Preoperative Denosumab may increase the Risk of Local Recurrence of Giant-cell Tumor of Bone Treated with Curettage: A Systematic Review and Meta-analysis

Management of Extensive Buccosinusal and Bucconasal Communications After Maxillary Giant Cell Tumor Resection Using the Cortical Bone Lamina Technique: A Case Report

Giant cell tumors are rare, locally aggressive non-odontogenic osteolytic tumors associated with high rates of local recurrence. Treatment modalities are subject to considerable controversy, with successful outcomes hinging on achieving complete tumor elimination through thorough curettage. A 78-year-old male referred in December 2023 for a persistent mucosal lesion in the right maxilla under a removable denture. Clinical examination revealed a well-defined erythematous nodular lesion measuring approximately 3 cm along its long axis, localized on ridge quadrant 1. Biopsy confirmed the diagnosis of giant cell tumor. Although complete resection with healthy margins may be justified for aggressive lesions, it often results in significant morbidity and requires immediate defect reconstruction. Some studies suggest favorable long-term outcomes with guided bone regeneration (GBR). The bone lamina technique uses a xenogeneic cortical bone membrane to maintain space and promote bone healing. This surgical approach promotes bone healing through the mechanical support and biological properties of the lamina. The purpose of this case report is to evaluate the efficacy of the bone lamina technique and its role in managing complications following giant cell tumor resection.

Denosumab Induces Neoplastic Stromal Cell Apoptosis Via p62 Downregulation Dependent on Autophagy Pathway in Giant Cell Tumour of Bone

BACKGROUND

As the only humanized monoclonal antibody against receptor activator of nuclear factor-κB ligand (RANKL) for giant cell tumour of bone (GCTB) therapy, denosumab has limited antitumour effect on neoplastic stromal cells. Nevertheless, its mechanism of action has not yet been clarified. A previous study has revealed that p62 may play an important role in the antitumour activity of denosumab.

OBJECTIVE

The study aimed to investigate if the mechanism by which denosumab inhibits GCTB neoplastic stromal cells growth is via p62 modulation and other related mechanisms.

METHODS

p62 expression before and after denosumab therapy was analysed by RT‒qPCR, western blot, ELISA, and immunohistochemical assays. Two primary neoplastic stromal cells were isolated from fresh GCTB tumour tissue (L cell) and metastatic tissue (M cell). Cell proliferation, migration, apoptosis, and autophagy were investigated in p62 knockdown neoplastic stromal cells transfected by short hairpin RNA lentivirus in vitro. Tumor growth was evaluated in the chick chorioallantoic membrane model in vivo.

RESULTS

p62 expression was found to be downregulated following denosumab therapy. The patients with a decrease in p62 expression had lower recurrence-free survival rates. The proliferation of M cells was not inhibited by denosumab therapy, but it was restored by p62 knockdown. Moreover, p62 knockdown inhibited tumour growth in vivo. Denosumab induced M cell apoptosis and arrested the cell cycle at the G1/G0 transition and these effects were also enhanced by p62 knockdown. Autophagic flux assays revealed p62 modulation to be dependent on autophagy following denosumab incubation.

CONCLUSION

Denosumab induced neoplastic stromal cells apoptosis via p62 downregulation dependent on autophagy pathway. The combination of p62 and RANKL knockdown might be a better strategy than RANKL knockdown alone for GCTB targeted therapy.

Denosumab for giant cell tumors of bone from 2010 to 2022: a bibliometric analysis

