Surgical treatment of sacral metastases: indications and results

Stereotactic Body Radiation Therapy for Sacral Metastases: Deviation From Recommended Target Volume Delineation Increases the Risk of Local Failure

PURPOSE

Although spine stereotactic body radiation therapy (SBRT) is considered a standard of care in the mobile spine, mature evidence reporting outcomes specific to sacral metastases is lacking. Furthermore, there is a need to validate the existing sacral SBRT international consensus contouring guidelines to define the optimal contouring approach. We report mature rates of local failure (LF), adverse events, and the effect of contouring deviations in the largest experience to date specific to sacrum SBRT.

METHODS AND MATERIALS

Consecutive patients who underwent sacral SBRT from 2010 to 2021 were retrospectively reviewed. The primary endpoint was magnetic resonance imaging-based LF with a focus on adherence to target volume contouring recommendations. Secondary endpoints included vertebral compression fracture and neural toxicity.

RESULTS

Of the 215 sacrum segments treated in 112 patients, most received 30 Gy/4 fractions (51%), 24 Gy/2 fractions (31%), or 30 Gy/5 fractions (10%). Sixteen percent of segments were nonadherent to the consensus guideline with a more restricted target volume (undercontoured). The median follow-up was 21.4 months (range, 1.5-116.9 months). The cumulative incidence of LF at 1 and 2 years was 18.4% and 23.1%, respectively. In those with guideline adherent versus nonadherent contours, the LF rate at 1 year was 15.1% versus 31.4% and at 2 years 18.8% versus 40.0% (hazard ratio [HR], 2.5; 95% CI, 1.4-4.6; P = .003), respectively. On multivariable analysis, guideline nonadherence (HR, 2.4; 95% CI, 1.3-4.7; P = .008), radioresistant histology (HR, 2.4; 95% CI, 1.4-4.1; P < .001), and extraosseous extension (HR, 2.5; 95% CI, 1.3-4.7; P = .005) predicted for an increased risk of LF. The cumulative incidence of vertebral compression fracture was 7.1% at 1 year and 12.3% at 2 years. Seven patients (6.3%) developed peripheral nerve toxicity, of whom 4 had been previously radiated.

CONCLUSIONS

Sacral SBRT is associated with high efficacy rates and an acceptable toxicity profile. Adhering to consensus guidelines for target volume delineation is recommended to reduce the risk of LF.

The management of sacral tumours

Tumours of the sacrum are difficult to manage. The sacrum provides the structural connection between the torso and lower half of the body and is subject to both axial and rotational forces. Thus, tumours or their treatment can compromise the stability of the spinopelvic junction. Additionally, nerves responsible for lower limb motor groups as well as bowel, bladder, and sexual function traverse or abut the sacrum. Preservation or sacrifice of these nerves in the treatment of sacral tumours has profound implications on the function and quality of life of the patient. This annotation will discuss current treatment protocols for sacral tumours.

Cite this article: Bone Joint J 2022;104-B(12):1284–1291.

Beyond Placement of Pedicle Screws - New Applications for Robotics in Spine Surgery: A Multi-Surgeon, Single-Institution Experience

Interest in robotic-assisted spine surgery has grown as surgeon comfort and technology has evolved to maximize benefits of time saving and precision. However, the Food and Drug Administration (FDA) has currently only approved robotics to assist in determining the ideal trajectory for pedicle screw placement after extensive research supporting its efficacy and efficiency. To be considered a durable and effective option, robotics need to expand beyond the indication of just placing pedicle screws. This article aims to illustrate a multi-surgeon, single-institution experience with unique applications of robotic technologies in spine surgery. We will explore accessing Kambin's Triangle in percutaneous transforaminal interbody fusion (percLIF), iliac fixation in metastatic cancer, and sacroiliac (SI) fusions. Each of these topics will be covered in depth with associated background information and subsequent discussion. We show that with proper understanding of its limitations, robots can help surgeons perform difficult surgeries in a safe manner.

