Protection of the Proximal Articular Cartilage During Percutaneous Thermal Ablation of Acetabular Metastasis Using Temperature Monitoring

Management of metastatic bone disease of the pelvis: current concepts

PURPOSE

Metastatic disease of the pelvis is frequently associated with severe pain and impaired ambulatory function. Depending on the patient's characteristics, primary tumor, and metastatic pelvic disease, the treatment choice may be varied. This study aims to report on the current management options of metastatic pelvic disease.

METHODS

We comprehensively researched multiple databases and evaluated essential studies about current concepts of managing a metastatic bone disease of the pelvis, focusing on specific indications as well as on the result of treatment.

RESULTS

Pelvic metastases not in the periacetabular region can be managed with modification of weight-bearing, analgesics, bisphosphonates, chemotherapy and/or radiotherapy. Minimally invasive approaches include radiofrequency ablation, cryoablation, embolization, percutaneous osteoplasty, and percutaneous screw placement. Pathological or impending periacetabular fracture, excessive periacetabular bone defect, radioresistant tumor, and persistent debilitating pain despite non-surgical treatment and/or minimally invasive procedures can be managed with different surgical techniques. Overall, treatment can be divided into nonoperative, minimally invasive, and operative based on specific indications, the expectations of the patient and the lesion.

CONCLUSION

Different treatment modalities exist to manage metastatic pelvic bone disease. Decision-making for the most appropriate treatment should be made with a multidisciplinary approach based on a case-by-case basis.

Effect of Thermal Ablation on Growth Plates: A Study to Explore the Thermal Threshold of Rabbit Growth Plates During Microwave Ablation

PURPOSE

To explore the temperature threshold of thermal damage to growth plates.

METHODS

Nine rabbits were divided into three groups for femoral ablation, exposing the growth plate to different temperatures (T1 = 43-45 °C; T2 = 46-48 °C; T3 = 49-51 °C). After 5 weeks, the changes in the femurs were assessed by macroscopic images, micro-CT, haematoxylin and eosin staining, and immunohistochemistry of Col2a1 (type II collagen). At the cellular level, rabbit epiphyseal chondrocytes were exposed to 37 °C, 44 °C, 47 °C and 50 °C for 5 min. Then, proliferation and chondrogenic differentiation were detected.

RESULTS

The rabbits in the T2 and T3 groups developed length discrepancies and axial deviations of femurs, abnormal newly formed bone in the marrow cavity, disorganized growth plates and decreased Col2a1 expression. At the cellular level, the cells exposed to 47 °C and 50 °C for 5 min showed decreased viability, increased apoptosis, decreased extracellular matrix synthesis and decreased matrix mineralization. However, the changes in rabbits in the T1 group and cells at 44 °C did not show a significant difference.

CONCLUSION

The ablation of growth plates at temperatures above 45 °C for 5 min results in decreased chondrocyte viability and disorganized growth plates, leading to growth disturbances. Further studies are warranted to confirm these promising initial results.

Ablation Techniques in Cancer Pain

Painful bone metastases are a frequently encountered problem in oncology practice. The skeletal system is the third most common site of metastatic disease and up to 85% of patients with breast, prostate, and lung cancer may develop bone metastases during the course of their disease.

Percutaneous management of bone metastases: State of the art

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty/vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600 Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900 MHz-2450 MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65 °C-85 °C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

Percutaneous management of bone metastases: state of the art

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty / vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. Tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900MHz to 2450MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65°C-85°C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

Musculoskeletal interventional oncology: current and future practices

Management of musculoskeletal (MSK) tumours has traditionally been delivered by surgeons and medical oncologists. However, in recent years, image-guided interventional oncology (IO) has significantly impacted the clinical management of MSK tumours. With the rapid evolution of relevant technologies and the expanding range of clinical indications, it is likely that the impact of IO will significantly grow and further evolve in the near future.

In this narrative review, we describe well-established and new interventional technologies that are currently integrating into the IO armamentarium available to radiologists to treat MSK tumours and illustrate new emerging IO indications for treatment.

French Multidisciplinary Approach for the Treatment of MSK Tumors

Several interventional treatments have recently been integrated into the therapeutic armamentarium available for the treatment of bone tumors. In some scenarios (e.g., osteoid osteoma), interventional treatments represent the sole and definitive applied treatment. Due to the absence of widely shared protocols and the complex multivariate scenarios underlying the clinical presentation of the remaining bone tumors including metastases, therapeutic strategies derived from a multidisciplinary tumor board are essential to provide effective treatments tailored to each patient. In the present review, we present the multidisciplinary therapeutic strategies commonly adopted for the most frequent bone tumors.

Acetabular roof lesions in children: a descriptive study and literature review

Background

Acetabular roof lesions (ARLs) in children are uncommon and may involve a variety of diseases. The acetabular roof is the main weight-bearing area of the hip joint, and lesions affecting the acetabular roof lead to fluid accumulation in the hip joint, causing hip pain and claudication. Methods for diagnosing and treating ARLs and the prognosis after treatment are rarely reported. We present our experience in a group of children and teenagers with ARLs to retrospectively explore the clinical and imaging features and histopathological diagnosis and report the treatment methods and follow-up observations.

Methods

Patients with ARLs admitted to the Children’s Hospital of Chongqing Medical University from April 2011 to September 2018 were selected retrospectively. We collected the basic information of patients (name, sex, age), main symptoms and signs, results of various laboratory tests, treatment methods, and intraoperative observations through the hospital medical record system. We collected X-ray, computed tomography (CT), magnetic resonance imaging (MRI) and pathological examination data through the Picture Archiving and Communications System. Follow-up data were collected through an outpatient medical record system, telephone, and chat software (such as WeChat). We used descriptive methods to analyze the lesion structure and destruction mode based on the imaging findings and histopathological diagnosis.

Results

There were 14 ARL patients, including 6 with eosinophilic granuloma (EG), 5 with chronic osteomyelitis, 2 with bone cyst, and 1 with tuberculosis. One patient underwent percutaneous needle biopsy, 2 underwent open biopsy, and 11 underwent curettage; among them, 5 patients also underwent bone grafting. These lesions had no characteristic imaging findings, and the diagnosis was mainly based on histopathological examination. Most patients showed complete symptom resolution and good hip function at the 1-year follow-up.

Conclusion

ARLs are not common in children. The types of lesions are diverse and mostly benign, with EG being most common. Malignant tumors may also occur, such as Ewing’s sarcoma, non-Hodgkin’s lymphoma, metastases and neuroblastoma. CT and MRI can be helpful in diagnosing certain cases, but incisional biopsy is required in most cases.