Image-guided Techniques Research Articles

Phase II Clinical Trial of Hypofractionated Image-Guided Proton Therapy with 12 Fractions for Prostate Cancer.

Towards hypofractionated proton therapy for prostate cancer for improving convenience for patients to receive treatment and improving therapeutic efficacy, image-guided technique with hydrogel spacer solved the late gastrointestinal toxicity, but it is unclear whether acute genitourinary (GU) toxicity is acceptable. The aim of this phase II study was to evaluate the safety and efficacy of hypofractionated image-guided proton therapy (IGPT) with 12 fractions for prostate cancer. Eligibility criteria were as follows: (1) histologically confirmed primary prostate cancer; (2) T1-T3bN0M0 staged by (UICC TNM8th); (3) ECOG-PS ≤ 2; (4) age ≥ 20 years; (5) no serious underlying disease or other cancers; (6) technically capable of proton therapy, and (7) written informed consent. Primary endpoint was the ratio of grade 2 or more acute genitourinary toxicity. We used the modified CTCAE grading of grade 2 GU toxicities, in which prescribing two and more types of drugs for dysuria within 3 months of the start of radiation was considered to indicate grade 2 GU toxicity. A phase II trial was planned based on the minimax Simon's two-stage design with a significance level of 0.05 and a power of 90%. The acceptable incidence is considered to be less than 5%, and the unacceptable incidence is considered to be more than 15%. A total of 83 patients is required for completion of the trial (7 patients or fewer). After evaluating the primary endpoint in 83 patients, 217 additional patients were registered and a total of 300 patients were registered in order to further examine the safety and efficacy. The prescribed dose to the isocenter was 51.6 GyRBE in 12 fractions (4 days a week). From January 2020 to March 2021, 30, 53, and 217 patients (total 300) were enrolled. The patient characteristics were as follows: median age, 70 (48-83) years; low/intermediate/high risk, 44/132/124. Forty-nine and 38 patients had benign prostatic hyperplasia and diabetes mellitus, respectively. Grade 2 acute GU toxicities were observed in 1, 5 and 13 patients, respectively (total 6.3%). No grade 3 or higher acute GU toxicities were observed. However, urinary retention during IGPT, which was not previously observed, was observed in 3 cases, and temporary urethral catheterization was performed (Grade 2). Most of the acute GU toxicity tended to improve at 1 month after IGPT, and almost improved at 3 months. Mean score deteriorations beyond the minimum clinically important difference threshold (1/2 SD) were observed only at 1 month in the following scales: summary (-6.0), bother (-7.0), and irritative/obstructive (-6.3). Hypofractionated IGPT with 12 fractions for prostate cancer is well tolerated in acute GU toxicities. Longer follow-up is necessary to evaluate the efficacy and late toxicities. Further investigation of hypofractionated IGPT with 12 fractions for prostate cancer is warranted. Since April 2021, an additional 1000 cases of prospective registration study have been conducted.

First Demonstration of the Commissioning of a New Multi-Modality Radiotherapy Platform

