Spine radiosurgery for the local treatment of spine metastases: Intensity-modulated radiotherapy, image guidance, clinical aspects and future directions

Many cancer patients will develop spinal metastases. Local control is important for preventing neurologic compromise and to relieve pain. Stereotactic body radiotherapy or spinal radiosurgery is a new radiation therapy technique for spinal metastasis that can deliver a high dose of radiation to a tumor while minimizing the radiation delivered to healthy, neighboring tissues. This treatment is based on intensity-modulated radiotherapy, image guidance and rigid immobilization. Spinal radiosurgery is an increasingly utilized treatment method that improves local control and pain relief after delivering ablative doses of radiation. Here, we present a review highlighting the use of spinal radiosurgery for the treatment of metastatic tumors of the spine. The data used in the review were collected from both published studies and ongoing trials. We found that spinal radiosurgery is safe and provides excellent tumor control (up to 94% local control) and pain relief (up to 96%), independent of histology. Extensive data regarding clinical outcomes are available; however, this information has primarily been generated from retrospective and nonrandomized prospective series. Currently, two randomized trials are enrolling patients to study clinical applications of fractionation schedules spinal Radiosurgery. Additionally, a phase I clinical trial is being conducted to assess the safety of concurrent stereotactic body radiotherapy and ipilimumab for spinal metastases. Clinical trials to refine clinical indications and dose fractionation are ongoing. The concomitant use of targeted agents may produce better outcomes in the future

The baboon (Papio anubis) extracranial carotid artery: An anatomical guide for endovascular experimentation

BACKGROUND: As novel endovascular strategies are developed for treating neurological disease, there is an increasing need to evaluate these techniques in relevant preclinical models. The use of non-human primates is especially critical given their structural and physiological homology with humans. In order to conduct primate endovascular studies, a comprehensive understanding of the carotid anatomy is necessary. We therefore performed a detailed examination of the vessel lengths, lumen diameters and angles of origin of the baboon extracranial carotid system. METHODS: We characterized the extracranial carotid system often male baboons (Papio anubis, range 15.1–28.4 kg) by early post-mortem dissection. Photographic documentation of vessel lengths, lumen diameters, and angles of origin were measured for each segment of the carotid bilaterally. RESULTS: The common carotid arteries averaged 94.7 ± 1.7 mm (left) and 87.1 ± 1.6 mm (right) in length. The average minimal common carotid lumen diameters were 3.0 ± 0.3 mm (left) and 2.9 ± 0.2 mm (right). Each animal had a common brachiocephalic artery arising from the aorta which bifurcated into the left common carotid artery and right braciocephalic artery after 21.5 ± 1.6 mm. The vascular anatomy was found to be consistent among animals despite a wide range of animal weights. CONCLUSIONS: The consistency in the Papio anubis extracranial carotid system may promote the use of this species in the preclinical investigation of neuro-interventional therapies

Streamlining the Journey of Research Into Clinical Practice: Making Your Patients and Practice Flourish Understanding and Setting Treatment Expectations for Patients With Metastatic Spine Tumors

Study Design: Literature review with clinical recommendation. Objective: A concise curation of the latest spine literature exploring the relationship between expectations and satisfaction for patients with metastatic spinal disease (MSD). Deliver recommendations to practicing clinicians regarding interpretation and utilisation of this evidence. Methods: The latest spine literature in the topic of factors affecting the expectations of patients with MSD was reviewed and clinical recommendations were formulated. Recommendations are graded as strong or Conditional. Results: 5 articles were selected. Article 1: risk factors for the development of dissatisfaction from a cohort of 362 MSD patients. Strong recommendation to incorporate risk factor assessment when considering treatment. Article 2: systematic review assessing the relationship between pre-operative patient expectations and subsequent satisfaction in allied disciplines. Conditional recommendation to optimize patient expectation to positively modify patient satisfaction. Article 3: qualitative study of how clinicians, from different specialties, counsel patients with MSD pre-treatment. Strong recommendation to use a multidisciplinary approach. Article 4 qualitative study of how MSD patients experience their pre-treatment counselling and how that affected their appreciation of treatment success. Conditional recommendation to furnish patients with tailored, expected outcomes in the context of systemic progression. Article 5 Design and validation of a pre-treatment questionnaire specific to MSD. A conditional recommendation to incorporate this questionnaire in clinical and research MSD practice. Conclusion: Patients with MSD are approaching end of life care and high levels of treatment satisfaction are crucial at this juncture. The role of expectation management and comprehensive counselling is critical

An Update In The Management Of Spinal Metastases.

