Bisphosphonate therapy for spinal aneurysmal bone cysts

Management of RANKL-mediated Disorders With Denosumab in Children and Adolescents: A Global Expert Guidance Document

CONTEXT

Denosumab is an effective treatment for many receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated disorders but there are potential safety considerations and limited data to guide its use in children and adolescents.

OBJECTIVE

This document seeks to summarize the evidence and provide expert opinion on safe and appropriate use of denosumab in pediatric RANKL-mediated disorders.

PARTICIPANTS

Ten experts in pediatric bone and mineral medicine from 6 countries with experience in the use of denosumab participated in the creation of this document.

EVIDENCE

Data were sourced from the published literature, primarily consisting of case reports/series and review articles because of the lack of higher level evidence. Expert opinion of the authors was used substantially when no published data were available.

CONCLUSION

Denosumab is an effective treatment for RANKL-mediated disorders in children and adolescents but is often not curative and, in some cases, is best used in conjunction with surgical or other medical treatments. Careful multidisciplinary planning is required to define the goals of treatment and expert oversight needed to manage the risk of mineral abnormalities. Substantive, collaborative research efforts are needed to determine optimal treatment regimens and minimize risks.

Management of aggressive recurrent thoracic spine aneurysmal bone cyst in a 7-year-old male: A case report and review of the literature

Background

Spinal aneurysmal bone cysts (ABCs) are rare, histologically benign tumors with aggressive behavior, which may cause bone and soft-tissue destruction, particularly affecting neural elements. Management of these tumors, including treatment modalities and follow-up protocols, remains challenging.

Case Description

A 7-year-old boy presented with chest wall pain persisting for two months before admission, accompanied by progressive mono paresis lasting ten days before admission. Myelopathy signs were evident during the examination. Imaging confirmed a multicystic lesion at the T6 level involving the posterior elements of the vertebra, with significant cord compression. Due to deteriorating neurological function, he underwent urgent laminectomy and neural decompression, followed by subtotal tumor resection. Postoperative histopathological examination confirmed the diagnosis of an ABC, and the patient experienced significant neurological recovery. However, after 21 days, the patient was readmitted to the emergency department with severe paraparesis. Magnetic resonance imaging revealed rapid growth of the residual tumor, leading to cord compression. He underwent aggressive total tumor resection, T6 vertebral body corpectomy, and fixation with pedicle screws and cage insertion. Following the second surgery, prompt neurological recovery occurred.

Conclusion

This rare case report emphasizes the importance of a close follow-up protocol for spinal ABCs in the pediatric population. It highlights the challenges in managing these tumors and the need for vigilant monitoring to detect and address rapid recurrences.

Sclerotherapy as a primary or salvage procedure for aneurysmal bone cysts: A single-center experience

BACKGROUND

Aneurysmal bone cysts (ABC) are benign cystic bone tumors of an osteolytic and locally aggressive nature. As an alternative to the primary treatment of choice, which consists of curettage with bone grafting, alternative treatment methods with promising results have been described. At our department, we have, in recent years, used percutaneous sclerotherapy with polidocanol. The objective of this study was to identify the healing rate and safety of sclerotherapy with polidocanol.

AIM

To identify the efficacy and safety of sclerotherapy with polidocanol in primary and recurrent ABC.

METHODS

Twenty-two consecutive patients (median age 12.5 years; range 1-27) with 23 ABCs treated with sclerotherapy with polidocanol from 2016-2021 were included retrospectively. Eleven patients (48%) had undergone different forms of previous treatment with recurrence. Under general anesthesia and fluoroscopic guidance, repeated percutaneous injections of 4mg polidocanol/kg body weight were performed. Through review of the electronic medical records, the following were identified: healing and recurrence rate, number of treatments, gender, age, comorbidity, location of the tumor and side effects / complications, as well as any previous surgery for ABC. The median length of radiographic follow-up was 19.5 mo.

RESULTS

All ABCs except one (96%) showed healing or stable disease after a median of 4 (range 1-8) injections. Complete clinical and radiographic healing was observed in 16 cysts (70%), while partial radiographic healing with resolution of pain was seen in 6 cases (26%) and considered as stable disease. The cyst that failed to heal had previously undergone curettage twice with recurrence. One patient with a large pelvic ABC experienced, right after two injections, a sudden drop in blood pressure, which could quickly be reversed. One patient with a juxtaphyseal ABC in the femoral neck showed a minor limb length discrepancy because of deformity. Beyond that, no complications were observed.

