Imaging in gynecological disease (26): clinical and ultrasound characteristics of benign retroperitoneal pelvic peripheral-nerve-sheath tumors

Precision-Guided Stealth Missiles in Biomedicine: Biological Carrier-Mediated Nanomedicine Hitchhiking Strategy

Nanodrug delivery systems (NDDS) have demonstrated broad application prospects in disease treatment, prevention, and diagnosis due to several advantages, including functionalization capability, high drug-loading capacity, drug stability protection, and the enhanced permeability and retention (EPR) effect. However, their clinical translation still faces multiple challenges, including rapid clearance by the reticuloendothelial system (RES), poor targeting specificity, and insufficient efficiency in crossing biological barriers. To address these limitations, researchers have developed the biological carrier-mediated nanomedicine hitchhiking strategy (BCM-NHS), which leverages circulating cells, proteins, or bacteria as natural "mobile carriers" to enhance drug delivery. This approach enables nanocarriers to inherit the intrinsic biological properties, endowing them with immune evasion, prolonged circulation, dynamic targeting, biocompatibility, biodegradability, and naturally optimized biological interfaces. Here, a systematic overview of the BCM-NHS is provided. First, the review delves into the methods of nanoparticles (NPs) binding and immobilization, encompassing both the surface-attachment-mediated "backpack" strategy and the encapsulation-based "Trojan horse" strategy. Second, the classification of biological carriers, including both cell-based and non-cell-based carriers, is elucidated. Third, the physical properties and release mechanisms of these nanomaterials are thoroughly described. Finally, the latest applications of BCM-NHS in therapeutic and diagnostic contexts across various disease models including tumor, ischemic stroke, and pneumonia are highlighted.

An optimized siamese neural network with deep linear graph attention model for gynaecological abdominal pelvic masses classification

An adnexal mass, also known as a pelvic mass, is a growth that develops in or near the uterus, ovaries, fallopian tubes, and supporting tissues. For women suspected of having ovarian cancer, timely and accurate detection of a malignant pelvic mass is crucial for effective triage, referral, and follow-up therapy. While various deep learning techniques have been proposed for identifying pelvic masses, current methods are often not accurate enough and can be computationally intensive. To address these issues, this manuscript introduces an optimized Siamese circle-inspired neural network with deep linear graph attention (SCINN-DLGN) model designed for pelvic mass classification. The SCINN-DLGN model is intended to classify pelvic masses into three categories: benign, malignant, and healthy. Initially, real-time MRI pelvic mass images undergo pre-processing using semantic-aware structure-preserving median morpho-filtering to enhance image quality. Following this, the region of interest (ROI) within the pelvic mass images is segmented using an EfficientNet-based U-Net framework, which reduces noise and improves the accuracy of segmentation. The segmented images are then analysed using the SCINN-DLGN model, which extracts geometric features from the ROI. These features are classified into benign, malignant, or healthy categories using a deep clustering algorithm integrated into the linear graph attention model. The proposed system is implemented on a Python platform, and its performance is evaluated using real-time MRI pelvic mass datasets. The SCINN-DLGN model achieves an impressive 99.9% accuracy and 99.8% recall, demonstrating superior efficiency compared to existing methods and highlighting its potential for further advancement in the field.

Standardized measurement of the piriformis muscle and the proximal portion of the sacral nerve roots using transvaginal ultrasound

To identify the sonomorphological appearance and to measure the thickness of the piriformis muscle (PM) and the proximal portion of the sacral nerve roots S1-S3 in healthy premenopausal women.This prospective multicentric observational study included a consecutive series of women undergoing transvaginal sonography (TVS) at 2 tertiary gynecological referral centers. Standardized assessment of the pelvic organs was performed, followed by an attempt to visualize the right and left PM and sacral nerve roots S1-S3 at their origin in proximity to the sacral neuroforamen. Visualization rates, diameters of the muscle and nerve thickness, and the time needed to identify the PM were recorded.305 patients were included in the study. In 293 women (96.1%), the PM was identified bilaterally. The median diameter of the PM was 18.3mm on the right side and 18.4mm on the left side. S1 nerve roots were successfully identified bilaterally in 224 (73.4%) patients. Their right and left median diameters were 4.8mm. Both S2 nerves were successfully identified in 215 (70.5%) patients. Their median diameter were 4.3mm on both sides. S3 nerve roots were successfully identified in 203 (66.6%) patients. Their median diameter were 3.2mm on both sides.We describe methods which allow consistent and rapid identification of the PM and the S1-S3 sacral nerve roots using TVS. Visualization of the PM and the proximal portion of the sacral plexus may be useful regarding identification of pathological changes in PM thickness and could help to distinguish perineural cysts from other gynecological pathologies.

