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Aziz K, Koffler D, Vassantachart A, Rattani A, Ankrah NK, Gogineni E, Andraos TY, Sahgal A, Vellayappan B, Dunne EM, Siva S, Moraes FY, Guckenberger M, Lubelski D, Chao S, Combs S, Chang E, Amin AG, Foote M, Gibbs I, Kim M, Palmer J, Lo S, Redmond KJ. Radiosurgery Society Case-Based Guide to Stereotactic Body Radiation Therapy for Challenging Cases of Spinal Metastases. Pract Radiat Oncol 2024:S1879-8500(24)00212-1. [PMID: 39233007 DOI: 10.1016/j.prro.2024.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 08/11/2024] [Accepted: 08/13/2024] [Indexed: 09/06/2024]
Abstract
PURPOSE Spinal stereotactic body radiation therapy (SBRT) has become the standard of care in management of patients with limited sites of metastatic disease, radio-resistant histologies, painful vertebral metastases with long life expectancy and cases of reirradiation. Our case-based guidelines aim to assist radiation oncologists in the appropriate utilization of SBRT for common, yet challenging, cases of spinal metastases. MATERIALS AND METHODS Cases were selected to include scenarios of large volume sacral disease with nerve entrapment, medically inoperable disease abutting the thecal sac, and local failure after prior SBRT. Relevant literature was reviewed, and areas requiring further investigation were discussed to offer a framework for evidence-based clinical practice. RESULTS Spinal SBRT can be effectively delivered in challenging cases following multidisciplinary discussion by utilizing a methodical approach to patient selection, appropriate dose selection, and adherence to evidence-based dose constraints. CONCLUSIONS The Radiosurgery Society's case-based practice review offers guidance to practicing physicians treating technically challenging SBRT candidate patients with spinal metastases.
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Affiliation(s)
- Khaled Aziz
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel Koffler
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USA
| | - April Vassantachart
- Department of Radiation Oncology, Keck School of Medicine of USC, Los Angeles, CA 90033, USA
| | - Abbas Rattani
- Department of Radiation Oncology, Tufts Medical Center, Boston, Massachusetts 02111, USA
| | - Nii-Kwanchie Ankrah
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Emile Gogineni
- Department of Radiation Oncology, Arthur G. James Cancer Hospital/The Ohio State University, Columbus, OH, USA
| | - Therese Y Andraos
- Department of Radiation Oncology, Arthur G. James Cancer Hospital/The Ohio State University, Columbus, OH, USA
| | - Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Health Science Centre, University of Toronto, Toronto, Ontario, Canada
| | - Balamurugan Vellayappan
- Department of Radiation Oncology, National University Cancer Institute Singapore, National University Hospital, Singapore
| | - Emma M Dunne
- Department of Radiation Oncology, British Columbia Cancer Agency - Vancouver Centre, Vancouver, British Columbia, Canada
| | - Shankar Siva
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
| | - Fabio Y Moraes
- Department of Oncology - Division of Radiation Oncology, Kingston Health Sciences Centre and Queen's University, Kingston, Canada
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Daniel Lubelski
- Department of Neurological Surgery, The Johns Hopkins University, Baltimore, MD 21287, USA
| | - Samuel Chao
- Department of Radiation Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, Ohio
| | - Stephanie Combs
- Department of Radiation Oncology, School of Medicine, Klinikum rechts der Isar, Technical University Munich (TUM), Munich, Germany; Institute of Radiation Medicine (IRM), Department of Radiation Sciences, Helmholtz Zentrum Munich, Neuherberg, Germany; German Cancer Consortium (DKTK), Partner Site Munich, Munich, Germany
| | - Eric Chang
- Department of Radiation Oncology, Keck School of Medicine of USC, Los Angeles, CA 90033, USA
| | - Anubhav G Amin
- Department of Neurological Surgery, University of Washington, Seattle, WA 98115, USA
| | - Matthew Foote
- Department of Radiation Oncology, Princess Alexandra Hospital, University of Queensland, and ICON Cancer Centre, Brisbane, Queensland, Australia
| | - Iris Gibbs
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Minsun Kim
- Department of Radiation Oncology, University of Washington, Seattle, WA, USA
| | - Joshua Palmer
- Department of Radiation Oncology, Arthur G. James Cancer Hospital/The Ohio State University, Columbus, OH, USA
| | - Simon Lo
- Department of Radiation Oncology, University of Washington, Seattle, WA, USA
| | - Kristin J Redmond