CONCLUSION

Percutaneous sclerotherapy with polidocanol appears to be a safe alternative for treatment of aneurysmal bone cysts. In our series of both primary and recurrent cysts, it showed the ability to achieve healing or stable disease in 22 of 23 cases (96%). Further studies are needed to decide if this provides a long-lasting effect.

Surgical Management and Denosumab for Aneurysmal Bone Cysts of the Spine in an Australian Tertiary Paediatric Centre

Aneurysmal bone cysts (ABC) are rare osteolytic, benign but often locally aggressive tumours of the long bones or vertebrae. For spinal ABC, surgical management, embolisation or sclerotherapy alone often carry high morbidity and/or high recurrence rates. Interruption of receptor activator of nuclear factor-kappa B ligand (RANKL) signalling holds promise as an effective therapeutic strategy for these tumours. We aimed to review the approach to surgical management and evaluate the efficacy and safety of denosumab for ABC of the spine in children. Retrospective review of 7 patients treated with denosumab using a standardised protocol for ABC of the spine in a tertiary paediatric centre. Surgical intervention was only conducted if there was spinal instability or significant neurological impairment. Denosumab 70 mg/m² was given 4-weekly for at least 6 months, followed by 2 doses of zoledronate 0.025 mg/kg, aiming to prevent rebound hypercalcaemia. All patients achieved stability of the spine and resolution of neurological impairment, if present. Six patients achieved metabolic remission and have ceased denosumab without recurrence to date; the other showed clinical and radiological improvement without complete metabolic remission. Three patients developed symptomatic hypercalcaemia 5-7 months after cessation of denosumab, requiring additional bisphosphonate treatment. We present our algorithm for the surgical and medical management of paediatric spinal ABC. Denosumab produced a radiological and metabolic response in all patients, with complete remission in most. Follow-up time was not long enough to evaluate the endurance of response after cessation in some patients. Incidence of rebound hypercalcaemia in this paediatric cohort was high, prompting a change to our protocol.

Minimally invasive treatment of aneurysmal bone cysts: Systematic literature review

INTRODUCTION

The optimal treatment of aneurysmal bone cysts (ABC) remains controversial. Surgery has long been considered as the treatment that yields the best outcomes. Some authors now prefer using less invasive options as the primary treatment. The primary objective of this systematic literature review was to determine if treatments that are less invasive than surgery are also effective in curing the ABC. The secondary objective was to determine the respective role of each treatment in the therapeutic arsenal.

HYPOTHESIS

Less invasive treatments can replace surgery as the base treatment for ABC.

PATIENTS AND METHODS

A PubMed® search was carried out for this review. The inclusion criteria were ABC treatment without cyst removal, case series, clinical case reports, reviews, publication in French or English. Excluded were articles that described the results of surgical treatment only, cranial or maxillofacial cysts, secondary ABC, duplicates, no abstract available. Based on the first six items of the "MINOR criteria", we selected 42 studies. For each selected study, we analyzed the number of cases, clinical response to treatment, radiological healing, recurrence or failure rate, complications and side effects of the treatment.

RESULTS

This review found that less invasive treatments generate results that are at least as good as surgery, often with fewer complications. Thus, in certain cases, these treatments can be recommended as first-line therapy. This category includes selective arterial embolization, sclerotherapy (alcohol, polidocanol) and injection of demineralized bone matrix.

DISCUSSION

Selective arterial embolization yields good results. While this is a difficult, operator-dependent technique that is not suitable for all ABCs (no identifiable feeding vessel), we recommend it as the primary treatment for spinal ABCs. For ABCs in other locations, sclerotherapy can be used as the primary treatment. However, this treatment becomes inconvenient if the number of injections is too high. Radiation therapy is not a first-line treatment because of its side effects. Bisphosphonates and denosumab can be used when the other treatments are contraindicated.

Current strategies for the treatment of solitary and aneurysmal bone cysts: A review of the literature

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SBCs can mostly be treated conservatively.

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In ABCs a biopsy is compulsory.

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ABCs can be treated by polidocanol instillations adequately.

This review of the literature aims to compare the etiology, the pathogenesis, the clinical diagnostics and the relevant treatment options of two different types of cystic bone lesions: the solitary bone cyst (SBC) and the aneurysmal bone cyst (ABC). Whereas the clinical symptoms and the radiographic appearance can be similar, the diagnostic pathway and the treatment options are clearly different.

