A critical appraisal of clinical practice guidelines on surgical treatments for spinal metastasis

PURPOSE

As an important treatment for spinal metastasis, surgery has strict applicable conditions. Although various organizations have formulated different guidelines on surgical treatment for spinal metastasis (SM), there are certain differences in the content, standardization and quality of the guidelines and it is necessary to make a critical appraisal of them. We aim to systematically review and appraise the current guidelines on surgical treatments of SM and summarize the related recommendations with the quality evaluation of supporting evidence, as to provide a reference for the standardization of surgical treatment plans, and help clinical front-line medical workers can make safe and effective clinical decisions faster.

METHODS

We searched Pubmed, Web of Science, and Embase for three major databases and online guideline databases. According to certain inclusion and exclusion criteria, the latest guidelines on the surgical treatment of SM were sorted out. AGREE II was used to evaluated the guideline's quality, and we extracted and compared the recommended treatment content of each guideline with evaluating by the evidence-grading scale.

RESULTS

Eight guidelines from 2013 to 2019 were included. Seven guidelines are comprehensive guidelines and one related to the reconstructive surgery of SM. Five guidelines were evaluated as "recommended," and three guidelines were evaluated as "recommended with modifications." Regarding the indications of surgery with SM, four guidelines, seven guidelines, seven guidelines, three guidelines and three guidelines recommended surgical treatment for patients with SM with intractable pain, mechanical instability, metastatic epidural spinal cord compression (MESCC), recurrent spinal metastasis (RSM), and survival predication, respectively. Regarding the surgical strategies, three guidelines recommended minimally invasive therapy but had strict indications. Six guidelines and five guidelines recommend palliative surgery and with receiving radiation therapy, respectively. For the aggressive surgery, only one guideline recommended to apply to patients in good general conditions who has isolated symptomatic SM. Regarding the surgical reconstructions, one guideline didn't recommend iliac bone graft and three guidelines recommended PMMA bone cement.

CONCLUSION

Most of the guidelines do not provide clear criteria for surgical application and provide more of a basic framework. The level of evidence for these surgical recommendations ranges from LOE B to D, and almost all guidelines recommend vertebroplasty and kyphoplasty, but for palliative and more aggressive surgery, which recommended to personalize specific surgical strategies with multidisciplinary collaboration.

Pulsed Electric Fields in Oncology: A Snapshot of Current Clinical Practices and Research Directions from the 4th World Congress of Electroporation

The 4th World Congress of Electroporation (Copenhagen, 9-13 October 2022) provided a unique opportunity to convene leading experts in pulsed electric fields (PEF). PEF-based therapies harness electric fields to produce therapeutically useful effects on cancers and represent a valuable option for a variety of patients. As such, irreversible electroporation (IRE), gene electrotransfer (GET), electrochemotherapy (ECT), calcium electroporation (Ca-EP), and tumour-treating fields (TTF) are on the rise. Still, their full therapeutic potential remains underappreciated, and the field faces fragmentation, as shown by parallel maturation and differences in the stages of development and regulatory approval worldwide. This narrative review provides a glimpse of PEF-based techniques, including key mechanisms, clinical indications, and advances in therapy; finally, it offers insights into current research directions. By highlighting a common ground, the authors aim to break silos, strengthen cross-functional collaboration, and pave the way to novel possibilities for intervention. Intriguingly, beyond their peculiar mechanism of action, PEF-based therapies share technical interconnections and multifaceted biological effects (e.g., vascular, immunological) worth exploiting in combinatorial strategies.

Treatment of Metastatic Spinal Disease; what the Radiologist needs to know

Advancements in technology and multidisciplinary management have revolutionized the treatment of spinal metastases. Imaging plays a pivotal role in determining the treatment course for spinal metastases. This article aims to review the relevant imaging findings in spinal metastases from the perspective of the treating clinician, describe the various treatment options, and discuss factors influencing choice for each available treatment option. Cases that once required radical surgical resection or low-dose conventional external beam radiation therapy, or both, are now being managed with separation surgery, spine stereotactic radiosurgery/stereotactic body radiation therapy, or both, with decreased morbidity, improved local control, and more durable pain control. The primary focus in determining treatment choice is now on tumor control outcomes, treatment-related morbidity, and quality of life.