A new multi-modality radiotherapy platform was developed and introduced into clinical application, which has received US FDA 510k(K210921) and National Medical Products Administration (NMPA) clearance in China (20223050973). This study, for the first time, presents the technological characteristics and commissioning results of the new platform. The platform consists of 3 modules: linear accelerator, rotating gamma system, and a kV imaging system within an O-ring gantry. The O-ring gantry can rotate continuously achieved by using a slip ring. The Linac delivers a 6 MV FFF photon beam with a variable dose rate of 50 to 1400 MU/min. The delivery techniques include 3D-CRT, IMRT, and VMAT. The rotating gamma system utilizes 18 Co-60 sources with a reference dose rate of 350 cGy/min. The image-guided techniques consist of kV-kV pairs and kV-CBCT. The X-ray intensity-modulated radiotherapy and γ-ray stereotactic radiotherapy can be delivered on the same platform. The acceptance test and commissioning were performed following the vendor's customer acceptance tests (CAT) and several AAPM Task Group reports/guidelines. Regarding the Linac, all applicable validation tests recommended by the MPPG 5.a (basic photon beam model validation, IMRT/VMAT validation, E2E tests, and patient-specific QA) were performed. For the rotating gamma system, the absorbed doses were measured using a PTW31014 and PTW60016. EBT3 films were employed to measure the relative output factors (ROFs). The E2E tests were performed using a PTW31014 and EBT3 films. The coincidence between the imaging isocenter and the Linac/gamma treatment isocenter was investigated using EBT3 films. The image quality was evaluated regarding the contrast-to-noise ratio (CNR), spatial resolution, and uniformity. All tests included in the CAT met the vendor's specifications. All MPPG 5.a tests complied with the tolerances. The confidence limits for IMRT/VMAT validation were achieved according to TG-119. The point dose differences were below 1.68% and gamma pass rates (3%/2 mm) were above 95.9% for the Linac E2E tests. All plans of patient-specific QA had point dose differences below 1.79% and gamma pass rates (3%/2 mm) above 96.1% suggested by TG-218. For the rotating gamma system, the differences between the calculated and measured absorbed doses were below 1.86%. The ROFs calculated by the TPS were independently confirmed within 2% using EBT3 films. The point dose differences were below 2.57% and gamma pass rates (2%/1 mm) were above 95.3% for the E2E tests. The coincidence between the imaging isocenter and the Linac/gamma treatment isocenter was within 0.5 mm. The image quality fully complied with the vendor's specifications regarding the CNR, spatial resolution, and uniformity. This is the first report about the commissioning of a new multi-modality radiotherapy platform. The platform has been successfully commissioned and exhibits good performance in mechanical and dosimetry accuracy.

Computed tomography and fluoroscopy versus radiographic guidance for internal fixation of simulated dorsomedial-plantarolateral central tarsal bone fractures in nonracehorses.

The aim of this study was to assess screw placement in simulated dorsomedial-plantarolateral central tarsal bone (CTB) fractures using two imaging guidance techniques - computed tomography (CT) with fluoroscopy compared to digital radiography alone (DR). Experimental study. Equine cadaver hindlimbs (n = 10 pairs). One tarsus per pair was randomly assigned to have a 4.5 mm cortical screw placed across the CTB using CT and fluoroscopy (CT/F group) or digital radiography alone (DR group). Postoperative CT was performed on all limbs. Variables related to marker placement, procedure time, and screw positioning were recorded and compared using a paired t-test for dependent means (p < .05). Time for marker placement was longer for the CT/F group (p = .001), with no difference in total procedure time (p = .12). CT/F was not superior to radiography alone (p > .05) for parameters related to screw positioning. Based on the 95% CI, there was greater range in relative screw length using radiography (76.5%-91.2%) versus CT/F (78.4%-84.0%). Internal fixation of CTB fractures can be successfully performed using either technique for imaging guidance. CT and fluoroscopy did not result in faster or more accurate screw placement compared to radiographs alone, except in determining screw length. Mild adjustments in fluoroscopic or radiographic angle appeared to be a point of variability in the perception of screw placement. While CT is recommended for improved understanding of fracture configuration and surgical planning, radiographic guidance may be a suitable alternative for internal fixation of dorsomedial-plantarolateral fractures.

Tips for Preparing and Practicing Thermal Ablation Therapy of Hepatocellular Carcinoma.

Thermal ablation therapy, including radiofrequency ablation (RFA) and microwave ablation (MWA), is considered the optimal locoregional treatment for unresectable early-stage hepatocellular carcinomas (HCCs). Percutaneous image-guided ablation is a minimally invasive treatment that is being increasingly performed because it achieves good clinical outcomes with a lower risk of complications. However, the physics and principles of RFA and MWA markedly differ. Although percutaneous thermal ablation under image guidance may be challenging in HCC cases with limited access or a risk of thermal injury, a number of ablative techniques, each of which may be advantageous and disadvantageous for individual cases, are available. Furthermore, even when a HCC is eligible for ablation based on tumor selection and technical factors, additional patient factors may have an impact on whether it is the appropriate treatment choice. Therefore, a basic understanding of the advantages and limitations of each ablation device and imaging guidance technique, respectively, is important. We herein provide an overview of the basic principles of tissue heating in thermal ablation, clinical and laboratory parameters for ablation therapy, preprocedural management, imaging assessments of responses, and early adverse events. We also discuss associated challenges and how they may be overcome using optimized imaging techniques.

