efficient model deployment on resource-constrained devices, to identify the implant-ridge relationship. Materials and methodsA total of 630 cone-beam computerized tomography (CBCT) slices from 412 patients were collected and manually classified according to Terheyden's definition, preprocessed, and fed to MobileNet for training under the conditions of limited datasets (219 slices, condition A) and full datasets (630 cases) without and with automatic gap filling (conditions B and C). ResultsThe overall model accuracy was 84.00% in condition A and 95.28% in conditions B and C. In condition C, the accuracy rates ranged from 94.00 to 99.21%, with F1 scores of 89.36–100.00%, and errors due to unidentifiable bone-implant contact and miscellaneous reasons were eliminated. ConclusionThe MobileNet architecture was able to identify the implant-ridge classification on CBCT slices and can assist clinicians in establishing a reliable preoperative diagnosis and treatment plan for dental implants. These results also suggest that artificial intelligence-assisted implant-ridge classification can be performed in the setting of general dental practice.

A novel one-to-multiple unsupervised domain adaptation framework for abdominal organ segmentation.

Abdominal multi-organ segmentation in multi-sequence magnetic resonance images (MRI) is of great significance in many clinical scenarios, e.g., MRI-oriented pre-operative treatment planning. Labeling multiple organs on a single MR sequence is a time-consuming and labor-intensive task, let alone manual labeling on multiple MR sequences. Training a model by one sequence and generalizing it to other domains is one way to reduce the burden of manual annotation, but the existence of domain gap often leads to poor generalization performance of such methods. Image translation-based unsupervised domain adaptation (UDA) is a common way to address this domain gap issue. However, existing methods focus less on keeping anatomical consistency and are limited by one-to-one domain adaptation, leading to low efficiency for adapting a model to multiple target domains. This work proposes a unified framework called OMUDA for one-to-multiple unsupervised domain-adaptive segmentation, where disentanglement between content and style is used to efficiently translate a source domain image into multiple target domains. Moreover, generator refactoring and style constraint are conducted in OMUDA for better maintaining cross-modality structural consistency and reducing domain aliasing. The average Dice Similarity Coefficients (DSCs) of OMUDA for multiple sequences and organs on the in-house test set, the AMOS22 dataset and the CHAOS dataset are 85.51%, 82.66% and 91.38%, respectively, which are slightly lower than those of CycleGAN(85.66% and 83.40%) in the first two data sets and slightly higher than CycleGAN(91.36%) in the last dataset. But compared with CycleGAN, OMUDA reduces floating-point calculations by about 87 percent in the training phase and about 30 percent in the inference stage respectively. The quantitative results in both segmentation performance and training efficiency demonstrate the usability of OMUDA in some practical scenes, such as the initial phase of product development.

455 Radiographic Features Predict Genomic Subtype in Meningioma

INTRODUCTION: Meningiomas are the most common primary intracranial neoplasms. While most meningiomas demonstrate benign behavior with low rates of recurrence, a large percentage are more aggressive and are currently most widely prognosticated by histological grade. Several groups have published classification systems grouping meningiomas into distinct subtypes based on transcriptomic, cytogenetic, and methylomic signatures that better characterize their activity compared with traditional grading. Methods to preoperatively predict genomic subtype are desired. METHODS: Resected tumor samples that were genomically classified through a protocol described in previous publications were included in this analysis. Corresponding preoperative MRIs were gathered. The tumors were characterized using a standardized sheet of semantic variables. Chi-square and Wilcoxon rank-sum tests followed by univariable generalized linear regression were used for feature selection. Random forest algorithms were trained to classify genomic subtype based on radiographic features alone and tested using an 80/20 pseudorandom split. RESULTS: One-hundred tumors were included (n = 69 MenG-A/B, 31 MenG-C). Males were significantly more likely to develop MenG-C tumors than females (OR 3.44 [1.43, 8.52] p = 0.006). MenG-C tumors had significantly lower recurrence-free survival than MenG-A/B tumors (log-rank p value &lt;0.01). Supratentorial status, parafalcine location, larger volume, moderate-severe edema, irregular enhancement, hypointensity on T1 non-contrast sequence, and indistinct tumor margins were significant predictors of more aggressive genomic class. A random forest model based on these features blindly predicted MenG-A/B class with 85% accuracy (sensitivity 83%, specificity 100%). Tumor volume, location grouping, and T1 hypointensity were the most important features in accurate classification. CONCLUSIONS: Aggressive genomic status in meningioma can be predicted on routine preoperative imaging. These results may aid in preoperative counseling and treatment planning and should be validated across multi-institutional datasets.

Hepatic vessels segmentation using deep learning and preprocessing enhancement.

