Vrx: A verify–record system for radiotherapy

Dickof, Peter; Morris, Phil B.; Getz, Darrell

doi:10.1118/1.595640

Cited by 7 publications

(3 citation statements)

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“…The first issue was related to quality assurance needs, in particular, the need to record and verify the delivery of radiation treatment. [6][7][8][9][10][11][12] Early record and verify systems were designed to simply confirm radiation therapy machine parameters that had been manually set and validate the consistency of these parameters. If treatment was terminated unexpectedly, these systems could store data relevant to partial treatment received, thus enabling therapists to resume and complete the interrupted treatment.…”

Section: Informatics In Radiation Therapymentioning

confidence: 99%

Anniversary Paper: Roles of medical physicists and health care applications of informatics

et al. 2007

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Over the past 100 years, both diagnostic radiology and radiation therapy have grown from infancy to maturity. Accompanying this growth, the discipline of medical physics has evolved and advanced accordingly. New diagnostic and therapeutic procedures continue to be developed, for example, multidetector computed tomography, multileaf collimation, magnetic resonance imaging, dual-source computed tomography, and intensity-modulated radiation therapy. These are now incorporated in health care facilities throughout the world. Modern technologies such as these provide information on underlying pathology at increasingly higher resolutions, generating more information; thus requiring complex methods of image recording and storage. The management of the storage and retrieval of accumulated information is a domain of informatics. In this short review, we describe the different roles of medical physicists and the effective contribution of the American Association of Physicists in Medicine in the evolution of informatics. Medical physicists have contributed to the development of informatics in numerous ways, such as designing hospital information systems and infrastructures that better serve radiologists and other physicians. In addition, the positive exploitation of knowledge gathered in medical settings and effective interdisciplinary collaborations between scientists of different backgrounds have increased. These developments provide future medical physicists the opportunity to develop strategic roles in information technology and thus better contribute to health care.

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Section: Informatics In Radiation Therapymentioning

confidence: 99%

Anniversary Paper: Roles of medical physicists and health care applications of informatics

et al. 2007

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“…Computer controlled radiotherapy and record and verify systems (R&V) were introduced to allow for complex treatments and increase the safety of radiation delivery. (1)(2)(3)(4)(5)(6)(7) It was found that these systems improve patient safety and reduce treatment errors when used properly. (8)(9)(10)(11)(12)(13)(14) The work presented here focuses on the use of one aspect of the R&V system related to the software interlock applied to the position of the treatment couch.…”

Section: Introductionmentioning

confidence: 99%

Analysis of couch position tolerance limits to detect mistakes in patient setup

Hadley

Balter

Lam

2009

J Applied Clin Med Phys

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This work investigates the use of the tolerance limits on the treatment couch position to detect mistakes in patient positioning and warn users of possible treatment errors. Computer controlled radiotherapy systems use the position of the treatment couch as a surrogate for patient position, and a tolerance limit is applied against a planned position. When the couch is out of tolerance, a warning is sent to a user to indicate a possible mistake in setup. A tight tolerance may catch all positioning mistakes while at the same time sending too many warnings; a loose tolerance will not catch all mistakes. We developed a statistical model of the absolute position for the three translational axes of the couch. The couch position for any fraction is considered a random variable xi. The ideal planned couch position xp is unknown before a patient starts treatment and must be estimated from the daily positions of xi. As such, xp is also a random variable. The tolerance, tol, is applied to the difference between the daily and planned position, di=xi−xp. The di is a linear combination of random variables and therefore the density of di is the convolution of distributions of xi and xp. Tolerance limits are based on the standard deviation of di such that couch positions that are more than two standard deviations away are considered out of tolerance. Using this framework, we investigated two methods of setting xp and tolerance limits. The first, called first day acquire (FDA), is to take couch position on the first day as the planned position. The second is to use the cumulative average (CumA) over previous fractions as the planned position. The standard deviation of di shrinks as more samples are used to determine xp and, as a result, the tolerance limit shrinks as a function of fraction number when a CumA technique is used. The metrics of sensitivity and specificity were used to characterize the performance of the two methods to correctly identify a couch position as in‐ or out‐of‐tolerance. These two methods were tested using simulated and real patient data. Five clinical sites with different indexed immobilization were tested. These were whole brain, head and neck, breast, thorax, and prostate. Analysis of the head and neck data shows that it is reasonable to model the daily couch position as a random variable in this treatment site. Using an average couch position for xp increased the sensitivity of the couch interlock and reduced the chances of acquiring a couch position that was a statistical outlier. Analysis of variation in couch position for different sites allowed the tolerance limit to be set specifically for a site and immobilization device. The CumA technique was able to increase the sensitivity of detecting out‐of‐tolerance positions while shrinking tolerance limits for a treatment course. Making better use of the software interlock on the couch positions could have a positive impact on patient safety and reduce mistakes in treatment delivery.PACS number: 87.55.Ne, 87.55.Qr, 87.55.tg, 87.55.tm

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“…There are two classifications of immobilization devices, namely simple and complex. Simple immobilization devices restrict "some" patient movement and therefore patient movements will not be entirely deterred [21][22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Analysis of Set-up Parameters in Head and Neck Patients at the Charlotte Maxeke Johannesburg Academic Hospital (A Review of Current Clinical Practice)

Wyk¹,

Dumela²,

Dg³

2017

J Integr Oncol

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This study aimed to collect and analyze the recorded daily setup parameters of the bed as incidentally captured on an integrated record and verify system. This was done on some radical head and neck patients treated from 2008 to 2010 at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in South Africa. Most of these patients had anterior neck fields that were set-up using fixed couch longitudinal movements (meaning more than one treatment isocentre). It was hoped that the ideal absolute position of the patient on the bed relative to the isocentre of the treatment machine, for a course of head and neck radiotherapy at CMJAH, could be established. Knowledge of the set-up margin achievable could also assist in defining the tolerance assigned to couch parameters on the electronic record and verify system, such that setup is restricted accordingly.

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Vrx: A verify–record system for radiotherapy

Cited by 7 publications

References 0 publications

Anniversary Paper: Roles of medical physicists and health care applications of informatics

Anniversary Paper: Roles of medical physicists and health care applications of informatics

Analysis of couch position tolerance limits to detect mistakes in patient setup

Analysis of Set-up Parameters in Head and Neck Patients at the Charlotte Maxeke Johannesburg Academic Hospital (A Review of Current Clinical Practice)

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