Post-COVID pneumatocele, a rare entity managed surgically: a case series

Introduction: A pulmonary pneumatocele is a thin air filled cavitatory lesion that develops within the lung parenchyma. It is a unique, rarely occurring complication of COVID-19 pneumonia, most commonly detected by chest radiographs and computed tomography scans. Case presentation: The authors present a case series of four separate cases, all of which had suffered from COVID pneumonia, and now developed symptomatic pneumatocele. Two patients out of the four had also developed pneumothorax for which a tube thoracostomy was done, which is an infrequent complication of pneumatocele. One had an accompanying fungal infected loculated effusion. In all of these patients surgical management was approached as a treatment modality with three patients requiring bullectomy and one requiring lobectomy since image-guided drainage technique is not widely available in our resource-limited setting. Discussion: A pneumatocele, also called a pseudocyst, due to the absence of epithelial lining, is a thin-walled cystic cavity, filled with air that develops in the pulmonary interstitium. The most common cause is iatrogenic injury, due to prolonged mechanical ventilation. Pneumatoceles are usually asymptomatic and resolve spontaneously; however, image-guided drainage and surgical management can be opted for, in the presence of the complications. Conclusion: From our case report, it can be concluded that the surgical approach is relatively safe and effective, with increased survival benefits, especially in those patients who develop complicated pneumatocele.

Stereotactic Body Radiation Therapy: A Radiosurgery Society Guide to the Treatment of Localized Prostate Cancer Illustrated by Challenging Cases

Traditionally, external beam radiotherapy (EBRT) for localized prostate cancer (PCa) involved lengthy courses with low daily doses. However, advancements in radiation delivery and a better understanding of prostate radiobiology have enabled the development of shorter courses of EBRT. Ultrahypofractionated radiotherapy, administering doses greater than 5 Gy per fraction, is now considered a standard of care regimen for localized PCa, particularly for intermediate-risk disease. Stereotactic body radiotherapy (SBRT), a specific type of ultrahypofractionated radiotherapy employing advanced planning, imaging, and treatment technology to deliver in five or fewer fractions, is gaining prominence as a cost-effective, convenient, and safe alternative to longer radiotherapy courses. It is crucial to address practical considerations related to patient selection, fractionation scheme, target delineation, and planning objectives. This is especially important in challenging clinical situations where clear evidence for guidance may be lacking. The Radiosurgery Society endorses this case-based guide with the aim of providing a practical framework for delivering SBRT to the intact prostate, exemplified by two case studies. The article will explore common SBRT dose/fractionation schemes and dose constraints for organs-at-risk. Additionally, it will review existing evidence and expert opinions on topics such as SBRT dose escalation, the use of rectal spacers, the role of androgen deprivation therapy in the context of SBRT, SBRT in special patient populations (e.g., high-risk disease, large prostate, high baseline urinary symptom burdens, and inflammatory bowel disease), as well as new imaging-guidance techniques like Magnetic Resonance Imaging for SBRT delivery.

Emerging Subspecialties in Neurology: Interventional Neurology: A Starter Guide for Neurology Residents.

Interventional neurology is a subspecialty at the cross-section of neurology, neurosurgery, and neuroradiology that uses image-guided endovascular catheter techniques to diagnose and treat neurovascular disorders. Although interventional neurology techniques have existed for decades, recent landmark trials in stroke thrombectomy have catalyzed dramatic changes to the interventional neurology field, and there is rising neurology interest and representation. Unlike other neurology subspecialties, however, interventional neurology training and fellowship applications are not standardized. Thus, it can be difficult for neurology trainees to navigate this rapidly changing and multidisciplinary field. This article seeks to provide neurology residents and residency program directors with a brief overview of the modern interventional neurology field, the current fellowship application process, and tips on how neurologists can best prepare for a career in interventional neurology. To this end, we conducted a nationwide survey of interventional neurology fellowship program directors regarding training neurologists. We distill survey responses into concrete, actionable items for neurology trainees.

