Quantifying Head Leakage Radiation in CyberKnife robotic radiosurgery Systems: A Multi-Modal Approach

Quantifying Head Leakage Radiation in CyberKnife robotic radiosurgery Systems: A Multi-Modal Approach | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Quantifying Head Leakage Radiation in CyberKnife robotic radiosurgery Systems: A Multi-Modal Approach Sandeep Singh, Manindra Bhushan, Debasish Sahoo, Pawan Kumar Singh, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6424742/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 07 Oct, 2025 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Aim The purpose of this study is to measure radiation head leakage of CyberKnife System for in-patient plane and out-of-patient plane using Optically stimulated luminescence dosimeters (OSLD), vented type ionization Chambers, and pressurized ionization chamber-based survey meter and to compare the leakage level with that recommended by the International Electrotechnical Commission (IEC) standard. Materials and Methods In this, CyberKnife (LINAC) having 6MV flattening filter free beam with maximum circular filed size of 6 cm diameter was used. Leakage was measured for both IRIS and FIXED type collimator in fully closed position. To measure the leakage, we had used three different methods, optically stimulated luminescence dosimeters (OSLD), vented ionization Chambers (IC), and pressurized ionization chamber-based survey meter (SM). Leakage measurement points were taken as per the IEC 60601-2-1 report both for in-patient plane and out-of-patient plane. The total number of monitor units (MU) delivered were 500 MU’s. Result The measured average in-patient plane leakage was 0.015% using IC, 0.100% using OSLD and 0.010% using SM, that is well within the tolerance limit of 0.1% according to IEC guidelines. The average leakage for out of patient plane was 0.037%, which is well within the limit of 0.5% as per IEC guidelines. Conclusion The study measured radiation head leakage of the CyberKnife System using OSLD, ionization chambers, and a survey meter. Leakage levels for both in-patient and out-of-patient planes were significantly below the IEC 60601-2-1 standard limits. This confirms the system's compliance with safety guidelines, ensuring minimal radiation exposure. Physical sciences/Physics/Applied physics Health sciences/Health care Leakage in-patient plane out of patient plane OSLD Survey meter Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction The stringent regulation and oversight of radiation delivering units by the Atomic Energy Regulatory Board, Mumbai, are fundamental for ensuring the safe and effective application of radiation treatment in India [ 1 ] . Before any radiation delivering unit can be used for clinical purposes, it must undergo a comprehensive evaluation process to meet rigorous national and international standards [ 2 , 3 ] . This process culminates in the issuance of a type approval certificate, affirming compliance with stringent criteria encompassing electrical, mechanical, dosimetric, and radiation safety parameters. A key part of radiation safety regulations is managing leakage that could endanger patients and healthcare workers. Leakage can come from the primary beam or secondary sources, such as scattered radiation in the treatment room. To address this, organizations like the IEC and national bodies set strict limits and guidelines to protect people outside the treatment area and ensure accurate radiation delivery [ 4 ] . Quality Assurance (QA) protocols are crucial in this process, involving thorough testing of equipment to ensure effective shielding and collimation [ 5 , 6 ] . By following these protocols, radiotherapy facilities improve treatment accuracy and maintain a safe environment for patients and staff. Measuring head-leakage radiation in clinical linear accelerators is crucial for ensuring the safety of patients, radiation workers, hospital staff, and the public. When the treatment beam is active, the radiation within the therapy room includes primary, scattered, head-leakage photons, and neutrons. The effectiveness of shielding and head design significantly impacts these leakage levels, making it essential to determine specific leakage values for each accelerator model [ 7 ] . The primary aim of this study is to comprehensively evaluate the radiation head leakage emitted from the CyberKnife System, both within the patient treatment plane (in-patient plane) and outside of it (out-of-patient plane) utilizing three types of dosimetric devices, vented type ionization Chambers, and pressurized ionization chamber-based survey meter and optically stimulated luminescence dosimeters. The assessment focuses on determining whether the leakage levels comply with the safety thresholds established by the International Electrotechnical Commission (IEC) standard 60601-2-1 [ 4 ] , which sets global guidelines for radiation safety in medical linear accelerators (LINAC). Method and material The acceptance and commissioning