Osteolytic vs. Osteoblastic Metastatic Lesion: Computational Modeling of the Mechanical Behavior in the Human Vertebra after Screws Fixation Procedure

Metastatic lesions compromise the mechanical integrity of vertebrae, increasing the fracture risk. Screw fixation is usually performed to guarantee spinal stability and prevent dramatic fracture events. Accordingly, predicting the overall mechanical response in such conditions is critical to planning and optimizing surgical treatment. This work proposes an image-based finite element computational approach describing the mechanical behavior of a patient-specific instrumented metastatic vertebra by assessing the effect of lesion size, location, type, and shape on the fracture load and fracture patterns under physiological loading conditions. A specific constitutive model for metastasis is integrated to account for the effect of the diseased tissue on the bone material properties. Computational results demonstrate that size, location, and type of metastasis significantly affect the overall vertebral mechanical response and suggest a better way to account for these parameters in estimating the fracture risk. Combining multiple osteolytic lesions to account for the irregular shape of the overall metastatic tissue does not significantly affect the vertebra fracture load. In addition, the combination of loading mode and metastasis type is shown for the first time as a critical modeling parameter in determining fracture risk. The proposed computational approach moves toward defining a clinically integrated tool to improve the management of metastatic vertebrae and quantitatively evaluate fracture risk.

Effect of the Timing of Surgery on Neurological Recovery for Patients with Incomplete Paraplegia Caused by Metastatic Spinal Cord Compression

Objective

This study aimed to investigate the effect of timing of surgery on neurological recovery for patients with metastatic spinal cord compression (MSCC).

Methods

According to the timing of surgery, 75 patients with incomplete paraplegia caused by MSCC were assigned to 3 groups: within 3 days (group A), between 4 days and 7 days (group B), and after 7 days (group C). T-test, one-way ANOVA, Mann–Whitney U-test, and Chi-square test were used to evaluate the difference in the improvement of American Spinal Injury Association Impairment Scale (AIS) and ambulatory status, the incidence of perioperative complications, surgical site infection, and the length of hospital stay between 3 groups.

Results

Patients with incomplete paraplegia treated in our department had an average of 17.4±1.8 days delayed and most occurred before hospitalization (4.0±0.4 vs 13.2±1.8, P<0.001). There was no significant difference in the AIS improvement between patients with different pre-op AIS. The timing of surgery was significantly correlated with AIS improvement (correlation coefficient=−0.257, P=0.019). Sub-analysis showed that patients who underwent surgery within 7 days (group A and group B) had significantly better AIS improvement compared with group C (improved at least 1 grade, P=0.043; improved more than 1 grade, P=0.039) and the surgery timing was more important for patients with AIS B and C. The timing of surgery was significantly correlated with the length of hospital stay (correlation coefficient=0.335, P=0.003). Patients of group C had the longest length of hospital stay (P=0.002). The incidence of perioperative complications and surgical site infection did not differ significantly between the 3 groups.

Conclusion

Delay surgery was common in incomplete paraplegia patients with MSCC. Patients with AIS B and C who underwent surgery within 7 days had better AIS improvement.

Machine Learning Algorithm Guiding Local Treatment Decisions to Reduce Pain for Lung Cancer Patients with Bone Metastases, a Prospective Cohort Study

INTRODUCTION

As life expectancy increases for lung cancer patients with bone metastases, the need for personalized local treatment to reduce pain is expanding.

METHODS

Patients were treated by a multidisciplinary team (MDT), and local treatment including surgery, percutaneous osteoplasty, or radiation. Visual analog scale (VAS) and quality of life (QoL) scores were analyzed. VAS at 12 weeks after treatment was the main outcome. We developed and tested machine learning models to predict which patients should receive local treatment. Model discrimination was evaluated by the area under curve (AUC), and the best model was used for prospective decision-making accuracy validation.

