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For: Jia Y, Zhao L, Cheng CW, McDonald MW, Das IJ. Dose perturbation effect of metallic spinal implants in proton beam therapy. J Appl Clin Med Phys 2015;16:333-343. [PMID: 26699317 PMCID: PMC5690149 DOI: 10.1120/jacmp.v16i5.5566] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 05/09/2015] [Accepted: 05/01/2015] [Indexed: 11/23/2022] Open

For:	Jia Y, Zhao L, Cheng CW, McDonald MW, Das IJ. Dose perturbation effect of metallic spinal implants in proton beam therapy. J Appl Clin Med Phys 2015;16:333-343. [PMID: 26699317 PMCID: PMC5690149 DOI: 10.1120/jacmp.v16i5.5566] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 05/09/2015] [Accepted: 05/01/2015] [Indexed: 11/23/2022] Open

Number

Cited by Other Article(s)

Lam FC, Guru S, AbuReesh D, Hori YS, Chuang C, Liu L, Wang L, Gu X, Szalkowski GA, Wang Z, Wohlers C, Tayag A, Emrich SC, Ustrzynski L, Zygourakis CC, Desai A, Hayden Gephart M, Byun J, Pollom EL, Rahimy E, Soltys S, Park DJ, Chang SD. Use of Carbon Fiber Implants to Improve the Safety and Efficacy of Radiation Therapy for Spine Tumor Patients. Brain Sci 2025;15:199. [PMID: 40002531 PMCID: PMC11852773 DOI: 10.3390/brainsci15020199] [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: 12/31/2024] [Revised: 01/22/2025] [Accepted: 02/13/2025] [Indexed: 02/27/2025] Open

Affiliation(s)

Fred C. Lam Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Santosh Guru Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Deyaldeen AbuReesh Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Yusuke S. Hori Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Cynthia Chuang Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Lianli Liu Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Lei Wang Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Xuejun Gu Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Gregory A. Szalkowski Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Ziyi Wang Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Christopher Wohlers Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Armine Tayag Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Sara C. Emrich Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Louisa Ustrzynski Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Corinna C. Zygourakis Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Atman Desai Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Melanie Hayden Gephart Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
John Byun Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Erqi Liu Pollom Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Elham Rahimy Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
Scott Soltys Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA; (C.C.); (L.L.); (L.W.); (X.G.); (G.A.S.); (Z.W.); (C.W.); (J.B.); (E.L.P.); (E.R.); (S.S.)
David J. Park Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)
Steven D. Chang Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA 94305, USA; (F.C.L.); (S.G.); (D.A.); (Y.S.H.); (A.T.); (S.C.E.); (L.U.); (A.D.); (M.H.G.); (D.J.P.)

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Arjunan M, Sharma Shamurailatpam D, Patro KC, Kaushik S, Krishnan G. Influence of spatial redistribution of heterogeneities in proton beam characteristics. Phys Med 2025;129:104882. [PMID: 39752801 DOI: 10.1016/j.ejmp.2024.104882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 08/29/2024] [Accepted: 12/23/2024] [Indexed: 01/11/2025] Open

Chhabra AM, Snider JW, Kole AJ, Stock M, Holtzman AL, Press R, Wang CJ, Li H, Lin H, Shi C, McDonald M, Soike M, Zhou J, Sabouri P, Mossahebi S, Colaco R, Albertini F, Simone CB. Proton Therapy for Spinal Tumors: A Consensus Statement From the Particle Therapy Cooperative Group. Int J Radiat Oncol Biol Phys 2024;120:1135-1148. [PMID: 39181272 DOI: 10.1016/j.ijrobp.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/29/2024] [Accepted: 04/03/2024] [Indexed: 08/27/2024]

Abstract

PURPOSE

Proton beam therapy (PBT) plays an important role in the management of primary spine tumors. The purpose of this consensus statement was to summarize safe and optimal delivery of PBT for spinal tumors.

METHODS AND MATERIALS

The Particle Therapy Cooperative Group Skull Base/Central nervous system/Sarcoma Subcommittee consisting of radiation oncologists and medical physicists with specific expertise in spinal irradiation developed expert recommendations discussing treatment planning considerations and current approaches in the treatment of primary spinal tumors.

RESULTS

Computed tomography simulation: factors that require significant consideration include (1) patient comfort, (2) setup reproducibility and stability, and (3) accessibility of appropriate beam angles.

SPINE STABILIZATION HARDWARE

If present, hardware should be placed with cross-links well above/below the level of the primary tumor to reduce the metal burden at the level of the tumor bed. New materials that can reduce uncertainties include polyether-ether-ketone and composite polyether-ether-ketone-carbon fiber implants.

