Design and 3D printing of pelvis phantoms for cementoplasty

BACKGROUND

Percutaneous image-guided cementoplasty is a medical procedure for strengthening bones structurally altered by disease, such as osteolytic metastasis. This procedure involves injecting biocompatible liquid bone cement, through one or more trocars into the damaged bone. Within a few minutes the bone cement hardens and restores the rigidity of the bony structure. The introduction of this technique in the case of large cancellous bones, such as the pelvis, raises some practical issues such as: how to manage the flow of cement with variable viscosity over time and how to inject a large amount of cement under fluoroscopy to effectively restore the patient's ability to bear weight?

PURPOSE

As a means of training for young practitioners to ensure maximal filling of a metastatic bone area, we have designed and manufactured a pelvic phantom capable of replicating cement diffusion in healthy and metastatic bone under fluoroscopic and computed tomography guidance.

METHODS

The preliminary stage of the study consisted of an analysis of various lattice structures, with the objective of reproducing the haptic feedback experienced during the needle insertion and diffusion of cement within the trabecular bone. Cementoplasty tests were conducted by an experienced radiologist under fluoroscopy and CT guidance to evaluate the performance of the lattice structure. The initial analysis provided the groundwork for the design of the phantom pelvis, which was then evaluated against a patient case. The phantom was divided into two distinct components: a disposable section with lattice structure, intended for the injection of cement, and a reusable part representing the pelvic bones. Two additive manufacturing methods were selected for the production of the phantom: Stereolithography (SLA) for the lattice structure and Fused Deposition Modeling (FDM) for the pelvic bones. The disposable component was composed of different lattice structures, selected to best match the anatomic conditions of both healthy and diseased areas visible on the patient images. Subsequently, the performance of the phantom was validated against patient images through a cementoplasty test.

RESULTS

A total of 12 distinct lattice structures were subjected to three tests of cementoplasty. Stochastic lattices with 500 microns beam thickness and densities varying from 15% to 5% demonstrated the most effective replication of the needle haptic feedback, as well as the diffusion of the cement into healthy and osteolytic cancellous bone. These structures were then implanted in the phantom and validated against one patient case.

CONCLUSIONS

A methodology to design and manufacture a phantom dedicated to cementoplasty from patient images is proposed. Initially, a series of lattice structures, exhibiting diverse structure types, thicknesses, and densities, were evaluated to assess their capacity to accurately reproduce the haptic feedback of the needle and the diffusion of cement in the trabecular bone. Subsequent to the outcomes of these investigations, several structures were selected for the development of a phantom capable of accurately replicating a cementoplasty procedure under fluoroscopy and CT guidance. This phantom will enable the training of future practitioners on the procedure of cementoplasty in the pelvis.

Restoring mobility: roles of percutaneous consolidation for pelvic ring bone lesions-a multicenter study

OBJECTIVES

This study aimed to assess the early functional rehabilitation outcomes following percutaneous consolidation for pelvic ring tumor lesions.

MATERIALS AND METHODS

In this multicenter retrospective study, patients with pelvic bone tumor lesions, whether primitive or metastatic, underwent percutaneous consolidation (cementoplasty, screw fixation, or both). The primary outcome was postoperative weight-bearing ambulation. Secondary outcomes included hospitalization duration, procedural complications, and long-term consolidation. Inclusion criteria were patients treated for prophylactic consolidation or pathological fractures. Kaplan-Meier analysis was used for the primary outcome and hospital stay, with p-values < 0.05 indicating significance.

RESULTS

A total of 143 consecutive procedures were performed in 138 patients (mean age, 65 years ± 13; 68 men) who underwent percutaneous screw fixation, cementoplasty, or both. Postoperative weight-bearing ambulation was achieved in 142/143 cases (99%). In total, 117/143 (82%) of these were in the first 24 h. 81/143 (57%) were discharged within 24 h (median, one day; Q3, one day; Q4, 112 days). 133/138 (96.5%) patients achieved long-term consolidation. The most common pattern was isolated acetabular involvement (N = 40; 28%). Of the 19 adverse events, 10 were asymptomatic. Three patients had delayed infections and one required screw removal.

