Zoledronic acid-loaded bone cement as a local adjuvant therapy for giant cell tumor of the sacrum after intralesional curettage

Zoledronic Acid Supplementation With Excision of a Giant Cell Tumor of the Distal End Radius to Prevent Recurrence: A Case Report

Giant cell tumors are benign yet locally aggressive neoplasms commonly observed in the distal radius, exhibiting higher recurrence rates compared to other tumor types. This study presents a case involving a 50-year-old farmer who presented with swelling at the distal end of his wrist. The patient underwent treatment involving intralesional curettage and supplementation with zoledronic acid, resulting in a significant reduction in the tumor's potential for recurrence. This approach aims to achieve an optimal balance between functional outcomes and disease management in the majority of cases. While this strategy proves effective in most instances, there may be scenarios where resection becomes imperative due to the severity of the disease, ensuring adequate disease clearance. In such circumstances, judicious decision-making coupled with an appropriate treatment plan is crucial to guarantee a satisfactory outcome, even in the face of challenges.

Treatment of pelvic giant cell tumor by wide resection with patient-specific bone-cutting guide and reconstruction with 3D-printed personalized implant

BACKGROUND

This study reports our experience in the treatment of aggressive pelvic GCT through wide resection assisted with patient-specific bone-cutting guides (PSBCGs) and subsequent reconstruction with 3D-printed personalized implants (3DPIs), aiming to present the operative technique of this method and evaluate its clinical efficacy.

METHODS

We retrospectively analyzed seven patients who underwent wide resection of pelvic GCT followed by reconstruction with 3DPIs from August 2019 to February 2021. There were two males and five females, with a mean age of 43 years. PSBCGs and 3DPIs were prepared using 3D-printing technology. The operational outcomes, local recurrence, radiological results, and any associated complications of this technique were assessed. And the functional outcomes were assessed according to the Musculoskeletal Tumor Society (MSTS) 93 functional score.

RESULTS

The mean follow-up time was 35.3 months (range 28-45 months). There was no intraoperative complication. Negative surgical margins were achieved in all patients. Postoperative pelvic radiographs showed that 3DPIs matched the shape and size of the bone defect. The anterior-posterior, inlet, and outlet pelvic radiograph demonstrated precise reconstruction consistent with the surgical planning. In addition, tomosynthesis-Shimadzu metal artifact reduction technology (T-SMART) showed good osseointegration at an average of three months after surgery (range 2-4 months). There was no local recurrence or tumor metastasis. The average MSTS score was 24.4 (range 23-27) at the last follow-up. Delayed wound healing was observed in one patient, and the wounds healed after debridement. Prosthesis-related complications were not detected during the follow-up, such as aseptic loosening or structure failure.

CONCLUSIONS

The treatment of aggressive pelvic GCTs through wide resection assisted with PSBCGs and subsequent reconstruction with 3DPIs is a feasible method, which provides good clinical results and reasonable functional outcomes.

Effect of bisphosphonates on bone giant cell tumor recurrence: a meta-analysis

Background

We examined the impact of bisphosphonates as adjuvant therapy on the recurrence of giant cell bone tumors and the impact of various tumor stages and surgical techniques on this effect. Following a thorough examination of the literature up to January 2022, 10 studies including 601 adults with giant cell tumors of the bone were reported; 295 of these subjects received bisphosphonates as adjuvant therapy following surgery, and 306 served as the control group. To examine the possibility of lowering the recurrence of giant cell bone tumors, a comparison between bisphosphonates and a control group was made. In order to evaluate the impact of bisphosphonates as adjuvant therapy on the recurrence of the giant cell bone tumor, odds ratios (OR) with 95% confidence intervals (CIs) were determined. Additionally, the dichotomous technique with a random or fixed-effect model was used to examine the effects of various tumor stages and pertinent surgical procedures.