FIELD ARRANGEMENT

Appropriate beam selection is required to ensure robust target coverage and organ at risk sparing. Commonly, 2 to 4 treatment fields, typically from posterior and/or posterior-oblique directions, are used.

TREATMENT PLANNING METHODOLOGY

Robust optimization is recommended for all pencil beam scanning plans (the preferred treatment modality) and should consider setup uncertainty (between 3 and 7 mm) and range uncertainty (3%-3.5%). In the presence of metal hardware, use of an increased range uncertainty up to 5% is recommended.

CONCLUSIONS

The Particle Therapy Cooperative Group Skull Base/Central nervous system/Sarcoma Subcommittee has developed recommendations to enable centers to deliver PBT safely and effectively for the management of primary spinal tumors.

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Bălan C, Granja C, Mytsin G, Shvidky S, Molokanov A, Marek L, Chiș V, Oancea C. Particle tracking, recognition and LET evaluation of out-of-field proton therapy delivered to a phantom with implants. Phys Med Biol 2024;69:165006. [PMID: 38986478 DOI: 10.1088/1361-6560/ad61b8] [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] [Received: 12/22/2023] [Accepted: 07/10/2024] [Indexed: 07/12/2024]

Abstract

Objective.This study aims to assess the composition of scattered particles generated in proton therapy for tumors situated proximal to some titanium (Ti) dental implants. The investigation involves decomposing the mixed field and recording Linear Energy Transfer (LET) spectra to quantify the influence of metallic dental inserts located behind the tumor.Approach.A therapeutic conformal proton beam was used to deliver the treatment plan to an anthropomorphic head phantom with two types of implants inserted in the target volume (made of Ti and plastic, respectively). The scattered radiation resulted during the irradiation was detected by a hybrid semiconductor pixel detector MiniPIX Timepix3 that was placed distal to the Spread-out Bragg peak. Visualization and field decomposition of stray radiation were generated using algorithms trained in particle recognition based on artificial intelligence neural networks (AI NN). Spectral sensitive aspects of the scattered radiation were collected using two angular positions of the detector relative to the beam direction: 0° and 60°.Results.Using AI NN, 3 classes of particles were identified: protons, electrons & photons, and ions & fast neutrons. Placing a Ti implant in the beam's path resulted in predominantly electrons and photons, contributing 52.2% of the total number of detected particles, whereas for plastic implants, the contribution was 65.4%. Scattered protons comprised 45.5% and 31.9% with and without metal inserts, respectively. The LET spectra were derived for each group of particles identified, with values ranging from 0.01 to 7.5 keVμm-1for Ti implants/plastic implants. The low-LET component was primarily composed of electrons and photons, while the high-LET component corresponded to protons and ions.Significance.This method, complemented by directional maps, holds the potential for evaluating and validating treatment plans involving stray radiation near organs at risk, offering precise discrimination of the mixed field, and enhancing in this way the LET calculation.

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Rijs Z, Kawsar KA, Saha P, van de Sande M, Lui D. Evaluation of computed tomography artefacts of carbon-fiber and titanium implants in patients with spinal oligometastatic disease undergoing stereotactic ablative radiotherapy. Sci Rep 2024;14:6700. [PMID: 38509154 PMCID: PMC10954645 DOI: 10.1038/s41598-024-52498-2] [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] [Received: 04/11/2023] [Accepted: 01/19/2024] [Indexed: 03/22/2024] Open

Kato R, Kato T, Murakami M. Radioactivation effects of titanium caused by clinical proton beam: a simulation study. Biomed Phys Eng Express 2024;10:025001. [PMID: 38128147 DOI: 10.1088/2057-1976/ad17fa] [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] [Received: 06/29/2023] [Accepted: 12/21/2023] [Indexed: 12/23/2023]

Abstract

Objective. In proton beam therapy (PBT), metals in the patient body perturb the dose distribution, and their radioactivation may affect the dose distribution around the metal; however, the radioactivation effect has been not clarified with PBT. In this study, we aimed to evaluate the radioactivation effect of metal depending on proton energies and secondary neutrons with a clinical proton beam using a Monte Carlo (MC) simulation.Approach.The radionuclides produced from a titanium alloy (Ti-6Al-4V) and their radioactivity were calculated using a 210-MeV passive scattering proton beam with a 60-mm Spread-out Bragg Peak, and the deposited doses caused by the radioactivation were computed using the MC simulation. The position of metal was changed according to the proton mean energy in water. To assess neutron effects on the radioactivation, we calculated the radioactivation in following three situations: (i) full MC simulation with neutrons, (ii) simulation without secondary neutrons generated from the beamline components, and (iii) simulation without any secondary neutrons.Main results.Immediately after the irradiation, the radionuclide with the largest activity was Sc-45 m (half-life of 318 ms) regardless of the proton energy and the presence of neutrons. Total radioactivity tended to increase according to the proton energy. The accumulated dose for 24 h caused by the metal activation showed an increasing trend with the proton energy, with a maximum increase rate of 0.045% to the prescribed dose. The accumulated dose at a distance of 10 mm from the metal was lower than 1/10 of that at a distance of 1 mm.Significance.The radioactivation effect of the titanium was comprehensively evaluated in the clinical passive scattering proton beam. We expect that radioactivation effects on the clinical dose distribution would be small. We consider that these results will help the clinical handling of high-Z metals in PBT.

