The role and limitations of radiofrequency ablation in treatment of bone and soft tissue tumors

The Efficacy of Radiofrequency Ablation for Bone Tumors Unsuitable for Radical Excision

Background

Bone tumors can cause severe pain and poor quality of life due to recurrence and non-achievement of complete remission after surgery, chemotherapy, or radiotherapy. Radiofrequency ablation (RFA) can be considered for minimally invasive treatment of bone tumors that are difficult to radically excise. In this study, RFA was performed for bone tumors that were difficult to radically excise and did not respond to surgery, chemotherapy, or radiotherapy due to their large sizes and/or locations. The purpose of this study was to retrospectively analyze the clinical characteristics and survival rates of bone tumors after RFA and provide one more treatment option for the future.

Methods

There were 43 patients with bone tumors who underwent percutaneous RFA at our hospital from April 2007 to October 2017. The median age of the patients was 59 years (range, 31–75 years), and the median follow-up duration was 67.2 months (range, 10.2–130.5 months). Of the 43 patients, 26 were male and 17 were female. Thirty-four cases were metastatic bone tumors, 5 were chordomas, 3 were osteosarcomas, and 1 was a giant cell tumor. Pain and functional ability of the patients were evaluated using a visual analog scale (VAS) and the Musculoskeletal Tumor Society (MSTS) functional scoring system, respectively. Scores were recorded preoperatively, 1 week postoperatively, and 4 weeks postoperatively. The 1-year, 2-year, and 5-year survival rates were evaluated using the Kaplan-Meier method.

Results

The mean VAS score was 8.21 preoperatively. The mean VAS score at 1 week, 4 weeks, 12 weeks, and 24 weeks postoperatively were 3.91, 3.67, 3.31, and 3.12, respectively. The mean preoperative MSTS score was 64.0% (range, 32%–87%). The mean postoperative MSTS score was 71.0% (range, 40%–90%). The 1-year, 2-year, and 5-year survival rates were 95.3%, 69.8%, and 30.2%, respectively.

Conclusions

As per our study findings, RFA was effective in reducing pain and improving functional ability of patients with bone tumors that were difficult to radically excise.

Vertebral collapse and polymethylmethacrylate breakage after vertebroplasty: A case report

RATIONALE

Vertebral augmentation has become the main treatment for osteoporotic vertebral fractures (VFs). In this article, we report a very rare case of vertebral collapse and polymethylmethacrylate (PMMA) breakage after vertebroplasty. We describe the clinical characteristics and revision surgery performed to remove the broken PMMA cement, maintain stability, and corrects the kyphotic deformity, and we analyze the possible causes.

PATIENT CONCERNS

A 72-year-old man who suffered back pain underwent first lumbar vertebra (L1) percutaneous vertebroplasty (PVP) due to osteoporosis and a vertebral fracture in May 2013. Postoperatively, the patient's back pain was markedly alleviated. Unfortunately, his lumbar back pain recurred in November 2015.

DIAGNOSES

Plain radiographs showed collapse of the L1 vertebral body, breakage of the PMMA cement, and severe kyphosis at the thoracolumbar junction.

INTERVENTIONS

The posterior pedicle was internally fixed and an anterior artificial vertebral body implant was placed to maintain stability and correct the kyphotic deformity in a 2-step surgical procedure.

OUTCOMES

The back pain was alleviated and the patient returned to daily life for more than two years.

LESSONS

This case demonstrates that PVP is not a simple minimally invasive surgery, and significant postsurgical care is necessary. The true cause of this rare phenomenon remains unclear, but the long-term use of steroids, new injuries, and poorly corrected kyphosis after PVP may play a role. Surgeons must be aware of the kinds of complications that may occur, including rare complications such as vertebral lysis.

Safety and Clinical Effectiveness of Percutaneous Vertebroplasty in the Elderly (≥80 years)

PURPOSE

To evaluate the safety and clinical effectiveness of percutaneous vertebroplasty (PVP) in patients aged 80 and over.

METHODS

One hundred and seventy-three patients (127 women, 46 men; mean age = 84.2y) underwent 201 PVP procedures (391 vertebrae) in our institution from June 2008 to March 2012. One hundred and twenty-six patients (73 %) had osteoporotic vertebral compression fractures (VCF), 36 (20.5 %) were treated for tumour lesions, and the remaining 11 (6.5 %) for lesions from another cause. Comorbidities and American Society of Anesthesiologists (ASA) scores were assessed before treatment. Periprocedural and delayed complications were systematically recorded. A qualitative scale was used to evaluate pain relief at 1-month follow-up, ranging from significant pain worsening to marked improvement or disappearance. New fracture occurrence was assessed on follow-up imaging.