Giant cell tumors of the bone (GCTB) are considered moderately malignant bone tumors. Denosumab, as a neoadjuvant therapy, provides new possibilities for treating GCTB. However, even after multiple studies and long-term clinical trials, there are limitations in the treatment process. Research data and Medical Subject Headings terms related to denosumab and GCTB were collected from January 2010 to October 2022 using the Web of Science and MeSH ( https://meshb.nlm.nih.gov ) browsers. These data were imported into CiteSpace and VOSviewer softwares for bibliometric analysis. Overall, 445 publications on denosumab and GCTB were identified. Over the last 12 years, the growth rate of the total number of publications has remained relatively stable. The USA published the highest number of articles (83) and had the highest centrality (0.42). Amgen Inc. and Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) First Ortoped Rizzoli were identified as the most influential institutions. Many authors have made outstanding contributions to this field. Lancet Oncology had the highest journal impact factor (54.433). Local recurrence and drug dosage are current research hotspots, and future development trends will mainly focus on prognostic markers of GCTB and the development of new therapies. Further research is required to analyze denosumab's safety and efficacy and understand its local recurrence of GCTB, to identify the optimal dose. Future progress in this field will likely focus on exploring new diagnostic and recurrence markers to monitor disease progression and examine new therapeutic targets and treatment strategies.

Management of a rare mandibular giant cell tumor of bone by neoadjuvant denosumab therapy and surgery: A 4-year follow-up case report

INTRODUCTION

Giant cell tumor of bone (GCTB) is a very rare tumor encountered in the jaws and its histology is quite similar to the more common giant cell granuloma of the jaws (GCGJ). These two entities can be easily confused in maxillofacial region. They are classically managed surgically, but in some localizations and in specific medical-surgical contexts, neoadjuvant therapy with denosumab may be indicated. This report tends to reinforce existing evidence in favor of the use of a neoadjuvant approach, particularly for localization of GCTB in the orofacial region.

PRESENTATION OF CASE

This is a 57-year-old female patient, an alcoholic smoker, in whom a voluminous mandibular radiolucent lesion was discovered during a routine X-ray by her dentist. After medical imaging assessment and incisional biopsy, diagnosis of GCTB was established. A neoadjuvant denosumab therapy was proposed first followed by a secondary surgical curettage. After 4 years' follow-up, complete healing was observed with no recurrence of the lesion.

DISCUSSION

Surgical management of aggressive GCTB is risky particularly in localizations involving the sacrum, spine or craniofacial skeleton with a high residual recurrence rate. The use of denosumab to stop tumor progression and facilitate secondary excision surgery is a recent approach that is now well documented in the literature showing promising results with a low rate of side effects.

CONCLUSION

This case of mandibular GCTB is to our knowledge the unique case described in this localization and treated by denosumab neoadjuvant therapy followed by surgery with a 4-year follow-up showing a complete healing.

'Triple clear': a systematic and comprehensive surgical process for Campanacci grades II and III giant cell tumors of the bone, with or without pathological fracture and slight joint invasion

BACKGROUND

In recent years, researchers have proposed a number of adjuvant methods for extended curettage of giant cell tumors of the bone. However, various schemes have significant differences in efficacy and safety. Therefore, this article will describe an empirical expanded curettage protocol, 'triple clear', in detail to show the effect of the efficient surgical protocol.

METHOD

Patients with Campanacci grades II and III primary GCTB who were treated with either SR (n = 39) or TC (n = 41) were included. Various perioperative clinical indicators, including the therapy modality, operation time, Campanacci grade, and filling material were recorded and compared. The pain level was determined by the visual analog scale. Limb function was determined by the Musculoskeletal Tumour Society (MSTS) score. Follow-up time, recurrence rates, reoperation rates, and complication rates were also recorded and compared.

RESULT

The operation time was 135.7 ± 38.4 min in the TC group and 174.2 ± 43.0 min in the SR group (P < 0.05). The recurrence rates were 7.3% in the TC group and 8.3% in the SR group (P = 0.37). The MSTS scores at three months after surgery were 19.8 ± 1.5 in the TC group and 18.8 ± 1.3 in the SR group. The MSTS scores at two years were 26.2 ± 1.2 in the TC group and 24.3 ± 1.4 in the SR group (P < 0.05).

CONCLUSION

TC is recommended for patients with Campanacci grade II-III GCTB and for those with a pathological fracture or slight joint invasion. Bone grafts may be more suitable than bone cement in the long term.