The solitary bone cyst (SBC) represents a tumor-like bone lesion, occurring most frequently in the humerus and femur in children and adolescents. Pain caused by intercurrent pathological fractures is often the first symptom, and up to 87% of the cysts are associated with pathological fractures. In the majority of cases SBCs can be treated conservatively, especially in the upper extremity. However, if a fracture is completely dislocated, joint affecting, unstable or open, surgical treatment is necessary. Pain under weight bearing or regaining the ability to mobilize after fracture timely can necessitate surgical treatment in SBCs affecting the lower extremity. Spontaneous resolution can be seen in rare cases.

The aneurysmal bone cyst (ABC) is a benign, locally aggressive tumor that occurs in childhood and early adulthood. It usually affects the metaphysis of long bones but can also occur in the spine or the pelvis. ABC can be primary but also secondary to other bone pathologies. The diagnosis has to be confirmed by biopsy and histopathological examinations. With cytogenetic studies and the detection of specific translocations of the ubiquitin-specific protease (USP) 6 gene primary ABCs can be differentiated from secondary ABCs and other bone lesions. Among various modalities of treatment i.e. en bloc resection, intralesional curettage with adjuvants, embolization or the systemic application of denosumab, intralesional sclerotherapy using polidocanol is an effective and minimally invasive treatment of primary ABCs.

Primary Aneurysmal Bone Cyst and Its Recent Treatment Options: A Comparative Review of 74 Cases

(1) Background: An aneurysmal bone cyst (ABC) is a benign, locally aggressive tumor. Different treatment modalities are described in the literature i.e., en bloc resection, intralesional curettage and percutaneous sclerotherapy. (2) Methods: This single-center study is a review of 74 patients with primary ABCs who underwent a surgical treatment or polidocanol instillation. Cyst volume measurements using MRI and conventional radiographs are compared. (3) Results: The mean pre-interventional MRI-based cyst volume was 44.07 cm³ and the mean radiographic volume was 27.27 cm³. The recurrence rate after intralesional curettage with the need for further treatment was 38.2% (13/34). The instillation of polidocanol showed a significant reduction of the initial cyst volume (p < 0.001) but a persistent disease occurred in 29/32 cases (90.6%). In 10 of these 29 cases (34.5%) further treatment was necessary. After en bloc resection (eight cases) a local recurrence occurred in two cases (25%), in one case with the need for further treatment. (4) Conclusions: MRI scans are superior to biplanar radiographs in the examination of ABCs. Sequential percutaneous instillations of polidocanol are equally effective in the therapy of primary ABCs compared to intralesional curettage. However, several instillations have to be expected. In a considerable number of cases, a conversion to intralesional curettage or en bloc resection may be necessary.

Primary aneurysmal bone cyst of sacrum for adolescent: Eleven cases experience and literature review

The present study is aiming to describe clinical characteristics, surgical flowchart and treatment results of eleven adolescent patients with primary aneurysmal bone cyst (ABC) of sacrum and review in the literature. We retrospectively reviewed eleven young patients with sacral primary ABC, which had the intact clinical and follow-up information at our bone tumor center from 2001 to 2018. The literature review was based on Google Scholar, Medline, EMBASE and Pubmed databases. The search was performed using terms of "aneurysmal bone cyst", "sacral tumor", "sacrum tumor" "spine tumor" and "spinal tumor" for the literature review from 1998 to 2019. There were six male and five female with a mean age of 13 years old at the presentation. The mean follow-up duration was 6.5 years. No patient died of disease and had the pulmonary metastasis. Two patients had wound complications, including onesurgical site infection and one wound dehiscence. No patient had the local recurrence and neurologic deficit. In the literature review, 11 articles were reviewed and 45 cases with sacral primary ABC were included. The rate of local recurrence may be higher than that in our cohort. We proposed our flow chart for preparation of surgery for patients. Preoperative selective arterial embolization and intraoperative aortic balloon occlusion could provide the clear surgical vision and guarantee complete tumor excision by intralesional curettage. Preoperative selective arterial embolization, intraoperative aortic balloon occlusion and complete tumor excision by intralesional curettage can yield satisfactory results with a low rate of recurrence in adolescent patients with a sacral primary ABC.

Percutaneous alcohol-based sclerotherapy in aneurysmal bone cyst in children and adolescents

INTRODUCTION

Aneurysmal bone cyst (ABC) is a benign bone lesion of childhood and adolescence. It can be locally aggressive, with risk of fracture. Management is controversial. The aim of the present study was to assess the efficacy, simplicity and tolerance of percutaneous alcohol-bases sclerotherapy in ABC.

