Morphologic Changes After Denosumab Therapy in Patients with Giant Cell Tumor of the Spine: Report of Four Cases and a Review of the Literature

Thoracic giant cell tumor after two total en bloc spondylectomies including one emergency surgery: A case report

BACKGROUND

For patients with acute paraplegia caused by spinal giant cell tumor (GCT) who require emergency decompressive surgery, there is still a lack of relevant reports on surgical options. This study is the first to present the case of an acute paraplegic patient with a thoracic spinal GCT who underwent an emergency total en bloc spondylectomy (TES). Despite tumor recurrence, three-level TES was repeated after denosumab therapy.

CASE SUMMARY

A 27-year-old female patient who underwent single-level TES in an emergency presented with sudden severe back pain and acute paraplegia due to a thoracic spinal tumor. After emergency TES, the patient's spinal cord function recovered, and permanent paralysis was avoided. The postoperative histopathological examination revealed that the excised neoplasm was a rare GCT. Unfortunately, the tumor recurred 9 months after the first surgery. After 12 months of denosumab therapy, the tumor size was reduced, and tumor calcification. To prevent recurrent tumor progression and provide a possible cure, a three-level TES was performed again. The patient returned to an active lifestyle 1 month after the second surgery, and no recurrence of GCT was found at the last follow-up.

CONCLUSION

This patient with acute paraplegia underwent TES twice, including once in an emergency, and achieved good therapeutic results. TES in emergency surgery is feasible and safe when conditions permit; however, it may increase the risk of tumor recurrence.

The risk of neurological deterioration while using neoadjuvant denosumab on patients with giant cell tumor of the spine presenting with epidural disease: a meta-analysis of the literature

BACKGROUND CONTEXT

Giant cell tumor (GCT) of bone is most commonly a benign but locally aggressive primary bone tumor. Spinal GCTs account for 2.7% to 6.5% of all GCTs in bone. En bloc resection, which is the preferred treatment for GCT of the spine, may not always be feasible due to the location, extent of the tumor, and/or the patient's comorbidities. Neoadjuvant denosumab has recently been shown to be effective in downstaging GCT, decreasing the size and extent of GCTs. However, the risk of neurologic deterioration is of major concern for patients with epidural spinal cord compression due to spinal GCT. We experienced this concern when a patient presented to our institution with a midthoracic spinal GCT with progressive epidural disease. The patient was not a good surgical candidate due to severe cardiac disease and uncontrolled diabetes. In considering nonoperative management for this patient, we asked ourselves the following question: What is the risk that this patient will develop neurologic deterioration if we do not urgently operate and opt to treat him with denosumab instead?

PURPOSE

The purpose of this study was to assess the literature to (1) determine the risk of neurological deterioration in patients receiving neoadjuvant denosumab for the treatment of spinal GCT and (2) to evaluate the secondary outcomes including radiographic features, surgical/technical complexity, and histological features after treatment.

STUDY DESIGN/SETTING

Meta-analysis of the literature.

PATIENT SAMPLE

Surgical cases of spinal GCT that (1) presented with type III Campanacci lesions, (2) had epidural disease classified as Bilsky type 1B or above and (3) received neoadjuvant denosumab therapy.

OUTCOME MEASURES

The primary outcome measure of interest was neurologic status during denosumab treatment. Secondary outcome measures of interest included radiographic features, surgical/technical complexity, histological features, tumor recurrence, and metastasis.

METHODS

Using predetermined inclusion and exclusion criteria, PubMed and Embase electronic databases were searched in August 2022 for articles reporting spinal GCTs treated with neoadjuvant denosumab and surgery. Keywords used were "Spine" AND "Giant Cell Tumor" AND "Denosumab."

RESULTS

A total of 428 articles were identified and screened. A total of 22 patients from 12 studies were included for review. 17 patients were female (17/22, 77%), mean age was 32 years (18-62 years) and average follow-up was 21 months. Most GCTs occurred in the thoracic and thoracolumbar spine (11 patients, 50%), followed by 36% in the lumbar spine and 14% in the cervical spine. Almost half of the patients had neurological deficits at presentation (10/22 patients, 45%), and more than 60% had Bilsky 2 or 3 epidural spinal cord compression. None of the patients deteriorated neurologically, irrespective of their neurological status at presentation (p-value=.02, CI -2.58 to -0.18). There were no local recurrences reported. One patient was found to have lung nodules postoperatively. More than 90% of cases had decreased overall tumor size and increased bone formation. Surgical dissection was facilitated in more than 85% of those who had documented surgical procedures. Four patients (18%) underwent initial spinal stabilization followed by neoadjuvant denosumab and then surgical excision of the GCT. Regarding the histologic analyses, denosumab eradicated the giant cells in 95% of cases. However, residual Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL)-positive stromal cells were noted, in 27% (6 cases).

CONCLUSIONS

Neoadjuvant denosumab was a safe and effective means of treating spinal GCTs prior to surgery. Neurologic status remained stable or improved in all cases included in our review, irrespective of the presenting neurologic status. The most appropriate dosage and duration of denosumab therapy is yet to be determined. We recommend future well-designed studies to further evaluate the use of neoadjuvant denosumab for patients with spinal GCT.

Radiologic and clinical changes after denosumab treatment for giant cell tumors of the mobile spine: a quantitative study

Objectives

To analyze the radiologic and clinical changes after denosumab treatment in patients with giant cell tumors (GCTs) in the mobile spine.