Results

Patients with giant cell tumors of the bone who received bisphosphonates as adjuvant therapy had significantly lower postoperative recurrence rates outcomes in all subjects with giant cell tumor of bone (OR 0.19; 95% CI 0.12–0.31, p = 0.001), patients with stage I–II giant cell tumors of the bone (OR 0.29; 95% CI 0.11–0.76, p = 0.01), patients with stage III giant cell tumors of the bone (OR 0.17; 95% CI 0.07–0.42, p < 0.001); and post-intralesional curettage (OR 0.18; 95% CI 0.06–0.49, p < 0.001) compared to control. Bisphosphonates were used in participants with giant cell tumors of the bone after broad excision, but there was no discernible difference between the two groups in terms of postoperative recurrence outcomes (OR 0.66; 95% CI 0.11–3.91, p = 0.65).

Conclusions

In patients with giant cell tumors of the bone after intralesional curettage, the use of bisphosphonates as adjuvant therapy may lower the incidence of postoperative recurrence outcomes, but no appreciable difference was identified after extensive resection. According to the observed relationship, using bisphosphonates is advised to lower the likelihood of postoperative recurrence that can happen in patients with giant cell tumors of the bone.

Resultados da curetagem estendida com e sem aloenxerto ósseo para tumores de células gigantes de grau II no joelho. Um estudo comparativo retrospectivo

Objetivo Este é o primeiro estudo a estabelecer a utilidade da curetagem estendida com ou sem enxerto ósseo em tumores de células gigantes (TCGs) de grau II na articulação do joelho com o objetivo de explorar os resultados funcionais pós-operatórios.

Métodos Revisamos retrospectivamente 25 casos de TCGs de grau II de Campanacci submetidos a curetagem estendida entre janeiro de 2014 e dezembro de 2019. Os participantes foram divididos em 2 grupos: um grupo de 12 pacientes foi submetido a curetagem estendida com aloenxerto ósseo e cimento ósseo, enquanto o outro grupo, com 13 pacientes, foi submetido a curetagem estendida apenas com cimento ósseo. A qualidade de vida foi avaliada pela Pontuação Revista da Musculoskeletal Tumor Society (MTS, na sigla em inglês) e pela Pontuação da Knee Society (KS, na sigla em inglês), enquanto as taxas de recidiva e complicações foram avaliadas em cada coorte na última consulta de acompanhamento. O teste de Fisher e os testes t de duas amostras foram usados para comparação de resultados categóricos e contínuos, respectivamente

Resultados A média de idade dos pacientes foi de 28,09 (7,44) anos; 10 (40%) pacientes eram do sexo masculino e 15 (60%) pacientes eram do sexo feminino. O fêmur distal e a tíbia proximal foram acometidos em 13 (52%) e 12 (48%) dos pacientes, respectivamente. Não houve diferença significativa na pontuação revista da MTS (25,75 versus 27,41; p = 0,178), na pontuação da KS (78,67 versus 81,46; p = 0,33) e nas taxas de recidiva (0 versus 0%; p = 1) e complicações (25 versus 7,69%; p = 0,21).

Conclusões A curetagem estendida com ou sem aloenxerto ósseo tem resultados funcionais semelhantes em pacientes com TCGs de grau II no joelho, sem qualquer diferença importante na incidência de recidivas e complicações. No entanto, a conveniência cirúrgica e o custo-benefício podem favorecer a utilização apenas de cimento ósseo, enquanto a prevenção da osteoartrite em longo prazo precisa ser investigada para favorecer o enxerto ósseo.

Intralesional nerve-sparing surgery versus non-surgical treatment for giant cell tumor of the sacrum

Background

There is no standard treatment for giant cell tumors of the sacrum. We compared the outcomes and complications in patients with sacral giant cell tumors who underwent intralesional nerve-sparing surgery with or without (neo-) adjuvant therapies versus those who underwent non-surgical treatment (denosumab therapy and/or embolization).