Barrigel Spacer Injection Technique

The combination of intensity modulated radiation therapy (IMRT) and image guidance technique (IGRT) has enhanced the sparing of normal tissue during definitive radiotherapy (RT) for organ-confined prostate cancer, allowing for dose escalation and reduced recurrence rates and toxicities associated with treatment. However, challenges arise as the close proximity of the posterior prostate to the anterior rectal wall often results in high rectal doses that IGRT alone cannot remedy. To address this issue, biodegradable inflatable balloons, polyethylene-glycol (PEG) based hydrogel, and more recently hyaluronic acid (HA), have been employed to improve rectal dose volume histograms by displacing the anterior rectal wall away from the prostate gland. Unlike other spacing products, HA is a sculptable gel that offers benefits including easy customization to the patient's anatomy without the need for hydrodissection and the ability to visualize the spacer throughout the implant procedure. As the HA gel placement can be both assessed and modified during the brief procedure, consistent quality placement is more readily achieved. Meticulous procedural technique is thus necessary to create a significant, symmetrical radioprotective space from prostate base to apex, leading to improved rectal dosimetry. This technical report outlines the specific technique for HA spacer placement which was employed to obtain the excellent patient outcomes recently reported in the Barrigel® IDE trial. These outcomes include a reduction in the volume of rectal tissue receiving the prescribed radiation dose and a significant reduction in the risk of grade 2+ GI toxicities following RT. Consistent spacing was observed throughout the treatment and no unexpected adverse device effects or HA spacer-related adverse events were reported. Overall, HA spacer is easy to use, safe, and allows for sculptable, customized spacing.

Intraosseous pressure measurement during iliac bone marrow biopsy: its feasibility and difference of IOP in diseased marrow and non-diseased marrow.

The purposes of this study were (1) to establish the feasibility and safety of an imaging-guided technique for intraosseous pressure (IOP) measurement in a large cohort of patients, and (2) to compare IOP values between normal and diseased bone marrow. Adult patients undergoing CT-guided marrow biopsy were prospectively and consecutively enrolled from November 2020 to February 2022. IOP measurements were obtained connecting the biopsy needle to a monitoring device using a standard arterial line setup. Clinical data including sex, age and pathology results were obtained. Student t test and Pearson correlation were used for continuous variables comparisons. Univariable analyses were performed using Fisher's exact test. A P value of .05 was considered statistically significant. A total of 139 participants were initially enrolled, and four were excluded during technique optimization. There were no complications related to the measurement technique. Ninety participants (90/135, 67%) had histology confirming marrow pathology. The participants in the diseased marrow group were older than those in the normal marrow group (63 ± 14 vs. 55 ± 14years; P < .01). There was no difference in mean IOP between both groups (66 ± 23 vs. 64 ± 28mmHg; P = .69). There was no correlation between mean arterial blood pressure and mean IOP (P = .08). There was no difference in IOP measurements between patients with normal and diseased marrow undergoing CT-guided biopsy. IOP does not appear to be influenced by systemic blood pressure. No complication occurred during the procedures.

An Animal Model of Functional Tricuspid Regurgitation by Leaflet Tethering Using Image-Guided Chordal Encircling Snares.

Several interventional therapies are in development to treat functional tricuspid regurgitation. Most have failed to achieve adequate efficacy, as animal models of this lesion are lacking. We developed a new image-guided technique in swine, by tethering the tricuspid valve chordae using echo-guided chordal encircling snares. Five swine underwent baseline echocardiographic assessment of tricuspid valve function, followed by echo-guided placement of snares that encircle the chordae inserting into the anterior and posterior tricuspid valve leaflets. Tethering these snares and stabilizing them on the right ventricle caused the regurgitant fraction to increase from 8.48±5.38% to 48.76±12.5%, and the valve tenting area to increase from 60.26±52.19 to 160.9±86.92 mm2. Image-guided chordal encircling snares could reproducibly induce clinically significant levels of functional tricuspid regurgitation and create a valve geometry like that seen in patients, providing a new animal model for use to study novel interventional devices.

