Primary Vertebral Tumors Recommendations

Incidence, epidemiology, classification, and radiology of primary vertebral tumors .

1: Primary tumors of the vertebral column are rare, with an estimated prevalence of 2.5 to 8.5 cases per 100,000 persons per year.

2: The most common malignant primary spinal neoplasm in adults is chordoma, followed by chondrosarcoma and osteosarcoma.

3: In children, the most common malignant primary vertebral tumor is Ewing's sarcoma.

The most common benign vertebral tumors are osteoid osteoma/osteoblastoma, aneurysmal bone cyst, and eosinophilic granuloma.

4: Chordoma represents about 2% to 4% of all spinal column tumors, 40% of primary spinal tumors and has a high propensity for the sacral and cervical regions.

5: Giant cell tumors demonstrate WHO grade I histopathology but are locally aggressive. They are the second most common primary bone tumor of the sacrum after chordomas.

6: The incidence of primary malignant vertebral tumors increases significantly in patients older than 40 years.

7: Biopsy is able to identify tumors and accurately determine the type, grade, and stage of tumors (96.4%).

Complication rates for percutaneous biopsy range between 1 and 3%, compared to 16% for open biopsy.

Lower accuracy rates have also been reported in fibrotic, collagenous, and inflammatory lesions, as well as for specific lesions such as aneurysmal bone cysts and hemangiomas.

Osteolytic or mixed lesions have a reported diagnostic yield of up to 88%, compared with sclerotic lesions at 67%.

 

General evaluation and decision making for primary vertebral tumors.

1 : MRI and / or CT are crucial to visualize neural compression, tumor load and bone structure. Plain radiographs may be used in primary tumors with spinal deformities. (5/5 agreement 100% consensus)

2 : Symptomatic benign vertebral lesions may require curettage or surgical removal .

3 : Gold standard for non-surgical treatment is radiotherapy ; In some cases such as Ewing's sarcoma adjuvant chemotherapy is indicated.

4 : Before advising surgery, the patient's general condition, Karnofsky score, tumor mass and histology, life expectancy must be considered.

5 : En-bloc excision is the gold standard for the malignant primary tumors of the spine. Stereotactic body radiation therapy (SBRT) maybe an emerging alternative strategy for unresectable primary malignant tumors.

 

Management of benign primary tumors.

1 : The Enneking and Weinstein-Boriani-Biagini (WBB) classification systems are the most widely accepted systems for classifying benign and malignant primary spinal tumors and provide recommendations on the best treatment option, including surgical approach.

2 : First-line treatment for osteoid osteomas is NSAIDs. For patients who fail conservative treatment, surgical resection may be considered. Minimally invasive procedures including radiofrequency ablation have similar outcomes to surgical excision of osteoid osteomas, but caution is warranted when the lesions are close to neural structures.

3 : For osteoblastomas, en bloc resection or maximal safe gross total resection to lower the risk of tumor recurrence is recommended. Further studies are needed to demonstrate the role of radiation and/or chemotherapy for inoperable or recurrent lesions.

4 : Pre-operative embolization followed by gross total resection, assuming favorable risk/benefit profile, of symptomatic aneurysmal bone cysts (ABCs) is recommended.

Further studies are needed to define the role of stand-alone selective arterial embolization, bone marrow aspirate injection, denosumab, doxycycline, and bisphosphonates in the primary treatment of ABCs.

5 : For giant cell tumors, pre-op embolization for hypervascular lesions, followed by en bloc or gross total resection is recommended to minimize tumor recurrence.

There may be a role for adjuvant bisphosphonates or denosumab, although further high-quality evidence is needed.

6 : Symptomatic vertebral hemangiomas should be treated with pre-operative embolization (given their high vascularity) followed by gross total resection as the first-line treatment. Vertebroplasty and radiation therapy can be used to obtain pain and local control.
 