RESULTS

Forty-five percent of patients had pretreatment ASA class scores ≥3. No major complication occurred. Pain was unchanged in 16.9 % of cases, mildly improved in 31.5 %, and disappeared in 47.8 %. We identified 27 (11 %) symptomatic new VCFs in patients with osteoporosis on follow-up imaging. The mean delay in diagnosis of new fractures was 5 ± 8.7 months.

CONCLUSIONS

Even in the elderly, PVP remains a safe and effective technique for pain relief, independently of the underlying disease.

KEY POINTS

• Post-PVP pain improvement was observed in 79.3 % of elderly patients. • PVP remains a safe technique in elderly patients. • No decompensation of comorbidity was observed in our series.

Biomechanical properties of bone treated by magnetic resonance-guided focused ultrasound - an in vivo porcine model study

The magnetic resonance-guided focused ultrasound (MRgFUS) system uses MR imaging for real-time aiming of thermal ablation of bone and soft tissue tumors. Past clinical studies showed no increase in fracture rate after MRgFUS treatment. The purpose of this study was to determine the effect of MRgFUS treatment on mechanical properties of bone and correlate the effect to histological findings of treated bone. Four fully grown mini-pigs were treated by MRgFUS. Six consecutive right normal ribs were treated in each animal, and the left corresponding ribs served as controls. The animals were sacrificed at pre-set intervals (0, 2, 6 and 12weeks after treatment), and the treated and control bones were extracted. Mechanical properties of each bone were examined using three points bending studies for comparing treated bones to the corresponding controls. Histologic properties using Masson and hematoxylin-eosin stains were also compared. The ratio between treated and control biomechanical properties showed reduction in bone biomechanical properties at 6weeks post-MRgFUS treatment. The mean±SD yield load ratio and maximum ratios were 0.69±0.11 and 0.71±0.13, respectively (both p=0.031). These findings showed some recovery trend at 12weeks after treatment. Histological analysis showed a reduction in mean osteon size at 2weeks after treatment (0.58×10(-3)±0.1×10(-3)mm and 0.16×10(-3)±0.017×10(-3)mm) in control vs. treated bones, respectively (p=0.005). Treatment with the MRgFUS system resulted in a ~30% reduction in mechanical strength at 6weeks post-treatment. The reduction showed a reversible trend, with a 25%-20% decrease in strength at 12weeks post-treatment.

Thermal ablation of painful bone metastases

Skeletal metastases are common in patients with advanced cancer. Although cancer pain can be complex, bone pain is one of the most common types of pain in oncology patients. Pain from skeletal metastases can be debilitating and result in significant morbidity and mortality. Although conventional therapies such as narcotic medication and radiation therapy remain the standard of care, many patients experience suboptimal and limited relief. Image-guided thermal ablation of bone metastases provides a minimally invasive alternative for pain palliation. This article reviews the use of radiofrequency ablation and cryoablation in the treatment of painful bone metastases.

Pulsed radiofrequency treatment of pain relieving point in a soft tissue

Pulsed radiofrequency (PRF) treatment of nervous tissue has been proposed as a less neurodestructive technique alternative to continuous RF heat lesioning. Recently, clinical reports using PRF have shown favorable effects in the treatment of a variety of focal pain areas, even in non-nervous tissues; however, the mechanism of effect underlying this treatment to non-nervous tissue remains unclear. We report the case of a 67-year-old male who presented with pain reliving point in the posterior neck. The patient had pain in the posterior neck for 3 years. The pain subsided with pressure applied to a point in the posterior neck. There were no specific abnormal findings on laboratory testing and radiologic examinations. After PRF treatment to the pain-relieving point, he had pain relief which lasted more than 5 months.