Defining the Planning Tumor Volume by analyzing Setup of Head &amp; Neck (H&amp;N) Carcinoma in Radiotherapy

Aim: To find out the setup error of Head and Neck patients treated with Intensity modulated radiation therapy (IMRT) on CLINAC-IX at Center for Nuclear medicine and Radiotherapy (CENAR) Quetta by using inbuilt electronic portal imaging device (EPID) to obtain the setup margin for clinical investigation. Methods: A total of 35 patients of head &amp; neck carcinoma were treated with Intensity modulated radiation therapy (IMRT) total dose of 69.96Gy in 33 fractions at CENAR from 1st January 2021 to 31st December 2022 were consider this retrospective study. PTV margin for different directions (Vertical, lateral &amp;Longitudinal) were analyzed by Van Herk’s formula Results: Data analyzed for calculating the mean displacement in X (Lateral), Y (Longitudinal) and Z (Vertical) directions, from where the mean systematic and random errors derived. These shifts (displacements) used for calculation of the final PTV margins by using Van Herk’s formula. The calculated mean (±SD) systematic errors in the Z (Vertical), X (Lateral) and Y (Longitudinal) and directions were 0.10cm, 0.06cm, and 0.07cm and the mean(±SD) random errors were 0.01cm, 0.004cm and 0.01cm respectively. Conclusion: In our study, less than3 mm is an optimal margin for GTV- PTV for head and neck cancer patients. The reduction in setup margin helps in prognosis of treatment results, reduce radiation related complication in normal tissue and reduce the local recurrence. Imaging guidance techniques is effective tool for setup margin. Keywords: Electronic Portal Imaging Device, Van Herk Equation, Systematic Error, Random Error, Head &amp; Neck Carcinoma,

Surgical pancreatic biopsies for cases with locally advanced pancreatic cancer with inconclusive histology after interventional biopsy

BackgroundHistopathological confirmation of malignancy is mandatory in patients with unresectable pancreatic cancer before initiation of palliative chemotherapy. When interventional biopsy proves unsuccessful, laparoscopic or open surgical biopsies become necessary. Methods66 consecutive surgical biopsies of the pancreas performed at a single institution between 01/2010 and 04/2020 were analyzed retrospectively. We analyzed sensitivity of histopathological confirmation of malignancy as well as complication rates of laparoscopic and open surgical biopsies in patients with suspected advanced pancreatic cancer after unsuccessful interventional biopsies. Results8 complications were observed in 46 patients requiring only a pancreatic biopsy (17.4 %) while in 13 of 20 patients complications were observed when additional procedures were necessary (65 %). Major complications CD ≥ III were observed in the “biopsy +/- port” group in 4 of 46 patients and in the “biopsy + additional procedure” cohort in 9 of 20 patients (8.7 vs. 45 %, p < 0.001). Despite the trend to reduced perioperative complications in laparoscopic biopsies, the reduction did not reach statistical significance when compared to open resections (11.1 vs. 26.3 %, p = 0.18). Surgical pancreatic biopsies reached a sensitivity regarding the correct definite histopathological result of 90.32 %, specificity was 100 %. ConclusionBoth laparoscopic and open biopsies can be performed at acceptable complication rates CD ≥ III of 8.7 % and present a valuable option after failure of image-guided techniques for biopsy. Additional operative measures in locally advanced pancreatic carcinoma ought to be critically reflected due to a substantially higher complication rate CD ≥ III of 45 %. Key messageLaparoscopic and open surgical biopsies in patients with unresectable pancreatic cancer demonstrate a high diagnostic sensitivity at acceptable complication rates. This finding is important because it provides further support for surgical biopsies to avoid delay before initiation of palliative therapy.

Image-Guided Ablations in Patients with Recurrent Renal Cell Carcinoma.

