Radiofrequency ablation of bone tumours

Saline-Infused Radiofrequency Ablation: A Review on the Key Factors for a Safe and Reliable Tumour Treatment

Radiofrequency ablation (RFA) combined with saline infusion into tissue is a promising technique to ablate larger tumours. Nevertheless, the application of saline-infused RFA remains at clinical trials due to the contradictory findings as a result of the inconsistencies in experimental procedures. These inconsistencies not only magnify the number of factors to consider during the treatment, but also obscure the understanding of the role of saline in enlarging the coagulation zone. Consequently, this can result in major complications, which includes unwanted thermal damages to adjacent tissues and also incomplete ablation of the tumour. This review aims to identify the key factors of saline responsible for enlarging the coagulation zone during saline-infused RFA, and provide a proper understanding on their effects that is supported with findings from computational studies to ensure a safe and reliable cancer treatment.

Introduction to interventional radiology's role in palliative care for children with cancer: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

As palliative care continues to be an area of increasing emphasis in pediatric oncology programs, it is important to raise awareness about minimally invasive, image-guided procedures that can supplement more conventional palliative interventions, such as systemic analgesics, external beam radiation, and locoregional anesthesia. These procedures, when performed for appropriately selected patients, can often facilitate discharge from an inpatient facility, and help patients meet their end-of-life goals. This article specifically discusses three palliative procedures performed by interventional radiologists that can assist pediatric palliative care teams in: (a) percutaneous thermal ablation of painful bone metastases, (b) cryoneurolysis, and (c) tunneled drainage catheter placement for malignant pleural effusions and ascites.

Short-term outcome of adrenal radiofrequency ablation of adrenal cysts: a single-center experience

Percutaneous thermal ablation is a minimally invasive treatment for liver, kidney, lung, bone, and thyroid tumors. This treatment also has been used to treat adrenal tumors in patients, but there is no evidence for the efficacy of thermal ablation of adrenal cysts. The present study was performed to analyze the experience of a single center with percutaneous radiofrequency ablation (RFA) of adrenal cysts and to evaluate its efficacy. The present study enrolled all patients who underwent percutaneous RFA for unilateral adrenal cysts from 2019 to 2021. All patients underwent USG-guided percutaneous aspiration of cystic fluid, followed by RFA. A total nine patients with adrenal cysts were included in this study. All of them underwent technically successful percutaneous RFA, with no immediate complication. Follow-up CT 3 months after RFA showed that six of the nine adrenal cysts showed good responses, with reductions in cyst volume ranging from 86.4 to 97.9%. One patient had poor response in the cyst size (volume reduction rate 11.2%). She underwent secondary RFA with resulting that the cyst volume reduced by 91.1%. After a median follow-up period of 17.2 months, eight patients showed no evidence of regrowth. The patient, who showed evidence of regrowth, declined any other treatment and has been under regular surveillance. None of the nine patients developed adrenal insufficiency during the follow-up period. In conclusion, percutaneous RFA is a safe and effective minimally invasive treatment for adrenal cysts, suggesting that percutaneous RFA may be a good alternative option in selected patients.

Temperature Monitoring in Hyperthermia Treatments of Bone Tumors: State-of-the-Art and Future Challenges

Bone metastases and osteoid osteoma (OO) have a high incidence in patients facing primary lesions in many organs. Radiotherapy has long been the standard choice for these patients, performed as stand-alone or in conjunction with surgery. However, the needs of these patients have never been fully met, especially in the ones with low life expectancy, where treatments devoted to pain reduction are pivotal. New techniques as hyperthermia treatments (HTs) are emerging to reduce the associated pain of bone metastases and OO. Temperature monitoring during HTs may significantly improve the clinical outcomes since the amount of thermal injury depends on the tissue temperature and the exposure time. This is particularly relevant in bone tumors due to the adjacent vulnerable structures (e.g., spinal cord and nerve roots). In this Review, we focus on the potential of temperature monitoring on HT of bone cancer. Preclinical and clinical studies have been proposed and are underway to investigate the use of different thermometric techniques in this scenario. We review these studies, the principle of work of the thermometric techniques used in HTs, their strengths, weaknesses, and pitfalls, as well as the strategies and the potential of improving the HTs outcomes.