HYPOTHESIS

Alcohol-based sclerotherapy for ABC under radiographic control is safe and effective.

MATERIAL AND METHODS

A single-center retrospective study for the period 2008-2016 included all of the 55 ABCs, in 54 patients, confirmed on pathology and treated by alcohol-based sclerotherapy under radiographic control. Mean age at diagnosis was 9.6 years. ABC involved the humerus in 30 cases (54%), tibia in 7 (13%) and femur in 5 (9%). Mean follow-up was 50.9 months (range, 16-117 months). Mean number of applications was 1.7 (range, 1-4). Results were assessed clinically (pain, return to sport, limb length and alignment, revision surgery) and radiologically. The main endpoint was lesion volume reduction. The secondary endpoint was failure, defined by open revision surgery or pain preventing return to a sports activity.

RESULTS

Clinical progression was favorable in 36 patients (67%), and radiological progression in 45 (85%). Only 1 cyst required secondary resection. One patient experienced spontaneously resolving intraoperative bradycardia. Male gender and young age emerged as factors for poorer response.

DISCUSSION

ABC management in children can be made difficult by lesion size, aggressiveness, location, proximity to the growth plate and small bone stock. Alcohol-based sclerotherapy is simple, reliable and effective in childhood ABC, and may be a first-line attitude, avoiding recourse to invasive surgery.

LEVEL OF EVIDENCE

IV, retrospective study.

Aneurysmal bone cyst of thoracic spine with neurological deficit and its recurrence treated with multimodal intervention - A case report

Background:

Aneurysmal bone cysts (ABCs) are rare, representing about 1% of primary bone tumors, and 15% of all primary spine/sacral tumors. Notably, when they are located in poorly accessible regions such as the spine and pelvis, their management may be challenging. Treatment options include selective arterial embolization (SAE), curettage, en bloc excision with reconstruction, and radiotherapy.

Case Description:

A 16-year-old male presented with 2 months of mid back pain, left-sided thoracic radiculopathy, and left lower limb weakness (MRC – 3/5). MR imaging revealed an expansile, lytic lesion involving the T9 vertebral body, and the left-sided posterior elements resulting in cord compression. He underwent SAE followed by intralesional excision, bone grafting, and a cage – instrumented fusion. ABC was diagnosed from the biopsy sample. Postoperatively, the pain was reduced, and he was neurologically intact. Five months later, he presented with a new lesion that was treated with repeated SAE and three doses of zoledronic acid. At the end of 2 years, the subsequent, MRI and CT studies documented new bone formation in the lytic areas, with healing of lesion; additionally, he clinically demonstrated sustained pain relief.

Conclusion:

Here, we emphasized the importance of surgery for patients with ABC who develop focal neurological deficits. Treatment options should include SAE with bisphosphonate therapy for lesions that recur without neurological involvement.

Bisphosphonates in common pediatric and adult bone sarcomas

The therapeutic strategies proposed currently for bone sarcomas are based on neo-adjuvant chemotherapy, delayed en-bloc wide resection, and adjuvant chemotherapy. Unfortunately, bone sarcomas are characterized by high rates of poor drug response, with a high risk of drug resistance, local recurrence and/or a high propensity for induced metastases. The pathogenesis of bone sarcomas is strongly associated with dysregulation of local bone remodeling and increased osteolysis that plays a part in tumor development. In this context, bisphosphonates (BPs) have been proposed as a single agent or in combination with conventional drugs to block bone resorption and the vicious cycle established between bone and sarcoma cells. Pre-clinical in vitro studies revealed the potential "anti-tumor" activities of nitrogen-bisphosphonates (N-BPs). In pre-clinical models, N-BPs reduced significantly primary tumor growth in osteosarcoma and Ewing sarcoma, and the installation of lung metastases. In chondrosarcoma, N-BPs reduced the recurrence of local tumors after intralesional curettage, and increased overall survival. In pediatric and adult osteosarcoma patients, N-BPs have been assessed in combination with conventional chemotherapy and surgery in randomized phase 3 studies with no improvement in clinical outcome. The lack of benefit may potentially be explained by the biological impact of N-BPs on macrophage differentiation/recruitment which may alter CD8⁺-T lymphocyte infiltration. Thanks to their considerable affinity for the mineralized extracellular matrix, BPs are an excellent platform for drug delivery in malignant bone sites with reduced systemic toxicity, which opens up new opportunities for their future use.