Liver hepatic vessels segmentation is a crucial step for the diagnosis process in patients with hepatic diseases. Segmentation of liver vessels helps to study the liver internal segmental anatomy that helps in the preoperative planning of surgical treatment. Recently, the convolutional neural networks (CNN) have been proved to be efficient for the task of medical image segmentation. The paper proposes an automatic deep learning-based system for liver hepatic vessels segmentation of Computed Tomography (CT) datasets from different sources. The proposed work focuses on the combination of different steps; it starts by a preprocessing step to improve the vessels appearance within the liver region of interest in the CT scans. Coherence enhancing diffusion filtering (CED) and vesselness filtering methods are used to improve vessels contrast and intensity homogeneity. The proposed U-net based network architecture is implemented with modified residual block to include concatenation skip connection. The effect of enhancement using filtering step was studied. Also, the effect of data mismatch used in training and validation is studied. The proposed method is evaluated using many CT datasets. Dice similarity coefficient (DSC) is used to evaluate the method. The average DSC score achieved a score 79%. The proposed approach succeeded to segment liver vasculature from the liver envelope accurately, which makes it as potential tool for clinical preoperative planning.

Hip arthroplasty for patients with chronic renal failure on dialysis

An increasing number of chronic renal failure patients are experiencing hip joint disorders. This study aimed to analyze the outcomes of hip arthroplasty in chronic renal failure patients undergoing dialysis. Of 2364 hips that underwent hip arthroplasty during 2003–2017, 37 were retrospectively examined. Radiological and clinical outcomes of hip arthroplasty, and development of local and general complications during follow-up and their associations with dialysis duration were analyzed. The mean patient age, follow-up duration, and bone mineral density T-score were 60.6 years, 36.6 months, and − 2.62, respectively. Osteoporosis was noted in 20 cases. Most patients who underwent total hip arthroplasty with a cementless acetabular cup implant exhibited excellent radiological outcomes. There were no changes in femoral stem alignment, subsidence, osteolysis, and loosening. Thirty-three patients had an excellent or good Harris hip score. Complications developed in 18 patients within 1 year postoperatively. General complications developed in 12 patients at > 1 year postoperatively; no patient experienced local complications. In conclusion, hip arthroplasty for chronic renal failure patients on dialysis yielded excellent radiological and satisfactory clinical outcomes but may be associated with postoperative complications. Careful preoperative treatment planning and overall postoperative management are required to reduce the complication risk.

Predictive risk factors for mechanical complications after multilevel posterior cervical instrumented fusion.

Mechanical complications should be considered following the correction of multilevel posterior cervical instrumented fusion. This study aimed to investigate clinical data on the patients' pre- and postoperative cervical alignment in terms of the incidence of mechanical complications after multilevel posterior cervical instrumented fusion. Between January 2008 and December 2018, 156 consecutive patients who underwent posterior cervical laminectomy and instrumented fusion surgery of 4 or more levels and were followed up for more than 2 years were included in this study. Age, sex, bone mineral density (BMD), BMI, mechanical complications, and pre- and postoperative radiographic factors were analyzed using multivariate logistic regression analysis to investigate the factors related to mechanical complications. Of the 156 patients, 114 were men and 42 were women; the mean age was 60.38 years (range 25-83 years), and the mean follow-up duration of follow-up was 37.56 months (range 24-128 months). Thirty-seven patients (23.7%) experienced mechanical complications, and 6 of them underwent revision surgery. The significant risk factors for mechanical complications were low BMD T-score (-1.36 vs -0.58, p = 0.001), a large number of fused vertebrae (5.08 vs 4.54, p = 0.003), a large preoperative C2-7 sagittal vertical axis (SVA; 32.28 vs 23.24 mm, p = 0.002), and low preoperative C2-7 lordosis (1.85° vs 8.83°, p = 0.001). The clinical outcomes demonstrated overall improvement in both groups; however, the neck visual analog scale, Neck Disability Index, and Japanese Orthopaedic Association scores after surgery were significantly worse in the mechanical complication group compared with the group without mechanical complications. Low BMD, a large number of fused vertebrae, a large preoperative C2-7 SVA, and low C2-7 lordosis were significant risk factors for mechanical complications after posterior cervical fusion surgery. The results of this study could be valuable for preoperative counseling, medical treatment, or surgical planning when multilevel posterior cervical instrumented fusion surgery is performed.

