Guide to clinical use of electronic portal imaging

The Electronic Portal Imaging Device (EPID) provides localization quality images and computer‐aided analysis, which should in principal, replace portal film imaging. Modern EPIDs deliver superior image quality and an array of analysis tools that improve clinical decision making. It has been demonstrated that the EPID can be a powerful tool in the reduction of treatment setup errors and the quality assurance and verification of complex treatments. However, in many radiation therapy clinics EPID technology is not in routine clinical use. This low utilization suggests that the capability and potential of the technology alone do not guarantee its full adoption. This paper addresses basic considerations required to facilitate clinical implementation of the EPID technology and gives specific examples of successful implementations. © 2000 American College of Medical Physics. PACS number(s): 87.53.–j, 87.57.–s

[1]  Pictorial review: comparison of portal imaging and megavoltage verification films for conformal pelvic irradiation. , 1996, The British journal of radiology.

[2]  M van Herk,et al.  New method to obtain the midplane dose using portal in vivo dosimetry. , 1998, International journal of radiation oncology, biology, physics.

[3]  A Boxwala,et al.  Core-based portal image registration for automatic radiotherapy treatment verification. , 1995, International journal of radiation oncology, biology, physics.

[4]  J Yorkston,et al.  Initial performance evaluation of an indirect-detection, active matrix flat-panel imager (AMFPI) prototype for megavoltage imaging. , 1998, International journal of radiation oncology, biology, physics.

[5]  D. Gladstone,et al.  A numerical simulation of organ motion and daily setup uncertainties: implications for radiation therapy. , 1997, International journal of radiation oncology, biology, physics.

[6]  M van Herk,et al.  Automatic three-dimensional inspection of patient setup in radiation therapy using portal images, simulator images, and computed tomography data. , 1996, Medical physics.

[7]  J. Lewis,et al.  A computer-controlled conformal radiotherapy system. II: Sequence processor. , 1995, International journal of radiation oncology, biology, physics.

[8]  M van Herk,et al.  Sampling methods for a matrix ionization chamber system. , 1992, Medical physics.

[9]  K Lam,et al.  Measurement of prostate movement over the course of routine radiotherapy using implanted markers. , 1995, International journal of radiation oncology, biology, physics.

[10]  G T Chen,et al.  Online repositioning during treatment of the prostate: a study of potential limits and gains. , 1993, International journal of radiation oncology, biology, physics.

[11]  B. Heijmen,et al.  Portal dose measurement in radiotherapy using an electronic portal imaging device (EPID). , 1995, Physics in medicine and biology.

[12]  J Pouliot,et al.  Electronic portal imaging device detection of radioopaque markers for the evaluation of prostate position during megavoltage irradiation: a clinical study. , 1997, International journal of radiation oncology, biology, physics.

[13]  G K Svensson,et al.  Effect of set-up error on the dose across the junction of matching cranial-spinal fields in the treatment of medulloblastoma. , 1993, International journal of radiation oncology, biology, physics.

[14]  A Bel,et al.  Time trend of patient setup deviations during pelvic irradiation using electronic portal imaging. , 1993, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[15]  B. Heijmen,et al.  Verification of compensator thicknesses using a fluoroscopic electronic portal imaging device. , 1999, Medical physics.

[16]  P. Bergström,et al.  High-precision conformal radiotherapy (HPCRT) of prostate cancer--a new technique for exact positioning of the prostate at the time of treatment. , 1998, International journal of radiation oncology, biology, physics.

[17]  Michael G. Herman,et al.  58 Effects of respiration on target and critical structure positions during treatment assessed with movie-loop electronic portal imaging , 1997 .

[18]  M Goitein,et al.  Immobilization error: some theoretical considerations. , 1975, Radiology.

[19]  D. Gladstone,et al.  Verification of lung attenuator positioning before total body irradiation using an electronic portal imaging device. , 1993, International journal of radiation oncology, biology, physics.