Robotic-assisted percutaneous iliac screw fixation for destructive lumbosacral metastatic lesions: an early single-institution experience

BACKGROUND

Robotic-assisted surgery is becoming more widely applied in surgical subspecialties due to its intraoperative and postoperative advantages such as minimally invasive approach, reduced blood loss, shorter hospital stay, and decreased incidence of postoperative complications. However, robotic devices were only recently introduced in the field of spinal surgery. Specifically, percutaneous approaches involving computer-assisted image guidance are relatively new in iliac screw fixation. Previous methods focused on the use of S2-alar-iliac (S2AI) screw fixation which allows for pelvic fixation without a need for side connectors. However, for patients with destructive lesions of the sacrum, placement of these S2AI screws may not be feasible. The purpose of this technical note is to illustrate the implementation of robotic-assisted percutaneous iliac screw fixation in two cases which allows for minimally invasive attachment to the proximal lumbar screws without a side connector and eliminates a potential source of instrumentation failure.

METHODS

Robotic-assisted percutaneous iliac screw fixation was performed on two patients. The robotics system was used to merge the fluoroscopic images with intraoperative computed tomography (CT) images to plan the trajectories for placement of bilateral pedicle and iliac screws. Intraoperative CT scan was again performed to confirm proper placement of all screws. Rods were then engaged bilaterally with the pedicle and iliac screws without the use of side connectors.

RESULTS

The patients did not experience immediate postoperative complications and had stable hardware at one-month follow-up. Our cases demonstrate the surgical efficiency of robotic-assisted lumbo-iliac instrumentation which obviates the need to use a side connector, which is commonly used in iliac fixation. This eliminates a step, which can reduce the possibility of instrumentation failure.

CONCLUSION

Robotic-assisted percutaneous iliac screw fixation is a safe and feasible technique to improve operative and clinical outcomes in complex spinal instrumentation surgeries.

Surgical Treatment of Sacral Metastatic Tumors

Objective

This study intends to retrospectively analyze the data of patients with sacral metastases in our center, and analyze the treatment methods and therapeutic effects of sacral metastases.

Methods

73 patients with sacral metastases treated in our hospital from June 2013 to June 2019 were retrospectively analyzed. There were 54 cases of neurological symptoms, 42 cases of sacroiliac joint instability, 24 cases of lower limb muscle weakness and 19 cases of abnormal urination and defecation. Four patients with tumors below S3 underwent complete tumor resection, 23 patients with tumors above S3 and without sacroiliac joint instability underwent tumor curettage and nerve root lysis, 34 patients with tumors above S3 and sacroiliac joint instability underwent tumor curettage, nerve root release and screw rod reconstruction. 12 patients with multiple metastases underwent percutaneous radiofrequency ablation and sacroplasty. VAS was used to evaluate the preoperative and postoperative pain scores, and the postoperative pain relief, neurological function, bowel function, wound healing and complications were evaluated.

Results

There were no perioperative death, 8 cases of poor wound healing, 5 cases of nerve injury, postoperative sensory and motor loss of lower limbs. Cerebrospinal fluid (CSF) leak in 7 cases. The patients were followed up for 6-25 months (mean 12 months). The VAS scores of patients with pain symptoms were 7 points before operation and 1.44 points after operation, In 19 patients with abnormal urination and defecation function, 12 patients recovered to normal 3-6 months after operation, 5 cases had no significant change compared with preoperative, and 2 cases had aggravated symptoms; 17 cases of patients with lower limb muscle strength were significantly recovered after operation, and the average muscle strength was increased by 2 grades; 30 cases of patients with unstable sacroiliac joint got internal fixation had significantly pain relief. Pain symptoms of 9 patients were significantly relieved after percutaneous radiofrequency ablation.

Conclusion

the operation of sacral metastases mainly adopts a relatively conservative surgical method, which can effectively improve the quality of life of patients with sacral metastases by retaining the nerve function and relieving the pain of patients, combining with radiofrequency ablation, sacroplasty and targeted drugs.

