Advertisement

The physics of small megavoltage photon beam dosimetry

  • Pedro Andreo
    Correspondence
    Address: Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
    Affiliations
    Department of Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
    Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
    Search for articles by this author
Published:November 27, 2017DOI:https://doi.org/10.1016/j.radonc.2017.11.001

      Abstract

      The increased interest during recent years in the use of small megavoltage photon beams in advanced radiotherapy techniques has led to the development of dosimetry recommendations by different national and international organizations. Their requirement of data suitable for the different clinical options available, regarding treatment units and dosimetry equipment, has generated a considerable amount of research by the scientific community during the last decade. The multiple publications in the field have led not only to the availability of new invaluable data, but have also contributed substantially to an improved understanding of the physics of their dosimetry. This work provides an overview of the most important aspects that govern the physics of small megavoltage photon beam dosimetry.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Radiotherapy and Oncology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Leksell L.
        The stereotaxic method and radiosurgery of the brain.
        Acta Chir Scand. 1951; 102: 316-319
        • Leksell L.
        Cerebral radiosurgery. I. Gammathalanotomy in two cases of intractable pain.
        Acta Chir Scand. 1968; 134: 585-595
      1. ICRU Report 91. Prescribing, recording and reporting of stereotactic treatments with small photon beams. Bethesda, MD: International Commission on Radiation Units and Measurements; 2017.

      2. Bogdanich W, Ruiz RR. Radiation errors reported in Missouri. The New York Times (New York Edition), p1 A17, 25 February 2010.

      3. Derreumaux S, Boisserie G, Brunet G, Buchheit I, Sarrazin T. Concerns in France about the dose delivered to the patients in stereotactic radiation therapy. Standards, applications and quality assurance in medical radiation dosimetry (Proc int symp Vienna): IAEA, Vienna; 2011.