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Patel PP, Esposito EP, Zhu J, Chen X, Khan M, Kleinberg L, Lubelski D, Theodore N, Lo SFL, Hun Lee S, Kebaish K, Bydon A, Redmond KJ. Antiresorptive Medications Prior to Stereotactic Body Radiotherapy for Spinal Metastasis are Associated with Reduced Incidence of Vertebral Body Compression Fracture. Global Spine J 2024; 14:1778-1785. [PMID: 36749660 PMCID: PMC11268289 DOI: 10.1177/21925682231156394] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
STUDY DESIGN Retrospective Cohort. OBJECTIVE Antiresorptive drugs are often given to minimize fracture risk for bone metastases, but data regarding optimal time or ability to reduce stereotactic body radiotherapy (SBRT)-induced fracture risk is limited. This study examines the association between antiresorptive use surrounding spinal SBRT and vertebral compression fracture (VCF) incidence to provide information regarding effectiveness and optimal timing of use. METHODS Patients treated with SBRT for spinal metastases at a single institution between 2009-2020 were included. Kaplan-Meier analysis was used to compare cumulative incidence of VCF for those taking antiresorptive drugs pre-SBRT, post-SBRT only, and none at all. Cox proportional hazards and Fine-Gray competing risk models were used to identify additional factors associated with VCF. RESULTS Of the 234 patients (410 vertebrae) analyzed, 49 (20.9%) were taking bisphosphonates alone, 42 (17.9%) were taking denosumab alone, and 25 (10.7%) were taking both. Kaplan-Meier analysis revealed a statistically significant lower VCF incidence for patients initiating antiresorptive drugs before SBRT compared to those taking none at all (4% vs 12% at 1 year post-SBRT, P = .045; and 4% vs 23% at 2 years, P = .008). On multivariate analysis, denosumab duration (HR: .87, P = .378) or dose (HR: 1.00, P = .644) as well as bisphosphonate duration (HR: .98, P= .739) or dose (HR: .99, P= .741) did not have statistical significance on VCF incidence. CONCLUSION Initiating antiresorptive agents before SBRT may reduce the risk of treatment-induced VCF. Antiresorptive drugs are underutilized in patients with spine metastases and may represent a useful intervention to minimize toxicity and improve long-term outcomes.
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Affiliation(s)
- Palak P. Patel
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Edward P. Esposito
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jiafeng Zhu
- Department of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD, USA
| | - Xuguang Chen
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Majid Khan
- Department of Radiology, Thomas Jefferson University Sidney Kimmel Medical College, Philadelphia, PA, USA
| | - Lawrence Kleinberg
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Daniel Lubelski
- Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Nicholas Theodore
- Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Sheng-fu Larry Lo
- Department of Neurosurgery, Zucker School of Medicine at Hoftstra, Manhasset, NY, USA
| | - Sang Hun Lee
- Department of Orthopedic Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Khaled Kebaish
- Department of Orthopedic Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Ali Bydon
- Department of Orthopedic Surgery, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Kristin J. Redmond
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
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Berk L. The effects of high-dose radiation therapy on bone: a scoping review. Radiat Oncol J 2024; 42:95-103. [PMID: 38946071 PMCID: PMC11215508 DOI: 10.3857/roj.2023.00969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 07/02/2024] Open
Abstract
PURPOSE This scoping review presents the preclinical and clinical data on the effects of high-dose radiation therapy (RT) on bone structure and function. MATERIALS AND METHODS An extensive PubMed search was performed for the relevant questions. The data were then synthesized into a comprehensive summary of the available relevant in-vitro, preclinical and clinical literature. RESULTS In-vitro studies of high-dose RT on cell cultures show considerable damage in the viability and functional capacity of the primary cells of the bones; the osteoclasts, the osteoblasts, and the osteocytes. In-vivo animal models show that high-dose RT induces significant morphological changes to the bone, inhibits the ability of bone to repair damage, and increases the fragility of the bone. Clinical data show that there is an increasing risk over time of damage to the bone, such as fractures, after high-dose RT. CONCLUSION These findings suggest that there may be a limit to the safe dose for single-fraction RT, and the long-term consequences of high-dose RT for the patients must be considered.