of medical linear accelerator undergoes rigorous scrutiny, and one of them is the measurement and control of in-patient plane leakage. Understanding, measuring, and controlling this leakage is vital for several reasons, each contributing to the overarching goal of ensuring patient safety, treatment efficacy, and compliance with regulatory standards. The primary concern with in-patient plane leakage is its potential to deliver unintended doses of radiation to healthy tissues and organs, adjacent to the treatment area [ 8 , 9 ] . Even small doses of unintended radiation can lead to long-term side effects, such as secondary cancers [ 10 – 12 ] . Therefore, monitoring and minimizing leakage is crucial. Accurate measurement of in-patient plane leakage involves using sophisticated equipment such as ionization chambers, film dosimeters, and optically stimulated luminescence dosimeters (OSLDs). These tools are essential for detecting and quantifying the leakage radiation. We used three dosimetry tools to measure the leakage radiation in the CyberKnife machine shown in Fig. 1. The PTW30013 FC-65 0.6 cm 3 (PTW GmBH, Freiberg Germany ) ionization chamber plays a pivotal role in radiotherapy, and is the gold standard for measurement [ 13 , 14 ] . For measurement of leakage, the chamber with brass build-up cap should be placed on 24 points given by IEC-60601-2-1. Out of 24 points only 16 are accessible ,the points and their location were shown in the Fig. 2 . The survey meter (Fluke 451P Radiation Detector), equipped with a 230-cc volume pressurized air ionization chamber, maintains accuracy within 10% of the reading between 10% and 100% of the full-scale indication on any range, exclusive of energy response. This detector can detect beta radiation above 1 MeV, as well as gamma and x-rays above 25 keV [ 15 ] . The OSLD system (RadPro International GmbH, Germany) comprises multiple myOSLchips, a handheld manual OSL reader, an eraser including 24 blue power light-emitting diodes for annealing, and software for registration, calibration, and measurement [ 16 ] . The myOSLchips had a disk of dimension 4.7 x 4.7x 0.5 mm, of Beryllium Oxide (BeO). The size of dosimeter with plastic holder is 10 x 9.5 x 2 mm. It has the energy response from 16 KeV to 25 MeV. The dose range of the chip is 0.05 mGy to 10 Gy and dose response is linear upto10 Gy. For out-of-patient plane leakage measurement, the ion chamber is solely used. The different points of measurements used for this was shown in Fig. 3 . The dose comparison in this study was performed at d max (dose at maximum depth), 6 cm diameter field size at the central axis at NTD and represented as ‘Percentage Dose fraction’. According to the International Electrotechnical Commission (IEC) 60601-2-1 standard, the maximum allowable head-leakage for photons is 0.2%, with an average of 0.1%, d max for a 6 cm diameter circular field at the central axis [ 4 ] . The formula used to calculate the Relative Dose was given as, It is possible to obtain high-accuracy data in real time from ionization chambers. In addition to these measurements, a survey meter can provide instantaneous readings of dose rates, which can be of assistance in conducting rapid evaluations and maintaining continuous monitoring of radiation levels. OSLD, on the other hand, offers leakage at all locations in one go, which helps reduce time for leakage measurement. Results In-patient plane Leakage values The Ionization Chamber measurements for the IRIS setup had a maximum radiation leakage of 0.1741% and an average leakage of 0.0253%, whereas the FIXED Collimator had a maximum leakage of 0.0264% and an average of 0.0148%. The Survey Meter results showed a maximum leakage of 0.012% and an average of 0.011% for the IRIS, and a maximum of 0.012% and an average of 0.010% for the FIXED Collimator. OSLD measurements for the IRIS setup had a maximum leakage of 0.168% and an average leakage of 0.095%, while the FIXED Collimator had a maximum of 0.167% and an average of 0.100%. The radiation leakage is significantly below the permissible limits of 0.2% for maximum leakage and 0.1% for average leakage, based on the maximum absorbed dose at the nominal treatment distance (NTD) for a 6 cm radiation field size as given by IEC standards. Fig:4 and 5 shows the different values of leakage for all the points using IRIS and FIXED collimator. For out of patient plane, the maximum leakage value was 0.049% for FIXED collimator and 0.053% per IRIS collimator. Figure 6 shows values for different points for out of patient plane. Out of patient plane Leakage values The PTW30013 ionization chamber was the only one that we had used for the out of patient treatment. When measured at a distance of one meter from the source path, the highest radiation leakage for an IRIS collimator was 0.05%, whereas a FIXED collimator gave a maximum leakage of 0.05%. Discussion Comparing the graphs, the In-Patient Plane Leakage measurements using OSLDs were approximately four times higher than