Progress on Denosumab Use in Giant Cell Tumor of Bone: Dose and Duration of Therapy

Giant cell tumor of bone (GCTB) is an aggressive non-cancerous bone tumor associated with risks of sarcoma and metastasis. Once malignancy occurs, the prognosis is generally poor. Surgery remains the main treatment for GCTB. Multidisciplinary management is a feasible option for patients wherein surgical resection is not an option or for those with serious surgery-related complications. Denosumab is an anti-nuclear factor kappa B ligand approved for the treatment of postmenopausal women with osteoporosis, bone metastases, and advanced or inoperable GCTB. However, the guidelines for treating GCTB are unclear; its short-term efficacy and safety in inoperable patients have been demonstrated. Lengthier therapies (high cumulative doses) or pre-operative adjuvant therapy may be associated with severe complications and high local recurrence rates. Short-term administration helps attain satisfactory local control and functionality. As a result, lately, the impact of different doses and lengths of treatment on the efficacy of denosumab in GCTB treatment, the incidence of complications, and recurrence rates have gained attention. The efficacy and safety of denosumab against GCTB, its impact on imaging assessment, related complications, and recurrence of GCTB were previously reviewed. For further research direction, this paper reviews the progress of studies evaluating the impact of the dose and duration of denosumab therapy for GCTB.

A Retrospective Audit of Demography and Different Surgical Modalities Adopted for Giant Cell Tumor of Bone in Eastern India

Background and objective

There is scarce data on demography and different surgical treatment modalities for giant cell tumor of bone (GCTB) from eastern India. In light of this, the present study aimed to examine the demographic characteristics, different surgical treatment modalities, and recurrence rate of GCTB at a tertiary care institute in Bihar.

Materials and methods

A retrospective audit of 52 GCTB patients who were treated at the center from January 2016 to December 2020 was conducted. The minimum follow-up period was one year. GCTB patients underwent surgical procedures ranging from extended intralesional curettage with bone graft or bone cement with or without fixation to wide local excision to resection with or without reconstruction or amputation depending on the stage and site of the tumors.

Results

The mean age of patients was 31.86 years (range: 13-67 years). The distal femur (20 patients, 38.46%) and proximal tibia (11 patients, 21.15%) were the most common sites of the tumor. Sixty-eight confirmed cases (male: 32, female: 36) of GCTB were operated on, with a male-to-female ratio of 1:1.125. Sixteen patients (four males and 12 females) were lost to follow-up. So, the final study consisted of 52 patients with a median age of 28 years (first quartile: 24 years, third quartile: 38 years). The majority of patients (32 patients, 61.53%) were in the third and fourth decades of life.

Conclusion

Based on this retrospective audit, it is concluded that the knee region is the most common site of GCTB. Surgery is the mainstay of management. Most of the patients came under Campanacci Grade 3 with low compliance with follow-up and adherence to the treatment. Hence, educational programs, the establishment of early detection centers, and timely referral to expert treatment are necessary.

Outcomes in Bone Giant Cell Tumors Treated With Surgical Resection With and Without Denosumab Injection: A Single-Institution Retrospective Study

Background: Giant cell tumors of the bone (GCTB) are rare, benign, aggressive, recurrent tumors that are most often found at the ends of long bones. They account for 5% of all primary bone tumors and 20% of all benign bone tumors. The clinical features of GCTB include local swelling, pain, and limitations in joint movement. Approximately half of GCTB arise around the knee joint, affecting either the distal femur or proximal tibia. Tissue biopsy reveals an excess of multinucleated giant cells on a stromal cell background, indicating a diagnosis. Intralesional curettage is used to treat GCTB and is associated with minimal disability; however, local recurrence may occur in many patients. Resection and endoprosthetic repair or bone graft reconstruction are often used to treat GCTB near the joint. To our knowledge, there are currently no studies on this topic in the city of Jeddah, where we conducted our study. Our aim was to evaluate the outcome of surgical resection accompanied by denosumab injection compared to that of surgery alone in treating GCTB.

