Manejo actual de las metástasis vertebrales: un trabajo en equipo / Current management of vertebral metastases: teamwork

La enfermedad metastásica vertebral es frecuente en los pacientes con cáncer avanzado, y conlleva a complicaciones inherentes a su progresión, como lo son la fractura patológica vertebral y la compresión neural metastásica. Se realizó una revisión de los aspectos terapéuticos actuales del manejo de la progresión y de las complicaciones de la enfermedad metastásica vertebral, enfatizando su enfrentamiento sistémico y personalizado. Nuestro objetivo principal es proporcionar información sobre el tratamiento actual de esta afección y la utilidad del manejo sistémico y multidisciplinario.

Metastatic spinal disease is common in patients with advanced cancer, and leads to complications inherent in its progression, such as pathological vertebral fracture and metastatic neural compression. A review of the current therapeutic aspects regarding the progression and complications of metastatic spinal disease was performed, highlighting its systemic, personalized approach. Our aim is to provide information about the current treatment of this condition and the usefulness of its systemic and multidisciplinary management.

The evolution of surgical management for vertebral column tumors.

In BriefThere has been a significant shift in treatment paradigms for both primary and metastatic spine tumors over the last several decades. This article highlights some of the more important treatment advances that practitioners should be made aware of. It is important to not only incorporate these changes into individual practice but also appreciate the treatment trends that herald a significantly different future for spine tumor treatment.

Treatment planning for spinal radiosurgery : A competitive multiplatform benchmark challenge.

PURPOSE: To investigate the quality of treatment plans of spinal radiosurgery derived from different planning and delivery systems. The comparisons include robotic delivery and intensity modulated arc therapy (IMAT) approaches. Multiple centers with equal systems were used to reduce a bias based on individual's planning abilities. The study used a series of three complex spine lesions to maximize the difference in plan quality among the various approaches. METHODS: Internationally recognized experts in the field of treatment planning and spinal radiosurgery from 12 centers with various treatment planning systems participated. For a complex spinal lesion, the results were compared against a previously published benchmark plan derived for CyberKnife radiosurgery (CKRS) using circular cones only. For two additional cases, one with multiple small lesions infiltrating three vertebrae and a single vertebra lesion treated with integrated boost, the results were compared against a benchmark plan generated using a best practice guideline for CKRS. All plans were rated based on a previously established ranking system. RESULTS: All 12 centers could reach equality (n = 4) or outperform (n = 8) the benchmark plan. For the multiple lesions and the single vertebra lesion plan only 5 and 3 of the 12 centers, respectively, reached equality or outperformed the best practice benchmark plan. However, the absolute differences in target and critical structure dosimetry were small and strongly planner-dependent rather than system-dependent. Overall, gantry-based IMAT with simple planning techniques (two coplanar arcs) produced faster treatments and significantly outperformed static gantry intensity modulated radiation therapy (IMRT) and multileaf collimator (MLC) or non-MLC CKRS treatment plan quality regardless of the system (mean rank out of 4 was 1.2 vs. 3.1, p = 0.002). CONCLUSIONS: High plan quality for complex spinal radiosurgery was achieved among all systems and all participating centers in this planning challenge. This study concludes that simple IMAT techniques can generate significantly better plan quality compared to previous established CKRS benchmarks.

Current Treatment of Metastatic Spine Tumors - Surgery and Stereotactic Radiosurgery.

There has been significant progress and innovation in the treatment of patients with metastatic spinal tumors over the last two to three decades that has impacted our ability to provide individualized care that improves a patient's quality of life and degree of neurologic impairment. Advances in surgical techniques and radiation delivery modalities have dramatically improved our ability to decrease local tumor recurrence rates, improve pain control, and provide more durable spinal stability. Modern day spine tumor resection and reconstruction techniques have been shown to improve and prolong patients' ability to ambulate, maintain continence, and reduce the need for pain medications. Spinal radiosurgery, the focused delivery of radiation to a target in the spine, has significantly enhanced the ability to provide a high degree of local tumor control in a non-invasive manner, even for tumors that are deemed radioresistant by conventional radiation therapy standards. In most patients, a combination of treatment modalities, including both surgery and radiation, is the mainstay of any comprehensive treatment plan for metastatic spinal tumors. [Full article available at http://rimed.org/rimedicaljournal-2017-06.asp].

Spine radiosurgery: lessons learned from the first 100 treatment sessions.

OBJECTIVE Local therapy to spine tumors has been shown to be effective in selected cases. Spinal radiosurgery (SRS) is an evolving radiotherapy regimen allowing for noninvasive, highly efficacious local treatment. The learning curve can compromise the results of any newly employed technology and should be studied to minimize its effects. In this paper the first 100 SRSs performed at several medical centers are presented and analyzed for the effects of the learning curve on outcome. METHODS A retrospective analysis was undertaken to evaluate data from patients treated with SRS at Sheba Medical Center and Assuta Medical Centers in the period from September 2011 to February 2016. Medical history, clinical and neurological findings, pathological diagnoses, SRS variables, complications, and follow-up data were collected and analyzed. Local control rates were calculated, and local treatment failure cases were qualitatively studied. RESULTS One hundred treatment sessions were performed for 118 lesions at 179 spinal levels in 80 patients. The complication rate was low and did not correlate with a learning curve. Mean follow-up time was 302 days, and the overall local control rate was 95%. The local control rate was dose dependent and increased from 87% (among 35 patients receiving a dose of 16 Gy) to 97% (among 65 patients receiving a dose of 18 Gy). The 6 treatment failure cases are discussed in detail. CONCLUSIONS Spinal radiosurgery is a safe and effective treatment. Comprehensive education of the treating team and continuous communication are essential to limit the effects of the learning curve on outcome.