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Long JR, Kalani MA, Goulding KA, Ashman JB, Flug JA. Carbon-fiber-reinforced polyetheretherketone orthopedic implants in musculoskeletal and spinal tumors: imaging and clinical features. Skeletal Radiol 2023;52:393-404. [PMID: 35536358 DOI: 10.1007/s00256-022-04069-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/27/2022] [Accepted: 04/27/2022] [Indexed: 02/02/2023]

Chang C, Charyyev S, Harms J, Slopsema R, Wolf J, Refai D, Yoon T, McDonald MW, Bradley JD, Leng S, Zhou J, Yang X, Lin L. A component method to delineate surgical spine implants for proton Monte Carlo dose calculation. J Appl Clin Med Phys 2023;24:e13800. [PMID: 36210177 PMCID: PMC9859997 DOI: 10.1002/acm2.13800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/09/2022] [Accepted: 09/22/2022] [Indexed: 01/26/2023] Open

Abstract

PURPOSE

Metallic implants have been correlated to local control failure for spinal sarcoma and chordoma patients due to the uncertainty of implant delineation from computed tomography (CT). Such uncertainty can compromise the proton Monte Carlo dose calculation (MCDC) accuracy. A component method is proposed to determine the dimension and volume of the implants from CT images.

METHODS

The proposed component method leverages the knowledge of surgical implants from medical supply vendors to predefine accurate contours for each implant component, including tulips, screw bodies, lockers, and rods. A retrospective patient study was conducted to demonstrate the feasibility of the method. The reference implant materials and samples were collected from patient medical records and vendors, Medtronic and NuVasive. Additional CT images with extensive features, such as extended Hounsfield units and various reconstruction diameters, were used to quantify the uncertainty of implant contours.

RESULTS

For in vivo patient implant estimation, the reference and the component method differences were 0.35, 0.17, and 0.04 cm3 for tulips, screw bodies, and rods, respectively. The discrepancies by a conventional threshold method were 5.46, 0.76, and 0.05 cm3 , respectively. The mischaracterization of implant materials and dimensions can underdose the clinical target volume coverage by 20 cm3 for a patient with eight lumbar implants. The tulip dominates the dosimetry uncertainty as it can be made from titanium or cobalt-chromium alloys by different vendors.

CONCLUSIONS

A component method was developed and demonstrated using phantom and patient studies with implants. The proposed method provides more accurate implant characterization for proton MCDC and can potentially enhance the treatment quality for proton therapy. The current proof-of-concept study is limited to the implant characterization for lumbar spine. Future investigations could be extended to cervical spine and dental implants for head-and-neck patients where tight margins are required to spare organs at risk.

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Kato R, Kato T, Narita Y, Sasaki S, Takayama K, Murakami M. Identification of Induced Radionuclides Produced from Dental Metals in Proton Beam Therapy for Head and Neck Cancer. Adv Radiat Oncol 2022;8:101153. [PMID: 36798730 PMCID: PMC9926195 DOI: 10.1016/j.adro.2022.101153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 12/11/2022] [Indexed: 12/26/2022] Open

Abstract

Purpose

To identify the induced radionuclides produced from dental metals in proton beam therapy and investigate the accuracy of the Monte Carlo (MC) simulation by comparing the measured radioactivity.

Methods and Materials

Two dental metals of pure titanium and gold-silver-palladium alloy, commonly used in Japan, were used in this study. The dental metal placed at the center of Spread-out Bragg Peak was irradiated by 150-MeV passive scattering proton beam. The gamma rays emitted from the activated dental metals were measured using a high purity germanium (HPGe) detector. The induced radionuclides were identified from the measured gamma-ray energies. Furthermore, the Particle and Heavy Ion Transport code System v.3.24 and DCHAIN were used for the MC simulation. The measured radionuclides and their radioactivity were compared with the simulation results.