Renal cell carcinoma (RCC) is one of the most frequently diagnosed tumors and a leading cause of death. The high risk of local recurrence and distant metastases represent a significant clinical issue. Different image-guided ablation techniques can be applied for their treatment as an alternative to surgery, radiotherapy or systemic treatments. A retrospective analysis was conducted at our institution, including a total number of 34 RCC patients and 44 recurrent RCC tumors in different locations (kidney, lung, adrenal gland, liver, pancreas, pararenal and other) using microwave ablation, radiofrequency ablation, cryoablation and laser ablation. The estimated time to local and distant tumor progression after treatment were 22.53 ± 5.61 months and 24.23 ± 4.47 months, respectively. Systemic treatment was initiated in 10/34 (29%) treated patients with a mean time-to-systemic-therapy of 40.92 ± 23.98 months. Primary technical success was achieved in all cases and patients while the primary efficacy rate was achieved in 43/44 (98%) cases and 33/34 (97%) patients, respectively, with a secondary technical success and efficacy rate of 100%. At a mean follow-up of 57.52 months ± 27.86 months, local tumor progression occurred in 3/44 (7%) cases and distant progression in 25/34 (74%) patients. No significant complications occurred. Image-guided ablations can play a role in helping to better control recurrent disease, avoiding or delaying the administration of systemic therapies and their significant adverse effects.

Preoperative CT-Guided Coil Localization of Lung Nodule Resection: A Single-Center Experience.

The increased use of computed tomography (CT) for lung cancer screening has led to an increase in the incidence of lung nodules. However, accurately localizing small or deep-seated nodules remains challenging and often requires image-guided techniques. CT-guided coil localization has emerged as a popular method for precise localization. A retrospective analysis was conducted on a cohort of patients who underwent CT-guided coil localization followed by surgical resection of lung nodules at the National University Hospital, Singapore, between 2015 and 2021. The study examined the rates of successful localization, procedural complications, and postoperative length of stay. Descriptive statistics were employed for data analysis. This retrospective study included 55 patients with pulmonary nodules, of whom 76.4% had a history of previous malignancy. A total of 58 nodules were successfully localized using coil placement and distributed across various lung lobes. The average dimensions of the nodules were 8.4 ± 3.2 mm × 10.1 ± 4.0 mm, with an average distance of 10.9 ± 9.0 mm from the pleura. Surgical resection of the coiled nodules resulted in an average resected volume of 91.1 ± 76.0 cm3 and a resection margin of 9.5 ± 7.3 mm. Failed localization occurred in only 3.6% of cases. Procedural complications were observed in 21.8% of patients, including hemothorax, persistent air leaks, pneumothoraces, pleural effusion, pneumonia, and atelectasis, all of which were appropriately managed. The average length of postoperative hospital stay was 6.7 ± 15.9 days. Preoperative CT-guided coil localization is a reliable and safe technique for accurately localizing lung nodules before surgical resection. The high success rate of this approach enables precise intraoperative planning. Despite procedural complications, their manageable nature and the absence of major adverse events highlight the safety of this technique. Incorporating CT-guided coil localization into routine clinical practice can significantly enhance surgical planning, improve patient outcomes, and optimize resource utilization.

Towards a single-use, low-cost endoscope for gastroenterological diagnostics.

Early diagnosis and treatment of diseases in the gastrointestinal (GI) tract including colorectal cancers (CRC) via natural orifices have led to a significant increase in patient survival rates. Most screening procedures utilize image-guided techniques via a conventional endoscope. The cost of conventional endoscopes is substantial, ranging in the tens of thousands of USD or more. This presents significant burden for developing countries, which are disproportionally affected by gastroenterological diseases. Conventional endoscopes also require sterilization between use. This increases the chance of cross-infection between patients. To address these problems, this paper introduces a soft endoscope with a disposable insertion tube that can be articulated. This prototype device is hydraulically actuated, capable of a 10 mm bend radius and 180-degree bend angle. The camera system provides 110 degrees field-of-view. The component parts of this disposable endoscope costs less than 200 USD.Clinical relevance-Our low-cost, single-use endoscope eliminates the sterilization step required by conventional systems, thereby reducing the risks of infection and lowering the operating costs. There is also significant scope for our device to be used beyond the human GI track, such as screening for lung or bladder cancers. Given the compact footprint, the minimal cost of the disposable parts, the proposed platform can widen cancer screening programs with quantifiable economic benefit for many patients, particularly those in developing countries.

Intra-articular injections in the TMJ inferior joint space: a scoping review.