        • Aspradakis M.M.
        • Byrne J.P.
        • Palmans H.
        • Conway J.
        • Rosser K.
        • Warrington A.P.
        • et al.
        Small field MV photon dosimetry.
        Institute of Physics and Engineering in Medicine, York, UK2010
        • Palmans H.
        • Andreo P.
        • Christaki K.
        • Huq M.S.
        • Seuntjens J.
        Dosimetry of small static fields used in external beam radiotherapy: an IAEA-AAPM international code of practice for reference and relative dose determination.
        International Atomic Energy Agency, Vienna2017
        • Alfonso R.
        • Andreo P.
        • Capote R.
        • Huq M.S.
        • Kilby W.
        • Kjall P.
        • et al.
        A new formalism for reference dosimetry of small and nonstandard fields.
        Med Phys. 2008; 35: 5179-5186
        • Das I.J.
        • Ding G.X.
        • Ahnesjö A.
        Small fields: non-equilibrium radiation dosimetry.
        Med Phys. 2008; 35: 206-215
        • Crop F.
        • Reynaert N.
        • Pittomvils G.
        • Paelinck L.
        • De Wagter C.
        • Vakaet L.
        • et al.
        The influence of small field sizes, penumbra, spot size and measurement depth on perturbation factors for microionization chambers.
        Phys Med Biol. 2009; 54: 2951-2969
        • Cranmer-Sargison G.
        • Weston S.
        • Evans J.A.
        • Sidhu N.P.
        • Thwaites D.I.
        Implementing a newly proposed Monte Carlo based small field dosimetry formalism for a comprehensive set of diode detectors.
        Med Phys. 2011; 38: 6592-6602
        • Francescon P.
        • Cora S.
        • Satariano N.
        Calculation of kQclin,Qmsrfclin,fmsr for several small detectors and for two linear accelerators using Monte Carlo simulations.
        Med Phys. 2011; 38: 6513-6527
        • Cranmer-Sargison G.
        • Weston S.
        • Evans J.A.
        • Sidhu N.P.
        • Thwaites D.I.
        Monte Carlo modelling of diode detectors for small field MV photon dosimetry: detector model simplification and the sensitivity of correction factors to source parameterization.
        Phys Med Biol. 2012; 57: 5141-5153
        • Pantelis E.
        • Moutsatsos A.
        • Zourari K.
        • Petrokokkinos L.
        • Sakelliou L.
        • Kilby W.
        • et al.
        On the output factor measurements of the CyberKnife iris collimator small fields: experimental determination of the kQclin,Qmsrfclin,fmsr correction factors for microchamber and diode detectors.
        Med Phys. 2012; 39: 4875-4885
        • Ralston A.
        • Liu P.
        • Warrener K.
        • McKenzie D.
        • Suchowerska N.
        Small field diode correction factors derived using an air core fibre optic scintillation dosimeter and EBT2 film.
        Phys Med Biol. 2012; 57: 2587-2602
        • Scott A.J.D.
        • Kumar S.
        • Nahum A.E.
        • Fenwick J.D.
        Characterizing the influence of detector density on dosimeter response in non-equilibrium small photon fields.
        Phys Med Biol. 2012; 57: 4461-4476
        • Bassinet C.
        • Huet C.
        • Derreumaux S.
        • Brunet G.
        • Chea M.
        • Baumann M.
        • et al.
        Small fields output factors measurements and correction factors determination for several detectors for a CyberKnife and linear accelerators equipped with microMLC and circular cones.
        Med Phys. 2013; 40: 071725
        • Lechner W.
        • Palmans H.
        • Sölkner L.
        • Grochwska P.
        • Georg D.
        Detector comparison for small field output factor measurements in flattening filter free photon beams.
        Radioth Oncol. 2013; 109: 356-360
        • Fenwick J.D.
        • Kumar S.
        • Scott A.J.
        • Nahum A.E.
        Using cavity theory to describe the dependence on detector density of dosimeter response in non-equilibrium small fields.
        Phys Med Biol. 2013; 58: 2901-2923
        • Czarnecki D.
        • Zink K.
        Monte Carlo calculated correction factors for diodes and ion chambers in small photon fields.
        Phys Med Biol. 2013; 58: 2431-2444
        • Underwood T.S.
        • Winter H.C.
        • Hill M.A.
        • Fenwick J.D.
        Detector density and small field dosimetry: integral versus point dose measurement schemes.
        Med Phys. 2013; 40: 082102
        • Wuerfel J.U.
        Dose measurements in small fields.
        Med Phys Int. 2013; 1: 81-90
        • Azangwe G.
        • Grochowska P.
        • Georg D.
        • Izewska J.
        • Hopfgartner J.
        • Lechner W.
        • et al.
        Detector to detector corrections: a comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams.
        Med Phys. 2014; 41: 072103
        • Benmakhlouf H.
        • Sempau J.
        • Andreo P.
        Output correction factors for nine small field detectors in 6 MV radiation therapy photon beams: a PENELOPE Monte Carlo study.
        Med Phys. 2014; 41: 041711
        • Francescon P.
        • Beddar S.
        • Satariano N.
        • Das I.J.
        Variation kQclin,Qmsrfclin,fmsr of for the small-field dosimetric parameters percentage depth dose, tissue-maximum ratio, and off-axis ratio.
        Med Phys. 2014; 41: 101708
        • Moignier C.
        • Huet C.
        • Makovicka L.
        Determination of the kQclin,Qmsrfclin,fmsr correction factors for detectors used with an 800 MU/min CyberKnife system equipped with fixed collimators and a study of detector response to small photon beams using a Monte Carlo method.
        Med Phys. 2014; 41: 071702
        • Morales J.E.
        • Crowe S.B.
        • Hill R.
        • Freeman N.
        • Trapp J.V.
        Dosimetry of cone-defined stereotactic radiosurgery fields with a commercial synthetic diamond detector.
        Med Phys. 2014; 41: 111702
        • Papaconstadopoulos P.
        • Tessier F.
        • Seuntjens J.
        On the correction, perturbation and modification of small field detectors in relative dosimetry.
        Phys Med Biol. 2014; 59: 5937-5952
        • Ralston A.
        • Tyler M.
        • Liu P.
        • McKenzie D.
        • Suchowerska N.
        Over-response of synthetic microDiamond detectors in small radiation fields.
        Phys Med Biol. 2014; 59: 5873-5881
        • Andreo P.
        • Palmans H.