[20]  R E Vijlbrief,et al.  Setup deviations in wedged pair irradiation of parotid gland and tonsillar tumors, measured with an electronic portal imaging device. , 1995, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[21]  Z Li,et al.  Verification of milled two-dimensional photon compensating filters using an electronic portal imaging device. , 1996, Medical physics.

[22]  M van Herk,et al.  First clinical tests using a liquid-filled electronic portal imaging device and a convolution model for the verification of the midplane dose. , 1998, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[23]  D P Dearnaley,et al.  Portal imaging protocol for radical dose-escalated radiotherapy treatment of prostate cancer. , 1998, International journal of radiation oncology, biology, physics.

[24]  M G Herman,et al.  Clinical use of on-line portal imaging for daily patient treatment verification. , 1994, International journal of radiation oncology, biology, physics.

[25]  P. Munro,et al.  A review of electronic portal imaging devices (EPIDs). , 1992, Medical physics.

[26]  A Fenster,et al.  Daily monitoring and correction of radiation field placement using a video-based portal imaging system: a pilot study. , 1992, International journal of radiation oncology, biology, physics.

[27]  D. Dearnaley,et al.  Accuracy of pelvic radiotherapy: prospective analysis of 90 patients in a randomised trial of blocked versus standard radiotherapy. , 1996, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[28]  A Fenster,et al.  A digital fluoroscopic imaging device for radiotherapy localization. , 1990, International journal of radiation oncology, biology, physics.

[29]  M van Herk,et al.  Transmission dosimetry with a liquid-filled electronic portal imaging device. , 1996, International journal of radiation oncology, biology, physics.

[30]  W. De Neve,et al.  Clinical implementation of an objective computer-aided protocol for intervention in intra-treatment correction using electronic portal imaging. , 1995, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[31]  E E Klein,et al.  A quality assurance program for ancillary high technology devices on a dual-energy accelerator. , 1996, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[32]  A G Haus,et al.  Localization error in the radiotherapy of Hodgkin's disease and malignant lymphoma with extended mantle fields , 1974, Cancer.

[33]  L E Reinstein,et al.  Assessment of geometric treatment accuracy using time-lapse display of electronic portal images. , 1992, International journal of radiation oncology, biology, physics.

[34]  K. Leszczynski,et al.  Optimization of metal/phosphor screens for on-line portal imaging. , 1994, Medical physics.

[35]  R K Valicenti,et al.  An analysis of intratreatment and intertreatment displacements in pelvic radiotherapy using electronic portal imaging. , 1996, International journal of radiation oncology, biology, physics.

[36]  K S Lam,et al.  An on-line electronic portal imaging system for external beam radiotherapy. , 1986, The British journal of radiology.

[37]  D Verellen,et al.  Interactive use of on-line portal imaging in pelvic radiation. , 1993, International journal of radiation oncology, biology, physics.

[38]  A G Haus,et al.  The value of frequent treatment verification films in reducing localization error in the irradiation of complex fields , 1976, Cancer.

[39]  K W Leszczynski,et al.  An image registration scheme applied to verification of radiation therapy. , 1998, The British journal of radiology.

[40]  S Shalev,et al.  Pseudocorrelation: a fast, robust, absolute, grey-level image alignment algorithm. , 1994, Medical physics.

[41]  R. Boellaard,et al.  A convolution model to convert transmission dose images to exit dose distributions. , 1997, Medical physics.

[42]  L. Vanuytsel,et al.  Localization errors in mantle-field irradiation for Hodgkin's disease. , 1989, International journal of radiation oncology, biology, physics.

[43]  A G Visser,et al.  Performance of a prototype fluoroscopic radiotherapy imaging system. , 1990, International journal of radiation oncology, biology, physics.

[44]  W P Mayles,et al.  Design of compensators for breast radiotherapy using electronic portal imaging. , 1995, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[45]  J. Leong,et al.  Use of digital fluoroscopy as an on-line verification device in radiation therapy. , 1986, Physics in medicine and biology.

[46]  J Wong,et al.  Effects of treatment setup variation on beam's eye view dosimetry for radiation therapy using the multileaf collimator vs. the cerrobend block. , 1995, International journal of radiation oncology, biology, physics.

