Minimally invasive "separation surgery" plus adjuvant stereotactic radiotherapy in the management of spinal epidural metastases

Role of Minimally Invasive Spine Surgery in Spine Oncology

The application of minimally invasive spine surgery (MISS) in degenerative spine disease and deformity has seen rapid growth in the past 20 years. Building on this experience, such methods have been adopted into spine oncology in the past decade, particularly for metastatic disease. The impetus for this growth stems from the benefits of surgical decompression combined with radiation treatment in patients with metastatic disease in conjunction with the need for less morbid interventions in a patient population with limited life expectancy. The result of these two realizations was the application of minimally invasive techniques for the treatment of spine tumors including re-establishment of spinal stability, decompression of the spinal cord or nerve roots, and restoration of spinal alignment. Technological advancement and improvement in biomaterials have allowed for durable stabilization with short constructs even for patients with poor bone quality. The implementation of navigation and robotic capabilities has transformed MISS by streamlining surgery and further reducing the surgical footprint while laser ablation, endoscopy, and robotic surgery hold the potential to minimize the surgical footprint even further. MISS for intradural tumors is commonly performed, while the role for other primary tumors has yet to be defined. In this article, we describe the evolution of and indications for MISS in spine oncology through a retrospective literature review.

Radiotherapy with 15 × 2.633 Gy vs. 20 × 2.0 Gy in Patients with Malignant Spinal Cord Compression and Favorable Survival Prognoses: A Secondary Analysis of the RAMSES-01 Trial

Many patients with malignant spinal cord compression (MSCC) who are not candidates for neurosurgery receive radiotherapy alone. This study compared 15 × 2.633 Gy over three weeks to 20 × 2.0 Gy over four weeks in patients with favorable survival prognoses. The outcomes of 34 patients treated with 15 × 2.633 Gy (equivalent dose 41.6 Gy10) in the RAMSES-01 trial were compared to 239 patients from an existing database receiving 20 × 2.0 Gy using propensity-score-adjusted Cox and logistic regression models. All patients had favorable survival prognoses. Endpoints included local progression-free survival (LPFS), improvement of motor function, post-treatment ambulatory status, and overall survival (OS). After propensity score adjustment, the 12-month rates of LPFS and OS were 98.1% (RAMSES-01 cohort) vs. 91.6% (p = 0.265) and 79.1% vs. 82.2% (p = 0.704), respectively. Regarding improvement of motor function, 15 × 2.633 Gy appeared superior (p = 0.073). No significant difference was observed regarding ambulatory status (p = 0.822). The three-week regimen for MSCC has similar outcomes and reduces treatment time when compared to a four-week regimen.

Transpedicular Corpectomy in Minimally Invasive Surgery for Metastatic Spinal Cord Compression: A Single-Center Series

Introduction The role of separation surgery in managing symptomatic spinal metastases has been increasing in recent years, and it represents a crucial part of the definitive management of this condition. Methods We report on a series of seven patients treated at the National Cancer Institute in Mexico using minimally invasive approaches to perform transpedicular corpectomy. The goal was to obtain a margin of tumor-free tissue, enabling the completion of oncological treatment with radiotherapy. Results We collected data from six cases. The mean age was 61.2 years. Surgical outcomes were good in 83.3% of patients. Ranging from minimally invasive instrumentations to total or partial corpectomies, these procedures achieved their intended function of generating healthy neural tissue free of tumor. This ensures that the radiation gradient does not affect this tissue. No surgical complications were reported. The objective of these surgeries was to establish a radiotherapy or radiosurgery regimen as soon as possible, thereby improving patients' quality of life (QoL). Conclusions Low-cost transpedicular corpectomy via minimally invasive surgery (MIS) is a safe and effective method that meets the goals of separation surgery. However, prospective studies are needed to directly compare open techniques with minimally invasive methods.

A new era in the management of spinal metastasis

Despite the recent advances in cancer treatment, the incidence of patients with spinal metastases continues to grow along with the total number of cancer patients. Spinal metastases can significantly impair activities of daily living (ADL) and quality of life (QOL), compared with other types of bone metastases, as they are characterized with severe pain and paralysis caused by skeletal-related events. Reduced ADL can also lead to treatment limitations as certain anticancer agents and radiation therapy are not compatible treatments; thus, leading to a shorter life expectancy. Consequently, maintaining ADLs in patients with spinal metastases is paramount, and spine surgeons have an integral role to play in this regard. However, neurosurgeon, orthopedic and spinal surgeons in Japan do not have a proactive treatment approach to spinal metastases, which may prevent them from providing appropriate treatment when needed (clinical inertia). To overcome such endemic inertia, it is essential for 1) spine surgeons to understand and be more actively involved with patients with musculoskeletal disorders (cancer locomo) and cancer patients; 2) the adoption of a multidisciplinary approach (coordination and meetings not only with the attending oncologist but also with spine surgeons, radiologists, rehabilitation specialists, and other professionals) to preemptive treatment such as medication, radiotherapy, and surgical treatment; and 3) the integration of the latest findings associated with minimally invasive spinal treatments that have expanded the indications for treatment of spinal metastases and improved treatment outcomes. This heralds a new era in the management of spinal metastases.