Methods

We retrospectively investigated 15 cases of sacral giant cell tumors treated at two institutions between 2005 and 2020. Nine patients underwent intralesional nerve-sparing surgery with or without (neo-) adjuvant therapies, and six patients received non-surgical treatment. The mean follow-up period was 85 months for the surgical group (range, 25–154 months) and 59 months (range, 17–94 months) for the non-surgical group.

Results

The local recurrence rate was 44% in the surgical group, and the tumor progression rate was 0% in the non-surgical group. There were two surgery-related complications (infection and bladder laceration) and three denosumab-related complications (apical granuloma of the tooth, stress fracture of the sacroiliac joint, and osteonecrosis of the jaw). In the surgical group, the mean modified Biagini score (bowel, bladder, and motor function) was 0.9; in the non-surgical group, it was 0.5. None of the 11 female patients became pregnant or delivered a baby after developing a sacral giant cell tumor.

Conclusions

The cure rate of intralesional nerve-sparing surgery is over 50%. Non-surgical treatment has a similar risk of complications to intralesional nerve-sparing surgery and has better functional outcomes than intralesional nerve-sparing surgery, but patients must remain on therapy over time. Based on our results, the decision on the choice of treatment for sacral giant cell tumors could be discussed between the surgeon and the patient based on the tumor size and location.

Role of Zoledronic Acid Supplementation in Reducing Post-Surgical Recurrence of Giant Cell Tumor of Bone: A Meta-Analysis of Comparative Studies

Zoledronic acid is a bisphosphonate that has recently gained interest in adjuvant therapy for giant cell tumor of bone (GCTB). It has an apoptotic effect on osteoclasts that are precursors of GCTB. However, the evidence suggesting the role of zoledronic acid in preventing GCTB recurrence is mixed, and therefore, a consensus is yet to be established. The purpose of the current meta-analysis was to analyze the impact of zoledronic acid supplementation on tumor recurrence in surgical treated GCTB.

A systematic search was conducted on PubMed, Embase, and Web of Science databases to identify studies that analyzed the impact of local or systemic zoledronic acid supplementation on clinical outcomes in surgically treated GCTB. The data from the comparative studies were pooled and analyzed to investigate the association of zoledronic acid supplementation with tumor recurrence. Additionally, other factors such as age, gender, soft tissue extension, polymethyl methacrylate (PMMA) cement application, recurrent presentation, and extended curettage were also investigated for any association with tumor recurrence.

Of the 271 results, 13 unique studies reported the clinical outcomes in GCTB. Seven studies compared the outcomes of zoledronic acid supplementation with control groups. Six studies presented the tumor recurrence-related data among the comparison groups. The zoledronic acid supplementation was associated with significantly lower tumor recurrence rates (p = 0.007). Additionally, a significant association of soft tissue extension and non-usage of PMMA cement with tumor recurrence were observed.

The current meta-analysis suggests that zoledronic acid supplementation reduces tumor recurrence rates in surgically treated GCTB. We, therefore, recommend the use of zoledronic acid following aggressive extended curettage of the tumor. Further, well-planned randomized controlled trials will help strengthen this evidence.

Combination of Melatonin and Zoledronic Acid Suppressed the Giant Cell Tumor of Bone in vitro and in vivo

Melatonin (Mlt) confers potential antitumor effects in various types of cancer. However, to the best of our knowledge, the role of Mlt in the giant cell tumor of bone (GCTB) remains unknown. Moreover, further research is required to assess whether Mlt can enhance the therapeutic effect of zoledronic acid (Zol), a commonly used anti-GCTB drug. In this research, we investigated the effects of Mlt, Zol, and the combination of these two drugs on GCTB cells’ characteristics, including cell proliferation, apoptosis, osteogenic differentiation, migration, and invasion. The cell counting kit-8 (CCK-8) assay, colony formation assay, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay (TUNEL), alkaline phosphatase (ALP) staining, alizarin red staining (ARS), scratch wound healing assay, and transwell experiment were performed, respectively. Our results showed that Mlt could effectively inhibit the proliferation, migration, and invasion of GCTB cells, as well as promote the apoptosis and osteogenic differentiation of tumor cells. Of note, a stronger antitumor effect was observed when Mlt was combined with Zol treatment. This therapeutic effect might be achieved by inhibiting the activation of both the Hippo and NF-κB pathways. In conclusion, our study suggests that Mlt can be a new treatment for GCTB, which could further enhance the antitumor effect of Zol.