Ultrasound assessment of the pelvic sidewall: methodological consensus opinion

A standardized methodology for the ultrasound evaluation of the pelvic sidewall has not been proposed to date. Herein, a collaborative group of gynecologists and gynecological oncologists with extensive ultrasound experience presents a systematic methodology for the ultrasonographic evaluation of structures within the pelvic sidewall. Five categories of anatomical structures are described (muscles, vessels, lymph nodes, nerves and ureters). A step-by-step transvaginal ultrasound (or, when this is not feasible, transrectal ultrasound) approach is outlined for the evaluation of each anatomical landmark within these categories. Accurate assessment of the pelvic sidewall using a standardized approach improves the detection and diagnosis of non-gynecological pathologies that may mimic gynecological tumors, reducing the risk of unnecessary and even harmful intervention. Furthermore, it plays an important role in completing the staging of malignant gynecological conditions. Transvaginal or transrectal ultrasound therefore represents a viable alternative to magnetic resonance imaging in the preoperative evaluation of lesions affecting the pelvic sidewall, if performed by an expert sonographer. A series of videoclips showing normal and abnormal findings within each respective category illustrates how establishing a universally applicable approach for evaluating this crucial region will be helpful for assessing both benign and malignant conditions affecting the pelvic sidewall. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Image features and clinical analysis of retroperitoneal pelvic schwannoma: a case report

BACKGROUND

Schwannomas are benign usually encapsulated nerve sheath tumors derived from the Schwann cells, and affecting single or multiple nerves. The tumors commonly arise from the cranial nerves as acoustic neurinomas but they are extremely rare in the pelvis and the retroperitoneal area. Retroperitoneal pelvic schwannomas often present with non-specific symptoms leading to misdiagnosis and prolonged morbidity.

CASE PRESENTATION

We report the case of a 59-year-old woman presenting with a feeling of heaviness in the lower abdomen who was found to have a retroperitoneal pelvic schwannoma originating from the right femoral nerve. She had a history of two resections of peripheral schwannomas at four different sites of limbs. After conducting magnetic resonance imaging, this pelvic schwannoma was misdiagnosed as a gynecological malignancy. The tumor was successfully removed by laparoscopic surgery. Pathological analysis of the mass revealed a benign schwannoma of the femoral nerve sheath with demonstrating strong, diffuse positivity for S-100 protein.

CONCLUSIONS

Although retroperitoneal pelvic schwannoma is rare, it should be considered in the differential diagnosis of pelvic masses, especially in patients with a history of neurogenic mass or the presence of neurogenic mass elsewhere.

Clinical and ultrasound characteristics of deep endometriosis affecting sacral plexus

OBJECTIVE

To describe the sonomorphological changes and appearance of deep endometriosis (DE) affecting the nervous tissue of the sacral plexus (SP).

METHODS

This was a retrospective study of symptomatic patients who underwent radical resection of histologically confirmed DE affecting the SP and who had undergone preoperative transvaginal sonography (TVS) between 2019 and 2023. Lesions were described based on the terms and definitions of the International Deep Endometriosis Analysis (IDEA), International Ovarian Tumor Analysis (IOTA) and Morphological Uterus Sonographic Assessment (MUSA) groups. A diagnosis of DE affecting the SP on TVS was made when the sonographic criteria of DE were visualized in conjunction with fibers of the SP and the presence of related symptoms corresponding to sacral radiculopathy. Clinical symptoms, ultrasound features and histological confirmation were analyzed for each patient included.