CONCLUSION

Percutaneous consolidation effectively achieved postoperative weight-bearing ambulation and represents a safe and durable treatment option for patients with pelvic bone lesions.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT06155890.

KEY POINTS

Question How can radiology continue to help improve care for patients with metastatic pelvic ring lesions? Findings 99% of patients achieved postoperative weight-bearing, with 82% doing so within 24 h. Clinical relevance Percutaneous consolidation enabled rapid functional rehabilitation of oncology patients, allowing short hospital stays with low complication rates, and demonstrating the expanding role of radiologists in diagnosis, risk assessment, and treatment planning, thereby enhancing patient care.

Interventional Radiology Management of Bone Metastasis Pain: Strategies and Techniques

Osseous metastases are common in cancer patients, and pain is one of the most frequent associated symptoms. The management of cancer-related pain is still problematic worldwide with 40 to 50% of patients still being undertreated. A significant proportion of cancer patients will require discontinuation of traditional analgesic treatments such as opioids due to unsuccessful pain relief or severe unmanageable toxicity and may, therefore, benefit from alternative treatments. Over the last few decades, several interventional radiology (IR) minimally invasive treatment options have been introduced into the cancer pain management toolbox and can be proposed to cancer patients. This article reviews the main IR treatment options for painful bone metastases which include vertebral augmentation, percutaneous osteosynthesis, tumoral ablation, electrochemotherapy, intra-arterial therapies, and percutaneous neurolysis.

Effectiveness of RF ablation and cementoplasty in enhancing functional capacity in pelvic malignant bone metastases

PURPOSE

Pelvic and sacral bone metastases cause significant morbidity. The primary aim of the study is to thoroughly evaluate the increase in functional capacity resulting from combined RF ablation and cementoplasty surgery applied to malignant bone metastases of the pelvic bones.

METHODS

Twenty patients who underwent RF ablation and cementoplasty for malign pelvic bone and sacrum metastases between January 2014 and December 2021 were retrospectively identified. The inclusion criteria were having a life expectancy of more than 1 month, being > 18 years old, and having at least 1 month of follow-up. The Visual Anlogue Scale (VAS) pain, Karnofsky Performance Status (KP), and Musculoskelatal Tumor Society (MSTS) scores were calculated.

RESULTS

VAS pain values decreased, and KP values increased postoperatively (p = 0.006 and p = 0,013). There was no statistically significant increase in MSTS (p > 0.05). The correlation relationships between lesion filling ratio and VAS pain, KP, and MSTS scores were not statistically significant (p > 0.05). Cement leakage was observed in 5 patients (25.0%), and no symptoms related to this leakage were observed.

CONCLUSION

The pelvic region, given its close proximity to blood vessels, nerves, and joint areas, along with the distinct challenges associated with its surgery, requires separate evaluation. In studies evaluating applications in the isolated pelvic ring region, as in our study, functional gains have been most comprehensively assessed in this study, demonstrating that the procedure results in significant functional improvements.

Percutaneous Fixation with Internal Cemented Screws for Iliac Lytic Bone Metastases: Assessment of Pain and Quality of Life on Long Term Follow-up

PURPOSE

To assess effectiveness on pain, quality of life and late adverse events of percutaneous fixation with internal cemented screw (FICS) among patients with iliac lytic bone metastases with or without pathological fractures.

MATERIALS AND METHODS

This retrospective exploratory study analyzed FICS procedures on iliac osteolytic bone lesions with and without pathological fracture performed from July 2019 to January 2022 in one tertiary level university hospital. The procedure were performed under general anesthesia, and were CT and fluoroscopically guided. Numerical Pain Rate Score (NPRS), mean EuroQol visual analogue scale (EQ VAS), morphine consumption, walking ability, walking perimeter and presence of walking aids and the appearance of complications were evaluated.