those obtained with the Ionization Chamber and Survey Meter. Despite this discrepancy, the maximum values for all three measurement methods were found at the same point, indicating the precision of the measurements. The deviation observed with the OSLDs may be attributed to factors such as inherent sensitivity and background noise, as different OSLDs were used for each position. Also, the properties of the OSLD material gets changed after every annealing cycle, which lead to over-response of the dosimeter. To improve the accuracy of OSL measurements, particularly given a minimum dose response of 0.5 mSv, accumulating more doses relative to the monitor units (MU) fired could be beneficial. OSLDs offer the advantage of measuring doses at all positions simultaneously, which can save time compared to the Ionization Chamber and Survey Meter. In contrast, the Out-of-Patient Plane leakage was notably observed in the IRIS setup due to its limitations in achieving a completely closed field size. Conclusion The study successfully measured the radiation head leakage of the CyberKnife System for both in-patient and out-of-patient planes using three different methods: optically stimulated luminescence dosimeters (OSLD), vented ionization chambers (IC), and pressurized ionization chamber-based survey meters (SM). The results demonstrated that the measured leakage levels for both IRIS and FIXED collimator types, in both patient planes, are well within the limits prescribed by the IEC 60601-2-1 standard. Specifically, the in-patient plane leakage was significantly below the 0.1% tolerance limit, and the out-of-patient plane leakage was well below the 0.5% threshold. This indicates that the CyberKnife System adheres to safety standards, ensuring minimal radiation leakage and safeguarding patient and operator safety. Declarations Ethical Approval and Consent to Participate: Not applicable Consent for Publication: Not applicable Funding : Not applicable Data Availability : All the data has been shared within the manuscript. All data generated or analysed during this study are included in this published article and its supplementary information files are also shared Author Contribution Sandeep Singh- Original Draft of Manuscript, Manindra Bhushan- Review and Final modification of Manuscript, Debasish Sahoo- Data Collection, Pawan Kumar Singh - Modification, Benoy Kumar Singh- Supervisor, Dipesh- Statistical Analysis, Abhay Kumar Singh- Figure Preparation, Mahipal Poonia- Data Collection, Supratik Sen- Data Collection, Munish Gairola- Supervisor. The authors have no relevant financial or non-financial interests to disclose.The authors have no conflicts of interest to declare that are relevant to the content of this article.All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.The authors have no financial or proprietary interests in any material discussed in this article. Acknowledgement Not applicable References CODE NO. AERB/RF-MED/SC-1 (Rev. 1) GOVERNMENT OF INDIA RADIATION THERAPY SOURCES, EQUIPMENT AND INSTALLATIONS AERB SAFETY CODE ATOMIC ENERGY REGULATORY BOARD. Potters L, Kavanagh B, Galvin JM, Hevezi JM, Janjan NA, Larson DA, et al. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Performance of Stereotactic Body Radiation Therapy. Int J Radiat Oncol Biol Phys [Internet] 2010 [cited 2024 Oct 14];76(2):326–32. Available from: http://www.redjournal.org/article/S0360301609033045/fulltext Kutcher GJ, Coia L, Gillin M, Hanson WF, Leibel S, Morton RJ, et al. Comprehensive Qa for Radiation Oncology: Report of Aapm Radiation Therapy Committee Task Group 40. Med Phys 1994;21(4):581–618. Iec. IEC 60601-2-1 INTERNATIONAL STANDARD NORME INTERNATIONALE Medical electrical equipment-Part 2-1: Particular requirements for the basic safety and essential performance of electron accelerators in the range 1 MeV to 50 MeV Appareils électromédicaux-Partie 2-1: Exigences particulières pour la sécurité de base et les performances essentielles des accélérateurs d’électrons dans la gamme de 1 MeV à 50 MeV INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE. 2020; Klein EE, Hanley J, Bayouth J, Yin FF, Simon W, Dresser S, et al. Task Group 142 report: Quality assurance of medical acceleratorsa). Med Phys [Internet] 2009 [cited 2024 Oct 14];36(9Part1):4197–212. Available from: https://onlinelibrary.wiley.com/doi/full/10.1118/1.3190392 Fraass B, Doppke K, Hunt M, Kutcher G, Starkschall G, Stern R, et al. American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: Quality assurance for clinical radiotherapy treatment planning. Med Phys [Internet] 1998 [cited 2024 Oct 14];25(10):1773–829. Available from: https://onlinelibrary.wiley.com/doi/full/10.1118/1.598373 NCRP Reports 151 - NCRP | Bethesda, MD [Internet]. [cited 2024 Oct 14];Available from: https://ncrponline.org/publications/reports/ncrp-reports-151/ López PO, Podgorsak EB. Chapter 16 RADIATION PROTECTION AND SAFETY IN RADIOTHERAPY. Taylor M, Kron T. Consideration of the radiation dose delivered away from the treatment