Current Concepts in the Treatment of Giant Cell Tumors of Bone

Simple Summary

According to the 2020 World Health Organization classification, a giant cell tumor of bone is an intermediate malignant bone tumor. Denosumab treatment before curettage should be avoided due to the increased risk of local recurrence. Administration of denosumab before en bloc resection of the giant cell tumors of the pelvis and spine facilitates en bloc resection. Nerve-sparing surgery after embolization is a possible treatment for giant cell tumors of the sacrum. Denosumab therapy with or without embolization is indicated for inoperable giant cell tumors of the pelvis, spine, and sacrum. A wait-and-see approach is recommended for lung metastases at first, then denosumab should be administered to the growing lesions. Radiotherapy is not recommended owing to the risk of malignant transformation. Local recurrence after 2 years or more should be indicative of malignant transformation. This review summarizes the treatment approaches for non-malignant and malignant giant cell tumors of bone.

Abstract

The 2020 World Health Organization classification defined giant cell tumors of bone (GCTBs) as intermediate malignant tumors. Since the mutated H3F3A was found to be a specific marker for GCTB, it has become very useful in diagnosing GCTB. Curettage is the most common treatment for GCTBs. Preoperative administration of denosumab makes curettage difficult and increases the risk of local recurrence. Curettage is recommended to achieve good functional outcomes, even for local recurrence. For pathological fractures, joints should be preserved as much as possible and curettage should be attempted. Preoperative administration of denosumab for pelvic and spinal GCTBs reduces extraosseous lesions, hardens the tumor, and facilitates en bloc resection. Nerve-sparing surgery after embolization is a possible treatment for sacral GCTBS. Denosumab therapy with or without embolization is indicated for inoperable pelvic, spinal, and sacral GCTBs. It is recommended to first observe lung metastases, then administer denosumab for growing lesions. Radiotherapy is associated with a risk of malignant transformation and should be limited to cases where surgery is impossible and denosumab, zoledronic acid, or embolization is not available. Local recurrence after 2 years or more should be indicative of malignant transformation. This review summarizes the treatment approaches for non-malignant and malignant GCTBs.

The current standing on the use of denosumab in giant cell tumour of the bone

Giant cell tumour of the bone (GCTB) has been classically treated surgically. With the advent of denosumab, there is potential to use it as a targeted therapy to downstage the tumour and control its progression. Like all new therapies, the dosage, duration, and long-term effects of treatment can only be determined over the time through numerous trials and errors. The current recommendation of use of the monoclonal antibody is 3-4 months of neoadjuvant denosumab in patients with advanced GCTB for cases who were not candidates for primary curettage initially, and prolonged use for surgically unsalvageable GCTB. The use of Denosumab in the adjuvant setting to prevent recurrence is not established.

Current concepts in the treatment of giant cell tumour of bone

PURPOSE OF REVIEW

Giant cell tumour of bone (GCTB) is an intermediate, locally aggressive primary bone tumour. In addition to local therapy, new drugs became available for this disease. Denosumab, a receptor activator of nuclear factor κ-B-ligand inhibitor, was introduced as systemic targeted therapy for advanced or inoperable and metastatic GCTB. Also, the bisphosphonate zoledronic acid has activity in GCTB by directly targeting the neoplastic stromal cells.