        • Marteinsdottir M.
        • Benmakhlouf H.
        • Carlson-Tedgren A.
        On the Monte Carlo simulation of small-field micro-diamond detectors for megavoltage photon dosimetry.
        Phys Med Biol. 2015; 61: L1-L10
        • Benmakhlouf H.
        • Johansson J.
        • Paddick I.
        • Andreo P.
        Monte Carlo calculated and experimentally determined output correction factors for small field detectors in Leksell Gamma Knife Perfexion beams.
        Phys Med Biol. 2015; 60: 3959-3973
        • Benmakhlouf H.
        Key data for the reference and relative dosimetry of radiotherapy and diagnostic and interventional radiology beams.
        ([Ph.D. thesis]) Stockholm University, 2015
        • Bouchard H.
        • Seuntjens J.
        • Duane S.
        • Kamio Y.
        • Palmans H.
        Detector dose response in megavoltage small photon beams. I. Theoretical concepts.
        Med Phys. 2015; 42: 6033-6047
        • Bouchard H.
        • Kamio Y.
        • Palmans H.
        • Seuntjens J.
        • Duane S.
        Detector dose response in small megavoltage photon beams. II. Pencil beam perturbation effects.
        Med Phys. 2015; 42: 6048-6061
        • González-López A.
        • Vera-Sánchez J.A.
        • Lago-Martín J.D.
        Small fields measurements with radiochromic films.
        J Med Phys. 2015; 40: 61-67
        • Kumar S.
        • Fenwick J.D.
        • Underwood T.S.
        • Deshpande D.D.
        • Scott A.J.
        • Nahum A.E.
        Breakdown of Bragg-Gray behaviour for low-density detectors under electronic disequilibrium conditions in small megavoltage photon fields.
        Phys Med Biol. 2015; 60: 8187-8212
        • Lárraga-Gutiérrez J.M.
        • Ballesteros-Zebadúa P.
        • Rodríguez-Ponce M.
        • García-Garduño O.A.
        • Galván de la Cruz O.O.
        Properties of a commercial PTW-60019 synthetic diamond detector for the dosimetry of small radiotherapy beams.
        Phys Med Biol. 2015; 60: 905-924
        • Ploquin N.
        • Kertzscher G.
        • Vandervoort E.
        • Cygler J.E.
        • Andersen C.E.
        • Francescon P.
        Use of novel fibre-coupled radioluminescence and RADPOS dosimetry systems for total scatter factor measurements in small fields.
        Phys Med Biol. 2015; 60: 1-14
        • Tanny S.
        • Sperling N.
        • Parsai E.I.
        Correction factor measurements for multiple detectors used in small field dosimetry on the Varian Edge radiosurgery system.
        Med Phys. 2015; 42: 5370-5376
        • Underwood T.S.
        • Rowland B.C.
        • Ferrand R.
        • Vieillevigne L.
        Application of the Exradin W1 scintillator to determine Ediode 60017 and microDiamond 60019 correction factors for relative dosimetry within small MV and FFF fields.
        Phys Med Biol. 2015; 60: 6669-6683
        • Andreo P.
        • Palmans H.
        Comment on “Experimental determination of the PTW 60019 microDiamond dosimeter active area and volume”.
        Med Phys. 2016; 43: 6667
        • Marinelli M.
        • Prestopino G.
        • Vernoa C.
        • Verona-Rinat G.
        Experimental determination of the PTW 60019 microDiamond dosimeter active area and volume.
        Med Phys. 2016; 43: 5205-5212
        • O’Brien D.J.
        • Leon-Vintro L.
        • McClean B.
        Small field detector correction factors for silicon-diode and diamond detectors with circular 6 MV fields derived using both empirical and numerical methods.
        Med Phys. 2016; 43: 411-423
        • Andreo P.
        • Benmakhlouf H.
        Role of the density, density effect and mean excitation energy in solid-state detectors for small photon fields.
        Phys Med Biol. 2017; 62: 1518-1532
        • Benmakhlouf H.
        • Andreo P.
        Spectral distribution of particle fluence in small field detectors and its implication on small field dosimetry.
        Med Phys. 2017; 44: 713-724
        • Li X.A.
        • Soubra M.
        • Szanto J.
        • Gerig L.H.
        Lateral electron equilibrium and electron contamination in measurements of head-scatter factors using miniphantoms and brass caps.
        Med Phys. 1995; 22: 1167-1170
        • Papaconstadopoulos P.
        On the detector response and the reconstruction of the source intensity distribution in small photon fields.
        ([Ph.D. thesis]) McGill University, Montreal2016
        • Sánchez-Doblado F.
        • Andreo P.
        • Capote R.
        • Leal A.
        • Perucha M.
        • Arrans R.
        • et al.
        Ionization chamber dosimetry of small photon fields: a Monte Carlo study on stopping-power ratios for radiosurgery and IMRT beams.
        Phys Med Biol. 2003; 48: 2081-2099
        • Andreo P.
        • Brahme A.
        Stopping power data for high-energy photon beams.
        Phys Med Biol. 1986; 31: 839-858
        • Eklund K.
        • Ahnesjö A.
        Fast modeling of spectra and stopping-power ratios using differentiated fluence pencil kernels.
        Phys Med Biol. 2008; 53: 4231-4247
        • Kawachi T.
        • Saitoh H.
        • Inoue M.
        • Katayose T.
        • Myojoyama A.
        • Hatano K.
        Reference dosimetry condition and beam quality correction factor for CyberKnife beam.
        Med Phys. 2008; 35: 4591-4598
        • Andreo P.
        • Burns D.T.
        • Nahum A.E.
        • Seuntjens J.
        • Attix F.H.
        Fundamentals of ionizing radiation dosimetry.
        Wiley-VCH, Weinheim, Germany2017
        • Sempau J.
        • Andreo P.
        • Aldana J.
        • Mazurier J.
        • Salvat F.
        Electron beam quality correction factors for plane-parallel ionization chambers: Monte Carlo calculations using the PENELOPE system.
        Phys Med Biol. 2004; 49: 4427-4444
        • Andreo P.
        Dose to “water-like” media or dose to tissue in MV photons radiotherapy treatment planning: still a matter of debate.
        Phys Med Biol. 2015; 60 (Corrigendum in p. 2619): 309-337
        • O’Connor J.E.
        The variation of scattered x-rays with density in an irradiated body.
        Phys Med Biol. 1957; 1: 352-369
      4. ICRU Report 90. Key data for ionizing radiation dosimetry: measurement standards and applications. Bethesda, MD: International Commission on Radiation Units and Measurements; 2016.