Percutaneous image-guided thermal ablation of bone metastases: a retrospective propensity study comparing the safety profile of radio-frequency ablation and cryo-ablation

OBJECTIVES

To retrospectively compare the safety profile of percutaneous image-guided radiofrequency ablation (RFA) and cryoablation (CA) of bone metastases (BM) with and without a propensity score analysis.

METHODS

Between January 2008 and April 2018, 274 consecutive patients (mean age 61.6 ± 12.1 years) with BM were treated at our Institution with RFA (53 patients; 66 BM) or CA (221 patients; 301 BM) and included in this study. Complications were assessed according to the type of ablation modality before and after applying a 1:1 propensity score method taking into account patient's demographics, BM features, procedural details and follow-up findings.

RESULTS

In the whole 9 BM (2.5%) reported major complications without significant difference between RFA (1/66; 1.5%) and CA (8/301; 2.7%; p = 1); 40 BM (10.9%) showed minor complications, which were more common with RFA (22/66; 33.3%) than with CA (18/301; 6.0%, p<.001) mainly due to post-procedural pain occurring more frequently with RFA than CA (20/66; 30.3% vs. 7/301; 2.3%, p<.001). Following 1:1 matching, similar results were obtained, since there were similar rates of major complications with RFA and CA (1/66 [1.5%] and 0/66 [0.0%], respectively; p = 1); and higher rates of minor complications with RFA compared to CA [33.3% (22/66) vs. 2/66 (3%); p<.001] due to preponderant postprocedural pain (90.9% [20/22] minor complications with RFA).

CONCLUSIONS

Similar low rates of major complications are expected with RFA and CA of BM. In the post-operative period, RFA appears more painful than CA, thus warranting for adoption of dedicated analgesic protocols for patients undergoing RFA.

Multipoint Temperature Monitoring of Microwave Thermal Ablation in Bones through Fiber Bragg Grating Sensor Arrays

Bones are a frequent site of metastases that cause intolerable cancer-related pain in 90% of patients, making their quality of life poor. In this scenario, being able to treat bone oncology patients by means of minimally invasive techniques can be crucial to avoid surgery-related risks and decrease hospitalization times. The use of microwave ablation (MWA) is gaining broad clinical acceptance to treat bone tumors. It is worth investigating temperature variations in bone tissue undergoing MWA because the clinical outcomes can be inferred from this parameter. Several feasibility studies have been performed, but an experimental analysis of the temperature trends reached into the bone during the MWA has not yet been assessed. In this work, a multi-point temperature study along the bone structure during such treatment is presented. The study has been carried out on ex vivo bovine femur and tibia, subjected to MWA. An overall of 40 measurement points covering a large sensing area was obtained for each configuration. Temperature monitoring was performed by using 40 fiber Bragg grating (FBGs) sensors (four arrays each housing 10 FBGs), inserted into the bones at specific distances to the microwave antenna. As result, the ability of this experimental multi-point monitoring approach in tracking temperature variations within bone tissue during MWA treatments was shown. This study lays the foundations for the design of a novel approach to study the effects of MWA on bone tumors. As consequence, the MWA treatment settings could be optimized in order to maximize the treatment effects of such a promising clinical application, but also customized for the specific tumor and patient.

Principles of Management of Spine Metastasis

BACKGROUND

With evolution of medicine, radiation therapy and surgical methods, cancer care has improved the quality of life for patients with improved survival and functional status in patients with skeletal metastasis. The most common site of skeletal metastases from other primary malignant neoplasms is the spine, hence, understanding the epidemiology of metastatic spine disease and its presentation is essential for developing a diagnostic and treatment strategy which eventually results in optimum care to reduce disease-related morbidity.

PURPOSE

With this review article we intend to describe an evidence-based review on the presentation, diagnosis and treatment of metastatic spinal disease.

METHODS

We reviewed the current available literature on management of spinal metastasis and have described a step wise evaluation and management strategy of metastatic spine disease.

CONCLUSION

The present review article addresses various aspects and related controversies related to evaluation, staging and treatment options in the management of spinal metastasis.

Multi-segmental spine image registration supporting image-guided interventions of spinal metastases

BACKGROUND

Radiofrequency ablation was introduced recently to treat spinal metastases, which are among the most common metastases. These minimally-invasive interventions are most often image-guided by flat-panel CT scans, withholding soft tissue contrast like MR imaging. Image fusion of diagnostic MR and operative CT images could provide important and useful information during interventions.

