Development of EPID-based Real time Dose Verification for Dynamic IMRT
An electronic portal image device (EPID) has become
a method of patient-specific IMRT dose verification for radiotherapy.
Research studies have focused on pre and post-treatment verification,
however, there are currently no interventional procedures using EPID
dosimetry that measure the dose in real time as a mechanism to
ensure that overdoses do not occur and underdoses are detected as
soon as is practically possible. As a result, an EPID-based real time
dose verification system for dynamic IMRT was developed and was
implemented with MATLAB/Simulink. The EPID image acquisition
was set to continuous acquisition mode at 1.4 images per second. The
system defined the time constraint gap, or execution gap at the image
acquisition time, so that every calculation must be completed before
the next image capture is completed. In addition, the <=-evaluation
method was used for dose comparison, with two types of comparison
processes; individual image and cumulative dose comparison
monitored. The outputs of the system are the <=-map, the percent of
<=<1, and mean-<= versus time, all in real time. Two strategies were
used to test the system, including an error detection test and a clinical
data test. The system can monitor the actual dose delivery compared
with the treatment plan data or previous treatment dose delivery that
means a radiation therapist is able to switch off the machine when the
error is detected.
[1] van Elmpt, W., L. McDermott, et al. (2008). "A literature review of
electronic portal imaging for radiotherapy dosimetry." Radiotherapy and
Oncology 88: 289-309.
[2] McDermott, L. N., M. Wendling, et al. (2007). "Replacing pretreatment
verification with in vivo EPID dosimetry for prostate IMRT." Int J
Radiat Oncol Biol Phys 67(5): 1568-77.
[3] Mans, A., M. Wendling, et al. (2010). "Catching errors with in vivo
EPID dosimetry." Med Phys 37(6): 2638-44.
[4] Bogdanich, W. (2010). "Radiation Offers New Cures, and Ways to Do
Harm." From
http://www.nytimes.com/2010/01/24/health/24radiation.html
[5] McCurdy, B. M. and P. B. Greer (2009). "Dosimetric properties of an
amorphous-silicon EPID used in continuous acquisition mode for
application to dynamic and arc IMRT." Med Phys 36(7): 3028-39.
[6] Low, D. A., W. B. Harms, et al. (1998). "A technique for the
quantitative evaluation of dose distributions." Med Phys 25(5): 656-61.
[7] Stock, M., B. Kroupa, et al. (2005). "Interpretation and evaluation of the
gamma index and the gamma index angle for the verification of IMRT
hybrid plans." Phys Med Biol 50(3): 399-411.
[8] Jiang, S. B., G. C. Sharp, et al. (2006). "On dose distribution
comparison." Phys Med Biol 51(4): 759-76.
[1] van Elmpt, W., L. McDermott, et al. (2008). "A literature review of
electronic portal imaging for radiotherapy dosimetry." Radiotherapy and
Oncology 88: 289-309.
[2] McDermott, L. N., M. Wendling, et al. (2007). "Replacing pretreatment
verification with in vivo EPID dosimetry for prostate IMRT." Int J
Radiat Oncol Biol Phys 67(5): 1568-77.
[3] Mans, A., M. Wendling, et al. (2010). "Catching errors with in vivo
EPID dosimetry." Med Phys 37(6): 2638-44.
[4] Bogdanich, W. (2010). "Radiation Offers New Cures, and Ways to Do
Harm." From
http://www.nytimes.com/2010/01/24/health/24radiation.html
[5] McCurdy, B. M. and P. B. Greer (2009). "Dosimetric properties of an
amorphous-silicon EPID used in continuous acquisition mode for
application to dynamic and arc IMRT." Med Phys 36(7): 3028-39.
[6] Low, D. A., W. B. Harms, et al. (1998). "A technique for the
quantitative evaluation of dose distributions." Med Phys 25(5): 656-61.
[7] Stock, M., B. Kroupa, et al. (2005). "Interpretation and evaluation of the
gamma index and the gamma index angle for the verification of IMRT
hybrid plans." Phys Med Biol 50(3): 399-411.
[8] Jiang, S. B., G. C. Sharp, et al. (2006). "On dose distribution
comparison." Phys Med Biol 51(4): 759-76.
@article{"International Journal of Medical, Medicine and Health Sciences:50704", author = "Todsaporn Fuangrod and Daryl J. O'Connor and Boyd MC McCurdy and Peter B. Greer", title = "Development of EPID-based Real time Dose Verification for Dynamic IMRT", abstract = "An electronic portal image device (EPID) has become
a method of patient-specific IMRT dose verification for radiotherapy.
Research studies have focused on pre and post-treatment verification,
however, there are currently no interventional procedures using EPID
dosimetry that measure the dose in real time as a mechanism to
ensure that overdoses do not occur and underdoses are detected as
soon as is practically possible. As a result, an EPID-based real time
dose verification system for dynamic IMRT was developed and was
implemented with MATLAB/Simulink. The EPID image acquisition
was set to continuous acquisition mode at 1.4 images per second. The
system defined the time constraint gap, or execution gap at the image
acquisition time, so that every calculation must be completed before
the next image capture is completed. In addition, the ", keywords = "real-time dose verification, EPID dosimetry, simulation, dynamic IMRT", volume = "5", number = "8", pages = "301-4", }