RESULTS

Nineteen procedures among 18 patients were carried out with a mean follow up time of 243.3 ± 243.2 days. The mean of the maximum NPRS decreased from 8.4 ± 1.3 to 2.2 ± 3.1 at 1 month (p < 0.01) and remained between 1.3 and 4.1 during a follow-up consultation period of 3-24 months. The mean EQ VAS rose from 42.0 ± 12.5 to 57.3 ± 13.9 at 1 month (p < 0.01) follow-up and remained between 55.8 and 62.5 thereafter. No patient scores returned to pre-procedure levels during follow-up. Mean morphine use decreased from 111.1 ± 118.1 to 57.8 ± 70.3 mg/d at 1 month (p > 0.05) follow-up. No late adverse events were reported.

CONCLUSION

Percutaneous FICS is a safe procedure with fast and long-standing effect on pain, mobility and quality of life. It can be used as a complement to the known analgesic therapeutic arsenal for bone metastases.

Robotic-assisted CT-guided percutaneous thermal ablation of abdominal tumors: An analysis of 41 patients

PURPOSE

Robotic assistance is rapidly evolving and may help physicians optimize needle guidance during percutaneous interventions. The purpose of the study was to report feasibility, safety, accuracy, immediate clinical success and short-term local tumor control after robotic-assisted computed tomography (CT)-guided thermal ablation of abdominal tumors.

MATERIALS AND METHODS

Forty-one patients who underwent percutaneous thermal ablation of abdominal tumors using robotic-assisted CT-guided were included. All ablations were performed with robotic assistance, using an optically-monitored robotic system with a needle guide sent to preplanned trajectories defined on three-dimensional-volumetric CT acquisitions with respiration monitoring. Endpoints were technical success, safety, distance from needle tip to planned trajectory and number of needle adjustments, and complete ablation rate.

RESULTS

Forty-one patients (31 men; mean age, 66.7 ± 9.9 [standard deviation (SD)] years [age range: 41-84 years]) were treated for 48 abdominal tumors, with 79 planned needles. Lesions treated were located in the liver (23/41; 56%), kidney (14/41;34%), adrenal gland (3/41; 7%) or retroperitoneum (1/41; 2%). Technical success was achieved in 39/41 (95%) patients, and 76/79 (96%) needle insertions. The mean lateral distance between the needle tip and planned trajectory was 3.2 ± 4.5 (SD) mm (range: 0-20 mm) before adjustments, and the mean three-dimensional distance was 1.6 ± 2.6 (SD) mm (range: 0-13 mm) after 29 manual depth adjustments (29/78; 37%) and 33 lateral adjustments (33/78; 42%). Two (2/79; 3%) needles required complete manual reinsertion. One grade 3 complication was reported in one patient (1/41; 2%). The overall clinical success rate was 100%. The 3-month local tumor control rate (progression free survival) was 95% (38/41).

CONCLUSION

These results provide further evidence on the use of robotic-assisted needle insertion regarding feasibility, safety, and accuracy, resulting in effective percutaneous thermal ablation of abdominal tumors.

Interventional management of malignant bone tumours

In the last few decades, interventional radiology (IR) has significantly increased its role in the management of bone tumours including bone metastases (BM) that represent the most common type of tumour involving the bone. The current IR management of BM is based on the 'palliative-curative' paradigm and relies on the use of consolidative (i.e. osteplasty, osteosynthesis) and/or ablation (i.e. cryoablation, radiofrequency ablation, electrochemotherapy) techniques. The present narrative review will overview the current role of IR for the management of BM.

Bone Consolidation: A Practical Guide for the Interventional Radiologist

In recent years, interventional radiologists have been increasingly involved in the management of bone fractures resulting from benign (osteoporosis and trauma), as well as malignant (tumor-related impending or pathologic fractures) conditions. Interventional techniques used to fix fractures include image-guided osteoplasty, screw-mediated osteosynthesis, or combinations of both. In the present narrative review, we highlight the most common clinical scenarios that may benefit from such interventional techniques with specific focus on spine, pelvic ring, and long bones.

