A National project for in vivo dosimetry procedures in radiotherapy: First results

Piermattei, Angelo; Greco, Francesca; Azario, L.; Porcelli, A.; Cilla, Savino; Zucca, S.; Russo, A.; Castro, Elisabetta Di; Russo, Mariateresa; Caivano, Rocchina; Fusco, Vincenzo; Morganti, Alessio Giuseppe; Fidanzio, A.

doi:10.1016/j.nimb.2011.12.004

Cited by 31 publications

(44 citation statements)

References 21 publications

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“…In this context, the strength of our method is twofold. First of all, our method adopts a generalized algorithm that can be easily implemented with a minimal workload for all Varian, Elekta and Siemens linacs and related EPIDs, with a few commissioning measurements time reduced to less than 30 minutes per linac [14,16]. Secondly, the software is interfaced with the Record&Verify system of the radiotherapy unit, allowing a direct and fast access to EPID images and treatment planning network.…”

Section: Discussionmentioning

confidence: 99%

“…This research led to the foundation of an Italian national project financed by the Istituto Nazionale di Fisica Nucleare (INFN) and the Diso software was extensively applied in clinical routine in several Italian centers. The first clinical results showed that IVD has a unique feature to assess all clinically relevant differences between planned and delivered dose, detecting the presence of dose discrepancies in 10% of the tests, mainly due to incorrect set-ups, presence of attenuators on the beams path and patient morphological changes [16]. Recently, the results of a 3-year experience including more than 1300 patients at Catholic University in Rome reported again about 10% of all IVD checks out of 5% tolerance level [17].…”

Section: Introductionmentioning

confidence: 99%

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Initial clinical experience with Epid-based in-vivo dosimetry for VMAT treatments of head-and-neck tumors

et al. 2016

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Initial clinical experience with Epid-based in-vivo dosimetry for VMAT treatments of head-and-neck tumors

et al. 2016

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“…7) and the TMRM ratios (Eq. 8) were fitted by polynomial functions using a software package that minimize the sum of the residuals squares that are the differences between the experimental and the computed values [23]. …”

Section: Resultsmentioning

confidence: 99%

“…The method is based on the correlation ratios between the EPID transit signals and the doses at the isocenter point of SPs. The recent results [8, 23] are obtained for the 3D-CRT beams encouraged for the application in IMRT to develop a IVD procedure for Varian dynamic IMRT beams, based on a generalized algorithm. Correlation functions have been obtained irradiating SPs of different thicknesses, w = 12, 22, 32, 42, 52 cm by a set of square simulated IMRT beams with L = 5, 10, 12 and 17 cm at the SAD (Sect.…”

Section: Methodsmentioning

confidence: 99%

“…However, 350 in vivo tests supplied an average ratio R equal to 1.004 ± 0.040. The in vivo dosimetry procedure here presented is among the objectives of a National Project financially supported by the Istituto Nazionale di Fisica Nucleare for the development of in vivo dosimetry procedures (Piermattei et al in Nucl Instrum Methods Phys Res B 274:42–50, 2012) connected to the Record–Verify system of the radiotherapy center.…”

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aSi-EPID transit signal calibration for dynamic beams: a needful step for the IMRT in vivo dosimetry

Greco

Piermattei

Azario

et al. 2013

Med Biol Eng Comput

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This work reports a method based on correlation functions to convert EPID transit signals into in vivo dose values at the isocenter point, Diso, of dynamic IMRT beams supplied by Varian linac. Dose reconstruction for intensity-modulated beams required significant corrections of EPID response, due to the X-ray component transmitted through multileaf collimator. The algorithm was formulated using a set of simulated IMRT beams. The beams were parameterized by means of a fluence inhomogeneity index, FI, introduced to describe the degree of beam modulation with respect to open beams. This way, all dosimetric parameters involved in Diso reconstruction algorithm, such as the correlation functions, the correction factor for EPID to phantom distance and the modulated tissue maximum ratios, were determined as a function of the FI index. Clinical IMRT beams were used to irradiate a homogeneous phantom, and for each beam, the agreement between the reconstructed dose, Diso, and the dose computed by TPS, Diso,TPS, was well within 5 %. Moreover, the average ratios, R, between the Diso, and Diso,TPS, resulted equal to 1.002 ± 0.030. Thirty-five IMRT fields of 5 different patients undergoing radiotherapy for head–neck tumors were tested and the results were displayed on a computer screen after 2 min from the end of the treatment. However, 350 in vivo tests supplied an average ratio R equal to 1.004 ± 0.040. The in vivo dosimetry procedure here presented is among the objectives of a National Project financially supported by the Istituto Nazionale di Fisica Nucleare for the development of in vivo dosimetry procedures (Piermattei et al. in Nucl Instrum Methods Phys Res B 274:42–50, 2012) connected to the Record–Verify system of the radiotherapy center.

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EPID‐based in vivo dosimetry using Dosimetry Check™: Overview and clinical experience in a 5‐yr study including breast, lung, prostate, and head and neck cancer patients

Nailon

Welsh

McDonald

et al. 2018

J Applied Clin Med Phys

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BackgroundIndependent verification of the dose delivered by complex radiotherapy can be performed by electronic portal imaging device (EPID) dosimetry. This paper presents 5‐yr EPID in vivo dosimetry (IVD) data obtained using the Dosimetry Check (DC) software on a large cohort including breast, lung, prostate, and head and neck (H&N) cancer patients.Material and MethodsThe difference between in vivo dose measurements obtained by DC and point doses calculated by the Eclipse treatment planning system was obtained on 3795 radiotherapy patients treated with volumetric modulated arc therapy (VMAT) (n = 842) and three‐dimensional conformal radiotherapy (3DCRT) (n = 2953) at 6, 10, and 15 MV. In cases where the dose difference exceeded ±10% further inspection and additional phantom measurements were performed.ResultsThe mean and standard deviation (normalμ±normalσ) of the percentage difference in dose obtained by DC and calculated by Eclipse in VMAT was: 0.19±3.89% in brain, 1.54±4.87% in H&N, and 1.23±4.61% in prostate cancer. In 3DCRT, this was 1.79±3.51% in brain, −2.95±5.67% in breast, −1.43±4.38% in bladder, 1.66±4.77% in H&N, 2.60 ± 5.35% in lung and −3.62±4.00% in prostate cancer. A total of 153 plans exceeded the ±10% alert criteria, which included: 88 breast plans accounting for 7.9% of all breast treatments; 28 H&N plans accounting for 4.4% of all H&N treatments; and 12 prostate plans accounting for 3.5% of all prostate treatments. All deviations were found to be as a result of patient‐related anatomical deviations and not from procedural errors.ConclusionsThis preliminary data shows that EPID‐based IVD with DC may not only be useful in detecting errors but has the potential to be used to establish site‐specific dose action levels. The approach is straightforward and has been implemented as a radiographer‐led service with no disruption to the patient and no impact on treatment time.

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A National project for in vivo dosimetry procedures in radiotherapy: First results

Cited by 31 publications

References 21 publications

Initial clinical experience with Epid-based in-vivo dosimetry for VMAT treatments of head-and-neck tumors

Initial clinical experience with Epid-based in-vivo dosimetry for VMAT treatments of head-and-neck tumors

aSi-EPID transit signal calibration for dynamic beams: a needful step for the IMRT in vivo dosimetry

EPID‐based in vivo dosimetry using Dosimetry Check™: Overview and clinical experience in a 5‐yr study including breast, lung, prostate, and head and neck cancer patients

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