METHOD

Diagnostic MR and interventional flat-panel CT scans of 19 patients, who underwent radiofrequency ablations of spinal metastases were obtained. Our presented approach piecewise rigidly registers single vertebrae using normalized gradient fields and embeds them within a fused image. Registration accuracy was determined via Euclidean distances between corresponding landmark pairs of ground truth data.

RESULTS

Our method resulted in an average registration error of 2.35mm. An optimal image fusion performed by landmark registrations achieved an average registration error of 1.70mm. Additionally, intra- and inter-reader variability was determined, resulting in mean distances of corresponding landmark pairs of 1.05mm (MRI) and 1.03mm (flat-panel CT) for the intra-reader variability and 1.36mm and 1.28mm for the inter-reader variability, respectively.

CONCLUSIONS

Our multi-segmental approach with normalized gradient fields as image similarity measure can handle spine deformations due to patient positioning and avoid time-consuming manually performed registration. Thus, our method can provide practical and applicable intervention support without significantly delaying the clinical workflow or additional workload.

Developments in the management of bone metastases with interventional radiology

Interventional radiology has known an exponential growth in the last years. Technological advances of the last decades, have made it possible to use new treatments on a larger scale, with safe and effective results. They could be considered as palliative treatments for painful lesions but also curative procedures, as single treatment or specially in combination with other techniques (surgery, radiation and oncology therapies, etc.).The main diffuse techniques are those of thermal ablation that destroy the target lesion through the heat; however there are also endovascular therapies that destroy the target tissue thanks to devascularization. Finally the is also the possibility to stabilize pathological fractures or impending fractures. In this paper all the most diffuse and effective techniques are reviewed and also a discussion of the main indications is done, with an analisys of the success and complications rates.

Osteoblastoma of the elbow: analysis of 13 patients and literature review

PURPOSE

To analyze the clinical and radiographic characteristics, treatment, and outcome of patients with elbow osteoblastoma.

PATIENTS AND METHODS

We present 13 patients (7 males and 6 females; mean age, 28 years) diagnosed and treated for an elbow osteoblastoma from 1975 to 2012. Mean follow-up was 29 months (range 12-60 months). Clinical presentation, imaging, surgical treatment, complications, range of elbow motion, and functional outcome were evaluated. The MSTS, DASH, and OXFORD scores were used.

RESULTS

Main symptom was pain (all patients) accompanied by stiffness (8 patients) and swelling or tumefaction (7 patients), with a median duration of symptoms of 32 months (range 6-96 months). Distal humerus was affected in 10 patients, proximal ulna in 2 patients, and proximal radius in one patient. All patients underwent surgical therapy that consisted of curettage of the lesion (7 patients), curettage and bone allografting (3 patients), wide resection (2 patients; total distal humerus and resection of the radial head), and radiofrequency thermal ablation (1 patient). One patient experienced a recurrence after surgical treatment. The mean MSTS score after treatment was 87% (range 50-100%), which corresponds to excellent results.

CONCLUSIONS

Intralesional surgery is successful in tumor control in most patients with osteoblastoma of the elbow. Thermal ablation may be successful for smaller lesions. Most of the patients had a good-to-excellent functional outcome even if they had tumor-related elbow stiffness at diagnosis.

LEVEL OF EVIDENCE

Therapeutic study, Level IV-1.

Intra-articular benign bone lesions treated with Magnetic Resonance-guided Focused Ultrasound (MRgFUS): imaging follow-up and clinical results

Purpose of this study was to evaluate the employment of MRI-guided Focused Ultrasound (MRgFUS) for treatment of intra-articular benign bone lesions as alternative to surgery, and to monitor the success of the treatment on CT and MRI images. From March 2011 to August 2013, 14 intra-articular benign bone lesions were treated with MRgFUS. All patients were studied by CT and MR imaging. Pain was measured using the visual analogue scale (VAS) before and after treatment (6 and 12 months). All patients in our series demonstrated regression in painful symptomatology during screening. A significant drop in the mean VAS pain score (from 7.8 to 0.6) was observed at 12-month follow-up, and pain medication was no longer needed after treatment. No complications were observed. Three diagnostic imaging signs were found suggesting absence of biological activity and confirming the clinical findings: calcification of the treated lesion, lack of contrast enhancement and disappearance of bone oedema around the lesions.