Preoperative Workup, Staging, and Treatment Planning of Colorectal Cancer

AbstractColorectal cancer (CRC) remains a leading cause of death in the United States. CRC is the second to third most common cancer globally and it impacts both genders. Screening initiatives are of paramount importance to eradicate the disease at a precancerous or early stage. Recommendations for screening are based on multiple factors including age, ethnicity, individual patient risk factors, and family history. Short- and long-term outcomes and survival data correlate with the stage of disease at the time of diagnosis emphasizing the need for appropriate baseline staging. Furthermore, stage of disease determines the necessity for any neoadjuvant or adjuvant therapy and provides recommendations for long-term oncologic follow-up. Preoperative workup includes physical examination, blood tests such as tumor markers and liver function tests, endoscopic evaluation, and cross-sectional imaging. In a select group of patients, genetic testing is part of the initial evaluation as it can impact the treatment plan, long-term follow-up, and testing of potential offspring. In general, surgical intervention remains the predominant treatment modality for stage I to III colon cancers with chemotherapy administration as adjuvant therapy for stages II to III to minimize recurrence or as a palliative modality for patients with stage IV disease. The treatment of rectal cancer remains more complex. Traditionally, early rectal cancer has been treated with surgical resection and locally advanced rectal cancer with neoadjuvant chemoradiation followed by surgical resection and postoperative chemotherapy. In the last decade, several protocols have been implemented to modify the neoadjuvant treatment with a trend toward more extended chemotherapy with the intent to further downstage the rectal cancer. Furthermore, the introduction of various protocols of total neoadjuvant chemoradiation may offer in a select group of patients with complete pathologic response, the possibility of observation without surgery. Finally, the management of stage IV CRC is in continuous evolution with the palliative goal of prolonging survival in most patients while offering the opportunity in some patients with limited metastatic disease to become potential candidates for resection of the primary lesion in addition to the metastatic disease.

High-throughput 3DRA segmentation of brain vasculature and aneurysms using deep learning

Background and Objectives:Automatic segmentation of the cerebral vasculature and aneurysms facilitates incidental detection of aneurysms. The assessment of aneurysm rupture risk assists with pre-operative treatment planning and enables in-silico investigation of cerebral hemodynamics within and in the vicinity of aneurysms. However, ensuring precise and robust segmentation of cerebral vessels and aneurysms in neuroimaging modalities such as three-dimensional rotational angiography (3DRA) is challenging. The vasculature constitutes a small proportion of the image volume, resulting in a large class imbalance (relative to surrounding brain tissue). Additionally, aneurysms and vessels have similar image/appearance characteristics, making it challenging to distinguish the aneurysm sac from the vessel lumen.Methods:We propose a novel multi-class convolutional neural network to tackle these challenges and facilitate the automatic segmentation of cerebral vessels and aneurysms in 3DRA images. The proposed model is trained and evaluated on an internal multi-center dataset and an external publicly available challenge dataset.Results:On the internal clinical dataset, our method consistently outperformed several state-of-the-art approaches for vessel and aneurysm segmentation, achieving an average Dice score of 0.81 (0.15 higher than nnUNet) and an average surface-to-surface error of 0.20 mm (less than the in-plane resolution (0.35 mm/pixel)) for aneurysm segmentation; and an average Dice score of 0.91 and average surface-to-surface error of 0.25 mm for vessel segmentation. In 223 cases of a clinical dataset, our method accurately segmented 190 aneurysm cases.Conclusions:The proposed approach can help address class imbalance problems and inter-class interference problems in multi-class segmentation. Besides, this method performs consistently on clinical datasets from four different sources and the generated results are qualified for hemodynamic simulation. Code available at https://github.com/cistib/vessel-aneurysm-segmentation.

Dosimetric evaluation of iodine-125 brachytherapy for brain tumors using MR guidance combined with a three-dimensional non co-planar template

PURPOSETo investigate the consistency between preoperative and postoperative dosimetry when 125I brachytherapy for brain tumors is performed with magnetic resonance (MR) guidance and a three-dimensional non co-planar template (3DNPT). METHODS AND MATERIALSThirty patients with brain tumors (metastatic or gliomas) underwent radioactive 125I seed implantation. A preoperative treatment plan was determined with MR imaging, and the operation was done under 3DNPT assistance and MR guidance. The dosimetry was verified postoperatively based on postoperative CT–MR fusion images. Postoperative dosimetric parameters and implant quality indices were defined and compared with those in the preoperative treatment plan. Furthermore, a comparison of preoperative and postoperative doses to normal brain tissues and organs at risk was also performed. RESULTSAll mean postoperative dosimetries were calculated. Target coverage parameters D90, D100, %CTV100, %CTV150, and %CTV200 were 143.6 cGy, 76.6 cGy, 88.2%, 63.1%, and 41.4%, respectively. The values of implant quality indices CI, EI, and HI were 0.75, 0.14, and 0.28, respectively. No significant differences between most preoperative and postoperative dosimetric parameters were found (p > 0.05). The differences were also insignificant for organs at risk. Postoperative %CTV150 and %CTV200 were higher than the preoperative, whereas postoperative HI was significantly lower than in the treatment plan. CONCLUSIONSMagnetic resonance guidance combined with 3DNPT allows accurate positioning and direction in 125I brachytherapy for brain tumors. However, seed distribution and dose homogeneity require further improvement.