[47]  K S Lam,et al.  On-line measurement of field placement errors in external beam radiotherapy. , 1987, The British journal of radiology.

[48]  J Wong,et al.  Adaptive modification of treatment planning to minimize the deleterious effects of treatment setup errors. , 1997, International journal of radiation oncology, biology, physics.

[49]  M C Kirby,et al.  The use of an electronic portal imaging device for exit dosimetry and quality control measurements. , 1995, International journal of radiation oncology, biology, physics.

[50]  M Partridge,et al.  Independent verification using portal imaging of intensity-modulated beam delivery by the dynamic MLC technique. , 1998, Medical physics.

[51]  J. Palta,et al.  Comprehensive QA for radiation oncology: report of AAPM Radiation Therapy Committee Task Group 40. , 1994, Medical physics.

[52]  D. G. Lewis,et al.  A linear array, scintillation crystal-photodiode detector for megavoltage imaging. , 1991, Medical physics.

[53]  Y. Zhu,et al.  Portal dosimetry using a liquid ion chamber matrix: dose response studies. , 1995, Medical physics.

[54]  D Verellen,et al.  Electronic portal imaging with on-line correction of setup error in thoracic irradiation: clinical evaluation. , 1998, International journal of radiation oncology, biology, physics.

[55]  F. V. Heuvel,et al.  Clinical implementation of an objective computer-aided protocol for intervention in intra-treatment correction using electronic portal imaging , 1995 .

[56]  M van Herk,et al.  First clinical experience with a newly developed electronic portal imaging device. , 1990, International journal of radiation oncology, biology, physics.

[57]  P M Evans,et al.  The application of transit dosimetry to precision radiotherapy. , 1996, Medical physics.

[58]  M van Herk,et al.  Optimization of automatic portal image analysis. , 1995, Medical physics.

[59]  P M Evans,et al.  Practical implementation of compensators in breast radiotherapy. , 1998, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[60]  D Yan,et al.  A new model for "accept or reject" strategies in off-line and on-line megavoltage treatment evaluation. , 1995, International journal of radiation oncology, biology, physics.

[61]  R K Valicenti,et al.  Is weekly port filming adequate for verifying patient position in modern radiation therapy? , 1994, International journal of radiation oncology, biology, physics.

[62]  A Fenster,et al.  X-ray scatter in megavoltage transmission radiography: physical characteristics and influence on image quality. , 1994, Medical physics.

[63]  D Yan,et al.  The use of on-line image verification to estimate the variation in radiation therapy dose delivery. , 1993, International journal of radiation oncology, biology, physics.

[64]  M C Schell,et al.  Input/output characteristics of a matrix ion-chamber electronic portal imaging device. , 1994, Medical physics.

[65]  P M Evans,et al.  Image comparison techniques for use with megavoltage imaging systems. , 1992, The British journal of radiology.

[66]  A G Visser,et al.  Quality assurance using portal imaging: the accuracy of patient positioning in irradiation of breast cancer. , 1993, International journal of radiation oncology, biology, physics.

[67]  J Yorkston,et al.  Megavoltage imaging with a large-area, flat-panel, amorphous silicon imager. , 1996, International journal of radiation oncology, biology, physics.

[68]  K S Lam,et al.  On-line portal imaging: computer-assisted error measurement. , 1991, Radiology.

[69]  M van Herk,et al.  A matrix ionisation chamber imaging device for on-line patient setup verification during radiotherapy. , 1988, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[70]  P. Munro,et al.  Optimal radiographic magnification for portal imaging. , 1994, Medical physics.

[71]  The use of an electronic portal imaging system to measure portal dose and portal dose profiles. , 1998, Medical physics.

[72]  J Pouliot,et al.  The role of electronic portal imaging in tangential breast irradiation: a prospective study. , 1995, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[73]  P. Evans,et al.  Reproducibility of patient positioning during routine radiotherapy, as assessed by an integrated megavoltage imaging system. , 1995, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[74]  E. Van Der Schueren,et al.  A model for calculating the costs of in vivo dosimetry and portal imaging in radiotherapy departments. , 1993, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[75]  L Dong,et al.  Verification of radiosurgery target point alignment with an electronic portal imaging device (EPID). , 1997, Medical physics.