field to patients in radiotherapy. J Med Phys [Internet] 2011 [cited 2024 Oct 14];36(2):59–71. Available from: https://journals.lww.com/jomp/fulltext/2011/36020/consideration_of_the_radiation_dose_delivered_away.2.aspx Dörr W. Pathogenesis of normal tissue side effects. Basic Clinical Radiobiology [Internet] 2018 [cited 2024 Oct 14];152–70. Available from: https://www.taylorfrancis.com/chapters/edit/10.1201/9780429490606-14/pathogenesis-normal-tissue-side-effects-wolfgang-d%C3%B6rr Boivin JF. Second Cancers and Other Late Side Effects of Cancer Treatment A Review. [cited 2024 Oct 14];Available from: https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/1097-0142 Linet MS, Slovis TL, Miller DL, Kleinerman R, Lee C, Rajaraman P, et al. Cancer risks associated with external radiation from diagnostic imaging procedures. CA Cancer J Clin [Internet] 2012 [cited 2024 Oct 14];62(2):75–100. Available from: https://onlinelibrary.wiley.com/doi/full/10.3322/caac.21132 Kumar P, Srinivas C, Vadhiraja B, Banerjee S, Shreyas R, Prakash Saxena P, et al. Simultaneous measurement of in vivo and transit mid-plane doses with ionization chambers in gynecological malignancy patients undergoing three-dimensional conformal radiotherapy. J Med Phys [Internet] 2020 [cited 2024 Oct 14];45(2):123–9. Available from: https://journals.lww.com/jomp/fulltext/2020/45020/simultaneous_measurement_of_in_vivo_and_transit.9.aspx Absorbed Dose Determination in External Beam Radiotherapy An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water. P Radiation Detector - Pressurized | Fluke Biomedical [Internet]. [cited 2024 Oct 14];Available from: https://www.flukebiomedical.com/products/radiation-measurement/radiation-safety/451p-radiation-detector-pressurized myOSLchip - myOSL [Internet]. [cited 2024 Oct 14];Available from: https://www.myosl.eu/myoslchip/ Additional Declarations No competing interests reported. Supplementary Files Data.xlsx Cite Share Download PDF Status: Published Journal Publication published 07 Oct, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 14 Jul, 2025 Reviews received at journal 11 Jul, 2025 Reviewers agreed at journal 30 Jun, 2025 Reviews received at journal 26 May, 2025 Reviewers agreed at journal 08 May, 2025 Reviewers invited by journal 02 May, 2025 Editor assigned by journal 02 May, 2025 Editor invited by journal 21 Apr, 2025 Submission checks completed at journal 19 Apr, 2025 First submitted to journal 11 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6424742","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":452089142,"identity":"1ba6e77a-8577-4ea2-bad6-41bccb443535","order_by":0,"name":"Sandeep 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1","display":"","copyAsset":false,"role":"figure","size":363347,"visible":true,"origin":"","legend":"\u003cp\u003ethe dosimetric devices used in the study (A) Optically Luminescence Dosimeter, (B) Pressurized ion chamber-based survey meter, (C) Farmer type ion chamber with brass build-up cap\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6424742/v1/34b1434bf7b91d7686a8b8eb.png"},{"id":82350701,"identity":"920e91cd-993c-4880-93af-c05539f5cfe1","added_by":"auto","created_at":"2025-05-09 10:53:13","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":429214,"visible":true,"origin":"","legend":"\u003cp\u003eRepresents the 24-measurement points according to IEC standard, out of which 16 were 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the Head leakage values for FIXED and IRIS collimator at 1 meter from the source path on both sides of head\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6424742/v1/a91eb7ee56d6c71f18370763.png"},{"id":93419717,"identity":"8af67e75-84cd-44ee-9994-7a7de6fa8b91","added_by":"auto","created_at":"2025-10-13 16:06:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1523346,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6424742/v1/454a9eff-7351-4bd4-9d8f-b3e326db4ff7.pdf"},{"id":82350705,"identity":"8f46bd7f-da38-4d18-9aaa-4d94be84293f","added_by":"auto","created_at":"2025-05-09 10:53:13","extension":"xlsx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":45264,"visible":true,"origin":"","legend":"","description":"","filename":"Data.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-6424742/v1/7e3f8570993dc9490e2df8c0.