Musculoskeletal Interventional Oncology: A Contemporary Review

Musculoskeletal interventional oncology is an emerging field that addresses the limitations of conventional therapies for bone and soft-tissue tumors. The field's growth has been driven by evolving treatment paradigms, expanding society guidelines, mounting supportive literature, technologic advances, and cross-specialty collaboration with medical, surgical, and radiation oncology. Safe, effective, and durable pain palliation, local control, and stabilization of musculoskeletal tumors are increasingly achieved through an expanding array of contemporary minimally invasive percutaneous image-guided treatments, including ablation, osteoplasty, vertebral augmentation (with or without mechanical reinforcement via implants), osseous consolidation via percutaneous screw fixation (with or without osteoplasty), tumor embolization, and neurolysis. These interventions may be used for curative or palliative indications and can be readily combined with systemic therapies. Therapeutic approaches include the combination of different interventional oncology techniques as well as the sequential application of such techniques with other local treatments, including surgery or radiation. This article reviews the current practice of interventional oncology treatments for the management of patients with bone and soft-tissue tumors with a focus on emerging technologies and techniques.

Comparison of Percutaneous Interventional Ablation-Osteoplasty-Reinforcement-Internal Fixation (AORIF), Long Intramedullary Nailing, and Hemiarthroplasty for the Treatment of Focal Metastatic Osteolytic Lesions in the Femoral Head and Neck

PURPOSE

Osteolytic metastatic lesions in the femoral head and neck are traditionally treated with intramedullary long nailing (IM) or hemiarthroplasty (HA). Recovery, surgical complications, and medical co-morbidities delay oncologic care. This study sought to elucidate the comparative efficacy of percutaneous ablation-osteoplasty-reinforcement-internal fixation (AORIF), IM, and HA in stabilizing osteolytic lesions in the femoral head and neck.

METHODS

A retrospective study of 67 patients who underwent IM, AORIF, or HA for osteolytic femoral head and neck lesions was performed. Primary outcome was assessed using a combined pain and ambulatory score (Range 1-10: 1 = bedbound, 10 = normal ambulation) at first follow-up (~ 2 weeks). Surgical complications associated with each treatment were compared.

RESULTS

Sixty-seven patients (mean age, 65 ± 13, 36 men and 31 women) underwent IM (40), AORIF (19), and HA (8) with a mean follow-up of 9 ± 11 months. Two patients in the IM group (5%), three in the AORIF group (16%), and none in the HA (0%) group required revision procedures. AORIF demonstrated superior early improvement in combined pain and ambulatory function scores by 3.0 points [IQR = 2.0] (IM p = 0.0008, HA p = 0.0190). Odds of post-operative complications was 10.3 times higher in HA than IM (95% confidence interval 1.8 to 60.3). Future revision procedures were not found to be statistically significant between AORIF and IM (p = 0.234).

CONCLUSIONS

A minimally invasive interventional skeletal procedure for focal femoral head and neck osteolytic lesions may serve as an effective alternative treatment to traditional surgical approaches, conferring a shorter recovery time and fewer medical complications.

Multimodal locoregional procedures for cancer pain management: a literature review

Pain is the most common and fearsome symptom in cancer patients, particularly in the advanced stage of disease. In cancer pain management, the first option is represented by analgesic drugs, whereas surgery is rarely used. Prior to considering surgical intervention, less invasive locoregional procedures are available from the wide pain management arsenal. In this review article, comprehensive information about the most commonly used locoregional options available for treating cancer pain focusing on interventional radiology (neurolysis, augmentation techniques, and embolization) and interventional radiotherapy were provided, also highlighting the potential ways to increase the effectiveness of treatments.