[76]  M van Herk,et al.  Fast evaluation of patient set-up during radiotherapy by aligning features in portal and simulator images. , 1991, Physics in medicine and biology.

[77]  G T Chen,et al.  Correlation of projection radiographs in radiation therapy using open curve segments and points. , 1992, Medical physics.

[78]  M C Schell,et al.  A technique of automating compensator design for lung inhomogeneity correction using an electron portal imaging device. , 1994, Medical physics.

[79]  S Shalev,et al.  Video techniques for on-line portal imaging. , 1989, Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society.

[80]  P. Munro,et al.  Portal Imaging Technology: Past, Present, and Future. , 1995, Seminars in radiation oncology.

[81]  R M Harrison,et al.  A method and contrast-detail phantom for the quantitative assessment of radiotherapy portal imaging systems. , 1994, The British journal of radiology.

[82]  S Shalev,et al.  A quality control test for electronic portal imaging devices. , 1996, Medical physics.

[83]  S Shalev,et al.  Assessing radiation and light field congruence with a video based electronic portal imaging device. , 1996, Medical physics.

[84]  B J Mijnheer,et al.  Accuracy in tangential breast treatment set-up: a portal imaging study. , 1991, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology.

[85]  A L Boyer,et al.  An image correlation procedure for digitally reconstructed radiographs and electronic portal images. , 1995, International journal of radiation oncology, biology, physics.

[86]  S. Shalev,et al.  Pelvic irradiation of the obese patient: a treatment strategy involving megavoltage simulation and intratreatment setup corrections. , 1996, Medical physics.

[87]  T E Schultheiss,et al.  Intra- and interfractional reproducibility of tangential breast fields: a prospective on-line portal imaging study. , 1996, International journal of radiation oncology, biology, physics.

[88]  B R Paliwal,et al.  Modeling dose distributions from portal dose images using the convolution/superposition method. , 1996, Medical physics.

[89]  J M Balter,et al.  Determination of rotations in three dimensions using two-dimensional portal image registration. , 1998, Medical physics.

[90]  M W Vannier,et al.  A method to analyze 2-dimensional daily radiotherapy portal images from an on-line fiber-optic imaging system. , 1991, International journal of radiation oncology, biology, physics.

[91]  A Bel,et al.  High-precision prostate cancer irradiation by clinical application of an offline patient setup verification procedure, using portal imaging. , 1996, International journal of radiation oncology, biology, physics.

[92]  M. Goitein,et al.  Accuracy of radiation field alignment in clinical practice. , 1985, International journal of radiation oncology, biology, physics.

[93]  B. Fallone,et al.  Preliminary study of a metal/a-Se-based portal detector. , 1998, Medical physics.

[94]  J. Chu,et al.  A simple algorithm for planar image registration in radiation therapy. , 1998, Medical physics.

[95]  P. Dunscombe,et al.  The Siemens virtual wedge. , 1997, Medical dosimetry : official journal of the American Association of Medical Dosimetrists.

[96]  A R Smith,et al.  Improved methods for determination of variability in patient positioning for radiation therapy using simulation and serial portal film measurements. , 1992, International journal of radiation oncology, biology, physics.

[97]  T D Kampp,et al.  Fluoroscopic visualization of megavoltage therapeutic x ray beams. , 1980, International journal of radiation oncology, biology, physics.

[98]  A Fenster,et al.  Therapy imaging: a signal-to-noise analysis of a fluoroscopic imaging system for radiotherapy localization. , 1990, Medical physics.

[99]  T E Schultheiss,et al.  An evaluation of setup uncertainties for patients treated to pelvic sites. , 1995, International journal of radiation oncology, biology, physics.

[100]  D. Nelson,et al.  An observer study for direct comparison of clinical efficacy of electronic to film portal images. , 1996, International journal of radiation oncology, biology, physics.