Methods: All cases of GCTB at King Abdulaziz Medical City, Jeddah, between January 2008 and December 2018, that fulfilled the inclusion and exclusion criteria were included. All cases of GCTB in the pre-specified period were classified as surgical resection with denosumab injection or surgical resection alone. The outcomes of the two modalities were compared. Recurrence was investigated in patients belonging to both the groups.

Results: Twenty-six cases that met the inclusion criteria were included in the study and the data were analyzed. The subjects were divided into two groups: denosumab and surgery (n = 7) and surgery alone (n = 19). Patients treated with denosumab and surgery had a higher recurrence rate (57%); however, the difference was not significant (p = 0.407).

Conclusion: Our study showed that when comparing local recurrence after curettage in patients treated with denosumab and patients who did not receive it, preoperative denosumab therapy was associated with an increased incidence of local recurrence. We recommend a systematic review that can include more studies in this field to acquire more definitive results regarding this topic.

Updated concepts in treatment of giant cell tumor of bone

PURPOSE OF REVIEW

Giant cell tumors of bone (GCTB) are intermediate, locally aggressive primary bone tumors. For conventional GCTB, surgery remains treatment of choice. For advanced GCTB, a more important role came into play for systemic therapy including denosumab and bisphosphonates over the last decade.

RECENT FINDINGS

In diagnostics, focus has been on H3F3A (G34) driver mutations present in GCTB. The most frequent mutation (G34W) can be detected using immunohistochemistry and is highly specific in differentiating GCTB from other giant cell containing tumors. PD-L1 expression can be used as biological marker to predict higher recurrence risks in GCTB patients.The use of bisphosphonate-loaded bone cement is under investigation in a randomized controlled trial. A new technique consisting of percutaneous microwave ablation and bisphosphonate-loaded polymethylmethacrylate cementoplasty was proposed for unresectable (pelvic) GCTB.Increased experience with use of denosumab raised concern on elevated recurrence rates. However, conclusions of meta-analyses should be interpreted with risk of indication bias in mind. Several small studies are published with short-course denosumab (varying from 3 to 6 doses). One small trial directly compared denosumab and zoledronic acid, with no statistical differences in radiological and clinical outcome, and nonsignificantly higher recurrence rate after denosumab. As bisphosphonates directly target neoplastic stromal cells in GCTB, larger directly comparative trials are still warranted.

SUMMARY

Neoadjuvant denosumab is highly effective for advanced GCTB, and a short-course is advised to facilitate surgery, whereas increased recurrence rates remain of concern. Randomized controlled trials are conducted on bisphosphonate-loaded bone cement and on optimal dose and duration of neoadjuvant denosumab. PD-L1 could be a potential new therapy target in GCTB.

Denosumab in Giant Cell Tumor of Bone: Multidisciplinary Medical Management Based on Pathophysiological Mechanisms and Real-World Evidence

Simple Summary

The widely accepted local therapy in extremity giant cell tumor of bone (GCTB) is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. Most GCTB patients with localized disease can be successfully treated with surgical curettage; patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Abstract

(1) Despite the benign nature of the giant cell tumor of bone (GCTB), it shows a local recurrence rate of up to 50% and a chance of malignant transformation. The widely accepted local therapy in extremity GCTB is surgery, in the form of extended intralesional curettage with adequate disease clearance and retention of the limb, wherever possible. Denosumab, a human monoclonal antibody directed against the RANKL and associated inhibition of the RANKL pathway, is a relevant therapy option for advanced GCTB, to benefit tumor response and surgical down-staging. (2) The literature review of patients with GCTB treated with denosumab is performed via PubMed, using suitable keywords from January 2009 to January 2021. (3) Current indications for denosumab use are not definitively clear and unambiguous. Most GCTB patients with localized disease can be successfully treated with surgical curettage, and the role of denosumab in preoperative therapy in this patient population remains unclear. (4) However, patients with primary unresectable lesions or metastases may experience long-term clinical and radiological remission and pain control with denosumab treatment, and in this clinical situation, denosumab is currently the treatment of choice.

Ultra-Short Course of Neo-Adjuvant Denosumab for Nerve-Sparing Surgery for Giant Cell Tumor of Bone in Sacrum

STUDY DEIGN

This was a retrospective study about sacral giant cell tumor of bone (GCTB).