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Quantifying Head Leakage Radiation in CyberKnife robotic radiosurgery Systems: A Multi-Modal Approach","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe stringent regulation and oversight of radiation delivering units by the Atomic Energy Regulatory Board, Mumbai, are fundamental for ensuring the safe and effective application of radiation treatment in India\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. Before any radiation delivering unit can be used for clinical purposes, it must undergo a comprehensive evaluation process to meet rigorous national and international standards\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. This process culminates in the issuance of a type approval certificate, affirming compliance with stringent criteria encompassing electrical, mechanical, dosimetric, and radiation safety parameters. A key part of radiation safety regulations is managing leakage that could endanger patients and healthcare workers. Leakage can come from the primary beam or secondary sources, such as scattered radiation in the treatment room. To address this, organizations like the IEC and national bodies set strict limits and guidelines to protect people outside the treatment area and ensure accurate radiation delivery\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Quality Assurance (QA) protocols are crucial in this process, involving thorough testing of equipment to ensure effective shielding and collimation\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. By following these protocols, radiotherapy facilities improve treatment accuracy and maintain a safe environment for patients and staff. Measuring head-leakage radiation in clinical linear accelerators is crucial for ensuring the safety of patients, radiation workers, hospital staff, and the public. When the treatment beam is active, the radiation within the therapy room includes primary, scattered, head-leakage photons, and neutrons. The effectiveness of shielding and head design significantly impacts these leakage levels, making it essential to determine specific leakage values for each accelerator model\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe primary aim of this study is to comprehensively evaluate the radiation head leakage emitted from the CyberKnife System, both within the patient treatment plane (in-patient plane) and outside of it (out-of-patient plane) utilizing three types of dosimetric devices, vented type ionization Chambers, and pressurized ionization chamber-based survey meter and optically stimulated luminescence dosimeters. The assessment focuses on determining whether the leakage levels comply with the safety thresholds established by the International Electrotechnical Commission (IEC) standard 60601-2-1 \u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e, which sets global guidelines for radiation safety in medical linear accelerators (LINAC).\u003c/p\u003e "},{"header":"Method and material","content":"\u003cp\u003eThe acceptance and commissioning of medical linear accelerator undergoes rigorous scrutiny, and one of them is the measurement and control of in-patient plane leakage. Understanding, measuring, and controlling this leakage is vital for several reasons, each contributing to the overarching goal of ensuring patient safety, treatment efficacy, and compliance with regulatory standards. The primary concern with in-patient plane leakage is its potential to deliver unintended doses of radiation to healthy tissues and organs, adjacent to the treatment area \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. Even small doses of unintended radiation can lead to long-term side effects, such as secondary cancers \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. Therefore, monitoring and minimizing leakage is crucial. Accurate measurement of in-patient plane leakage involves using sophisticated equipment such as ionization chambers, film dosimeters, and optically stimulated luminescence dosimeters (OSLDs). These tools are essential for detecting and quantifying the leakage radiation. We used three dosimetry tools to measure the leakage radiation in the CyberKnife machine shown in Fig. 1.\u003c/p\u003e\n\u003cp\u003eThe PTW30013 FC-65 0.6 cm\u003csup\u003e3\u003c/sup\u003e (PTW GmBH, Freiberg Germany ) ionization chamber plays a pivotal role in radiotherapy, and is the gold standard for measurement \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e. For measurement of leakage, the chamber with brass build-up cap should be placed on 24 points given by IEC-60601-2-1. Out of 24 points only 16 are accessible ,the points and their location were shown in the Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e. The survey meter (Fluke 451P Radiation Detector), equipped with a 230-cc volume pressurized air ionization chamber, maintains accuracy within 10% of the reading between 10% and 100% of the full-scale indication on any range, exclusive of energy response. This detector can detect beta radiation above 1 MeV, as well as gamma and x-rays above 25 keV \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. The OSLD system (RadPro International GmbH, Germany) comprises multiple myOSLchips, a handheld manual OSL reader, an eraser including 24 blue power light-emitting diodes for annealing, and software for registration, calibration, and measurement \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e. The myOSLchips had a disk of dimension 4.7 x 4.7x 0.5 mm, of Beryllium Oxide (BeO). The size of dosimeter with plastic holder is 10 x 9.5 x 2 mm. It has the energy response from 16 KeV to 25 MeV. The dose range of the chip is 0.05 mGy to 10 Gy and dose response is linear upto10 Gy.