Percutaneous techniques and ablation for primary vertebral tumors

1: Percutaneous CT-guided biopsy is preferable over fluoroscopy-guided biopsy. Vertebral tumors biopsies should be performed in a center with full surgical and histo-pathological facilities.

2: In 96.4% of biopsy it is possible to identify tumors and accurately define the type, grade and stage. Osteolytic or mixed lesions have a reported diagnostic yield of up to 88% compared with sclerotic lesions at 67%. For aneurysmal bone cysts and hemangioma usually biopsy is not needed for the high risk of bleeding and low accuracy.

Complication rates for percutaneous biopsy range between 1-3% compared to 16% for open biopsy.

3 : Vertebral augmentation (vertebroplasty or kyphoplasty) can be considered for patients with severe pain secondary to pathological vertebral compression fractures.

4 : Radiofrequency ablation, percutaneous laser, cryoablation and similar treatment procedures may have a role in the treatment of primary spine tumor, but evidence is lacking. Their effect largely depends on histology of the vertebral lesion.
 

Management of chordomas and sarcomas.

1 : Chordoma is a malignant tumor localized in sacrum (50%), skull base (30%), and mobile spine (20%). Management of chordomas is challenging, and there are high recurrence rates.

2 : Radical resection (Enneking negative) at first presentation should be attempted on all chordomas because the extent of resection is the best prognostic factor.

Although recurrences are common, total sacrectomy is a viable option especially for sacral chordomas at S2 and below.

3 : Preferred treatment of chordomas is surgical resection followed by radiotherapy. They are highly resistant to chemotherapy.

4 : The average life expectancy of chordomas is 6 years. The 5-year survival rate is 70%, 10-year survival rate is 40%.

In the advanced stages 30-40% of the patients have metastasis. Sacral chordomas tend to metastasize more often than mobile spine chordomas.

5 : En bloc resection with wide, disease-free margins is the gold standard for primary treatment of chondrosarcoma.

6 : Radiation therapy after piecemeal excision increased overall survival, however, do not reach clinical significance.

7 : The use of chemotherapy in chondrosarcoma is limited as this type of tumor is found to be typically resistant to chemotherapy.

8 : Surgical resection is the primary treatment modality for chondrosarcoma and osteosarcoma. In contrast, Ewing sarcoma necessitates a multimodal approach, combining neoadjuvant chemotherapy, surgical resection and radiation therapy.

9 : Surgical resection in primary spinal chondrosarcoma, Ewing's sarcoma, and osteosarcoma leads to overall improved survival, regardless of patient age, tumor invasion, or location.

10 : Chemotherapy followed by surgery and radiotherapy in a multidisciplinary approach can be instrumental in improving outcomes for Ewing's sarcoma. Wide excisions with adequate surgical margins may benefit after neoadjuvant therapy.

11 : Neoadjuvant therapy followed by surgery improves the outcome for spinal osteosarcoma. It helps shrink tumors, facilitates surgical resection, potentially reduces blood loss, and may target micrometastases.

12 : Surgery is an independent prognostic factor in osteosarcoma for both overall survival and cancer-specific survival.

En bloc resection (Enneking-appropriate = EA) significantly reduced recurrence and improved survival compared to intralesional resection.

 

Radiation therapy and radiosurgery for primary vertebral tumors.

1 : Stereotactic radiosurgery (SRS) serves as a promising postoperative adjuvant or salvage treatment for achieving good local control in primary malignant spinal tumors, especially following cEBRT, suggesting improved patient outcomes.

2 : Conventional photon radiotherapy is supplanted by more advanced techniques, including modified fraction radiotherapy, internal radiation therapy, and particle therapy, due to low accuracy and toxicity in surrounding tissue.

3 : Combined intensity-modulated proton therapy (IMPT) and intensity-modulated radiation therapy (IMRT) have promising long-term results in spine tumor patients.

4 : Charged-particle therapies for sarcomas affecting the spine and sacrum are limited by current evidence, the preliminary findings suggest a potential for comparable local control and overall survival at 5 years among various charged-particle options.