RECENT FINDINGS

In a small RCT, bisphosphonates were successful in controlling tumour growth and a higher apoptotic index of tumour cells was seen after zoledronic acid versus controls. Although bisphosphonate-loaded bone cement has not been studied to a large extent, it does not seem harmful and may constitute a logical local adjuvant. From the largest clinical trial to date, the risk-to-benefit ratio for denosumab in patients with advanced GCTB remains favourable, also in facilitating less morbid surgery. Concerns have arisen that recurrence rates would be higher than after conventional treatment, ranging from 20 to 100% in a systematic review, although this may be because of bias. H3F3A (G34W) driver mutations are helpful in the differentiation between GCTB and other giant cell-containing malignancies. H3.3-G34W proved sufficient to drive tumourigenesis. The cumulative incidence of malignancy in GCTB is estimated at 4%, of which primary malignancy 1.6% and secondary malignancy 2.4%, the latter mainly after radiation. To date, a potential causal relationship between denosumab and pulmonary metastases has not been confirmed; if they do not behave indolently, it would be advised to reassess diagnosis and consider malignancy.

SUMMARY

Denosumab remains a highly effective treatment option for patients with advanced GCTB. A short duration of 2-4 months neoadjuvant denosumab is advised to facilitate less morbid surgery and prevent incomplete curettage by macroscopic tumour alterations. Reduced dose intensity is being studied to reduce long term side-effects. Further research on bisphosphonates and other targets including H3.3-G34W remains warranted.

Adjuvant Zoledronic Acid in High-Risk Giant Cell Tumor of Bone: A Multicenter Randomized Phase II Trial

Lessons Learned.

Adjuvant treatment with zoledronic acid did not decrease the recurrence rate of giant cell tumor of bone (GCTB) in this study. The efficacy could not be determined because of the small sample size.

GCTB recurrences, even in the denosumab era, are still an issue; therefore, a randomized study exploring the efficacy of zoledronic acid in the adjuvant setting in GCTB is still valid.

Background.

Bisphosphonates are assumed to inhibit giant cell tumor of bone (GCTB)‐associated osteoclast activity and have an apoptotic effect on the neoplastic mononuclear cell population. The primary objective of this study was to determine the 2‐year recurrence rate of high‐risk GCTB after adjuvant zoledronic acid versus standard care.

Methods.

In this multicenter randomized open‐label phase II trial, patients with high‐risk GCTB were included (December 2008 to October 2013). Recruitment was stopped because of low accrual after the introduction of denosumab. In the intervention group, patients received adjuvant zoledronic acid (4 mg) intravenously at 1, 2, 3, 6, 9, and 12 months after surgery.

Results.

Fourteen patients were included (intervention n = 8, controls n = 6). Median follow‐up was long: 93.5 months (range, 48–111). Overall 2‐year recurrence rate was 38% (3/8) in the intervention versus 17% (1/6) in the control group (p = .58). All recurrences were seen within the first 15 months after surgery.

Conclusion.

Adjuvant treatment with zoledronic acid did not decrease the recurrence rate of GCTB in this study. The efficacy could not be determined because of the small sample size. Because recurrences, even in the denosumab era, are still an issue, a randomized study exploring the efficacy of zoledronic acid in the adjuvant setting in GCTB is still valid.

Effect of bisphosphonates on local recurrence of giant cell tumor of bone: a meta-analysis

Background

Giant cell tumor of bone (GCTB) is a locally aggressive tumor, and its postoperative recurrence remains a problem. The present meta-analysis aimed to analyze the effect of bisphosphonates (BPs) on local recurrence of GCTB.

Methods

Seven case-control studies were included by computerized searches of bibliographic databases (PubMed, AMED, EMBASE, the Cochrane library, ISI Web of Science, and China National Knowledge Infrastructure). The pooled adjusted ORs were calculated to evaluate the local recurrence of GCTB.

Results

The BP group presented significantly lower total local recurrence rate than the control group in GCTB (P<0.01). Subgroup analysis shows BP group presented significantly lower local recurrence than the control group in GCTB with different tumor grades (P<0.05). In patients who underwent intralesional curettage, a significantly lower local recurrence rate was found in the BP group compared with the control group (P<0.01), but no significance was found for patients who underwent wide resection (P=0.16). None of the included studies described severe adverse effects related to BPs.