Osteoid osteoma: fluoroscopic guided percutaneous excision technique - our experience

Osteoid osteoma is a small benign bone lesion. It generally affects children and young adults. Traditional treatment of osteoid osteoma includes excision either by wide resection, or by the removal of the nidus using curettes and burrs after opening the overlying cortex. Newly developed techniques involve percutaneous ablation of the tumor by computed tomography-guided core-drill excision and destruction of the nidus by thermocoagulation. Fluoroscopic guided percutaneous extirpation and drilling resection procedures have been performed at the Institute for Health Care of Children and Youth, Pediatric Surgery Clinic in Novi Sad, Serbia. Some modifications in the methods were made and implemented, which resulted in an excellent cost-benefit ratio, shorter period of hospitalization, and faster recovery. The aim of this paper is to present the experience gained in the treatment of osteoid osteomas in the last 5 years at the Pediatric Surgery Clinic in Novi Sad and to describe the modifications to the percutaneous biopsy technique of osteoid osteoma that have been implemented.

Image-guided ablation therapy of bone tumors

A wide range of thermal and cryoablation methods is currently available for the curative eradication or palliative treatment of a variety of bone and soft-tissue tumors. Radiofrequency ablation has been developed as a multipurpose tool for the skeletal system. Cryoablation has the added advantages of direct computed tomography or magnetic resonance visualization and monitoring of treatment outcome with less peri- and postoperative pain. Use of appropriate thermo-sensors and insulation techniques, like carbon dioxide insufflation, results in enhanced safety and efficacy. Ablation of weight-bearing bones has to be supplemented with cement consolidation. The authors present an overview of the current status of percutaneous image-guided ablation therapy of bone and soft-tissue tumors, analyze the merits and limitations of the various systems available, and discuss possible new applications for the future.

Non-surgical treatment of pulmonary and extra-pulmonary metastases

Studies have demonstrated that chemotherapy alone is usually unsuccessful as exclusive therapy for osteosarcoma (Cancer 95:2202-2201, 2002). Information will be presented for situations where non-surgical alternatives could be considered as useful, if not necessary, adjuncts to chemotherapy. In the thorax these include treatment of pleural effusions, chest wall lesions, central lung or mediastinal osteosarcoma, as well as recurrences in patients with limited pulmonary reserve. Other situations include too many metastases to easily resect, axial osteosarcomas, bone metastases, liver and brain metastases. Non-surgical local control measures include radiation with chemotherapy for radiosensitization, bone-seeking radioisotopes (e.g., 153Sm-EDTMP, 223Ra), bisphosphonates, heat (radiofrequency ablation), freezing and thawing (cryoablation), and intracavitary or regional (aerosol) therapy. Because of the predictable and common pattern of pulmonary metastases in osteosarcoma, aerosol therapy also offers an attractive regional treatment strategy. Principles and use of aerosol cytokines (e.g., GM-CSF, IL-2), and aerosol chemotherapy with gemcitabin will be discussed. Individual cases illustrating strategy and techniques will be presented.

Recurrent, refractory, metastatic and/or unresectable pediatric sarcomas: treatment options for young people ‘off the roadmap’

Although sarcoma surgery is very important for cancer control, it is not always possible or practical to offer in some situations, including sarcoma recurrences, metastatic disease and/or unacceptable loss of function. We review some pragmatic approaches and examples of how to balance indications, risks and alternatives to control cancer in young people with sarcomas that are no longer using ‘front-line’ therapy. Radiotherapy combined with chemotherapy and outpatient ‘continuation’ chemotherapy regimens using drugs that cause less alopecia can improve function and quality of life. Some effective strategies to help cope when cure is not possible may include tumor ablation techniques performed in interventional radiology and percutaneous nerve blocks. Family centered care and effective problem solving of difficult issues can be greatly facilitated by consultation with a multidisciplinary team experienced in the management of very difficult cases. Treatment of young people with recurrent, relapsed and/or metastatic sarcoma still remains an art very much in the realm of compassion not protocol and persistent advocacy is required for the young person for whom cure may not be possible. A reduction of suffering and assistance in writing more chapters of a rich life narrative is the goal.

Long-term oncological and overall outcomes of percutaneous radio frequency ablation in high risk surgical patients with a solitary small renal mass

PURPOSE

We present long-term outcomes in patients receiving RFA for solitary small renal masses.

MATERIALS AND METHODS

We reviewed the overall oncological and survival outcomes of patients with a solitary renal mass treated with radio frequency ablation in whom it had been at least 40 months since treatment. Patients were offered radio frequency ablation due to the high risk of surgical management and surgeon preference. Followup consisted of serum creatinine measurement, physical examination and serial contrast enhanced computerized tomography or magnetic resonance imaging.