Results

In the MC simulation for the activated titanium, vanadium-47, with a half-life of 32.6 minutes had the strongest radioactivity among the induced radionuclides. The energy peaks of gamma rays emitted from titanium-51, scandium-43, scandium-44, and annihilation gamma rays were observed for the activated titanium in the HPGe detector. In the MC simulation for the activated gold-silver-palladium alloy, silver-108, with a half-life of 2.4 minutes had the strongest radioactivity. The energy peaks of gamma rays emitted from silver-104, silver-104 m, silver-108, and annihilation gamma rays were observed for the activated gold-silver-palladium alloy in the HPGe detector. Furthermore, the induced radionuclides and their radioactivity in the MC simulation were consistent with the measurement results for both dental metals, except for a few radionuclides.

Conclusions

We identify the induced radionuclides produced from 2 dental metals and compared their radioactivity between the measurements and the MC simulation. Although the identification of the induced radionuclides using the MC simulation remains uncertain, the MC simulation can be clinically effective for pre-estimating the induced radionuclides in proton beam therapy.

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Qualitative Assessment of Titanium versus Carbon Fiber/Polyetheretherketone Pedicle Screw-Related Artifacts: A Cadaveric Study. World Neurosurg 2022;166:e155-e162. [PMID: 35803562 DOI: 10.1016/j.wneu.2022.06.135] [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: 03/09/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 12/15/2022]

Yang Y, Muller OM, Shiraishi S, Harper M, Amundson AC, Wong WW, McGee LA, Rwigema JCM, Schild SE, Bues M, Fatyga M, Anderson JD, Patel SH, Foote RL, Liu W. Empirical Relative Biological Effectiveness (RBE) for Mandible Osteoradionecrosis (ORN) in Head and Neck Cancer Patients Treated With Pencil-Beam-Scanning Proton Therapy (PBSPT): A Retrospective, Case-Matched Cohort Study. Front Oncol 2022;12:843175. [PMID: 35311159 PMCID: PMC8928456 DOI: 10.3389/fonc.2022.843175] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open

Abstract

Purpose

To retrospectively investigate empirical relative biological effectiveness (RBE) for mandible osteoradionecrosis (ORN) in head and neck (H&N) cancer patients treated with pencil-beam-scanning proton therapy (PBSPT).

Methods

We included 1,266 H&N cancer patients, of which, 931 patients were treated with volumetric-modulated arc therapy (VMAT) and 335 were treated with PBSPT. Among them, 26 VMAT and 9 PBSPT patients experienced mandible ORN (ORN group), while all others were included in the control group. To minimize the impact of the possible imbalance in clinical factors between VMAT and PBSPT patients in the dosimetric comparison between these two modalities and the resulting RBE quantification, we formed a 1:1 case-matched patient cohort (335 VMAT patients and 335 PBSPT patients including both the ORN and control groups) using the greedy nearest neighbor matching of propensity scores. Mandible dosimetric metrics were extracted from the case-matched patient cohort and statistically tested to evaluate the association with mandibular ORN to derive dose volume constraints (DVCs) for VMAT and PBSPT, respectively. We sought the equivalent constraint doses for VMAT so that the critical volumes of VMAT were equal to those of PBSPT at different physical doses. Empirical RBEs of PBSPT for ORN were obtained by calculating the ratio between the derived equivalent constraint doses and physical doses of PBSPT. Bootstrapping was further used to get the confidence intervals.

Results

Clinical variables of age, gender, tumor stage, prescription dose, chemotherapy, hypertension or diabetes, dental extraction, smoking history, or current smoker were not statistically related to the incidence of ORN in the overall patient cohort. Smoking history was found to be significantly associated with the ORN incidence in PBSPT patients only. V40Gy[RBE], V50Gy[RBE], and V60Gy[RBE] were statistically different (p<0.05) between the ORN and control group for VMAT and PBSPT. Empirical RBEs of 1.58(95%CI: 1.34-1.64), 1.34(95%CI: 1.23-1.40), and 1.24(95%: 1.15-1.26) were obtained for proton dose at 40 Gy[RBE=1.1], 50 Gy[RBE=1.1] and 60 Gy[RBE=1.1], respectively.

Conclusions

Our study suggested that RBEs were larger than 1.1 at moderate doses (between 40 and 60 Gy[RBE=1.1]) with high LET for mandible ORN. RBEs are underestimated in current clinical practice in PBSPT. The derived DVCs can be used for PBSPT plan evaluation and optimization to minimize the incidence rate of mandible ORN.