​​to perform a scoping review to identify the available evidence regarding intra-articular injections in the inferior joint space (IJS) of the temporomandibular joint (TMJ). An electronic search of the PubMed, Web of Science and Scopus databases was performed using the following terms: "Arthrocentesis", "injection", "joint injection", "technique", "Temporomandibular joint" , "Temporomandibular joint disorder". Full-text articles were obtained from the records after applying the inclusion/exclusion criteria. Only articles with full-text access were included. 13 articles were included for analysis - one technical note, three cadavers studies, one animal study, two case reports, five randomised clinical trials, and one retrospective study; studies were classified as "patients-based studies" and "non-patients-based studies". Most "patients-based studies" show moderate or high risk of bias. Techniques were categorised as "anatomical technique" and "image-guided technique". Most "patients-based studies" show favourable outcomes such as pain reduction, increase in maximum mouth opening, improvement in quality of life and improvement in TMJ dysfunction indexes, for the treatment of arthrogenic TMDs. Comparisons between superior and IJS injections are scarce. On the other hand, "non-patients-based" studies show that image-guided or ultrasound checked injection techniques achieved a higher effectiveness for needle location than anatomical (or blind) techniques. The amount of available evidence is scarce, heterogeneous in design, and most "patients-based studies" show moderate or high risk of bias, which demands the generation of new research to obtain definitive conclusions. The tendency observed suggests that intra-articular injections for the IJS of the TMJ are able to relieve TMJ pain, increase mouth opening and improve TMJ dysfunction, and image-guided injection techniques seem to be more effective than anatomical techniques to locate the needle in the IJS.

Intensity-Modulated Radiation Therapy for Early-Stage Squamous Cell Carcinoma of the Glottic Larynx: A Systematic Review and Meta-Analysis

Early-stage squamous cell carcinoma of the glottic larynx is commonly treated with 2-dimensional or 3-dimensional conventional radiation therapy (CRT). Despite its use in other head and neck cancers, intensity-modulated radiation therapy (IMRT) remains controversial in this patient population. A systematic review was performed by querying 3 databases (Pubmed, Embase, Web of Science) for articles published between December 1, 2000 and September 2, 2022. Included studies reported outcomes in at least 10 patients treated with IMRT for early-stage glottic cancer. Data were extracted and reported following PRISMA standards. Pooled outcomes were estimated using random-effects models. Primary outcome was the rate of local failure (LF) following IMRT. Secondary outcomes included rates of regional failure (RF) following IMRT and rates of LF and RF following CRT. A total of 15 studies (14 retrospective, 1 prospective) consisting of 2083 patients were identified. IMRT was used in 873 patients (64% T1, 28% T2). Multiple treatment (partial larynx, single vocal cord carotid sparing) and image-guided radiation therapy techniques were used. The pooled crude rate of LF was 7.6% (95% confidence inverval [CI], 3.6%-11.5%) and actuarial LF rates at 3 and 5 years were 6.3% (95% CI, 2.2%-10.3%) and 9.0% (95% CI, 4.4%-13.5%), respectively. The pooled crude rate of RF after IMRT was 1.5% (95% CI, 0.5%-2.5%). On metaregression analysis, increased rate of LF was significantly associated with T2 disease (P < .001) and grade 2 to 3 histology (P < .001). Treatment with CRT was reported in 738 patients (76% T1, 22% T2). Among the studies reporting outcomes of both modalities, there was no significant difference in LF (log odds ratio; P=.12) or RF (log odds ratio; P=.58) between IMRT or CRT. In patients with early-stage glottic cancer, retrospective data suggests local and regional control are similar for patients treated with IMRT and CRT. Additional prospective studies with uniform methods of volume delineation and image guidance are needed to confirm the efficacy of IMRT.

Role of neuronavigation in the surgical management of brainstem gliomas.