\u003c/p\u003e\n\u003cp\u003eFor out-of-patient plane leakage measurement, the ion chamber is solely used. The different points of measurements used for this was shown in Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eThe dose comparison in this study was performed at d\u003csub\u003emax\u003c/sub\u003e (dose at maximum depth), 6 cm diameter field size at the central axis at NTD and represented as \u0026lsquo;Percentage Dose fraction\u0026rsquo;. According to the International Electrotechnical Commission (IEC) 60601-2-1 standard, the maximum allowable head-leakage for photons is 0.2%, with an average of 0.1%, d\u003csub\u003emax\u003c/sub\u003e for a 6 cm diameter circular field at the central axis \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. The formula used to calculate the Relative Dose was given as,\u003c/p\u003e\u003cp\u003e\u003cimg 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\" style=\"width: 467px; height: 57.5753px;\" width=\"467\" height=\"57.5753\"\u003e\u003c/p\u003e\n\u003cp\u003eIt is possible to obtain high-accuracy data in real time from ionization chambers. In addition to these measurements, a survey meter can provide instantaneous readings of dose rates, which can be of assistance in conducting rapid evaluations and maintaining continuous monitoring of radiation levels. OSLD, on the other hand, offers leakage at all locations in one go, which helps reduce time for leakage measurement.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eIn-patient plane Leakage values\u003c/h2\u003e \u003cp\u003eThe Ionization Chamber measurements for the IRIS setup had a maximum radiation leakage of 0.1741% and an average leakage of 0.0253%, whereas the FIXED Collimator had a maximum leakage of 0.0264% and an average of 0.0148%. The Survey Meter results showed a maximum leakage of 0.012% and an average of 0.011% for the IRIS, and a maximum of 0.012% and an average of 0.010% for the FIXED Collimator. OSLD measurements for the IRIS setup had a maximum leakage of 0.168% and an average leakage of 0.095%, while the FIXED Collimator had a maximum of 0.167% and an average of 0.100%. The radiation leakage is significantly below the permissible limits of 0.2% for maximum leakage and 0.1% for average leakage, based on the maximum absorbed dose at the nominal treatment distance (NTD) for a 6 cm radiation field size as given by IEC standards. Fig:4 and 5 shows the different values of leakage for all the points using IRIS and FIXED collimator.\u003c/p\u003e \u003cp\u003eFor out of patient plane, the maximum leakage value was 0.049% for FIXED collimator and 0.053% per IRIS collimator. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e6\u003c/span\u003e shows values for different points for out of patient plane.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eOut of patient plane Leakage values\u003c/h3\u003e\n\u003cp\u003eThe PTW30013 ionization chamber was the only one that we had used for the out of patient treatment. When measured at a distance of one meter from the source path, the highest radiation leakage for an IRIS collimator was 0.05%, whereas a FIXED collimator gave a maximum leakage of 0.05%.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eComparing the graphs, the In-Patient Plane Leakage measurements using OSLDs were approximately four times higher than those obtained with the Ionization Chamber and Survey Meter. Despite this discrepancy, the maximum values for all three measurement methods were found at the same point, indicating the precision of the measurements. The deviation observed with the OSLDs may be attributed to factors such as inherent sensitivity and background noise, as different OSLDs were used for each position. Also, the properties of the OSLD material gets changed after every annealing cycle, which lead to over-response of the dosimeter. To improve the accuracy of OSL measurements, particularly given a minimum dose response of 0.5 mSv, accumulating more doses relative to the monitor units (MU) fired could be beneficial. OSLDs offer the advantage of measuring doses at all positions simultaneously, which can save time compared to the Ionization Chamber and Survey Meter. In contrast, the Out-of-Patient Plane leakage was notably observed in the IRIS setup due to its limitations in achieving a completely closed field size.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe study successfully measured the radiation head leakage of the CyberKnife System for both in-patient and out-of-patient planes using three different methods: optically stimulated luminescence dosimeters (OSLD), vented ionization chambers (IC), and pressurized ionization chamber-based survey meters (SM). The results demonstrated that the measured leakage levels for both IRIS and FIXED collimator types, in both patient planes, are well within the limits prescribed by the IEC 60601-2-1 standard. Specifically, the in-patient plane leakage was significantly below the 0.1% tolerance limit, and the out-of-patient plane leakage was well below the 0.5% threshold. This indicates that the CyberKnife System adheres to safety standards, ensuring minimal radiation leakage and safeguarding patient and operator safety.