The best clinical treatment for spinal metastases requires an integrated approach with input from an interdisciplinary cancer team. The principle goals of treatment are maintenance or improvement in neurologic function and ambulation, spinal stability, durable tumor control, and pain relief. The past decade has witnessed an explosion of new technologies that have impacted our ability to reach these goals, such as separation surgery and minimally invasive spinal procedures. The biggest advance, however, has been the evolution of stereotactic radiosurgery that has demonstrated durable tumor control both when delivered as definitive therapy and as a postoperative adjuvant even for tumors considered markedly resistant to conventional external beam radiation. In this paper, we perform an update on the management of spinal metastases demonstrating the integration of these new technologies into a decision framework NOMS that assesses four basic aspects of a patient's spine disease: Neurologic, Oncologic, Mechanical Instability and Systemic disease.73795-80

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

An Evidence-Based Review and Survey of Expert Opinion of Reconstruction of Metastatic Spine Tumors

STUDY DESIGN.: Systematic review and consensus expert opinion. OBJECTIVE.: To provide surgeons and other health care professionals with guidelines for surgical reconstruction of metastatic spine disease based on evidence and expert opinion. SUMMARY OF BACKGROUND DATA.: The surgical treatment of spinal metastases is controversial. Specifically two aspects of surgical reconstruction are addressed in this study: choice of bone graft used during surgery for metastatic spine tumors and the design of reconstruction or construct to stabilize. METHODS.: A systematic review of the available medical literature from 1980 to 2015 was conducted, and combined with consensus expert opinion from a recent survey of spine surgeons who treat metastatic spine tumors. RESULTS.: There is very little evidence in the literature to provide guidance on the use of bone graft in metastatic tumor reconstruction. There is little evidence in the literature to support the preferential use of one graft type over the other. 41% of respondents said they used bone graft or bone graft substitutes to accomplish fusion. There were 17 studies that described the use of a prefabricated prosthetic, 10 studies describing the use of polymethyl methacrylate (PMMA) bone cement, and only 3 studies describing the use of bone graft for anterior column reconstruction. The use of structural allograft was most popular amongst the experts for anterior reconstruction, followed by cage reconstruction, and PMMA bone cement. CONCLUSIONS.: Achieving bony union may be of importance for the maintenance of spinal stability in the long-term after reconstruction. Whether bony union is required for patients with shorter life expectancies is debatable. The literature supports the use of anterior reconstruction with either a prefabricated prosthetic or PMMA bone cement. It also supports the use of an anterior construct reinforced with bilateral posterior instrumentation when performing a three column reconstruction

Molecular Markers and Targeted Therapeutics in Metastatic Tumors of the Spine: Changing the Treatment Paradigms

STUDY TYPE.: Review of the Literature OBJECTIVE.: To discuss the evolution of molecular signatures and the history and development of targeted therapeutics in metastatic tumor types affecting the spinal column. SUMMARY OF BACKGROUND DATA.: Molecular characterization of metastatic spine tumors is expected to usher in a revolution in diagnostic and treatment paradigms. Molecular characterization will provide critical information that can be used for initial diagnosis, prognosticating the ideal treatment strategy, assessment of treatment efficacy, surveillance and monitoring recurrence, and predicting complications, clinical outcome, and overall survival in patients diagnosed with metastatic cancers to the spinal column. METHODS.: A review of the literature was performed focusing on illustrative examples of the role that molecular based therapeutics have played in clinical outcomes for patients diagnosed with metastatic tumor types affecting the spinal column. RESULTS.: The impact of molecular therapeutics including receptor tyrosine kinases and immune checkpoint inhibitors and the ability of molecular signatures to provide prognostic information are discussed in metastatic breast cancer, lung cancer, prostate cancer, melanoma, and renal cell cancer affecting the spinal column. CONCLUSION.: For the providers who will ultimately counsel patients diagnosed with metastases to the spinal column, molecular advancements will radically alter the management/surgical paradigms utilized. Ultimately, the translation of these molecular advancements into routine clinical care will greatly improve the quality and quantity of life for patients diagnosed with spinal malignancies and provide better overall outcomes and counseling for treating physicians.Level of Evidence: N/