NeuroNavigation (NN) is a widely used intraoperative imaging guidance technique in neurosurgical operations; however, its value in brainstem glioma (BSG) surgery is inadequately reported and lacks objective proof. This study aims to investigate the applicational value of NN in BSG surgery. A retrospective analysis was performed on 155 patients with brainstem gliomas who received craniotomy from May 2019 to January 2022 at Beijing Tiantan Hospital. Eighty-four (54.2%) patients received surgery with NN. Preoperative and postoperative cranial nerve dysfunctions, muscle strength, and Karnofsky (KPS) were evaluated. Patients' radiological features, tumor volume, and extent of resection (EOR) were obtained from conventional MRI data. Patients' follow-up data were also collected. Comparative analyses on these variables were made between the NN group and the non-NN group. The usage of NN is independently related to a higher EOR in diffuse intrinsic pontine glioma (DIPG) (p=0.005) and non-DIPG group (p<0.001). It was observed that fewer patients in the NN group suffered from deterioration of KPS (p=0.032) and cranial nerve function (p=0.017) in non-DIPG group, and deterioration of muscle strength (p=0.040) and cranial nerve function (p=0.038) in DIPG group. Moreover, the usage of NN is an independent protective factor for the deterioration of KPS (p=0.04) and cranial nerve function (p=0.026) in non-DIPG patients and the deterioration of muscle strength (p=0.009) in DIPG patients. Furthermore, higher EOR subgroups were found to be independently related to better prognoses in DIPG patients (p=0.008). NN has significant value in BSG surgery. With the assistance of NN, BSG surgery achieved higher EOR without deteriorating patients' functions. In addition, DIPG patients may benefit from the appropriate increase of EOR.

Towards transcervical ultrasound image guidance for transoral robotic surgery.

Trans-oral robotic surgery (TORS) using the da Vinci surgical robot is a new minimally-invasive surgery method to treat oropharyngeal tumors, but it is a challenging operation. Augmented reality (AR) based on intra-operative ultrasound (US) has the potential to enhance the visualization of the anatomy and cancerous tumors to provide additional tools for decision-making in surgery. We propose a US-guided AR system for TORS, with the transducer placed on the neck for a transcervical view. Firstly, we perform a novel MRI-to-transcervical 3D US registration study, comprising (i) preoperative MRI to preoperative US registration, and (ii) preoperative to intraoperative US registration to account for tissue deformation due to retraction. Secondly, we develop a US-robot calibration method with an optical tracker and demonstrate its use in an AR system that displays anatomy models in the surgeon's console in real-time. Our AR system achieves a projection error from the US to the stereo cameras of 27.14 and 26.03 pixels (image is 540[Formula: see text]960) in a water bath experiment. The average target registration error (TRE) for MRI to 3D US is 8.90mm for the 3D US transducer and 5.85mm for freehand 3D US, and the TRE for pre-intra operative US registration is 7.90mm. We demonstrate the feasibility of each component of the first complete pipeline for MRI-US-robot-patient registration for a proof-of-concept transcervical US-guided AR system for TORS. Our results show that trans-cervical 3D US is a promising technique for TORS image guidance.

Lumboperitoneal shunt using fluoroscopy and a peel-away sheath

BackgroundAfter placement of the spinal catheter into the spinal canal during lumboperitoneal shunt (LPS) placement, the spinal catheter needs to be connected to the programmable valve. Although surgeons always try to secure the spinal catheter position during procedures, it may be accidentally pulled and displaced. This article aimed to introduce a “one-piece method” of LPS using fluoroscopy and peel-away sheath without connecting the spinal catheter to the programmable valve. MethodsAn abdominal shunt catheter, valve, and spinal shunt catheter were connected and tunneled to the back for insertion into the lumbar spinal subarachnoid space. The spinal catheter was cut to a length of 15 cm. Lumbar puncture was performed using a 14-gauge Tuohy needle inserted at the L2-3 intervertebral space using an image-guided paramedian technique, and a 0.035-inch guidewire was passed gently through the Tuohy needle under fluoroscopic guidance. The Tuohy needle was withdrawn, and a 5-Fr peel-away sheath was advanced over the wire. The dilator and guide wire were removed, the distal end of the 5-Fr peel-away sheath was checked to ensure that the cerebrospinal fluid flowed out, and the spinal shunt catheter was passed down the sheath. After confirming under fluoroscopic guidance that the catheter was properly positioned, the peel-away sheath was removed. ResultsLPS was performed using this method in seven patients without complications. ConclusionThis simple “one-piece method” using fluoroscopy and peel-away sheath is safe and effective for positioning the spinal catheter.