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Shi C, Lin H, Huang S, Xiong W, Hu L, Choi I, Press R, Hasan S, Simone C, Chhabra A. Comprehensive Evaluation of Carbon-Fiber-Reinforced Polyetheretherketone (CFR-PEEK) Spinal Hardware for Proton and Photon Planning. Technol Cancer Res Treat 2022;21:15330338221091700. [PMID: 35410544 PMCID: PMC9009152 DOI: 10.1177/15330338221091700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open

Abstract

Purpose: To evaluate a novel spine implant, carbon-fiber-reinforced polyetheretherketone (CFR-PEEK), for proton and photon treatment planning. Materials and Methods: We compared target coverage and sparing of organs-at-risk (OARs) for a spinal phantom with 4 different spine configurations: (a) normal (no implant); (b) Titanium; (c) CFR-PEEK; and (d) hybrid (CFR-PEEK with Titanium tulip head). The spinal phantom was imaged via computed tomography (CT) scan, and the iterative Metal Artifact Reduction (iMAR) CT set was used for planning. A representative spinal chordoma target and associated OARs were contoured. The prescription dose was 50 Gy to the initial target volume, followed by a 24 Gy boost, for which multi-field optimization (MFO) proton plans were developed with a 3 mm setup and 3.5% range uncertainties. For photon planning, volumetric modulated arc therapy (VMAT) plans were developed for the initial and boost plans. OAR dose constraints were set according to our institutional guidelines. Results: For the 4 spine configurations, the proton plans achieved similar nominal target coverage and OARs sparing. While evaluating coverage and OAR dose under uncertainty scenario analysis for initial clinical target volume (CTV) 50 Gy 95% and 90% coverage, higher means and the narrower band of doses variations were achieved for the normal and CFR-PEEK plans. Similarly, uncertainty analysis of spinal cord D_max showed tighter distribution for normal and CFR-PEEK plans. Overall plan quality showed no significant difference for photon planning when compared to normal spine versus other inserts. However, for proton planning, there is a larger difference for the normal spine insert scenario versus the Titanium insert scenario. For each insert scenario comparison between photon and proton plans, there was a larger difference for OARs: heart and spinal cord. Conclusion: The CFR-PEEK implant has similar clinical properties to a normal spine for proton planning, allowing us to pass protons through the material and achieve superior target coverage and OAR sparing under nominal and uncertainty conditions.

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Mutter RW, Choi JI, Jimenez RB, Kirova YM, Fagundes M, Haffty BG, Amos RA, Bradley JA, Chen PY, Ding X, Carr AM, Taylor LM, Pankuch M, Vega RBM, Ho AY, Nyström PW, McGee LA, Urbanic JJ, Cahlon O, Maduro JH, MacDonald SM. Proton Therapy for Breast Cancer: A Consensus Statement From the Particle Therapy Cooperative Group Breast Cancer Subcommittee. Int J Radiat Oncol Biol Phys 2021;111:337-359. [PMID: 34048815 PMCID: PMC8416711 DOI: 10.1016/j.ijrobp.2021.05.110] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 05/12/2021] [Accepted: 05/17/2021] [Indexed: 12/23/2022]

Affiliation(s)

Robert W Mutter Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
J Isabelle Choi Department of Radiation Oncology, New York Proton Center and Memorial Sloan Kettering Cancer Center, New York, New York
Rachel B Jimenez Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts
Youlia M Kirova Department of Radiation Oncology, Institut Curie, Paris, France
Marcio Fagundes Department of Radiation Oncology, Miami Cancer Institute, Miami, Florida
Bruce G Haffty Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey
Richard A Amos Proton and Advanced Radiotherapy Group, Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
Julie A Bradley Department of Radiation Oncology, University of Florida, Jacksonville, Florida
Peter Y Chen Department of Radiation Oncology, Beaumont Health, Royal Oak, Michigan
Xuanfeng Ding Department of Radiation Oncology, Beaumont Health, Royal Oak, Michigan
Antoinette M Carr Department of Radiation Oncology, Beaumont Health, Royal Oak, Michigan
Leslie M Taylor Department of Radiation Oncology, Beaumont Health, Royal Oak, Michigan
Mark Pankuch Department of Radiation Oncology, Northwestern Medicine Proton Center, Warrenville, Illinois
Raymond B Mailhot Vega Department of Radiation Oncology, University of Florida, Jacksonville, Florida
Alice Y Ho Department of Radiation Oncology, New York Proton Center and Memorial Sloan Kettering Cancer Center, New York, New York
Petra Witt Nyström The Skandion Clinic, Uppsala, Sweden and the Danish Centre for Particle Therapy, Aarhus, Denmark
Lisa A McGee Department of Radiation Oncology, Mayo Clinic Hospital, Phoenix, Arizona
James J Urbanic Department of Radiation Medicine and Applied Sciences, UC San Diego Health, Encinitas, California
Oren Cahlon Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York
John H Maduro Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
Shannon M MacDonald Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts

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Neal MT, Richards AE, Curley KL, Patel NP, Ashman JB, Vora SA, Kalani MA. Carbon fiber-reinforced PEEK instrumentation in the spinal oncology population: a retrospective series demonstrating technique, feasibility, and clinical outcomes. Neurosurg Focus 2021;50:E13. [PMID: 33932921 DOI: 10.3171/2021.2.focus20995] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/17/2021] [Indexed: 11/06/2022]

Abstract

OBJECTIVE

The authors aimed to demonstrate the feasibility and advantages of carbon fiber-reinforced PEEK (CFRP) composite implants in patients with both primary and secondary osseous spinal tumors.

METHODS

Twenty-eight spinal tumor patients who underwent fixation with CFRP hardware were retrospectively identified in a Spine Tumor Quality Database at a single institution. Demographic, procedural, and follow-up data were retrospectively collected.

RESULTS

The study population included 14 females and 14 males with a mean age of 60 years (range 30-86 years). Five patients had primary bone tumors, and the remaining patients had metastatic tumors. Breast cancer was the most common metastatic tumor. The most common presenting symptom was axial spine pain (25 patients, 89%), and the most common Spine Instability Neoplastic Score was 7 (range 6-14). Two patients in this series had anterior cervical procedures. The remaining patients underwent posterior thoracolumbar fixation. The average fusion length included 4.6 vertebral segments (range 3-8). The mean clinical follow-up time with surgical or oncology teams was 6.5 months (range 1-23 months), and the mean interval for last follow-up imaging (CT or MRI) was 6.5 months (range 1-22 months). Eighteen patients received postoperative radiation at the authors' institution (16 with photon therapy, 2 with proton therapy). Eleven of the patients (39%) in this series died. At the last clinical follow-up, 26 patients (93%) had stable or improved neurological function compared with their preoperative status. At the last imaging follow-up, local disease control was observed in 25 patients (89%). Two patients required reoperation in the immediate postoperative period, one for surgical site infection and the other for compressive epidural hematoma. One patient was noted to have lucencies around the most cephalad screws 3 months after surgery. No hardware fracture or malfunction occurred intraoperatively. No patients required delayed surgery for hardware loosening, fracture, or other failure. Early tumor recurrence was detected in 3 patients. Early detection was attributed to the imaging characteristics of the CFRP hardware.

CONCLUSIONS

CFRP spinal implants appear to be safe and comparable to conventional titanium implants in terms of functionality. The imaging characteristics of CFRP hardware facilitate radiation planning and assessment of surveillance imaging. CFRP hardware may enhance safety and efficacy, particularly with particle therapy dosimetry. Larger patient populations with longer-term follow-up are needed to confirm the various valuable aspects of CFRP spinal implants.

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Parham MD, Ahmad S, Jin H. Dosimetric Effect of Biozorb Markers for Accelerated Partial Breast Irradiation in Proton Therapy. Int J Part Ther 2021;7:19-28. [PMID: 33829070 PMCID: PMC8019574 DOI: 10.14338/ijpt-20-00077.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/22/2020] [Indexed: 11/21/2022] Open

Abstract

Purpose

To investigate dosimetric implications of biodegradable Biozorb (BZ) markers for proton accelerated partial breast irradiation (APBI) plans.

Materials and Methods

Six different BZs were placed within in-house breast phantoms to acquire computed tomography (CT) images. A contour correction method with proper mass density overriding for BZ titanium clip and surrounding tissue was applied to minimize inaccuracies found in the CT images in the RayStation planning system. Each breast phantom was irradiated by a monoenergetic proton beam (103.23 MeV and 8×8 cm²) using a pencil-beam scanning proton therapy system. For a range perturbation study, doses were measured at 5 depths below the breast phantoms by using an ionization chamber and compared to the RayStation calculations with 3 scenarios for the clip density: the density correction method (S1: 1.6 g/cm³), raw CT (S2), and titanium density (S3: 4.54 g/cm³). For the local dose perturbation study, the radiographic EDR2 film was placed at 0 and 2 cm below the phantoms and compared to the RayStation calculations. Clinical effects of the perturbations were retrospectively examined with 10 APBI plans for the 3 scenarios (approved by our institutional review board).

Results

In the range perturbation study, the S1 simulation showed a good agreement with the chamber measurements, while excess pullbacks of 1∼2 mm were found in the S2 and S3 simulations. The film study showed local dose shadowing and perturbation by the clips that RayStation could not predict. In the plan study, no significant differences in the plan quality were found among the 3 scenarios. However, substantial range pullbacks were observed for S3.