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Affiliation(s)
- Lawrence Berk
- Winter Haven Hospital, Baycare Health System, Winter Haven, FL, USA
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Sacino AN, Chen H, Sahgal A, Bettegowda C, Rhines LD, Maralani P, Redmond KJ. Stereotactic body radiation therapy for spinal metastases: A new standard of care. Neuro Oncol 2024; 26:S76-S87. [PMID: 38437670 PMCID: PMC10911798 DOI: 10.1093/neuonc/noad225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024] Open
Abstract
Advancements in systemic therapies for patients with metastatic cancer have improved overall survival and, hence, the number of patients living with spinal metastases. As a result, the need for more versatile and personalized treatments for spinal metastases to optimize long-term pain and local control has become increasingly important. Stereotactic body radiation therapy (SBRT) has been developed to meet this need by providing precise and conformal delivery of ablative high-dose-per-fraction radiation in few fractions while minimizing risk of toxicity. Additionally, advances in minimally invasive surgical techniques have also greatly improved care for patients with epidural disease and/or unstable spines, which may then be combined with SBRT for durable local control. In this review, we highlight the indications and controversies of SBRT along with new surgical techniques for the treatment of spinal metastases.
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Affiliation(s)
- Amanda N Sacino
- Department of Neurosurgery, John Hopkins University, Baltimore, Maryland, USA
| | - Hanbo Chen
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Arjun Sahgal
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Chetan Bettegowda
- Department of Neurosurgery, John Hopkins University, Baltimore, Maryland, USA
| | - Laurence D Rhines
- Department of Neurosurgery, MD Anderson Cancer Center, Houston, Texas, USA
| | - Pejman Maralani
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Kristin J Redmond
- Department of Radiation and Molecular Oncology, John Hopkins University, Baltimore, Maryland, USA
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Redmond KJ, Hattangadi-Gluth J, Pollum EL, Trifiletti DM, Kim MM, Milano M. Navigating the Spinal Frontier: Recent Data on Stereotactic Body Radiation Therapy for Spine Metastases. Int J Radiat Oncol Biol Phys 2024; 118:313-317. [PMID: 38220248 DOI: 10.1016/j.ijrobp.2023.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 01/16/2024]
Affiliation(s)
- Kristin J Redmond
- Department of Radiation Oncology & Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| | | | - Erqi Liu Pollum
- Department of Radiation Oncology, Stanford University Medical Center, Stanford, California
| | | | - Michelle M Kim
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan
| | - Michael Milano
- Department of Radiation Oncology, University of Rochester, Rochester, New York
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Desai SU, Srinivasan SS, Kumbar SG, Moss IL. Hydrogel-Based Strategies for Intervertebral Disc Regeneration: Advances, Challenges and Clinical Prospects. Gels 2024; 10:62. [PMID: 38247785 PMCID: PMC10815657 DOI: 10.3390/gels10010062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 01/23/2024] Open
Abstract
Millions of people worldwide suffer from low back pain and disability associated with intervertebral disc (IVD) degeneration. IVD degeneration is highly correlated with aging, as the nucleus pulposus (NP) dehydrates and the annulus fibrosus (AF) fissures form, which often results in intervertebral disc herniation or disc space collapse and related clinical symptoms. Currently available options for treating intervertebral disc degeneration are symptoms control with therapy modalities, and/or medication, and/or surgical resection of the IVD with or without spinal fusion. As such, there is an urgent clinical demand for more effective disease-modifying treatments for this ubiquitous disorder, rather than the current paradigms focused only on symptom control. Hydrogels are unique biomaterials that have a variety of distinctive qualities, including (but not limited to) biocompatibility, highly adjustable mechanical characteristics, and most importantly, the capacity to absorb and retain water in a manner like that of native human nucleus pulposus tissue. In recent years, various hydrogels have been investigated in vitro and in vivo for the repair of intervertebral discs, some of which are ready for clinical testing. In this review, we summarize the latest findings and developments in the application of hydrogel technology for the repair and regeneration of intervertebral discs.