CONCLUSION

the employment of MRgFUS is safe and effective in the treatment of intra-articular benign bone lesions. The clinical outcome is satisfactory, and the success of the treatment is confirmed by diagnostic imaging.

Local treatment of metastases from differentiated thyroid cancer

OBJECTIVES

To study the various local treatments available for thyroid cancer metastases, investigate techniques and assess their advantages and limitations and roles in the overall treatment strategy for metastatic disease.

RESULTS

We investigated metastases surgery, external radiation therapy, embolization, chemoembolization, cementoplasty, radiofrequency ablation and cryotherapy, describing techniques, advantages and drawbacks and possible complications. Indications were reviewed according to metastases location, and the roles of the various techniques are discussed in the overall treatment strategy for thyroid cancer metastases. Despite the advent of new targeted therapies, local treatment still has an important role to play: either palliative or, in oligometastatic involvement, curative. Even in extensive disease, it may allow postponement of tyrosine kinase inhibitor therapy, which, once initiated, has to be continued life-long, is expensive and is not free of side-effects.

Treatment of focal benign lesions of the bone: MRgFUS and RFA

The objective of this study was to evaluate the role of MR-guided focused ultrasound surgery and radiofrequency ablation in the management of bone and soft-tissue lesions. Musculoskeletal interventional radiology represents an interesting option for the treatment of benign bone and soft-tissue lesions to avoid the invasiveness of surgery and related risks. The imaging techniques now available, besides representing an optimal guide, allow control of the temperature reached in the region of interest, avoiding or minimizing damage to the sensitive structures surrounding the lesion.

A Novel, Minimally Invasive Resection of a Pediatric Cervical Spine Osteoblastoma: A Case Report

CASE

An eleven-year-old girl with a left C6 pedicle mass consistent with an osteoblastoma was treated with a minimally invasive procedure with use of intraoperative imaging to guide intralesional curettage and grafting.

CONCLUSION

Intraoperative navigation allowed localization of the tumor. We used a muscle-splitting approach and avoided the muscle stripping and blood loss associated with a standard midline incision. Performing tumor resection with minimally invasive methods enabled us to avoid a spinal fusion; this eliminated the additional risks associated with fusion, including nonunion, loss of motion, and future revisions related to the instrumentation.

A novel treatment for bone lesions of multifocal epithelioid sarcoma-like hemangioendothelioma

Epithelioid sarcoma-like hemangioendothelioma (ES-H) is a rare, indolent vascular neoplasm with characteristics similar to epithelioid sarcoma. It typically affects young males who present with skin and subcutaneous lesions in the extremities. Bone lesions, occurring in approximately 20% of patients, are often multifocal, seen in conjunction with soft tissue lesions, and usually found in bones of the lower extremities. This report details the case of a 20-year-old male who presented with a 1-year history of painful skin lesions on his left lower extremity. Staging studies revealed bone lesions in the cuboid and calcaneus. Bone and soft tissue pathology was consistent with ES-H. The soft tissue lesions were treated with wide excision and the bony lesions with radiofrequency ablation (RFA). The patient had no evidence of recurrence at the 2-year follow-up. Treatment of ES-H typically consists of wide excision of all soft tissue lesions and possible adjuvant radiation therapy. Management of bony lesions has included marginal excision, wide excision, amputation, chemotherapy, observation, or a combination of these modalities. ES-H has the potential for distant metastases. There is no consensus regarding the appropriate treatment of multifocal epithelioid sarcoma-like hemangioendothelioma involving bone. A potential treatment strategy of wide excision of soft tissue lesions and RFA of bone lesions is proposed.

The electromagnetic spectrum: current and future applications in oncology

The electromagnetic spectrum is composed of waves of various energies that interact with matter. When focused upon and directed at tumors, these energy sources can be employed as a means of lesion ablation. While the use of x-rays is widely known in this regard, a growing body of evidence shows that other members of this family can also achieve oncologic success. This article will review therapeutic application of the electromagnetic spectrum in current interventions and potential future applications.