OBJECTIVE

This study aimed to investigate whether ultra-short course of neo-adjuvant denosumab treatment for sacral GCTB could (1) induce radiological and histological response? (2) Facilitate nerve-sparing surgery? (3) Achieve satisfactory oncological and functional outcomes?

SUMMARY OF BACKGROUND DATA

Previous reports on long course of neo-adjuvant denosumab treatment for GCTB showed significant tumor response and a relatively high recurrent rate after curettage.

METHODS

Sixty-six patients with sacral GCTB treated with neoadjuvant denosumab and nerve-sparing surgery were categorized into ultra-short course group (≤3 doses and operation within D21 since 1st dose, 41 patients) or conventional group (>3 doses or operation after D21 since 1st dose, 25 patients). The radiological and histological response, operative data, oncological and functional outcomes were compared.

RESULTS

The ultra-short course group demonstrated fewer doses of neo-adjuvant denosumab (mean: 2.1 vs. 4.8, P  < 0.001) and shorter time to surgery (12.2 days vs. 72.3 days, P < 0.001). Similar patterns of radiological and histological response were observed in the two groups with less fibrosis and ossification in the ultra-short course group. The operative duration (199.9 min vs. 187.8 min, P = 0.364) and estimated blood loss (1552.4 mL vs. 1474.0 mL, P = 0.740) were comparable. Most (94.8%) of the patients received adjuvant denosumab. After a mean follow-up of 29.4 months, three cases (8.8%) and five cases (20.8%) showed local recurrence in each group (P = 0.255). The estimated recurrence-free survival (56.2 vs. 51.2 months, P = 0.210) and the functional status [Motor-Urination-Defecation scores: 25.9 vs. 25.7, P = 0.762] did not differ between the two groups.

CONCLUSION

Ultra-short course of neo-adjuvant denosumab for sacral GCTB could elicit radiological and histological responses as conventional course did. The less degree of fibrosis and ossification might facilitate nerve-sparing surgery and help to achieve satisfactory local control and functional status.Level of Evidence: 4.

Current management of giant-cell tumor of bone in the denosumab era

Giant-cell tumor of bone is a rare, locally aggressive and rarely metastasizing primary bone tumor. The mainstay of treatment remains controversial and is decided by the balance between adequate surgical margin and sufficient adjacent joint function. Although curettage with a high-speed burr and local adjuvants can maintain normal joint function, many reports have revealed a high local recurrence rate. Conversely, en bloc resection and reconstruction with prostheses for highly aggressive lesions have reportedly lower local recurrence rates and poorer functional outcomes. Denosumab-a full human monoclonal antibody that inhibits receptor activator of nuclear factor-kappa β ligand-was approved by the Food and Drug Authority in 2013 for use in surgically unresectable or when resection is likely to result in severe morbidity for skeletally mature adolescents and adults with giant-cell tumor of bone. However, subsequent studies have suggested that the local recurrence rate would be increased by preoperative use of denosumab. In systematic reviews of the local recurrence rate after preoperative use of denosumab, conclusions vary due to the small sample sizes of the studies reviewed. Therefore, controversy regarding the treatment of giant-cell tumor of bone is ongoing. Here, this review elucidates the management of giant-cell tumor of bone, especially with the local adjuvant and neoadjuvant use of denosumab, and presents the current, evidence-based treatment for giant-cell tumor of bone.

Evaluating the Optimal Management of Inoperable Giant Cell Tumors of the Spine: A Systematic Review and Meta-Analysis

Simple Summary

Spine giant cell tumors (SGCTs) are intermediate malignant bone tumors, sometimes aggressive and responsible for debilitating axial pain and sensorimotor impairments. Non-surgical therapies, including denosumab, radiotherapy, and selective arterial embolization (SAE), have shown promising results in the treatment of patients with inoperable SGCTs. In this systematic review, we aimed to comprehensively analyze the current literature on denosumab, radiotherapy, and SAE for inoperable SGCTs, comparing treatment outcomes and complications using a random-effect model meta-analysis. We found that all three treatments were equally effective in providing symptom improvement and radiological tumor response, also showing low and comparable rates of treatment-related complications. Patients treated with denosumab showed lower rates of local recurrences and distant metastases.