RESULTS

Twenty-seven patients with DE infiltrating the SP were identified in two contributing tertiary referral centers. Median age was 37 (range, 29-45) years and all patients were symptomatic and presented one or more of the following neurological symptoms: dysesthesia in the ipsilateral lower extremity (n = 17); paresthesia in the ipsilateral lower extremity (n = 10); chronic pelvic pain radiating in the ipsilateral lower extremity (n = 9); chronic pain radiating in the pudendal region (n = 8); and motor weakness in the ipsilateral lower extremities (n = 3). All DE lesions affecting the SP were purely solid tumors in the posterior parametrium in direct contact with, or infiltrating, the S1, S2, S3 and/or S4 roots of the SP. The median of the largest diameter recorded for each of the DE nodules was 35 (range, 18-50) mm. Echogenicity was non-uniform in 23 (85%) of the DE nodules, with all but one of these nodules containing hyperechogenic areas. The shape of the lesions was irregular in 24 (89%) cases. Only one lesion exhibited a lobulated form, with all other irregular lesions showing a spiculated appearance. An acoustic shadow was produced in 20 (74%) of the nodules, all of which were internal. On color or power Doppler examination, 21 (78%) of the nodules showed no signal (color score of 1). The remaining six (22%) lesions showed a minimal color content (color score of 2). According to pattern recognition, most DE nodules were purely solid, non-uniform, hypoechogenic nodules containing hyperechogenic areas, with internal shadows and irregular spiculated contours, and were poorly vascularized on color/power Doppler examination.

CONCLUSION

The ultrasound finding of a parametrial, unilateral, solid, non-uniform, hypoechogenic nodule with hyperechogenic areas and possible internal shadowing, as well as irregular spiculated contours, demonstrating poor vascularization on Doppler examination in proximity to or involving the structures of the SP, indicates DE affecting the SP. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Integration of O2-economised tumour-targeted photosensitive magnetic nanomaterials in the diagnosis and therapy of gastric cancer

Hypoxia in the tumour microenvironment is a major limiting factor in photodynamic therapy. The present study employed a novel O2-economised photosensitizer, ACSN, to effectively curtail oxygen consumption by impeding the aerobic respiration of tumour cells, thereby increasing the reactive oxygen species (ROS) production in photodynamic therapy. To enhance the efficacy of photodynamic therapy, the active targeting peptide iRGD was employed to facilitate drug accumulation in the tumour tissue. Therefore, we constructed a targeted drug platform, ACSN/Fe3O4@MSNs-iRGD, that integrates diagnosis and treatment. The drug exhibited excellent active targeting ability towards gastric cancer MGC-803 cells and can efficiently penetrate the mitochondria upon cellular internalisation. The photosensitizer ACSN, released from the drug, effectively suppressed mitochondrial aerobic respiration to conserve oxygen and exhibited robust ROS production upon laser excitation. The core-shell structure comprises Fe3O4, which offers excellent T2 dark contrast for real-time tumour monitoring through MRI imaging. By incorporating excellent photodynamic therapy and MRI imaging capabilities, this drug can serve as an effective platform for the integration of tumour diagnosis and treatment, thus addressing the limitations associated with conventional tumour therapies. It is anticipated that this approach will soon be clinically translated.

The Role of Imaging in Cervical Cancer Staging: ESGO/ESTRO/ESP Guidelines (Update 2023)

Following the European Society of Gynaecological Oncology (ESGO), the European Society for Radiotherapy and Oncology (ESTRO), and the European Society of Pathology (ESP) joint guidelines (2018) for the management of patients with cervical cancer, treatment decisions should be guided by modern imaging techniques. After five years (2023), an update of the ESGO-ESTRO-ESP recommendations was performed, further confirming this statement. Transvaginal/transrectal ultrasound (TRS/TVS) or pelvic magnetic resonance (MRI) enables tumor delineation and precise assessment of its local extent, including the evaluation of the depth of infiltration in the bladder- or rectal wall. Additionally, both techniques have very high specificity to confirm the presence of metastatic pelvic lymph nodes but fail to exclude them due to insufficient sensitivity to detect small-volume metastases, as in any other currently available imaging modality. In early-stage disease (T1a to T2a1, except T1b3) with negative lymph nodes on TVS/TRS or MRI, surgicopathological staging should be performed. In all other situations, contrast-enhanced computed tomography (CECT) or 18F-fluorodeoxyglucose positron emission tomography combined with CT (PET-CT) is recommended to assess extrapelvic spread. This paper aims to review the evidence supporting the implementation of diagnostic imaging with a focus on ultrasound at primary diagnostic workup of cervical cancer.