RESULTS

Under the direction of MDT, 161 patients in the training set, 32 patients in the test set, and 36 patients in the validation set underwent local treatment. VAS in surgery, percutaneous osteoplasty, and radiation groups decreased significantly to 4.78 ± 1.28, 4.37 ± 1.36, and 5.39 ± 1.31 at 12 weeks, respectively (p < 0.05), with no significant differences among the three datasets, and improved QoL was also observed (p < 0.05). A decision tree (DT) model that included VAS, bone metastases character, Frankel classification, Mirels score, age, driver gene, aldehyde dehydrogenase 2, and enolase 1 expression had a best AUC in predicting whether patients would receive local treatment of 0.92 (95% CI 0.89-0.94) in the training set, 0.85 (95% CI 0.77-0.94) in the test set, and 0.88 (95% CI 0.81-0.96) in the validation set.

CONCLUSION

Local treatment provided significant pain relief and improved QoL. There were no significant differences in reducing pain and improving QoL among training, test, and validation sets. The DT model was best at determining whether patients should receive local treatment. Our machine learning model can help guide clinicians to make local treatment decisions to reduce pain.

TRIAL REGISTRATION

Trial registration number ChiCRT-ROC-16009501.

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.

Electrochemotherapy of superficial tumors - Current status:: Basic principles, operating procedures, shared indications, and emerging applications

Treatment of superficial tumors with electrochemotherapy (ECT) has shown a steep rise over the past decade and indications range from skin cancers to locally advanced or metastatic neoplasms. Based on reversible electroporation, which is a physical method to achieve transient tumor cell membrane permeabilization by means of short electric pulses, ECT increases cellular uptake of bleomycin and cisplatin and their cytotoxicity by 8,000- and 80-fold, respectively. Standard operating procedures were established in 2006 and updated in 2018. Ease of administration, patient tolerability, efficacy across histotypes, and repeatability are peculiar advantages, which make standard ECT (ie, ECT using fixed-geometry electrodes) a reliable option for controlling superficial tumor growth locally and preventing their morbidity. Consolidated indications include superficial metastatic melanoma, breast cancer, head and neck skin tumors, nonmelanoma skin cancers, and Kaposi sarcoma. In well-selected patients with oropharyngeal cancers, ECT ensures appreciable symptom control. Emerging applications include skin metastases from visceral or hematological malignancies, vulvar cancer, and some noncancerous skin lesions (keloids and capillary vascular malformations). Repeatability and integration with other oncologic therapies allow for consolidation of response and sustained tumor control. In this review, we present the basic principles of ECT, recently updated operating procedures, anesthesiological management, and provide a synthesis of the efficacy of standard ECT across histotypes.

Biomimetic 3D-printed custom-made prosthesis for anterior column reconstruction in the thoracolumbar spine: a tailored option following en bloc resection for spinal tumors : Preliminary results on a case-series of 13 patients

PURPOSE

Various techniques for anterior column reconstruction have been described after en bloc resection of spinal tumors. Limited evidence exists regarding one being superior to another. The purpose of this study is to evaluate 3D-printed vertebral bodies for spinal reconstruction after en bloc resection in the thoracolumbar spine.

METHODS

Prospective observational study on custom-made 3D-printed titanium reconstruction of vertebral bodies after en bloc resection for spinal tumor was conducted between November 2015 and June 2017. 3D-printed vertebral bodies were monitored for mechanical complications such as (1) migration, (2) subsidence into the adjacent vertebral bodies, and/or (3) breakage. Complications and related details were recorded.

RESULTS

Thirteen patients (7 females and 6 males) were enrolled, and reconstruction of the anterior column was performed using custom-made 3D-printed titanium prosthesis after en bloc resection for spinal tumor (8 primary bone tumors and 5 solitary metastases). Subsidence into the adjacent vertebral bodies occurred in all patients at both proximal and distal bone-implant interfaces; however, it was clinically irrelevant (asymptomatic, and no consequences on posterior instrumentation), in 11 out of 12 patients (92%). In 1 patient (#4), severity of the subsidence led to revision of the construct. At an average 10-month follow-up (range 2-16), 1 implant was removed due to local recurrence of the disease and 1 was revisioned due to progressive distal junctional kyphosis.

CONCLUSION

Preliminary results from this series suggest that 3D printing can be effectively used to produce custom-made prosthesis for anterior column reconstruction. These slides can be retrieved under Electronic Supplementary Material.