Conclusion

The density correction method could minimize the dose and range difference between measurement and RayStation prediction. It should be avoided to simply override the known physical density of the BZ clips for treatment planning owing to overestimation of the range pullback.

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Charyyev S, Chang CW, Harms J, Oancea C, Yoon ST, Yang X, Zhang T, Zhou J, Lin L. A novel proton counting detector and method for the validation of tissue and implant material maps for Monte Carlo dose calculation. Phys Med Biol 2021;66:045003. [PMID: 33296888 DOI: 10.1088/1361-6560/abd22e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]

Abstract

The presence of artificial implants complicates the delivery of proton therapy due to inaccurate characterization of both the implant and the surrounding tissues. In this work, we describe a method to characterize implant and human tissue mimicking materials in terms of relative stopping power (RSP) using a novel proton counting detector. Each proton is tracked by directly measuring the deposited energy along the proton track using a fast, pixelated spectral detector AdvaPIX-TPX3 (TPX3). We considered three scenarios to characterize the RSPs. First, in-air measurements were made in the presence of metal rods (Al, Ti and CoCr) and bone. Then, measurements of energy perturbations in the presence of metal implants and bone in an anthropomorphic phantom were performed. Finally, sampling of cumulative stopping power (CSP) of the phantom were made at different locations of the anthropomorphic phantom. CSP and RSP information were extracted from energy spectra at each beam path. To quantify the RSP of metal rods we used the shift in the most probable energy (MPE) of CSP from the reference CSP without a rod. Overall, the RSPs were determined as 1.48, 2.06, 3.08, and 5.53 from in-air measurements; 1.44, 1.97, 2.98, and 5.44 from in-phantom measurements, for bone, Al, Ti and CoCr, respectively. Additionally, we sampled CSP for multiple paths of the anthropomorphic phantom ranging from 18.63 to 25.23 cm deriving RSP of soft tissues and bones in agreement within 1.6% of TOPAS simulations. Using minimum error of these multiple CSP, optimal mass densities were derived for soft tissue and bone and they are within 1% of vendor-provided nominal densities. The preliminary data obtained indicates the proposed novel method can be used for the validation of material and density maps, required by proton Monte Carlo Dose calculation, provided by competing multi-energy computed tomography and metal artifact reduction techniques.

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Zhao L, Moskvin VP, Cheng CW, Das IJ. Dose perturbation caused by metallic port in breast tissue expander in proton beam therapy. Biomed Phys Eng Express 2020;6. [PMID: 34035189 DOI: 10.1088/2057-1976/abc899] [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: 08/11/2020] [Accepted: 11/09/2020] [Indexed: 11/11/2022]

Abstract

Proton beam treatment is being looked favourably now in breast treatment. Tissue expanders are often placed after mastectomy that contains metallic port for saline injection which produces dose perturbations in proton beam therapy with uncertain dosimetry. Dose perturbation for a stainless-steel injection port from a breast implant is investigated in this study. Measurements, Monte-Carlo simulation, and calculated dose distribution of plans based on kVCT and MVCT images are compared. Treatment plans are performed on kVCT and MVCT images to observe the effect of metal artifact from the breast implant. The kVCT based plan underestimates the beam range due to the overestimated water equivalent thickness of the metal ports as a result of image degradation. Compared to the measurement with metal port in the proton beam, the MVCT-based treatment planning provides more accurate dose calculation than the kVCT-based results. The dose perturbation factor calculated from MVCT planning is within 10% of the measurement results while HU corrected kVCT plan still shows dose difference as large as 100% due to the incorrect range pull back calculation caused by the misrepresentation of the volume between the plastic cap and the stainless-steel base. The dose enhancement observed at the metal and solid water interface is as large as 15%, which needs to be accounted for in the planning process if there is a clinical concern. Dose reduction as large as 16% is observed with depth from 1 cm to 4 cm underneath the thickest part of the metallic port whereas lateral dose perturbation is also seen up to 7 mm. The measurement data are supported by the Monte-Carlo simulated results with a maximum dose difference of 6%. It is concluded that if proton beam is used with metallic port, MVCT imaging data is recommended. In lieu of MVCT, DECT, CT scanner with metal artifact reduction software or in the very least, extended HU range should be used to reduce the streaking artifact as well as to produce a more accurate image of the metallic port.