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval and Consent to Participate:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e: All the data has been shared within the manuscript. All data generated or analysed during this study are included in this published article and its supplementary information files are also shared\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSandeep Singh- Original Draft of Manuscript, Manindra Bhushan- Review and Final modification of Manuscript, Debasish Sahoo- Data Collection, Pawan Kumar Singh - Modification, Benoy Kumar Singh- Supervisor, Dipesh- Statistical Analysis, Abhay Kumar Singh- Figure Preparation, Mahipal Poonia- Data Collection, Supratik Sen- Data Collection, Munish Gairola- Supervisor. The authors have no relevant financial or non-financial interests to disclose.The authors have no conflicts of interest to declare that are relevant to the content of this article.All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.The authors have no financial or proprietary interests in any material discussed in this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eCODE NO. AERB/RF-MED/SC-1 (Rev. 1) GOVERNMENT OF INDIA RADIATION THERAPY SOURCES, EQUIPMENT AND INSTALLATIONS AERB SAFETY CODE ATOMIC ENERGY REGULATORY BOARD. \u003c/li\u003e\n\u003cli\u003ePotters L, Kavanagh B, Galvin JM, Hevezi JM, Janjan NA, Larson DA, et al. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Performance of Stereotactic Body Radiation Therapy. Int J Radiat Oncol Biol Phys [Internet] 2010 [cited 2024 Oct 14];76(2):326\u0026ndash;32. Available from: http://www.redjournal.org/article/S0360301609033045/fulltext\u003c/li\u003e\n\u003cli\u003eKutcher GJ, Coia L, Gillin M, Hanson WF, Leibel S, Morton RJ, et al. Comprehensive Qa for Radiation Oncology: Report of Aapm Radiation Therapy Committee Task Group 40. Med Phys 1994;21(4):581\u0026ndash;618. \u003c/li\u003e\n\u003cli\u003eIec. IEC 60601-2-1 INTERNATIONAL STANDARD NORME INTERNATIONALE Medical electrical equipment-Part 2-1: Particular requirements for the basic safety and essential performance of electron accelerators in the range 1 MeV to 50 MeV Appareils \u0026eacute;lectrom\u0026eacute;dicaux-Partie 2-1: Exigences particuli\u0026egrave;res pour la s\u0026eacute;curit\u0026eacute; de base et les performances essentielles des acc\u0026eacute;l\u0026eacute;rateurs d\u0026rsquo;\u0026eacute;lectrons dans la gamme de 1 MeV \u0026agrave; 50 MeV INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE. 2020;\u003c/li\u003e\n\u003cli\u003eKlein EE, Hanley J, Bayouth J, Yin FF, Simon W, Dresser S, et al. Task Group 142 report: Quality assurance of medical acceleratorsa). Med Phys [Internet] 2009 [cited 2024 Oct 14];36(9Part1):4197\u0026ndash;212. Available from: https://onlinelibrary.wiley.com/doi/full/10.1118/1.3190392\u003c/li\u003e\n\u003cli\u003eFraass B, Doppke K, Hunt M, Kutcher G, Starkschall G, Stern R, et al. American Association of Physicists in Medicine Radiation Therapy Committee Task Group 53: Quality assurance for clinical radiotherapy treatment planning. Med Phys [Internet] 1998 [cited 2024 Oct 14];25(10):1773\u0026ndash;829. Available from: https://onlinelibrary.wiley.com/doi/full/10.1118/1.598373\u003c/li\u003e\n\u003cli\u003eNCRP Reports 151 - NCRP | Bethesda, MD [Internet]. [cited 2024 Oct 14];Available from: https://ncrponline.org/publications/reports/ncrp-reports-151/\u003c/li\u003e\n\u003cli\u003eL\u0026oacute;pez PO, Podgorsak EB. Chapter 16 RADIATION PROTECTION AND SAFETY IN RADIOTHERAPY. \u003c/li\u003e\n\u003cli\u003eTaylor M, Kron T. Consideration of the radiation dose delivered away from the treatment field to patients in radiotherapy. J Med Phys [Internet] 2011 [cited 2024 Oct 14];36(2):59\u0026ndash;71. Available from: https://journals.lww.com/jomp/fulltext/2011/36020/consideration_of_the_radiation_dose_delivered_away.2.aspx\u003c/li\u003e\n\u003cli\u003eD\u0026ouml;rr W. Pathogenesis of normal tissue side effects. Basic Clinical Radiobiology [Internet] 2018 [cited 2024 Oct 14];152\u0026ndash;70. Available from: https://www.taylorfrancis.com/chapters/edit/10.1201/9780429490606-14/pathogenesis-normal-tissue-side-effects-wolfgang-d%C3%B6rr\u003c/li\u003e\n\u003cli\u003eBoivin JF. Second Cancers and Other Late Side Effects of Cancer Treatment A Review. [cited 2024 Oct 14];Available from: https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/1097-0142\u003c/li\u003e\n\u003cli\u003eLinet MS, Slovis TL, Miller DL, Kleinerman R, Lee C, Rajaraman P, et al. Cancer risks associated with external radiation from diagnostic imaging procedures. CA Cancer J Clin [Internet] 2012 [cited 2024 Oct 14];62(2):75\u0026ndash;100. Available from: https://onlinelibrary.wiley.com/doi/full/10.3322/caac.21132\u003c/li\u003e\n\u003cli\u003eKumar P, Srinivas