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Affiliation(s)
- Shivam U. Desai
- Department of Orthopedic Surgery, Central Michigan University, College of Medicine, Saginaw, MI 48602, USA
| | | | | | - Isaac L. Moss
- Department of Orthopedic Surgery, University of Connecticut, Storrs, CT 06269, USA
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Guckenberger M, Andratschke N, Belka C, Bellut D, Cuccia F, Dahele M, Guninski RS, Josipovic M, Mancosu P, Minniti G, Niyazi M, Ricardi U, Munck Af Rosenschold P, Sahgal A, Tsang Y, Verbakel W, Alongi F. ESTRO clinical practice guideline: Stereotactic body radiotherapy for spine metastases. Radiother Oncol 2024; 190:109966. [PMID: 37925107 DOI: 10.1016/j.radonc.2023.109966] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 10/18/2023] [Indexed: 11/06/2023]
Abstract
BACKGROUND AND PURPOSE Recent progress in diagnostics and treatment of metastatic cancer patients have improved survival substantially. These developments also affect local therapies, with treatment aims shifting from short-term palliation to long-term symptom or disease control. There is consequently a need to better define the value of stereotactic body radiotherapy (SBRT) for the treatment of spinal metastases. METHODS This ESTRO clinical practice guideline is based on a systematic literature review conducted according to PRISMA standards, which formed the basis for answering four key questions about the indication and practice of SBRT for spine metastases. RESULTS The analysis of the key questions based on current evidence yielded 22 recommendations and 5 statements with varying levels of endorsement, all achieving a consensus among experts of at least 75%. In the majority, the level of evidence supporting the recommendations and statements was moderate or expert opinion, only, indicating that spine SBRT is still an evolving field of clinical research. Recommendations were established concerning the selection of appropriate patients with painful spine metastases and oligometastatic disease. Recommendations about the practice of spinal SBRT covered technical planning aspects including dose and fractionation, patient positioning, immobilization and image-guided SBRT delivery. Finally, recommendations were developed regarding quality assurance protocols, including description of potential SBRT-related toxicity and risk mitigation strategies. CONCLUSIONS This ESTRO clinical practice guideline provides evidence-based recommendations and statements regarding the selection of patients with spinal metastases for SBRT and its safe implementation and practice. Enrollment of patients into well-designed prospective clinical trials addressing clinically relevant questions is considered important.
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Affiliation(s)
- M Guckenberger
- Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - N Andratschke
- Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - C Belka
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany; German Cancer Consortium (DKTK), partner site Munich, Munich, Germany; Bavarian Cancer Research Center (BZKF), Munich, Germany
| | - D Bellut
- University Hospital Zurich, University of Zurich, Department of Neurosurgery, Zurich, Switzerland
| | - F Cuccia
- ARNAS Civico Hospital, Radiation Oncology Unit, Palermo, Italy
| | - M Dahele
- Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Radiation Oncology and Cancer Center Amsterdam, de Boelelaan 1117, Amsterdam, the Netherlands
| | - R S Guninski
- Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - M Josipovic
- Department of Oncology, Centre for Cancer and Organ Diseases, Copenhagen University Hospital - Rigshospitalet, Blegdamsvej 9 2100, Copenhagen, Denmark; Department of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B 2200, Copenhagen, Denmark
| | - P Mancosu
- IRCCS Humanitas Research Hospital, Medical Physics Unit, Radiation Oncology department, via Manzoni 56 I-20089, Rozzano, Milan, Italy
| | - G Minniti
- Department of Radiological Sciences, Oncology and Anatomical Pathology Sapienza University of Rome, Rome, Italy; IRCCS Neuromed, Pozzilli, IS, Italy
| | - M Niyazi
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
| | - U Ricardi
- University of Turin, Department of Oncology, Turin, Italy
| | | | - A Sahgal
- Odette Cancer Center of the Sunnybrook Health Sciences Center, Department of Radiation Oncology, Toronto, Canada
| | - Y Tsang
- Princess Margaret Cancer Centre, Radiation Medicine Program, Toronto, Canada
| | - Wfar Verbakel
- Amsterdam University Medical Center, Department of Radiation Oncology, Amsterdam, the Netherlands
| | - F Alongi
- Advanced Radiation Department, IRCCS Ospedale Sacro Cuore Don Calabria, Negrar-Verona, Italy; University of Brescia, Italy
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Guckenberger M, Dahele M, Ong WL, Sahgal A. Stereotactic Body Radiation Therapy for Spinal Metastases: Benefits and Limitations. Semin Radiat Oncol 2023; 33:159-171. [PMID: 36990633 DOI: 10.1016/j.semradonc.2022.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Progress in biological cancer characterization, targeted systemic therapies and multimodality treatment strategies have shifted the goals of radiotherapy for spinal metastases from short-term palliation to long-term symptom control and prevention of compilations. This article gives an overview of the spine stereotactic body radiotherapy (SBRT) methodology and clinical results of SBRT in cancer patients with painful vertebral metastases, metastatic spinal cord compression, oligometastatic disease and in a reirradiation situation. Outcomes after dose-intensified SBRT are compared with results of conventional radiotherapy and patient selection criteria will be discussed. Though rates of severe toxicity after spinal SBRT are low, strategies to minimize the risk of vertebral compression fracture, radiation induced myelopathy, plexopathy and myositis are summarized, to optimize the use of SBRT in multidisciplinary management of vertebral metastases.