Percutaneous thermal ablation of sacral metastases: Assessment of pain relief and local tumor control

PURPOSE

To retrospectively report on safety, pain relief and local tumor control achieved with percutaneous ablation of sacral bone metastases.

MATERIALS AND METHODS

From February 2009 to June 2020, 23 consecutive patients (12 women and 11 men; mean age, 60±8 [SD] years; median, 60; range: 48-80 years) with 23 sacral metastases underwent radiofrequency (RFA) or cryo-ablation (CA), with palliative or curative intent at our institution. Patients' demographics and data pertaining to treated metastases, procedure-related variables, safety, and clinical evolution following ablation were collected and analyzed. Pain was assessed with numerical pain rating scale (NPRS).

RESULTS

Sixteen (70%) patients were treated with palliative and 7 (30%) with curative intent. Mean tumor diameter was 38±19 (SD) mm (median, 36; range: 11-76). External radiation therapy had been performed on five metastases (5/23; 22%) prior to ablation. RFA was used in 9 (39%) metastases and CA in the remaining 14 (61%). Thermo-protective measures and adjuvant bone consolidation were used whilst treating 20 (87%) and 8 (35%) metastases, respectively. Five (22%) minor complications were recorded. At mean 31±21 (SD) (median, 32; range: 2-70) months follow-up mean NPRS was 2±2 (SD) (median, 1; range: 0-6) vs. 5±1 (median, 5; range: 4-8; P<0.001) at the baseline. Three metastases out of 7 (43%) undergoing curative ablation showed local progression at mean 4±4 (SD) (median, 2; range: 1-8) months follow-up.

CONCLUSION

Percutaneous ablation of sacral metastases is safe and results in significant long-lasting pain relief. Local tumor control seems sub-optimal; however, further investigations are needed to confirm these findings due to paucity of data.

Clinical presentation, management and outcomes of sacral metastases: a multicenter, retrospective cohort study

Background

Sacral metastases are rare and literature regarding their management is sparse. This multicenter, prospective, observational study aimed to determine health related-quality of life (HRQOL) and pain in patients treated for sacral metastases with surgery and/or radiation therapy (RT). The secondary objectives were to describe the adverse event (AE) profile and change in neurologic function in this population.

Methods

Twenty-three patients presenting with symptomatic sacral metastases were identified from the Epidemiology, Process and Outcomes of Spine Oncology (EPOSO) dataset, a prospective multicenter study on spinal metastases. Patients requiring surgery and/or RT between August 2013 and February 2017 were prospectively enrolled. HRQOL, assessed by the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQv2.0), the Short Form-36 version 2 (SF-36v2), and the EuroQol-5Dimension (EQ-5D) was documented at baseline, 6 weeks, 3 and 6 months post-treatment. Pain numeric rating scale (NRS), AEs, lower extremities motor score (ASIA), and bowel and bladder function were also recorded.

Results

Eight patients underwent surgery ± RT and 15 patients underwent RT alone. Mean age was 59.3 (SD 11.7) years and 13 patients were female. At 6 months, 3 (37.5%) surgical patients and 2 (13.3%) RT patients were deceased. There was a trend showing that surgical patients had worse baseline HRQOL and pain. Pain NRS, EQ-5D, SOSGOQv2.0, and the mental component of the SF-36v2 showed improvement, irrespective of treatment (P>0.05). Ten AEs occurred in the surgical cohort, dominated by wound complications (n=3). Bowel and bladder function improved at 6 weeks in both groups.

Conclusions

Surgical treatment and RT are both valid treatment options for symptomatic sacral metastases. Improvement in HRQOL can be expected with an acceptable AE rate.