Conclusion

The results confirmed the effect of BPs on reducing the local recurrence of GCTB, and the effect is not influenced by the tumor grades. BPs are benefit for the patients who underwent intralesional curettage but not recommended for those who underwent wide resection.

Image-Guided Bone Consolidation in Oncology

Occurrence of bone metastases is a common event in oncology. Bone metastases are associated with pain, functional impairment, and fractures, particularly when weight-bearing bones are involved. Management of bone metastases has been improved by the development of various interventional radiology consolidation techniques. Cementoplasty is based on injection of acrylic cement into a weakened bone to reinforce it and to control pain. This minimally invasive technique has proven its efficacy for flat bone submitted to compression forces. However, resistance to torsion forces is limited and, thus, treatment of long bones should be considered with caution. In recent years, variant techniques of percutaneous bone consolidation have emerged, including expansion devices for vertebral augmentation and percutaneous screw fixation for pelvic bone and proximal femur tumors. Research projects are ongoing to develop drug-loaded cements to use them as therapeutic vectors. However, release of drugs is still poorly controlled and conventional polymethylmethacrylate cement remains the gold standard in oncology. Image-guided consolidation techniques enhance the array of treatments in bone oncology. Multidisciplinary approach is mandatory to select the best indications.

Minimally effective concentration of zoledronic acid to suppress osteoclasts in vitro

Zoledronic acid is regarded as the most potent bisphosphonate and is widely used in patients with osteoporosis; however, its side effects, including acute-phase reactions, gastrointestinal complaints, renal dysfunction and bisphosphonate-associated osteonecrosis impair the safety and quality of life of patients. The present study was designed to determine the minimal effective concentration of zoledronic acid through testing the dose-dependent effects of zoledronic acid on osteoclast suppression. A primary culture of bone marrow mononuclear cells obtained from C57 mice (age, 6 weeks) was established and induced to form osteoclasts. The number of multinuclear cells was determined by tartrate-resistant acid phosphatase staining and compared among cultured marrow cells treated with different concentrations of zoledronic acid. Furthermore, the cellular properties, including adhesion, migration and bone resorption, were compared at the minimal effective concentration. At a concentration of 1×10⁻⁶ mol/l, zoledronic acid significantly inhibited the formation of osteoclasts. This inhibitory effect was further enhanced at the concentration of 1×10⁻⁵ mol/l. However, the inhibitory effect of zoledronic acid tapered at the concentration of 1×10⁻⁴ mol/l and there was no further dose-dependent increase. In addition, the concentration of 1×10⁻⁶ mol/l was sufficient to alter cellular functions, including cell adhesion, migration and bone resorption. In conclusion, zoledronic acid was effective in reducing osteoclast formation and suppressing cellular functions. The minimal effective concentration of zoledronic acid in vitro was 1 µmol/l. Based on these results, a comparable dosage should be explored in clinical applications.

High-activity chitosan/nano hydroxyapatite/zoledronic acid scaffolds for simultaneous tumor inhibition, bone repair and infection eradication

Implanted biomaterials combined tumor inhibition and bone repair property are urgently needed to address the huge bone destruction and the high local recurrence following primary surgery in bone tumor therapy. In this work, a high-activity chitosan/nano hydroxyapatite (CS/nHA) scaffold containing zoledronic acid (CS/nHA/Zol) was prepared with a facile method. The prepared CS/nHA/Zol scaffolds exhibited excellent tumor inhibition property towards giant cell tumor of bone (GCT) in vitro through inducing cells apoptosis by up-regulating pro-apoptosis genes expression and reducing the osteoclastic activity of tumor cells by down-regulating osteoclastic genes. Meanwhile, the prepared scaffolds possessed well biocompatibility and osteoinductivity as compared to pure CS/nHA scaffolds. Furthermore, the prepared scaffolds also presented outstanding antibacterial activity against clinical pathogenic S. aureus and E. coli. These overall findings successfully demonstrated the prepared CS/nHA/Zol scaffolds had a multifunction of tumor therapy, bone repair, and antibacterium, which provides a new approach possessed promising advantages in bone tumor therapy.