Abstract

Background: Surgical resection remains the preferred treatment in spine giant cell tumors (SGCTs), but it is not always feasible. Conservative strategies have been studied for inoperable cases. We systematically reviewed the literature on inoperable SGCTs treated with denosumab, radiotherapy or selective arterial embolization (SAE). Methods: PubMed, Scopus, Web-of-Science, Ovid-EMBASE, and Cochrane were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to include studies of inoperable SGCTs treated with denosumab, radiotherapy or SAE. Treatment outcomes were analyzed and compared with a random-effect model meta-analysis. Results: Among the 17 studies included, 128 patients received denosumab, 59 radiotherapy, and 43 SAE. No significant differences in baseline patient characteristics were found between the three groups. All strategies were equally effective in providing symptom improvement (p = 0.187, I² = 0%) and reduction in tumor volume (p = 0.738, I² = 56.8%). Rates of treatment-related complications were low (denosumab: 12.5%; radiotherapy: 8.5%; SAE: 18.6%) and comparable (p = 0.311, I² = 0%). Patients receiving denosumab had significantly lower rates of local tumor recurrence (10.9%) and distant metastases (0%) compared to patients receiving radiotherapy (30.5%; 8.5%) or SAE (35.6%; 7%) (p = 0.003, I² = 32%; p = 0.002, I² = 47%). Denosumab was also correlated with significantly higher overall survival rates at 18 months (99.2%) and 24 months (99.2%) compared to radiotherapy (91.5%; 89.6%) and SAE (92.5%; 89.4%) (p = 0.019, I² = 8%; p = 0.004, I² = 23%). Mortality was higher in patients receiving SAE (20.9%) or radiotherapy (13.6%) compared to denosumab (0.8%) (p < 0.001), but deaths mostly occurred for unrelated diseases. Conclusions: Denosumab, radiotherapy, and SAE are safe and effective for inoperable SGCTs. Clinical and radiological outcomes are mostly comparable, but denosumab may provide superior tumor control.

State of the Art and New Concepts in Giant Cell Tumor of Bone: Imaging Features and Tumor Characteristics

Simple Summary

The 2020 World Health Organization classification of soft tissue and bone tumors classified the giant cell tumor of bone (GCTB) as an intermediate malignant tumor, with locally aggressive behavior and high recurrence rate. Imaging plays a pivotal role in the assessment of GCTB, and this review tries to summarize the main concepts about GCTB histopathogenesis and new biomarkers, describing those GCTB imaging findings which could possibly be explained by tumor molecular alterations. We have illustrated pre-operative imaging features related to prognosis and radiological findings for response evaluation after surgical treatment and denosumab administration. We have also reported the results described in literature regarding the role of radiomics in aiding GCTB diagnosis, predicting possible post-treatment recurrence and providing a quantitative assessment of the response to denosumab treatment.

Abstract

Giant cell tumor of bone (GCTB) is classified as an intermediate malignant tumor due to its locally aggressive behavior, burdened by high local recurrence rate. GCTB accounts for about 4–5% of all primary bone tumors and typically arises in the metaphysis and epiphyses of the long tubular bones. Mutation of gene H3F3A is at the basis of GCTB etiopathogenesis, and its immunohistochemical expression is a valuable method for practical diagnosis, even if new biomarkers have been identified for early diagnosis and for potential tumor recurrence prediction. In the era of computer-aided diagnosis, imaging plays a key role in the assessment of GCTB for surgical planning, patients’ prognosis prediction and post treatment evaluation. Cystic changes, penetrating irregular margins and adjacent soft tissue invasion on preoperative Magnetic Resonance Imaging (MRI) have been associated with a higher rate of local recurrence. Distance from the tumor edge to the articular surface and thickness of unaffected cortical bone around the tumor should be evaluated on Computed Tomography (CT) as related to local recurrence. Main features associated with local recurrence after curettage are bone resorption around the graft or cement, soft tissue mass formation and expansile destruction of bone. A denosumab positive response is represented by a peripherical well-defined osteosclerosis around the lesion and intralesional ossification. Radiomics has proved to offer a valuable contribution in aiding GCTB pre-operative diagnosis through clinical-radiomics models based on CT scans and multiparametric MR imaging, possibly guiding the choice of a patient-tailored treatment. Moreover, radiomics models based on texture analysis demonstrated to be a promising alternative solution for the assessment of GCTB response to denosumab both on conventional radiography and CT since the quantitative variation of some radiomics features after therapy has been correlated with tumor response, suggesting they might facilitate disease monitoring during post-denosumab surveillance.