        • Aird E.G.A.
        • Burns J.E.
        • Day M.J.
        • Duane S.
        • Jordan T.J.
        • Kacperek A.
        • et al.
        Central axis depth dose data for use in radiotherapy.
        The British Institute of Radiology, London1996
        • Podgorsak E.B.
        External photon beams: physical aspects. Radiation oncology physics: a handbook for teachers and students.
        International Atomic Energy Agency, Vienna2005: 161-217
        • Rosser K.E.
        • Bedford J.L.
        Application of a new dosimetry formalism to volumetric modulated arc therapy (VMAT).
        Phys Med Biol. 2009; 54: 7045-7061
      5. Öhrman T, Andreo P, Isacsson U, Montelius A. Analytical determination of a plan class specific reference (pcsr) field for reference dosimetry of IMRT fields. Book of extended synopsis, IAEA international symposium. Standards, applications and quality assurance in medical radiation dosimetry. Vienna, AUT: Vienna: International Atomic Energy Agency; 2010. p. 319–20.

        • Gago-Arias A.
        • Rodríguez-Romero R.
        • Sánchez-Rubio P.
        • González-Castaño D.M.
        • Gómez F.
        • Núñez L.
        • et al.
        Correction factors for A1SL ionization chamber dosimetry in TomoTherapy: machine-specific, plan-class, and clinical fields.
        Med Phys. 2012; 39: 1964-1970
        • Beddar A.S.
        • Briere T.M.
        Plastic scintillation detectors.
        in: Rogers D.W.O. Cygler J.E. Clinical dosimetry measurements in radiotherapy. Medical Physics Publishing, Madison, WI2009: 1059-1082
        • Beddar A.S.
        • Beaulieu L.
        Scintillation dosimetry.
        CRC Press-VitalSource Bookshelf Online, Boca Raton, FL2016
        • Al Shukaili K.
        • Petasecca M.
        • Newall M.
        • Espinoza A.
        • Perevertaylo V.L.
        • Corde S.
        • et al.
        A 2D silicon detector array for quality assurance in small field dosimetry: DUO.
        Med Phys. 2017; 44: 628-636
        • Loong Jong W.
        • Min Ung N.
        • Vannyat A.
        • Jamalludin Z.
        • Rosenfeld A.
        • Hsiu Ding Wong J.
        Edge-on MOSkin detector for stereotactic beam measurement and verification.
        Physica Med. 2017; 33: 127-135