Percutaneous-Reinforced Osteoplasty: A Review of Emerging Treatment Strategies for Bone Interventions

Percutaneous-reinforced osteoplasty is currently being investigated as a possible therapeutic procedure for fracture stabilization in high-risk patients, primarily in patients with bone metastases or osteoporosis. For these patients, a percutaneous approach, if structurally sound, can provide a viable method for treating bone fractures without the physiologic stress of anesthesia and open surgery. However, the low strength of fixation is a common limitation that requires further refinement in scaffold design and selection of materials, and may potentially benefit from tissue-engineering-based regenerative approaches. Scaffolds that have tissue regenerative properties and low inflammatory response promote rapid healing at the fracture site and are ideal for percutaneous applications. On the other hand, preclinical mechanical tests of fracture-repaired specimens provide key information on restoration strength and long-term stability and enable further design optimization. This review presents an overview of percutaneous-reinforced osteoplasty, emerging treatment strategies for bone repair, and basic concepts of in vitro mechanical characterization.

Combination of Percutaneous Screw Fixation and Cementoplasty for Lytic Bone Metastases: Feasibility, Safety and Clinical Outcomes

OBJECTIVE

To evaluate feasibility, safety and efficacy of a combination of screw fixation and cementoplasty for pathologic bone fracture.

METHODS

In this single-center prospective study, all consecutive percutaneous screw fixations under assisted CT guidance for palliation and fracture treatment of pathologic bone fracture were reviewed from July 2019 to February 2021. The primary outcome measure was the procedures' technical success, defined as the correct placement of the screw(s), without any complications. Secondary outcome measures were the safety, the procedures' early analgesic effects and impacts on quality of life at 4 weeks.

RESULTS

Technical success was achieved in 11/11 procedures (100%) among 11 patients. No major complications attributable to the procedure were noted. The mean pain scored significantly decreased at the initial follow-up: 8.0 ± 2.7 versus 1.6 ± 2.5 (p < 0.05). Opioid doses were statistically lower after procedure: 70.9 ± 37 versus 48.2 ± 46 mg/day (p < 0.05). The mean EQ5D score had significantly increased by the early post-procedure consultation: 42.5 ± 13.6 vs 63.6 ± 10.3 (p < 0.05).

CONCLUSION

Combination of percutaneous screw fixation and cementoplasty for pathologic bone fracture is feasible and safe. It is efficient to reduce pain, decrease the consumption of opioids and improve the quality of life at 4 weeks after the procedure.

Complications of percutaneous image-guided screw fixation: An analysis of 94 consecutive patients

PURPOSE

The purpose of this study was to retrospectively assess the safety profile of percutaneous image-guided screw fixation (PIGSF) for insufficiency, impending or pathological fractures.

MATERIALS AND METHODS

From July 2012 to April 2020, all consecutive patients who underwent PIGSF were retrospectively included in the study. Patient characteristics, fracture type, procedural data and complications were analyzed. Complications were divided into per-procedural, early (<24hours) and delayed (>24hours) and classified into minor (grade 1-2) and major complications (grade 3-5) according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

RESULTS

A total of 110 fractures (40 insufficiency [36%], 53 pathological [48.5%] and 17 impending [15.5%] fractures) in 94 patients (48 women, 46 men; mean age, 62.7±12.7 [SD] years; age range: 32-88 years) were treated with PIGSF during 95 procedures. Twenty-four-hours follow-up was available for all patients, and>24-hours follow-up was available for 79 (79/110; 71.8%) fractures in 69 (69/94; 73.4%) patients. Per-procedural complications occurred in 3/110 fractures (2.7%, all minor). Early complications were reported in 4/110 fractures (3.6%, 1 major and 3 minor) and delayed ones in 14/79 fractures (17.7%, 5 major and 9 minor). The most frequent major delayed complication was infection (3/79; 3.8%).

CONCLUSION

The rate of per-procedural and early (within 24hours) complications following PIGSF is extremely low with most complications being minor, with major complications being delayed ones (>24hours).