Giant cell tumour of bone in the denosumab era

Giant cell tumour of bone (GCTB) is an intermediate locally aggressive primary bone tumour, occurring mostly at the meta-epiphysis of long bones. Overexpression of receptor activator of nuclear factor kappa-B ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated osteoclast-like giant cells, causing lacunar bone resorption. Preferential treatment is curettage with local adjuvants such as phenol, alcohol or liquid nitrogen. The remaining cavity may be filled with bone graft or polymethylmethacrylate (PMMA) bone cement; benefits of the latter are a lower risk of recurrence, possibility of direct weight bearing and early radiographic detection of recurrences. Reported recurrence rates are comparable for the different local adjuvants (27-31%). Factors increasing the local recurrence risk include soft tissue extension and anatomically difficult localisations such as the sacrum. When joint salvage is impossible, en-bloc resection and endoprosthetic joint replacement may be performed. Local tumour control on the one hand and maintenance of a functional native joint and quality of life on the other hand are the main pillars of surgical treatment for this disease. Current knowledge and development in the fields of imaging, functional biology and systemic therapy are forcing us into a paradigm shift from a purely surgical approach towards a multidisciplinary approach. Systemic therapy with denosumab (RANKL inhibitor) or zoledronic acid (bisphosphonates) blocks, respectively inhibits, bone resorption by osteoclast-like giant cells. After use of zoledronic acid, stabilisation of local and metastatic disease has been reported, although the level of evidence is low. Denosumab is more extensively studied in two prospective trials, and appears effective for the optimisation of surgical treatment. Denosumab should be considered in the standard multidisciplinary treatment of advanced GCTB (e.g. cortical destruction, soft tissue extension, joint involvement or sacral localisation) to facilitate surgery at a later stage, and thereby aiming at immediate local control. Even though several questions concerning optimal treatment dose, duration and interval and drug safety remain unanswered, denosumab is among the most effective drug therapies in oncology.

Benign Tumors of the Spine: Has New Chemotherapy and Interventional Radiology Changed the Treatment Paradigm?

STUDY DESIGN

Clinically based systematic review.

OBJECTIVE

To determine the role of (A) medical treatment and (B) interventional radiology as either adjuvant or stand-alone treatment in primary benign bone tumors of the spine.

METHODS

A multidisciplinary panel of spine surgeons, radiation oncologists, and medical oncologists elaborated specific focused questions regarding aneurysmal bone cyst, giant cell tumor, and osteoid osteoma. Denosumab, bisphosphonate, interferon, bone marrow aspirate, doxycycline, thermal ablation, and selective arterial embolization were identified as areas of interest for the article. A systematic review was performed through MEDLINE and EMBASE. Recommendations based on the literature review and clinical expertise were issued using the GRADE system.

RESULTS

The overall quality of the literature is very low with few multicenter prospective studies. For giant cell tumor, combination with Denosumab identified 14 pertinent articles with four multicenter prospective studies. Nine studies were found on bisphosphonates and six for selective arterial embolization. The search on aneurysmal bone cyst and selective arterial embolization revealed 12 articles. Combination with Denosumab, Doxycycline, and bone marrow aspirate identified four, two, and three relevant articles respectively. Eleven focused articles were selected on the role of thermal ablation in osteoid osteoma.

CONCLUSION

Alternative and adjuvant therapy for primary benign bone tumors have emerged. Their ability to complement or replace surgery is now being scrutinized and they may impact significantly the algorithm of treatment of these tumors. Most of the data are still emerging and further research is desirable. Close collaboration between the different specialists managing these pathologies is crucial.

LEVEL OF EVIDENCE

N/A.