Methods

Clinical data and images by computed tomography and magnetic resonance imaging at a single center were retrospectively reviewed before and after denosumab treatment.

Results

Pre- and post-treatment data from 24 patients were evaluated. On imaging, marginal ossification and/or bone formation was observed in 22 patients (91.7%). The median maximum diameter of the GCT reduced from 52.5 to 48.2 mm (p < 0.001), and the mean proportion of tumor to spinal canal area decreased from 36.8 to 18.5% (p < 0.001). Out of six patients with compression, three patients (50%) showed no compression after treatment. The signal intensity (SI) ratio between the solid part of the tumor and the normal spinal cord on T2-weighted MR images was 0.77 ± 0.22 and decreased to 0.58 ± 0.22 (p = 0.001). On clinical symptoms, the mean visual analog scale scores were reduced from 5.3 to 2.0 (p < 0.001) and the Karnofsky Performance Scale scores increased from a median of 65 to 80 (p < 0.001). Post-treatment, performance scores improved in eight patients (33.3%) (p = 0.003), and the neurological function of four patients improved according to Frankel grade (p = 0.046).

Conclusions

Bone formation, tumor reduction, regression of epidural lesion and the decrease in SI ratio on T2-weighted image should be considered as the effectiveness of denosumab in the treatment of spinal GCT. In clinical application, denosumab can relieve pain, improve neurological function, and improve the quality of life of spinal GCT patients.

Diagnosis and Treatment of Lumbar Giant Cell Tumor of the Spine: Update on Current Management Strategies

(1) Background: Giant Cell Tumor of the spine remains a difficult tumor to treat. Recent advances in adjuvant therapy such as denosumab and innovations in surgical technique in the last 5 years have given providers new options for treatment after a successful diagnosis of the tumor. (2) Methods: Articles published between 1927 and 2021 were selected from PubMed and Scopus searches using key words “Giant Cell Tumor” AND “Lumbar Spine” AND “Treatment”. Relevant articles were reviewed and selected by the authors. (3) Results: A total of 191 articles were discovered. Complete en bloc spondylectomy remains the most definitive treatment option; however, this surgery is challenging and carries a high rate of complication. New adjuvant therapies including denosumab offer a viable alternative to surgery. (4) En bloc spondylectomy remains the gold standard treatment for Giant Cell Tumor of the spine with the lowest published recurrence rate. The use of (neo)adjuvant denosumab improves recurrence rates. More data are needed to determine if denosumab alone is a viable standalone definitive treatment.

LONG-TERM USE OF DENOSUMAB IN GIANT CELL TUMORS AND VERTEBRAL ANEURYSMAL BONE CYSTS

ABSTRACT Introduction: Denosumab is a human monoclonal antibody that binds to the receptor activator of nuclear factor kB (RANKL), it is used in the treatment of Osteoporosis. The Giant Cell Tumor (GCT) and the Aneurysmal Bone Cyst (ABC) use the same RANKL, and for this reason this drug began to be used for its treatment. There is consensus on the use, dose-time and 12-month duration for Denosumab treatment of GCT. Not so for ABC. In unresectable, disabling or recurrent tumors, its use could be for life. The adverse events of the habitual use of the drug are known, but it is not known if these increase with time. The objective of the present work is to identify the possible adverse events of treatment with Denosumab for more than 12 months. Material and Method: Series of cases with a diagnosis of GCT or ABC in spine, treated with Denosumab for more than 12 months. Adverse events are: arthralgia, fatigue, spinal pain, pain in extremities, headache, hypokalaemia, hypocalcemia, osteonecrosis of the jaw, malignant transformation, pathological fractures. Results: Eight patients, 6 TCG and 2 ABC, with a mean age at diagnosis of 25,6 years; presenting a mean treatment of 4.18 years (range 1.7 - 8.7). Of 6 operated patients, 4 had recurrence (2 to 36 months after surgery). One patient had to suspend treatment due to necrosis of the jaw, another hypocalcemia, both returned to treatment when stabilized. Conclusions: A minor adverse event (hypocalcemia) and a major adverse event (jaw bone necrosis) were observed. Level of Evidence IV; Original.

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

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.

Total en bloc spondylectomy is worth doing in complete paralysis spinal giant cell tumor, a minimum 1-year follow-up

OBJECTIVE

To investigate the neurological recovery of Frankel A spinal giant cell tumor (GCT) patients after they had received a Total En Bloc Spondylectomy (TES).

MATERIALS AND METHODS

We retrospectively recorded data of three patients (two females) with mobile spine GCT (T6, T10, and L2) Enneking stage III with complete paralysis before surgery, who had undergone TES in our institute from January 2018 to September 2020. The duration of neurologic recovery to Frankel E was the primary outcome. The intra-operative blood loss, operative time, operative-related complications, and the local recurrence were the secondary outcomes.

RESULTS

The duration of suffering from Frankel A to TES surgery was 2 months for the T6 patient, 3 weeks for the T10 patient, and 1 month for the L2 patient. Three patients had achieved full neurological recovery to Frankel E within 6 months after TES (T6 for 5 months, T10 for 3 months, and L2 for 3 months). The average blood loss was 2833.33 ml and the mean operative time was 400 min. Up until the last follow-up (13-25 months), no evidence of local recurrences had been found in any of the three patients.

CONCLUSION

Frankel A spinal GCT patients can achieve full neurological recovery after TES, if the procedure is performed within 3 months after complete paraplegia. TES can effectively control any local recurrences.