C, Vadhiraja B, Banerjee S, Shreyas R, Prakash Saxena P, et al. Simultaneous measurement of in vivo and transit mid-plane doses with ionization chambers in gynecological malignancy patients undergoing three-dimensional conformal radiotherapy. J Med Phys [Internet] 2020 [cited 2024 Oct 14];45(2):123\u0026ndash;9. Available from: https://journals.lww.com/jomp/fulltext/2020/45020/simultaneous_measurement_of_in_vivo_and_transit.9.aspx\u003c/li\u003e\n\u003cli\u003eAbsorbed Dose Determination in External Beam Radiotherapy An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water. \u003c/li\u003e\n\u003cli\u003eP Radiation Detector - Pressurized | Fluke Biomedical [Internet]. [cited 2024 Oct 14];Available from: https://www.flukebiomedical.com/products/radiation-measurement/radiation-safety/451p-radiation-detector-pressurized\u003c/li\u003e\n\u003cli\u003emyOSLchip - myOSL [Internet]. [cited 2024 Oct 14];Available from: https://www.myosl.eu/myoslchip/\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Leakage, in-patient plane, out of patient plane, OSLD, Survey meter","lastPublishedDoi":"10.21203/rs.3.rs-6424742/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6424742/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eAim\u003c/h2\u003e \u003cp\u003eThe purpose of this study is to measure radiation head leakage of CyberKnife System for in-patient plane and out-of-patient plane using Optically stimulated luminescence dosimeters (OSLD), vented type ionization Chambers, and pressurized ionization chamber-based survey meter and to compare the leakage level with that recommended by the International Electrotechnical Commission (IEC) standard.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e \u003cp\u003eIn this, CyberKnife (LINAC) having 6MV flattening filter free beam with maximum circular filed size of 6 cm diameter was used. Leakage was measured for both IRIS and FIXED type collimator in fully closed position. To measure the leakage, we had used three different methods, optically stimulated luminescence dosimeters (OSLD), vented ionization Chambers (IC), and pressurized ionization chamber-based survey meter (SM). Leakage measurement points were taken as per the IEC 60601-2-1 report both for in-patient plane and out-of-patient plane. The total number of monitor units (MU) delivered were 500 MU\u0026rsquo;s.\u003c/p\u003e\u003ch2\u003eResult\u003c/h2\u003e \u003cp\u003eThe measured average in-patient plane leakage was 0.015% using IC, 0.100% using OSLD and 0.010% using SM, that is well within the tolerance limit of 0.1% according to IEC guidelines. The average leakage for out of patient plane was 0.037%, which is well within the limit of 0.5% as per IEC guidelines.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe study measured radiation head leakage of the CyberKnife System using OSLD, ionization chambers, and a survey meter. Leakage levels for both in-patient and out-of-patient planes were significantly below the IEC 60601-2-1 standard limits. This confirms the system's compliance with safety guidelines, ensuring minimal radiation exposure.\u003c/p\u003e","manuscriptTitle":"Quantifying Head Leakage Radiation in CyberKnife robotic radiosurgery Systems: A Multi-Modal Approach","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-09 10:53:08","doi":"10.21203/rs.3.rs-6424742/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-14T06:34:09+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-11T21:17:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"111217251534913572347439017674762037225","date":"2025-06-30T12:40:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-26T14:57:13+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"104664627212572552917109202851669925145","date":"2025-05-08T19:29:25+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-02T15:57:59+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-05-02T15:38:12+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-04-21T09:38:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-19T05:49:10+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-04-11T04:39:42+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bb0592cb-61ea-40ff-8711-791702aefec6","owner":[],"postedDate":"May 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":48079804,"name":"Physical sciences/Physics/Applied physics"},{"id":48079805,"name":"Health sciences/Health care"}],"tags":[],"updatedAt":"2025-10-13T16:00:35+00:00","versionOfRecord":{"articleIdentity":"rs-6424742","link":"https://doi.org/10.1038/s41598-025-18689-1","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-10-07 15:57:25","publishedOnDateReadable":"October 7th, 2025"},"versionCreatedAt":"2025-05-09 10:53:08","video":"","vorDoi":"10.1038/s41598-025-18689-1","vorDoiUrl":"https://doi.org/10.1038/s41598-025-18689-1","workflowStages":[]},"version":"v1","identity":"rs-6424742","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6424742","identity":"rs-6424742","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}