J Benjamin Jackson1, Anthony J Crimaldi2, Richard Peindl3, H James Norton4, William E Anderson4, Joshua C Patt5. 1. Department of Orthopedics, University of South Carolina, Columbia, SC. 2. Department of Radiation Oncology, Levine Cancer Institute, Carolinas HealthCare System, Charlotte, NC. 3. Orthopedic Engineering Research, Carolinas Medical Center, Charlotte, NC. 4. Dickson Advanced Analytics, Carolinas HealthCare System, Charlotte, NC. 5. Department of Orthopedic Surgery, Carolinas Medical Center, Levine Cancer Institute, Charlotte, NC.
Abstract
STUDY DESIGN: Cadaveric model. OBJECTIVES: To compare the effect of PEEK versus conventional implants on scatter radiation to a simulated tumor bed in the spine SUMMARY OF BACKGROUND DATA.: Given the highly vasculature nature of the spine, it is the most common place for bony metastases. After surgical treatment of a spinal metastasis, adjuvant radiation therapy is typically administered. Radiation dosing is primarily limited by toxicity to the spinal cord. The scatter effect caused by metallic implants decreases the accuracy of dosing and can unintentionally increase the effective dose seen by the spinal cord. This represents a dose-limiting factor for therapeutic radiation postoperatively. METHODS: A cadaveric thorax specimen was utilized as a metastatic tumor model with two separate three-level spine constructs (one upper thoracic and one lower thoracic). Each construct was examined independently. All four groups compared included identical posterior instrumentation. The anterior constructs consisted of either: an anterior polyether ether ketone (PEEK) cage, an anterior titanium cage, an anterior bone cement cage (polymethyl methacrylate), or a control group with posterior instrumentation alone. Each construct had six thermoluminescent detectors to measure the radiation dose. RESULTS: The mean dose was similar across all constructs and locations. There was more variability in the upper thoracic spine irrespective of the construct type. The PEEK construct had a more uniform dose distribution with a standard deviation of 9.76. The standard deviation of the others constructs was 14.26 for the control group, 19.31 for the titanium cage, and 21.57 for the cement (polymethyl methacrylate) construct. CONCLUSION: The PEEK inter-body cage resulted in a significantly more uniform distribution of therapeutic radiation in the spine when compared with the other constructs. This may allow for the application of higher effective dosing to the tumor bed for spinal metastases without increasing spinal cord toxicity with either fractionated or hypofractionated radiotherapy. LEVEL OF EVIDENCE: N/A.
STUDY DESIGN: Cadaveric model. OBJECTIVES: To compare the effect of PEEK versus conventional implants on scatter radiation to a simulated tumor bed in the spine SUMMARY OF BACKGROUND DATA.: Given the highly vasculature nature of the spine, it is the most common place for bony metastases. After surgical treatment of a spinal metastasis, adjuvant radiation therapy is typically administered. Radiation dosing is primarily limited by toxicity to the spinal cord. The scatter effect caused by metallic implants decreases the accuracy of dosing and can unintentionally increase the effective dose seen by the spinal cord. This represents a dose-limiting factor for therapeutic radiation postoperatively. METHODS: A cadaveric thorax specimen was utilized as a metastatic tumor model with two separate three-level spine constructs (one upper thoracic and one lower thoracic). Each construct was examined independently. All four groups compared included identical posterior instrumentation. The anterior constructs consisted of either: an anterior polyether ether ketone (PEEK) cage, an anterior titanium cage, an anterior bone cement cage (polymethyl methacrylate), or a control group with posterior instrumentation alone. Each construct had six thermoluminescent detectors to measure the radiation dose. RESULTS: The mean dose was similar across all constructs and locations. There was more variability in the upper thoracic spine irrespective of the construct type. The PEEK construct had a more uniform dose distribution with a standard deviation of 9.76. The standard deviation of the others constructs was 14.26 for the control group, 19.31 for the titanium cage, and 21.57 for the cement (polymethyl methacrylate) construct. CONCLUSION: The PEEK inter-body cage resulted in a significantly more uniform distribution of therapeutic radiation in the spine when compared with the other constructs. This may allow for the application of higher effective dosing to the tumor bed for spinal metastases without increasing spinal cord toxicity with either fractionated or hypofractionated radiotherapy. LEVEL OF EVIDENCE: N/A.
Authors: Ori Barzilai; Natalie DiStefano; Eric Lis; Yoshiya Yamada; D Michael Lovelock; Andrew N Fontanella; Mark H Bilsky; Ilya Laufer Journal: J Neurosurg Spine Date: 2017-11-03
Authors: Giuseppe Di Perna; Fabio Cofano; Cristina Mantovani; Serena Badellino; Nicola Marengo; Marco Ajello; Ludovico Maria Comite; Giuseppe Palmieri; Fulvio Tartara; Francesco Zenga; Umberto Ricardi; Diego Garbossa Journal: J Bone Oncol Date: 2020-09-26 Impact factor: 4.072
Authors: Helena Milavec; Christoph Kellner; Nivetha Ravikumar; Christoph E Albers; Till Lerch; Sven Hoppe; Moritz C Deml; Sebastian F Bigdon; Naresh Kumar; Lorin M Benneker Journal: J Funct Biomater Date: 2019-07-02
Authors: Athan G Zavras; Andrew J Schoenfeld; Joshua C Patt; Mohammed A Munim; C Rory Goodwin; Matthew L Goodwin; Sheng-Fu Larry Lo; Kristin J Redmond; Daniel G Tobert; John H Shin; Marco L Ferrone; Ilya Laufer; Comron Saifi; Jacob M Buchowski; Jack W Jennings; Ali K Ozturk; Christina Huang-Wright; Addisu Mesfin; Chris Steyn; Wesley Hsu; Hesham M Soliman; Ajit A Krishnaney; Daniel M Sciubba; Joseph H Schwab; Matthew W Colman Journal: N Am Spine Soc J Date: 2022-02-23