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Kowalchuk RO, Johnson-Tesch BA, Marion JT, Mullikin TC, Harmsen WS, Rose PS, Siontis BL, Kim DK, Costello BA, Morris JM, Gao RW, Shiraishi S, Lucido JJ, Sio TT, Trifiletti DM, Olivier KR, Owen D, Stish BJ, Waddle MR, Laack NN, Park SS, Brown PD, Merrell KW. Development and Assessment of a Predictive Score for Vertebral Compression Fracture After Stereotactic Body Radiation Therapy for Spinal Metastases. JAMA Oncol 2022; 8:412-419. [PMID: 35084429 PMCID: PMC8796057 DOI: 10.1001/jamaoncol.2021.7008] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
IMPORTANCE Vertebral compression fracture (VCF) is a potential adverse effect following treatment with stereotactic body radiation therapy (SBRT) for spinal metastases. OBJECTIVE To develop and assess a risk stratification model for VCF after SBRT. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study conducted at a high-volume referral center included 331 patients who had undergone 464 spine SBRT treatments from December 2007 through October 2019. Data analysis was conducted from November 1, 2020, to August 17, 2021. Exclusions included proton therapy, prior surgical intervention, vertebroplasty, or missing data. EXPOSURES One and 3 fraction spine SBRT treatments were most commonly delivered. Single-fraction treatments generally involved prescribed doses of 16 to 24 Gy (median, 20 Gy; range, 16-30 Gy) to gross disease compared with multifraction treatment that delivered a median of 30 Gy (range, 21-50 Gy). MAIN OUTCOMES AND MEASURES The VCF and radiography components of the spinal instability neoplastic score were determined by a radiologist. Recursive partitioning analysis was conducted using separate training (70%), internal validation (15%), and test (15%) sets. The log-rank test was the criterion for node splitting. RESULTS Of the 331 participants, 88 were women (27%), and the mean (IQR) age was 63 (59-72) years. With a median follow-up of 21 months (IQR, 11-39 months), we identified 84 VCFs (18%), including 65 (77%) de novo and 19 (23%) progressive fractures. There was a median of 9 months (IQR, 3-21 months) to developing a VCF. From 15 candidate variables, 6 were identified using the backward selection method, feature importance testing, and a correlation heatmap. Four were selected via recursive partitioning analysis: epidural tumor extension, lumbar location, gross tumor volume of more than 10 cc, and a spinal instability neoplastic score of more than 6. One point was assigned to each variable, and the resulting multivariable Cox model had a concordance of 0.760. The hazard ratio per 1-point increase for VCF was 1.93 (95% CI, 1.62-2.30; P < .001). The cumulative incidence of VCF at 2 years (with death as a competing risk) was 6.7% (95% CI, 4.2%-10.7%) for low-risk (score, 0-1; 273 [58.3%]), 17.0% (95% CI, 10.8%-26.7%) for intermediate-risk (score, 2; 99 [21.3%]), and 35.4% (95% CI, 26.7%-46.9%) for high-risk cases (score, 3-4; 92 [19.8%]) (P < .001). Similar results were observed for freedom from VCF using stratification. CONCLUSIONS AND RELEVANCE The results of this cohort study identify a subgroup of patients with high risk for VCF following treatment with SBRT who may potentially benefit from undergoing prophylactic spinal stabilization or vertebroplasty.
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Affiliation(s)
| | | | | | - Trey C. Mullikin
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - William S. Harmsen
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, Minnesota
| | - Peter S. Rose
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
| | | | - Dong Kun Kim
- Department of Radiology, Mayo Clinic, Rochester, Minnesota
| | | | | | - Robert W. Gao
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Satomi Shiraishi
- Division of Medical Physics, Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - John J. Lucido
- Division of Medical Physics, Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Terence T. Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona
| | | | | | - Dawn Owen
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Bradley J. Stish
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Mark R. Waddle
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Nadia N. Laack
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Sean S. Park
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Paul D. Brown
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
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