Cerebrospinal fluid leaks after spine tumor resection: avoidance, recognition and management

Post-operative CSF leaks are a known complication of spine surgery in general, and patients undergoing surgical intervention for spinal tumors may be particularly predisposed due to the presence of intradural tumor and a number of other factors. Post-operative CSF leaks increase morbidity, lengthen hospital stays, prolong immobilization and subject patients to a number of associated complications. Intraoperative identification of unintended durotomies and effective primary repair of dural defects is an important first step in the prevention of post-operative CSF leaks, but in patients who develop post-operative pseudomeningoceles, durocutaneous fistulae or other CSF-leak-related sequelae, early recognition and secondary intervention are paramount to preventing further CSF-leak-related complications and achieving the best patient outcomes possible. In this article, the incidence, risk factors and complications of CSF leaks after spine tumor surgery are reviewed, with an emphasis on avoidance of post-operative CSF leaks, early post-operative identification and effective secondary intervention.

Management - spinal metastases

Due to a worldwide increase of cancer incidence and a longer life expectancy of patients with metastatic cancer, a rise in the incidence of symptomatic vertebral metastases has been observed. Metastatic spinal disease is one of the most dreaded complications of cancer as it is not only associated with severe pain, but also with paralysis, sensory loss, sexual dysfunction, urinary and fecal incontinency when the neurologic elements are compressed. Rapid diagnosis and treatment have been shown to improve both the quality and length of remaining life. This chapter on vertebral metastases with epidural disease and intramedullary spinal metastases will be discussed in terms of epidemiology, pathophysiology, demographics, clinical presentation, diagnosis, and management. With respect to treatment options, our review will summarize the evolution of conventional palliative radiation to modern stereotactic body radiotherapy for spinal metastases and the surgical evolution from traditional open procedures to minimally invasive spine surgery. Lastly, we will review the most common clinical prediction and decision rules, framework and algorithms, and guidelines that have been developed to guide treatment decision making.

Effect of early fasting and total parenteral nutrition support on the healing of incision and nutritional status in patients after sacrectomy

INTRODUCTION

Surgical site infection is one of the most common complications for patients after sacrectomy, which often accompanied by poor wound healing, sinus formation and serious metabolic disturbance.

HYPOTHESIS

We tried to avoid the surgical site infection caused by feces during early period after surgery through early fasting and total parenteral nutrition (TPN) support, then compared the clinical results of these patients with other patients that received enteral nutrition (EN) early after sacrectomy.

METHODS

Forty-eight patients after sacrectomy (the level of sacrectomy above S₂) were randomly divided into two groups: TPN group and EN group. The patients of two groups received different nutrition support from the first day to the seventh day after surgery, then the factors such as nutritional and metabolic status after surgery, incidence of complications as well as the time of incision healing and hospitalization were observed.

RESULTS

The p-value of total serum protein, albumin, serum alanine aminotransferase, total bilirubin at seventh day after sacrectomy between TPN group and EN group is <0.0005. The p-value of hemoglobin at seventh day after sacrectomy between TPN group and EN group is 0.001. The p-value of total serum protein at fourteenth day after sacrectomy between TPN group and EN group is 0.003. The p-value of albumin and total bilirubin at fourteenth day after sacrectomy between TPN group and EN group is 0.001. The p-value of hemoglobin, serum alanine aminotransferase at fourteenth day after sacrectomy between TPN group and EN group is <0.0005. The incidence of gastrointestinal complication and delay of apparition of feces in EN group were lower than that in TPN group (p=0.041, p<0.0005). The incidence of surgical site infection, the time of incision healing and hospitalization in TPN group were lower than that in EN group (p=0.048, p=0.008, p<0.0005).

CONCLUSIONS

The method of fasting and supported by TPN during the early period after sacrectomy contribute to the incision healing, meanwhile, it shortens the hospitalization time and abates the incidence of complications in patients after sacrectomy.

TYPE OF STUDY

It is a comparative randomized study.

LEVEL OF PROOF

High-powered prospective randomized trial.

What Is the Value of Surgical Intervention for Sacral Metastases?

Objective

To investigate the impact of surgery on local control and quality of life for patients with sacral metastases and to determine whether the complications of surgery were acceptable.