Stereotactic body radiotherapy for spine metastases: a review of 24 Gy in 2 daily fractions

PURPOSE

Stereotactic body radiotherapy (SBRT) has proven to be a highly effective treatment for selected patients with spinal metastases. Randomized evidence shows improvements in complete pain response rates and local control with lower retreatment rates favoring SBRT, compared to conventional external beam radiotherapy (cEBRT). While there are several reported dose-fractionation schemes for spine SBRT, 24 Gy in 2 fractions has emerged with Level 1 evidence providing an excellent balance between minimizing treatment toxicity while respecting patient convenience and financial strain.

METHODS

We provide an overview of the 24 Gy in 2 SBRT fraction regimen for spine metastases, which was developed at the University of Toronto and tested in an international Phase 2/3 randomized controlled trial.

RESULTS

The literature summarizing global experience with 24 Gy in 2 SBRT fractions suggests 1-year local control rates ranging from 83-93.9%, and 1-year rates of vertebral compression fracture ranging from 5.4-22%. Reirradiation of spine metastases that failed prior cEBRT is also feasible with 24 Gy in 2 fractions, and 1-year local control rates range from 72-86%. Post-operative spine SBRT data are limited but do support the use of 24 Gy in 2 fractions with reported 1-year local control rates ranging from 70-84%. Typically, the rates of plexopathy, radiculopathy and myositis are under 5% in those series reporting mature follow up, with no cases of radiation myelopathy (RM) reported in the de novo setting when the spinal cord avoidance structure is limited to 17 Gy in 2 fractions. However, re-irradiation RM has been observed following 2 fraction SBRT. More recently, 2-fraction dose escalation with 28 Gy, with a higher dose constraint to the critical neural tissues, has been reported suggesting improved rates of local control. This regimen may be important in those patients with radioresistant histologies, high grade epidural disease, and/or paraspinal disease.

CONCLUSION

The dose-fractionation of 24 Gy in 2 fractions is well-supported by published literature and is an ideal starting point for centers looking to establish a spine SBRT program.

Radiotherapy with or without Decompressive Surgery for Metastatic Spinal Cord Compression: A Retrospective Matched-Pair Study Including Data from Prospectively Evaluated Patients

Simple Summary

In a retrospective matched-pair study including data of prospectively evaluated patients who were treated for metastatic spinal cord compression, 79 patients assigned to surgery plus radiotherapy were compared to 79 patients receiving radiotherapy alone. Improvement of motor function occurred more significantly often after surgery plus radiotherapy, whereas no significant differences were found for post-treatment ambulatory rates, local progression-free survival, overall survival, and freedom from in-field recurrence. Ten patients died within 30 days after radiotherapy alone and 12 patients within 30 days after surgery. More than one third of surgically treated patients did not complete their radiotherapy due to early death or decreased performance score following surgery. Thus, when selecting a patient for upfront surgery, the individual patient’s prognosis must be considered and weighed against the risk of perioperative complications and 30-day mortality.

Abstract

In 2005, a randomized trial showed that addition of surgery to radiotherapy improved outcomes in patients with metastatic spinal cord compression (MSCC). Since then, only a few studies compared radiotherapy plus surgery to radiotherapy alone. We performed a retrospective matched-pair study including data from prospective cohorts treated after 2005. Seventy-nine patients receiving radiotherapy alone were matched to 79 patients assigned to surgery plus radiotherapy (propensity score method) for age, gender, performance score, tumor type, affected vertebrae, other bone or visceral metastases, interval tumor diagnosis to MSCC, time developing motor deficits, and ambulatory status. Improvement of motor function by ≥1 Frankel grade occurred more often after surgery plus radiotherapy (39.2% vs. 21.5%, p = 0.015). No significant differences were found for post-treatment ambulatory rates (59.5% vs. 67.1%, p = 0.32), local progression-free survival (p = 0.47), overall survival (p = 0.51), and freedom from in-field recurrence of MSCC (90.1% vs. 76.2% at 12 months, p = 0.58). Ten patients (12.7%) died within 30 days following radiotherapy alone and 12 patients (15.2%) died within 30 days following surgery (p = 0.65); 36.7% of surgically treated patients did not complete radiotherapy as planned. Surgery led to significant early improvement of motor function and non-significantly better long-term control. Patients scheduled for surgery must be carefully selected considering potential benefits and risk of perioperative complications.