Do Bisphosphonates Alleviate Pain in Children? A Systematic Review

PURPOSE OF REVIEW

The goal of this systematic review is to analyze the effectiveness of bisphosphonates (BPs) to treat bone pain in children and adolescents who have diseases with skeletal involvement.

RECENT FINDINGS

We included 24 studies (2 randomized controlled trials, 3 non-randomized controlled trials, 10 non-randomized open-label uncontrolled studies, 8 retrospective studies, and 1 study with design not specified). The majority of included studies assessed pain from a unidimensional approach, with pain intensity the most frequently evaluated dimension. Only 38% of studies used validated tools; visual analogue scale was the most frequently employed. BPs were used to alleviate bone pain in a wide variety of pediatrics conditions such as osteogenesis imperfecta, secondary osteoporosis, osteonecrosis related to chemotherapy, chronic non-bacterial osteitis, idiopathic juvenile osteoporosis, unresectable benign bone tumor, and cancer-related pain. Twenty of the 24 studies reported a positive effect of BPs for alleviating pain in different pathologies, but 58% of the studies were categorized as having high risk of bias. Intravenous BPs are helpful in alleviating bone pain in children and adolescents. It is advised that our results be interpreted with caution due to the heterogeneity of the doses used, duration of treatments, and types of pathologies included. In addition, this review shows the paucity of high-quality evidence in the available literature and further research is needed.

TRIAL REGISTRATION

Before the completion of this review, the protocol was registered to PROSPERO (International prospective register of systematic reviews), PROSPERO 2020 ID # CRD42020158316. Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020158316.

Spinal Aneurysmal Bone Cysts (ABCs): Optimal Management

Aim

To review the published literature on the treatment of aneurysmal bone cysts (ABCs).

Method

A systematic review of the English literature to April 2019 for all articles, with a minimum of three patients and 2-year follow-up, reporting on the treatment of spinal ABCs. The various treatment options were compared for the rates of recurrence, complications and mortality.

Results

Twenty-one articles and 272 patients (mean age 16.9 years, range 3–67) were included in this review. The overall recurrence rate for ABCs following all treatments is 12.8%. This is highest in those lesions described as being treated with isolated surgiflo injection into the lesion (100%), decompression/laminectomy (42.3%), partial excision/resection (35.7%) and curettage alone (25.0%). Radiotherapy alone or in conjunction with operative intervention offers excellent cure rates. Adjuncts to operative intervention, including cryotherapy or phenol reduce the recurrence rates, whereas embolization does not. The most common complications are persistent neurological deficits, spinal deformity, and continued pain. The overall mortality rates are low (1.5%). The reoperation rates are higher in surgical than non-surgical treatments and most are performed for progressive deformity.

Discussion

ABCs are highly radiosensitive. However, with the unknown longer-term risk of radiotherapy, surgical treatments, ideally with complete resection, and the use of adjunctive therapies such as cryotherapy or phenol, offer the best chance of cure. SAE is a useful adjunct to reduce intraoperative bleeding, but this study suggests that it only modestly improves recurrence rates. Newer techniques including bisphosphonate and doxycycline administration offer potential benefits, but their efficacy requires further investigation.

Symptomatic aneurysmal bone cysts of the spine: clinical features, surgical outcomes, and prognostic factors

PURPOSE

The aim of the study was to report the long-term outcomes and analyze the potential prognostic factors that may contribute to symptomatic patients with aneurysmal bone cyst (ABC) of the spine undergoing surgical treatments.

METHODS

A retrospective analysis of consecutive patients with ABCs of the spine was performed. The clinical features were reviewed, and the disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method. Factors with p values ≤ 0.05 were subjected to multivariate analysis by Cox proportional hazards model to identify the independent prognostic contributors. p values < 0.05 were considered statistically significant.

RESULTS

A total of 42 patients with ABCs of the spine were included in the study. All patients received surgical treatments. The mean follow-up period was 41.3 months (median 39.5, range 24-64). Local recurrence was detected in eight patients after surgery in our center, whereas death occurred in three patients. The estimated 5-year DFS and OS rate was 54.1% and 76.8%, respectively. The statistical analyses indicated that both en bloc resection and primary/secondary tumor status were independent prognostic factors for DFS.

CONCLUSIONS

Secondary ABC status may be associated with worse prognosis, and en bloc resection remains the treatment of choice for ABCs with neurologic deficits or spinal instability of the spine, which is correlated with better prognosis for local tumor control. These slides can be retrieved under Electronic Supplementary Material.