Methods

Curettage for metastatic lesions of the sacrum was performed in 154 patients with obvious sacral nerve compression symptoms between July 1997 and July 2014. Potential risk factors were evaluated in univariate analysis for associations with local control; multivariate conditional logistic regression was used to identify the combined effects. Complications were recorded. The pre- and postoperative visual analogue scale of pain, Eastern Cooperative Oncology Group (ECOG) scores, and quality of life scores were collected to evaluate the impact of surgery.

Results

The cumulative survival rates were 71.8%, 41.1%, and 22.5% and the local control rates were 95.4%, 90.9%, and 79.4% at 6, 12, and 24 months, respectively. Tumors with rapid growth, the lack of preoperative radiotherapy, and application of aortic balloon occlusion were significantly associated with good local control. There were 29 (18.8%) complications related to surgery. The mean pain scores were 7.04 preoperatively, 1.66 at 1 month postoperatively (p = 0.003), and 1.51 at 3 months postoperatively (p = 0.002). The mean ECOG scores were 2.82 preoperatively and 1.47 3 months postoperatively (p < 0.001). There were significant improvements from preoperatively to 3 months postoperatively in global health status (43.3 vs. 52.1), pain (62.0 vs. 33.2), and constipation (51.4 vs. 30.3) (p < 0.001).

Conclusions

Surgery for sacral metastasis is effective to palliate pain rapidly and improve constipation and quality of life and has a low rate of complications.

The Spinal Instability Neoplastic Score: Impact on Oncologic Decision-Making

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To address the following questions in a systematic literature review: 1. How is spinal neoplastic instability defined or classified in the literature before and after the introduction of the Spinal Instability Neoplastic Score (SINS)? 2. How has SINS affected daily clinical practice? 3. Can SINS be used as a prognostic tool?

SUMMARY OF BACKGROUND DATA

Spinal neoplastic-related instability was defined in 2010 and simultaneously SINS was introduced as a novel tool with criteria agreed upon by expert consensus to assess the degree of spinal stability.

METHODS

PubMed, Embase, and clinical trial databases were searched with the key words "spinal neoplasm," "spinal instability," "spinal instability neoplastic score," and synonyms. Studies describing spinal neoplastic-related instability were eligible for inclusion. Primary outcomes included studies describing and/or defining neoplastic-related instability, SINS, and studies using SINS as a prognostic factor.

RESULTS

The search identified 1414 articles, of which 51 met the inclusion criteria. No precise definition or validated assessment tool was used specific to spinal neoplastic-related instability prior to the introduction of SINS. Since the publication of SINS in 2010, the vast majority of the literature regarding spinal instability has used SINS to assess or describe instability. Twelve studies specifically investigated the prognostic value of SINS in patients who underwent radiotherapy or surgery.

CONCLUSION

No consensus could be determined regarding the definition, assessment, or reporting of neoplastic-related instability before introduction of SINS. Defining spinal neoplastic-related instability and the introduction of SINS have led to improved uniform reporting within the spinal neoplastic literature. Currently, the prognostic value of SINS is controversial.

LEVEL OF EVIDENCE

N/A.

Factors Affecting Survival in Patients Undergoing Palliative Spine Surgery for Metastatic Lung and Hepatocellular Cancer: Dose the Type of Surgery Influence the Surgical Results for Metastatic Spine Disease?

Background

Surgical treatment for metastatic spine disease has been becoming more prominent with the help of technological advances and a few favorable reports on the surgery. In cases of this peculiar condition, it is necessary to establish the role of surgery and analyze the factors affecting survival.

Methods

From January 2011 to April 2015, 119 patients were surgically treated for metastatic spine lesions. To reduce the bias along the heterogeneous cancers, the primary cancer was confined to either the lung (n = 25) or the liver (n = 18). Forty-three patients (male, 32; female, 11; mean age, 57.5 years) who had undergone palliative surgery were enrolled in this study. Posterior decompression and fusion was performed in 30 patients (P group), and anteroposterior (AP) reconstruction was performed in 13 patients (AP group) for palliative surgery. Pre- and postoperative (3 months) pain (visual analogue scale, VAS), performance status (Karnofsky performance score), neurologic status (American Spinal Injury Association [ASIA] grade), and spinal instability neoplastic score (SINS) were compared. The survival period and related hazard factors were also assessed by Kaplan-Meier and Cox regression analysis.