RESULTS

The 31 patients received a total of 34 radio frequency ablation treatments to a 1.0 to 4.0 cm solitary renal mass (median 2.0). Mean followup in survivors was 61.6 months (median 62.4, range 41 to 80). There was 1 primary treatment failure, which was successfully retreated. There were 3 recurrences 7, 13 and 31 months after radio frequency ablation, respectively. The overall recurrence-free survival rate was 90.3%. There was a 100% metastasis-free and disease specific survival rate in the cohort. Overall patient survival was 71.0% since 9 died of nonrenal cell carcinoma causes. Of the 31 patients 18 had pathologically confirmed renal cell carcinoma. In these 18 cases the actuarial disease specific, metastasis-free, recurrence-free and overall survival rates were 100%, 100%, 79.9% and 58.3%, respectively, at a mean of 57.4 months of followup. In the entire cohort the difference between the pretreatment and the last known serum creatinine level was 0.15 mg/dl (p = 0.06).

CONCLUSIONS

In patients who have limited life expectancy or are high risk surgical candidates radio frequency ablation provides reasonable long-term oncological control and it may have a role in the management of small renal masses. Meticulous long-term followup is required in patients receiving radio frequency ablation.

Efficacy of percutaneous radiofrequency ablation of osteoid osteoma in children

BACKGROUND

Percutaneous radiofrequency (RF) ablation of osteoid osteoma has high technical and clinical success rates. However, there are limited data on its use in the treatment of osteoid osteoma in children.

OBJECTIVE

To assess the safety and efficacy of CT-guided percutaneous RF ablation of osteoid osteoma in children and compare the outcomes with published data on its use in patients unselected for age.

MATERIALS AND METHODS

From January 2003 to July 2006, 23 children with osteoid osteoma were treated with CT-guided RF ablation using a straight rigid electrode. Their mean age was 11 years (range 3.5-16 years) and there were 15 boys and 8 girls. The procedures were carried out under general anaesthesia. Follow-up was performed to assess technical and clinical outcome. The mean follow-up period was 2.5 years (range 13-49 months).

RESULTS

Technical success was achieved in 21 children (91.3%). Failure occurred in two children, in one due to failure to adequately localize the nidus within the dense sclerosis and in the other because of a short ablation time (2 min) because he developed hyperthermia. Clinical success was achieved in 18 patients within 2-5 days (primary clinical success rate 78.2%).These patients were allowed to fully weight-bear and function without limitation 1 week after the procedure. Pain recurrence was observed in two patients; one was treated successfully with a second ablation after 6 months (secondary clinical success rate 82.6%). Hyperthermia was observed in two patients during the procedure. Three other minor complications were observed: wound infection in one child and skin burn in two children. No major immediate or delayed complications were observed.

CONCLUSION

Percutaneous CT-guided RF ablation is an effective and safe minimally invasive procedure for the treatment of osteoid osteoma in children. It has high technical and clinical success rates that are slightly lower than those of patients with a wider range of ages.

Bimodal electric tissue ablation (BETA) — in-vivo evaluation of the effect of applying direct current before and during radiofrequency ablation of porcine liver

AIM

To examine the effect of applying increasing amounts of direct current (DC) before and during alternating current radiofrequency ablation of porcine liver.

MATERIALS AND METHODS

Using a Radiotherapeutics RF3000 generator, a 9 V AC/DC transformer and a 16 G plain aluminium tube as an electrode, a control group of 24 porcine hepatic radiofrequency ablation zones was compared with 24 zones created using a bimodal electric tissue ablation (BETA) technique in three pigs. All ablations were terminated when tissue impedance rose to greater than 999 Omega or radiofrequency energy input fell below 5 W on three successive measurements taken at 1 min intervals. BETA ablations were performed in two phases: an initial phase of variable duration DC followed by a second phase during which standard radiofrequency ablation was applied simultaneously with DC. During this second phase, radiofrequency power input was regulated by the feedback circuitry of the RF3000 generator according to changes in tissue impedance. The diameters (mm) of each ablation zone were measured by two observers in two planes perpendicular to the plane of needle insertion. The mean short axis diameter of each ablation zone was subjected to statistical analysis.

RESULTS

With increased duration of prior application of DC, there was a progressive increase in the diameter of the ablation zone (p<0.001). This effect increased sharply up to 300 s of pre-treatment after which a further increase in diameter occurred, but at a much lesser rate. A maximum ablation zone diameter of 32 mm was produced (control diameters 10-13 mm).

CONCLUSION

Applying a 9 V DC to porcine liver in vivo, and continuing this DC application during subsequent radiofrequency ablation, results in larger ablation zone diameters compared with radiofrequency ablation alone.