[Stereotactic body radiation therapy for spine bone oligometastatic disease]

Stereotactic radiotherapy is an ever more common technique, regardless of the location treated. However, spinal stereotactic radiotherapy requires a particular technicality in order to ensure its proper realization. There is now a large literature defining the type of imaging to be used, the dose to be delivered and the delineation of target volumes. This technique can achieve a significant local control and an interesting analgesic efficiency. However, its place in relation to conventional radiotherapy remains limited because it requires MRI imaging and a significantly longer patient management during the treatment fraction. In this context, it is currently mainly restricted to oligometastatic patients or for re-irradiations.

Minimally Invasive Surgery Strategies: Changing the Treatment of Spine Tumors

Innovation in surgical technique and contemporary spinal instrumentation paired with intraoperative navigation/imaging concepts allows for safer and less-invasive surgical approaches. The combination of stereotactic body radiotherapy, contemporary surgical adjuncts, and less-invasive techniques serves to minimize blood loss, soft tissue injury, and length of hospital stay without compromising surgical efficacy, potentially enabling patients to begin adjuvant treatment sooner.

Separation surgery for metastatic epidural spinal cord compression: A qualitative review

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Separation surgery is a new concept for metastatic spinal cord compression treatment.

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Stereotactic radiosurgery increased local control, overcoming radio-resistance’s idea.

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The surgery goal shifted towards creating targets for radiations avoiding cord damages.

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Minimal invasive strategies could allow quick return to systemic therapies.

Introduction

The new concept of separation surgery has changed the surgical paradigms for the treatment of metastatic epidural spinal cord compression (MESCC), shifting from aggressive cytoreductive surgery towards less invasive surgery with the aim to achieve circumferential separation of the spinal cord and create a safe target for high dose Stereotactic Body Radiation Therapy (SBRT), which turned out to be the real game-changer for disease’s local control.

Discussion

In this review a qualitative analysis of the English literature has been performed according to the rating of evidence, with the aim to underline the increasingly role of the concept of separation surgery in MESCC treatment. A review of the main steps in the evolution of both radiotherapy and surgery fields have been described, highlighting the important results deriving from their integration.

Conclusion

Compared with more aggressive surgical approaches, the concept of separation surgery together with the advancements of radiotherapy and the use of SBRT for the treatment of MESCC showed promising results in order to achieve a valuable local control while reducing surgical related morbidities and complications.

Cholangiocarcinoma Metastasis to the Spine and Cranium

Background: Cholangiocarcinoma (CCC), a rare tumor arising from the viscera, has a poor prognosis. Although CCC is prone to metastasis, spread to the cranium and spine is exceedingly rare. Treatment for metastatic disease is palliative, with total resection of the primary lesion the only cure. We describe a case of metastatic CCC to the spine and cranium treated with surgical resection.

Case Report: A 61-year-old male with a history of hepatitis C with liver transplant and incidental discovery of CCC presented with gradually increasing back pain. Physical examination revealed a palpable nontender mass in the parieto-occipital area. Computed tomography survey of the spine and head revealed mixed sclerotic and lytic lesions of the T9, T11, L2, and L5 vertebral bodies, a lytic lesion on the T6 vertebral body, and a 1.4-cm lesion in the right occipital calvarium. The patient underwent right occipital craniotomy for excisional biopsy of the calvarial mass with gross total resection and immunohistochemical confirmation of CCC. The patient was started on gemcitabine chemotherapy and radiation therapy for spinal metastases. Three months later, the patient died from metastatic disease complications.

Conclusion: To our knowledge, only 6 cases of cranial CCC have been reported, and only 2 reported mixed cranial/spinal involvement. We report a rare case of CCC metastasis to the spine and cranium that was treated with surgery, chemotherapy, and radiotherapy. CCC should be considered an exceedingly rare etiology with treatment options aimed solely at palliation. This case supplements the existing literature to inform medical and surgical decision-making.

Minimally invasive versus conventional spine surgery for vertebral metastases: a systematic review of the evidence

One of the major determinants of surgical candidacy in patients with symptomatic spinal metastases is the ability of the patient to tolerate the procedure-associated morbidity. In other pathologies, minimally invasive (MIS) procedures have been suggested to have lower intra-operative morbidity while providing similar outcomes. We conducted a systematic review of the PubMed library searching for articles that directly compared the operative and post-operative outcomes of patients treated for symptomatic spinal metastases. Inclusion criteria were articles reporting two or more cases of patients >18 years old treated with MIS or open approaches for spinal metastases. Studies reporting results in spinal metastases patients that could not be disentangled from other pathologies were excluded. Our search returned 1,568 articles, of which 9 articles met the criteria for inclusion. All articles were level III evidence. Patients treated with MIS approaches tended to have lower intraoperative blood loss, shorter operative times, shorter inpatient stays, and fewer complications relative to patients undergoing surgeries with conventional approaches. Patients in the MIS and open groups had similar pain improvement, neurological improvement, and functional outcomes. Recent advances in MIS techniques may reduce surgical morbidity while providing similar symptomatic improvement in patients treated for spinal metastases. As a result, MIS techniques may expand the pool of patients with spinal metastases who are candidates for operative management.