Is endoprosthesis safer than internal fixation for metastatic disease of the proximal femur? A systematic review

INTRODUCTION

Metastases to the proximal femur are usually managed surgically by tumor resection and reconstruction with an endoprosthesis, or by fixation with osteosynthesis. Still controversy remains regarding the most appropriate surgical treatment. We posed the following questions: (1) Is the frequency of surgical revision greater in patients treated with internal fixation than endoprosthetic reconstruction, and (2) Do complications that do not require surgery occur more frequently in patients treated with internal fixation rather than in those with endoprosthetic reconstruction?

MATERIALS AND METHODS

A systematic review was performed of those studies reporting on surgical revision and complication rates comparing the two surgical methods. Ten studies including 1107 patients met the inclusion criteria, three with high methodological quality, three intermediate, and four with lowquality, according to the STROBE guidelines.

RESULTS

At present, prosthetic dislocation is the most common complication observed in patients managed by prosthesis replacement of the proximal femur, while loosening was the main cause of reoperation in the fixation group. Time to reintervention ranged from 3 to 11.6 months for the prosthetic replacement and from 7.8 to 22.3 months for the fixation group. Non surgical complications, (mainly dislocations and infections) were more commonly observed in patients operated on by prosthetic replacement.

CONCLUSIONS

Implant related complications and surgery-related morbidity should be taken into account in the decision-making process for the surgical management of these patients. These data can improve the surgeon-patient communication and guide further studies on patients' survival and complications with respect to surgery.

Surgical management of spinal fractures and neurological involvement in patients with myeloma

INTRODUCTION

Multiple Myeloma (MM) typically involves the spine and causes bone pain, pathological fractures and spinal cord compression with possible consequent neurological deficits. This retrospective study reports the results of surgery on a selected population of patients who underwent surgery for symptomatic spinal myeloma.

MATERIALS AND METHODS

A total of 26 patients who underwent surgery for spinal myeloma with neurological involvement were studied retrospectively. Neurological evaluation was performed according to the Frankel grade. Characteristics of this population, reconstructive techniques and surgery-related complications were reviewed.

RESULTS

The tumours involved the thoracic spine in 13 patients, the lumbar spine in 10 patients, and the cervical spine in three patients. The most common approach was a posterior-only approach (70%), followed by a staged, combined approach (20%), and an anterior-only approach (10%). The mean postoperative survival time was 43 months (range: 8-60 months). A significant improvement in neurological function was observed in the study population after surgery (p=0.001). There were seven early postoperative complications, two late complications and five surgery-related complications.

DISCUSSION

Surgery in selected patients affected by spinal myeloma with neurological involvement is associated with good clinical outcomes and neurological recovery and an acceptable rate of complications. Neurological deficit and segmental instability can be treated sufficiently in most cases by the implementation of a posterior-only approach; however, the final treatment should, when possible, include adjuvant chemotherapy and radiotherapy and rigorous bracing.

How do we estimate survival? External validation of a tool for survival estimation in patients with metastatic bone disease-decision analysis and comparison of three international patient populations

Background

We recently developed a clinical decision support tool, capable of estimating the likelihood of survival at 3 and 12 months following surgery for patients with operable skeletal metastases. After making it publicly available on www.PATHFx.org, we attempted to externally validate it using independent, international data.

Methods

We collected data from patients treated at 13 Italian orthopaedic oncology referral centers between 2010 and 2013, then applied to PATHFx, which generated a probability of survival at three and 12-months for each patient. We assessed accuracy using the area under the receiver-operating characteristic curve (AUC), clinical utility using Decision Curve Analysis (DCA), and compared the Italian patient data to the training set (United States) and first external validation set (Scandinavia).

Results

The Italian dataset contained 287 records with at least 12 months follow-up information. The AUCs for the three-month and 12-month estimates was 0.80 and 0.77, respectively. There were missing data, including the surgeon’s estimate of survival that was missing in the majority of records. Physiologically, Italian patients were similar to patients in the training and first validation sets. However notable differences were observed in the proportion of those surviving three and 12-months, suggesting differences in referral patterns and perhaps indications for surgery.

Conclusions

PATHFx was successfully validated in an Italian dataset containing missing data. This study demonstrates its broad applicability to European patients, even in centers with differing treatment philosophies from those previously studied.