Extended Curettage for Giant Cell Tumors of Bone: A Surgeon's View

The key to intralesional surgical treatment of giant cell tumor of bone (GCTB) is extended curettage. As GCTB is locally aggressive with a high propensity for local recurrence, a primary factor of surgical treatment is the ability to achieve local tumor clearance. GCTB commonly affects the epimetaphyseal region of the bone, which may compromise the integrity of the articular surface. With the exception of expendable bone that may be considered for resection without the challenge of reconstruction (e.g., the proximal aspect of the fibula or the distal aspect of the ulna), a large majority of cases of GCTB can be treated with joint-preserving techniques. In the present article, we share a video demonstration including the surgeon view of intralesional surgery for GCTB, with emphasis on the 360° visualization of the tumor cavity, dilemmas regarding use of adjuvants for extended curettage, and options in cavity reconstruction.

Description

The surgical procedure involves 4 essential components.(1) Surgical exposure and isolation of the soft tissues. The technique begins with a complete exposure that allows visualization of the entire tumor cavity. The initial part of the exposure involves getting to the bone and to the soft-tissue mass outside the bone, when present. The muscles are separated from the bone and retracted away from the soft-tissue component of the tumor. Soft tissue is adequately retracted to allow complete visualization of the tumor cavity. The tissues around the cavity are protected by placing hydrogen peroxide-soaked mops around the tumor cavity. The aim is to isolate the bone opening and avoid any contamination of soft tissue by the tumor, as hydrogen peroxide kills GCTB cells on contact¹. The soft-tissue mass of the tumor is removed en bloc with a cover of normal tissue in order to prevent spillage into uninvolved tissues. Ward and Li advise the use of cautery for this part of the exposure in order to minimize contamination because high-temperature cautery kills the tumor². The initial opening into the osseous tumor cavity is made smaller in order to control the tumor spillage, and then enlarged in order to gain complete visualization.(2) Curetting and burring for tumor clearance. The walls are curetted, using the sharp edges of the curet. Good visualization is the key to meticulous and complete curetting. We recommend the use of a surgical loupe and headlight for adequate visualization¹. Tumor cavities often have overhanging osseous ridges with tumor hidden behind them. A curet may not be useful for breaking these hard osseous ridges; a burr is best utilized for this task. In addition to breaking the ridges, a high-speed burr helps to extend the curettage for a few millimeters beyond the grossly visible tumor margin^3,4.(3) Use of adjuvants to achieve extended curettage. Various physical and chemical agents have been utilized to control the microscopic disease remaining in the walls following a thorough curettage. Liquid nitrogen, phenol, hydrogen peroxide, alcohol, electrocautery, bone cement, and argon plasma cautery have been utilized as adjuvants. Balke et al. showed that the rate of recurrence decreases with use of more adjuvants, with high-speed burring having the greatest effect on the rate of recurrence, likely as a result of the larger resection and the thermal effect of the burring⁵. We suggest a case-by-case use of specific adjuvants, but in our experience, a high-speed burr is always utilized, hydrogen peroxide is utilized commonly when safe, and argon-plasma cautery is utilized judiciously.(4) Reconstruction of the cavity. The defect may be filled with bone, cement, or a combination of both. We suggest an individual, case-by-case approach to the reconstruction. In cases in which >25% of the articular surface is undermined², subchondral bone grafting is recommended prior to cementing (i.e., a sandwich procedure).