Results

Most patients experienced improvements in pain and performance status (12.3% ± 17.2%) at 3 months postoperatively. In terms of neurologic recovery, 9 patients (20.9%) graded ASIA D experienced neurological improvement to ASIA E while the remainder was status quo. In an analysis according to operation type, there was no significant difference in patient demographics. At 12 months postoperatively, cumulative survival rates were 31.5% and 38.7% for the P group and the AP group, respectively (p > 0.05). Survival was not affected by the pre- and postoperative pain scale, Tokuhashi score, neurologic status, SINS, or operation type. Preoperative Karnofsky performance score (hazard ratio, 0.93; 95% confidence interval [CI], 0.89 to 0.96) and improvement of performance status after surgery (hazard ratio, 0.95; 95% CI, 0.92 to 0.97) significantly affected survival after operation.

Conclusions

There was no significant difference in surgical outcomes and survival rates between posterior and AP surgery for metastatic lesions resulting from lung and hepatocellular cancer. Preoperative Karnofsky score and improvement of performance status had a significant impact on the survival rate following surgical treatment for these metastatic spine lesions.

Surgical treatment of cauda equina compression as a result of metastatic tumours of the lumbo-sacral junction and sacrum

PURPOSE

We performed a retrospective analysis of all cases of lumbo-sacral or sacral metastases presenting with compression of the cauda equina who underwent urgent surgery at our institution. Our objective was to report our experience on the clinical presentation, management and finally the surgical outcome of this cohort of patients.

METHODS

We reviewed medical notes and images of all patients with compression of the cauda equina as a result of lumbo-sacral or sacral metastases during the study period (2004-2011). The collected clinical data consisted of time of onset of symptoms, neurology (Frankel grade), ambulatory status and continence. Operative data analysed were details of surgical procedure and complications. Post-operatively, we reviewed neurological outcome, ambulation, continence, destination of discharge and survival.

RESULTS

During the 8-year study period, 20 patients [11 males, 9 females; mean age 61.8 years (29-87)] had received urgent surgery for metastatic spinal cauda compression caused by lumbo-sacral or sacral metastases. The majority of patients presented with symptoms of pain and neurological deterioration (n = 14) with onset of pain considerably longer than neurology symptoms [197 days (3-1,825) vs. 46 days (1-540)]; all patients were Frankel C (n = 2, both non-ambulatory), D (n = 13) or E (n = 5) at presentation and three patients were incontinent of urine. Operative procedures performed were posterior decompression with (out) fusion (n = 12), posterior decompression with sacroplasty (n = 1), decompression with lumbo-pelvic stabilisation with (out) kyphoplasty/sacroplasty (n = 7) and posterior decompression/reconstruction with anterior corpectomy/stabilisation (n = 2). Post-operatively, 5/20 (20 %) patients improved one Frankel grade, 1/20 (5 %) improved two grades, 13/20 (65 %) remained stable (8 D, 5 E) and 1/20 (5 %) deteriorated. All patients were ambulatory and 19/20 were continent on discharge. The mean length of stay was 7 days (4-22). There were 6/20 (30 %) complications: three major (PE, deep wound infection, implant failure) and three minor (superficial wound infection, incidental durotomy, chest infection). All patients returned back to their own home (n = 14/20, 70 %) or a nursing home (n = 6/20, 35 %). Thirteen patients are deceased (mean survival 367 days (120-603) and seven are still alive [mean survival 719 days (160-1,719)].

CONCLUSION

Surgical intervention for MSCC involving the lumbo-sacral junction or sacral spine has a high but acceptable complication rate (6/20, 30 %), and can be important in restoring/preserving neurological function, assisting with ambulatory function and allowing patients to return to their previous residence.