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Niroomand‐Rad A, Chiu‐Tsao S, Grams MP, Lewis DF, Soares CG, Van Battum LJ, Das IJ, Trichter S, Kissick MW, Massillon‐JL G, Alvarez PE, Chan MF. Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG‐55. Med Phys 2020;47:5986-6025. [DOI: 10.1002/mp.14497] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open

Fellin F, Artoni M, Righetto R, Bellinzona VE, Widesott L, Dionisi F, Farace P. An avoidance method to minimize dose perturbation effects in proton pencil beam scanning treatment of patients with small high-Z implants. Phys Med Biol 2020;65:14NT01. [PMID: 32464619 DOI: 10.1088/1361-6560/ab9775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]

Abstract

To implement a multi-field-optimization (MFO) technique for treating patients with high-Z implants in pencil beam scanning proton-therapy and generate treatment plans that avoids small implants. Two main issues were addressed: (i) the assessment of the optimal CT acquisition and segmentation technique to define the dimension of the implant and (ii) the distance of pencil beams from the implant (avoidance margin) to assure that it does not affect dose distribution. Different CT reconstruction protocols (by O-MAR or standard reconstruction and by 12 bit or 16 bit dynamic range) followed by thresholding segmentation were tested on a phantom with lead spheres of different sizes. The proper avoidance margin was assessed on a dedicated phantoms of different materials (copper/tantalum and lead), shape (square slabs and spheres) and detectors (two-dimensional array chamber and radio-chromic films). The method was then demonstrated on a head-and-neck carcinoma patient, who underwent carotid artery embolization with a platinum coil close to the target. Regardless the application of O-MAR reconstruction, the CT protocol with a full 16 bit dynamic range allowed better estimation of the sphere volumes, with maximal error around -5% in the greater sphere only. Except the configuration with a shallow target (which required a pre-absorber), particularly with a retracted snout, an avoidance margin of around 0.9-1.3 cm allowed to keep the difference between planned and measured dose below 5-10%. The patient plan analysis showed adequate plan quality and confirmed effective implant avoidance. Potential target under-dosage can be produced by patient misalignment, which could be minimized by daily alignment on the implant, identifiable on orthogonal kilovolt images. By implant avoidance MFO it was possible to minimize potential dose perturbation effects produced by small high-Z implants. An advantage of such approach lies in its potential applicability for any type of implant, regardless the precise knowledge of its composition.

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Bhushan M, Tripathi D, Yadav G, Kumar L, Dewan A, Kumar G. Effect of Hip Prosthesis on Photon Beam Characteristics in Radiological Physics. Asian Pac J Cancer Prev 2020;21:1731-1738. [PMID: 32592371 PMCID: PMC7568891 DOI: 10.31557/apjcp.2020.21.6.1731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Indexed: 11/25/2022] Open

Müller BS, Ryang YM, Oechsner M, Düsberg M, Meyer B, Combs SE, Wilkens JJ. The dosimetric impact of stabilizing spinal implants in radiotherapy treatment planning with protons and photons: standard titanium alloy vs. radiolucent carbon-fiber-reinforced PEEK systems. J Appl Clin Med Phys 2020;21:6-14. [PMID: 32476247 PMCID: PMC7484848 DOI: 10.1002/acm2.12905] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 04/13/2020] [Accepted: 04/20/2020] [Indexed: 12/17/2022] Open

Lideståhl A, Mondlane G, Gubanski M, Lind PA, Siegbahn A. An in silico planning study comparing doses and estimated risk of toxicity in 3D-CRT, IMRT and proton beam therapy of patients with thymic tumours. Phys Med 2019;60:120-126. [DOI: 10.1016/j.ejmp.2019.03.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 12/25/2022] Open

Oancea C, Ambrožová I, Popescu A, Mytsin G, Vondráček V, Davídková M. LET spectra behind high-density titanium and stainless steel hip implants irradiated with a therapeutic proton beam. RADIAT MEAS 2018. [DOI: 10.1016/j.radmeas.2018.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]

Mastella E, Molinelli S, Magro G, Mirandola A, Russo S, Vai A, Mairani A, Choi K, Fiore M, Fossati P, Cuzzocrea F, Gasbarrini A, Benazzo F, Boriani S, Valvo F, Orecchia R, Ciocca M. Dosimetric characterization of carbon fiber stabilization devices for post-operative particle therapy. Phys Med 2017;44:18-25. [DOI: 10.1016/j.ejmp.2017.11.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 09/05/2017] [Accepted: 11/09/2017] [Indexed: 11/15/2022] Open

Placidi L, Bolsi A, Lomax AJ, Schneider RA, Malyapa R, Weber DC, Albertini F. Effect of Anatomic Changes on Pencil Beam Scanned Proton Dose Distributions for Cranial and Extracranial Tumors. Int J Radiat Oncol Biol Phys 2017;97:616-623. [DOI: 10.1016/j.ijrobp.2016.11.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/31/2016] [Accepted: 11/08/2016] [Indexed: 10/20/2022]