Novel therapeutic approaches in pediatric and young adult sarcomas

Novel therapy as part of sarcoma treatment schemas can enhance quality of life and is important in improving outcomes of high-risk sarcomas. Additional chemotherapy and biotherapy options to reduce tumor burden and prevent metastases include intra-arterial chemotherapy in osteosarcoma; intrapleural chemotherapy, aerosol 9-nitrocamptothecin, or protracted irinotecan and temozolomide in Ewing's sarcoma; continuous hyperthermic peritoneal perfusion for malignancy involving the peritoneum, such as desmoplastic small round cell tumor; and ifosfamide with muramyl tripeptide phosphatidyl ethanolamine liposomes in osteosarcoma. These treatments bring improved control of symptoms, including reduction in nausea, mucositis, cardiotoxicity, and central nervous system toxicity. Portable infusion devices have facilitated introduction of outpatient doxorubicin, ifosfamide, and methotrexate regimens and home-infusion irinotecan. Physical approaches to eliminate sarcoma tumors and metastases are critical for durable responses. Novel local control measures include embolization before surgery, radiosensitization, anti-vascular endothelial growth factor therapy during chemo-radiotherapy, proton therapy, samarium, thermal ablation (radiofrequency ablation), and cryoablation.

Improving outcomes in difficult bone cancers using multimodality therapy, including radiation: Physician and nursing perspectives

Principles of therapy are similar for Ewing's sarcoma and osteosarcoma. Chemotherapy or surgery alone cures few patients. Multimodality measures are needed for durable response. Quality of life and function are very important short- and long-term considerations. The spine, sacrum, pelvis, ankle, hand, mediastinum, pulmonary hilum, and chest wall are examples of bone cancer locations for which surgery is difficult. Patients with positive margins may need radiation and may experience systemic therapy delay, recurrence, loss of function, or any combination of these. When radiation is used as a means of local control, concomitant chemotherapy can increase its effectiveness. Options for difficult Ewing's sarcoma and osteosarcoma situations and multimodality solutions, including 1 mCi/kg of samarium and proton therapy, are discussed. Combination radiation and chemotherapy regimens are summarized, and organization of patients, caregivers, and medical teams for multimodality therapy is described, along with tools used in our institution that aid in this process.

Percutaneous radio frequency ablation of renal masses: results at a 2-year mean followup

PURPOSE

We describe our experience with and results of percutaneous computerized tomography guided radio frequency ablation (RFA) for small (less than 4 cm) renal tumors at a 2-year mean followup.

MATERIALS AND METHODS

A total of 49 patients (60 renal tumors) with a mean age of 63.9 years underwent percutaneous RFA. Indications for RFA were severe comorbidities or previous abdominal surgery precluding operative management, or hereditary conditions predisposing to multiple tumor recurrence. Persistent enhancement on initial followup imaging was considered incomplete treatment and all such patients underwent biopsy and were offered repeat RFA. Enhancement or enlargement on subsequent imaging was considered tumor recurrence and these patients were counseled regarding further therapy.

RESULTS

Three patients (4 tumors) were excluded from evaluation due to death from unrelated causes or loss to followup. A total of 46 patients (56 tumors) were available for evaluation at a mean followup of 27.5 months (range 12 to 48). Six tumors were incompletely treated with the first RFA and successfully treated with a second session. Recurrences after successful initial treatment were seen in 3 of 46 patients. These recurrences developed 24, 25 and 31 months following RFA, respectively, and all occurred in patients with a central tumor of 3.0 cm or greater. Overall local control was achieved in 94.6% of tumors (53 of 56).

CONCLUSIONS

RFA is an emerging alternative treatment modality for small renal tumors. Larger (greater than 3.0 cm) central tumors represent unique technical challenges, making these tumors more prone to recurrence. Long-term followup is needed to establish the oncological durability of this technique.

Concepts, Considerations, and Concerns on the Cutting Edge of Radiofrequency Ablation

Radiofrequency (RF) ablation is rapidly expanding from a tool to treat isolated hepatic malignancy to a therapy for patients with renal, adrenal, skeletal, breast, lung, and other soft-tissue neoplasms. The purpose of this article is to review the status of RF ablation outside the liver and lung and compare outcomes with current clinical standards when appropriate. The author also reviews how differences in local tissue environments play a role in creation of a thermal lesion and achievement of subsequent clinical success.