Alternatives

GCTB requires tumor clearance for local control. One alternative to intralesional surgical treatment performed around the knee is resection of the tumor-affected segment of bone and reconstruction with an endoprosthesis. This is a joint-sacrificing alternative and, in our experience, should be reserved for patients with joint involvement, multiply recurrent disease, or insufficient remaining wall to curet.

Rationale

When adequate tumor clearance is possible, joint-salvaging intralesional surgical treatment remains the superior option to achieve physiological joint function⁶. Indications for this procedure include maintained or restorable joint congruity and construct stability allowing early mobilization.

Expected Outcomes

The rate of local recurrence following intralesional surgical treatment ranges from 16% to 25%^1,7. The use of a high-speed burr is an essential part of the curettage⁵, and hydrogen peroxide is a safe choice for an adjuvant, if desired and when suitable, to provide greater local control⁸. Reconstruction with bone, cement, or both is acceptable, but we recommend building up a few millimeters of subchondral bone with bone graft before cement filling^1,9.

Important Tips

Illumination and magnification within the tumor cavity provide better visualization.Isolation of the soft tissue around the tumor with use of hydrogen peroxide-soaked mops can prevent seeding and contamination.Meticulous tumor clearance is more important to minimize recurrence than the use of adjuvants.Use of a C-arm helps to better guide extension of the curettage and avoid inadvertent joint penetration.Maintaining joint congruity is essential.

Research progress in strategies to improve the efficacy and safety of doxorubicin for cancer chemotherapy

INTRODUCTION

DOX exerts strong anticancer activity and is commonly used to treat different cancers, including bone sarcomas, soft tissues, bladder, ovary, stomach, thyroid, breast, acute lymphoblastic leukemia, Hodgkin lymphoma, lung cancer, and myeloblastic leukemia. However, the cumulative doses of DOX above 550mg/m2 cause irreversible cardiotoxicity and other severe adverse effects. In this context, concerning DOX, several patents have been published in the last two decades. This activity highlights various aspects of DOX, such as registered patent analysis, pharmacological action, toxicityminimization, formulation development such as those approved by FDA, under clinical trials, and newly developed nano-delivery systems.

AREAS COVERED

This review analyzes the different aspects of DOX-based chemotherapeutics and the development of drug delivery systems in theliterature published from 2000 to early 2020.

EXPERT OPINION

DOX-based chemotherapy is still few steps away from being "perfect and safe" therapy. Certain severe systemic side effects are associated with DOX therapy. It is expected that, in the near future, DOX therapy can be much effective by selecting an ideal nanocarrier system, DOX conjugates, proper structural modifications, DOX-immunotherapy, and combination therapy. The advanced formulationsof DOX from the registered patents and recent research articles need clinical trials to bring safe treatment for cancer patients.

Management of the Cavity After Removal of Giant Cell Tumor of the Bone

Purpose: To find out the most appropriate management scheme through the analysis and comparison of different inactivation methods and filling materials. Method: A systematic literature search was performed using the terms, anhydrous ethanol, phenol, hypertonic saline, cryotherapy, thermal therapy, bone reconstruction, GCTB, and etc., Selected articles were studied and summarized. The mechanism, clinical effects, and influence on bone repair of various methods are presented. Recent developments and perspectives are also demonstrated. Recent Findings: Compared to curettage alone, management of the residual cavity can effectively reduce the recurrence of giant cell tumours of bone. It is a complex and multidisciplinary process that includes three steps: local control, cavity filling, and osteogenic induction. In terms of local control, High-speed burring can enlarge the area of curettage but may cause the spread and planting of tumour tissues. Among the inactivation methods, Anhydrous ethanol, and hyperthermia therapy are relatively safe and efficient. The combination of the two may achieve a better inactivation effect. When inactivating the cavity, we need to adjust the approach according to the invasion of the tumour. Filling materials and bone repair should also be considered in management.