Clinical analysis of spinal stereotactic radiosurgery in the treatment of neurogenic tumors.

OBJECT: In this study the authors sought to evaluate clinical outcomes after using stereotactic radiosurgery (SRS) to treat benign and malignant spinal neurogenic tumors. METHODS: The authors reviewed a total of 66 procedures of spinal SRS performed between 2001 and 2013 for 110 tumors in 58 patients with spinal neurogenic tumors, which included schwannomas, neurofibromas, and malignant peripheral nerve sheath tumors (MPNSTs). The clinical and radiological findings were evaluated in patients with benign neurogenic tumors. For the 4 patients with MPNSTs, the authors reported overall survival and results of additional immunohistochemical staining to predict the survival difference among the patients. RESULTS: Of the 92 benign neurogenic tumors, 65 tumors that were serially followed up using MRI after SRS showed significant change in mean tumor volume, from a mean of 12.0 ± 2.6 cm3 pre-SRS to 10.8 ± 2.5 cm3 post-SRS (p = 0.027), over an average of 44 months. The local control rate of benign neurogenic tumors was 95.4%. The 34 patients who presented with clinical symptoms of pain showed a significant symptomatic improvement. The initial mean visual analog scale (VAS) score was 6.0 and decreased dramatically to 1.0 after SRS during an average follow-up period of 10.9 months (median of 8.1 months). Although the proportions of transient swelling and loss of intramural enhancement were significantly different among the groups, there was no statistically significant correlation between those 2 factors and local tumor control (p = 0.253 and 0.067, respectively; Fisher's exact text). Cross-table analysis also indicated that there was no statistically significant relationship between groups with loss of intramural enhancement and transient swelling. The median survival of neurofibromatosis Type 1 (NF1)-related and sporadic MPNSTs was 1.13 and 5.8 years, respectively. Immunohistochemical results showed that S100 was expressed in a sporadic MPNST or neurofibroma, whereas topoisomerase-IIa was expressed in NF1-related MPNSTs. CONCLUSIONS: SRS is an effective treatment modality for benign neurogenic tumors, while MPNSTs showed heterogeneity in their responses to SRS.

Dosimetric impact of angular deviations in positioning for spinal radiosurgery.

PURPOSE: During image-guided radiosurgery, it is common to account only for translational shifts while leaving rotational deviations uncorrected. The aim of this study is to investigate the rotational setup deviations and estimate the dosimetric impact in spinal radiosurgery. MATERIALS AND METHODS: Stereoscopic image registrations of 711 spine radiosurgery procedures (546 patients) were retrospectively reviewed and classified to cervical (C), thoracic (T), and lumbar (L) spines. The probability of rotational deviations were estimated in three orthogonal axis. In order to investigate the dosimetric impact, the original simulation CT images were rotated in the range of ±5 deg in each axis. Then, the dosimetric changes were recorded; including the coverage (V90) and minimum dose (Dmin) to the target, and the dose of 10% volume (D10) and maximum dose (Dmax) to the spinal cord. RESULTS: Target rotations of >5 deg and >3 deg occurred respectively in 1% and 8% of cases. The mean rotations were small (|µ|<0.6 deg) with no axis and site dependent trends. The standard deviations (σ) of different sites and axes ranged from 1.4 to 2.0 deg (mean σ=1.7 deg). The overall dosimetric changes of the target coverage(V90) and cord D10 were small. Five degree rotation resulted in a target V90 decrease of 1±1%, 2±2% and 3±1%, respectively in the lateral, vertical, and longitudinal axes. The corresponding cord D10 increased by 3±6%, 2±2%, and 6±5%. The changes in cord Dmax ranged from 92% to 138% of the original reference spinal cord. Corresponding changes in target Dmin were 59~106%. CONCLUSION: Large target rotations occurred in a small percentage of patients. The overall dosimetric impact on target coverage and cord D10 was small. However larger effects were observed on the target Dmin and cord Dmax. Special care must be taken for targets of elongated shapes involving multiple vertebrae.

Radiosurgery for Spinal Lesions

Spinal Stereotactic Radiosurgery (SRS) has become an important treatment modality for a broad range of spinal tumors and spinal vascular lesions. Recent clinical acceptance and awareness of the usefulness of spinal radiosurgery has escalated with the development of modern radiosurgical technology. Image-guided navigation systems incorporating non-invasive fiducial tracking and virtual simulation planning systems have made spinal radiosurgery increasingly effective and expanded the range of clinical applications for which it can be effectively used. Additional improvements such as Intensity Modulation and Micro-Multileaf Collimation that allow the accurate modulating and shaping of the radiation beam have also contributed greatly to the ability of clinicians to treat irregular and critically located lesions with greatly reduced collateral risk. Spinal Radiosurgery for spinal tumors can achieve similar clinical results to cranial stereotactic radiosurgery for brain tumors in terms of achieving local tumor control and improving quality of life and survival rates. Stereotactic radiosurgery, which has long been used for the treatment of intracranial lesions, is now recognized to be a viable option for treating spinal tumors and spinal vascular lesions.